Development Patterns and Controlling Factors of Tertiary Carbonate

www.elsevier.com/locate/sedgeo

Sedimentary Geology 17

Research paper

Development patterns and controlling factors of Tertiary carbonate

buildups: Insights from high-resolution 3D seismic and well data

in the Malampaya gas field (Offshore Palawan, Philippines)

F. FournierT, J. Borgomano, L.F. Montaggioni

Centre de Sedimentologie-Paleontologie, FRE-CNRS 2761 bDynamique des recifs et des plates-formes carbonateesQ,Case 67, Universite de Provence, 3, Place Victor Hugo, F-13331 Marseille cedex 03, France

Abstract

The comprehensive subsurface database of the Malampaya buildup (Late Eocene to Early Miocene, offshore NW Palawan)

provides a rare insight into the development of South-East Asian Cenozoic carbonate systems and their controlling factors. The

newly acquired high-resolution three-dimensional seismic survey, combined with facies and well-log analysis, allowed a better

understanding of the internal architecture of a carbonate platform whose development was largely controlled by tectonic

deformation. The Malampaya carbonate system was initiated in the Late Eocene, as an attached shelf influenced by significant

clastic input. The Late Eocene–Early Oligocene shelf was subject to syn-depositional extensional tectonics (eastward tilting and

block faulting) that favoured the development of small size buildups on structural highs. After a stage of eastward reef

progradation, an aggrading carbonate shelf, frequently affected by subaerial exposure, developed from the earliest Late

Oligocene to the Early Miocene. During this period, recurrent reactivation of highs along the western and northeastern buildup

margins determined the asymmetric morphology and internal architecture of the carbonate system. The final demise of the

carbonate buildup occurred in the late Early Miocene. It resulted from an increase in subsidence rate and/or a sharp increase in

nutrient input. Additional parameters like eustacy, oceanographic conditions and the type of carbonate producers played a

subordinate role in the buildup development and ultimate demise.

D 2005 Elsevier B.V. All rights reserved.

Keywords: Carbonates; Depositional processes; Tectonics; Seismic data; Tertiary; South-East Asia

0037-0738/$ - see front matter D 2005 Elsevier B.V. All rights reserved.

doi:10.1016/j.sedgeo.2005.01.009

T Corresponding author. Tel.: +33 491106178; fax: +33

491108523.

E-mail address: [email protected]

(F. Fournier).

1. Introduction

During the Cenozoic, extensive shallow marine

carbonate production took place in South-East Asia

within various passive and active tectonic settings

(Wilson, 2002). In the Southern margin of the South

China Sea, many carbonate build-ups developed on

5 (2005) 189–215

F. Fournier et al. / Sedimentary Geology 175 (2005) 189–215190

topographic highs inherited from block-tilting during

the Eocene to Early Oligocene rifting phase (Fulth-

orpe and Schlanger, 1989, Wiliams, 1997, Sales et al.,

1997).

Various examples of carbonate development and

depositional facies models have been described in the

Indo-Pacific region: e.g. the Miocene Luconia build-

ups (Epting, 1980), the Middle Oligocene Berai

Limestone (Saller et al., 1992), the Miocene Natuna

buildup (Rudolph and Lehmann, 1989; Dunn et al.,

1996). However, the role of tectonics on the develop-

ment patterns and stratigraphic architecture of these

systems is only documented in a few cases: the

Eocene to Middle Miocene Tonasa carbonate platform

of South Sulawesi (Wilson, 1999, 2000; Wilson et al.,

2000), and the Late Eocene to Miocene Gunungh

Putih carbonate complex (Cucci and Clark, 1993).

For the Malampaya gas field, Grotsch and Mer-

cadier (1999) provided a 3D model of the carbonate

buildup evolution. However, the relatively low verti-

cal resolution (80 m in the carbonates) of the seismic

records did not allow a detailed description of the

buildup internal architecture. This work is based on

the integration of higher resolution (25 m) 3D seismic

Fig. 1. (a) Depth (in metres subsea) of the top Nido Limestone and locatio

1999) within Block SC 38, offshore Palawan, Philippines. (b) Seismic line

(see panel a for location). (c) Simplified stratigraphic column.

data and detailed petrographic studies of rock samples

extracted from 10 wells.

The objective of this paper is threefold: 1) to

develop a 3D facies model of the Malampaya

carbonate buildup, 2) to reconstruct its development

history and to characterize its stratigraphic architec-

ture, 3) to define and assess the respective role of the

main controlling factors on the development of the

system. Special attention was given to the impact of

local tectonic deformation and differential subsidence

on the stratigraphic architecture of the carbonate

buildup.

2. Location and geological setting of the

Malampaya carbonate buildup

The Malampaya oil and gas accumulation is

located in the deep water Block SC 38 (850 to 1200

m) offshore Palawan (Philippines). This Late Eocene

to Early Miocene carbonate buildup is situated at a

depth of 3000 m below present sea level (Fig. 1) and

consists of a 5 km long and 1–2 km wide, NE–SW

oriented body. In the North Palawan Block, a number

n of wells, in the Malampaya gas field (after Grotsch and Mercadier,

showing the main morphologic features of the Malampaya buildup

F. Fournier et al. / Sedimentary Geology 175 (2005) 189–215 191

of hydrocarbon accumulations (Longman, 1985;

Wiliams, 1997; Sales et al., 1997) are positioned in

the Late Eocene to Early Miocene Nido Limestone.

The regional distribution of the Nido Limestone is

mainly controlled by the NE–SW trending extensional

basement faults related to the Eocene–Early Oligo-

cene rifting phase of the South China Sea (Fulthorpe

and Schlanger, 1989; Wiliams, 1997; Sales et al.,

1997). The break-up event related to this rifting phase

was dated on the basis of the mid-Oligocene magnetic

anomaly 11 (Briais et al., 1993). The spreading in the

South-China Sea led to a southward drift of the

Calamian–North Palawan–North Borneo micro-con-

tinent throughout the Late Oligocene and Early

Miocene. During the late Early Miocene, this micro-

continent collided with the accretion wedge of the

Paleogene subduction zone of North Cagayan

(Schluter et al., 1996), promoting the obduction of

the collision belt on the North Palawan block and

ceasing seafloor spreading (Briais et al., 1993).

Carbonate development in the area stopped in

response to downwarping of the north-western part

Fig. 2. Chronostratigraphic frameworks of the Nido Limestone, in the Ma

Fournier et al. (2004), (c) this study.

of the block and extensive clastic supply from the

uplifted Palawan island (Fulthorpe and Schlanger,

1989). The carbonate buildups of Block SC 38 were

sealed by Early to Middle Miocene basinal Pagasa

clastics.

The first model of long-term evolution of the

Malampaya buildup was proposed by Grotsch and

Mercadier (1999) using three-dimensional seismic

data and relatively sparse core and side-wall samples

from 4 wells (MA-1 to MA-4). These authors

distinguished three main phases of platform evolution:

1) development of an initial carbonate platform on the

crest of a tilted block (syn-rift phase, Late Eocene), 2)

progradational phase (Early Oligocene), 3) Aggrada-

tional phase and subsequent backstepping (Late

Oligocene–Early Miocene). The buildup finally

drowned during the Late Early Miocene.

The short-term depositional evolution was inves-

tigated by Fournier et al. (2004) utilizing core data

from wells MA-5 and MA-7. These authors showed

that the vertical and lateral facies distribution was

strongly controlled by high-frequency, relative sea-

lampaya buildup: (a) after Grotsch and Mercadier (1999), (b) after


level changes. Meteoric dissolution and cementation

during exposure events associated with these high

frequency variations in relative sea-level are a major

feature of the reservoir property evolution in Malam-

paya. The chronostratigraphic frameworks proposed

by Grotsch and Mercadier (1999) and Fournier et al.

(2004) are compared in Fig. 2.

3. Data and methods

The dataset used in this study consists of a three-

dimensional seismic survey acquired by Shell Phil-

ippines (SPEX) in 2002, and well data from 10 wells

(MA-1 to MA-10). Core sections are available in

wells MA-2, MA-3, MA-4, MA-5, MA-7, and MA-

9. The seismic interpretation used prestack time

migrated data (PSTM), with a zero-phase signal. The

seismic polarity is defined as follows: negative

amplitude means a downward increase in acoustic

impedance (positive reflection coefficient). The work

utilizes the depositional facies and diagenetic fea-

tures identified by Fournier et al. (2004) from MA-5

and MA-7, those obtained from new thin-section

analyses on MA-6, MA-8, MA-9, and MA-10 and

the re-examination of the rock material studied by

Grotsch and Mercadier (1999) from MA-1, MA-2,

and MA-3. Carbon and oxygen isotope analyses on

whole-rock samples were used to support diagenetic

interpretations.

The analysis and interpretation of the available

datasets was done through six successive steps: 1)

identification of depositional and diagenetic environ-

ments and age determinations based on biostratigra-

phy, from core, cuttings, and side-wall samples

analyses; 2) definition of the main stratigraphic units

based on the well analysis of the vertical succession of

depositional and diagenetic environments; 3) estab-

lishment of well correlations based on depositional

and diagenetic sequences, and biostratigraphic con-

straints; 4) 3D interpretation of the main structural

features using the new seismic survey; 5) 3D

interpretation of the 12 main seismic horizons

identified, and of their stratigraphic significance; and

6) construction of a platform development model and

identification of the main controls on this develop-

ment. A well correlation panel between MA-1, MA-5,

and MA-2 is shown in Fig. 3.

4. Results

4.1. Reconstruction of depositional and diagenetic

environments

4.1.1. Depositional facies and paleoenvironments

The analysis of the sediment bioclastic composi-

tion, foraminiferal, and red algal assemblages com-

bined with recognition of the sedimentological

features observed on cores and thin-sections allowed

the identification of 26 depositional facies (Tables 1

and 2). They cover the Late Eocene to the Early

Miocene and range from distal slope to inner-shelf

settings. In addition, the integration of seismic data

allowed to identify various buildup morphologies

during the development of the Malampaya carbonate

system. Depositional facies distributions and buildup

morphologies are summarized in Fig. 4.

4.1.1.1. Inner-shelf facies. Late Eocene and Early

Oligocene inner-shelf facies are dominated by

benthic foraminifers and calcareous algae (mainly

encrusting coralline algae and Halimeda); corals

become common in the upper part of the Early

Oligocene. The following facies were identified (see

Table 1 for description and paleoenvironmental

interpretations): 1) bryozoan–foraminiferal–algal

packstone E1 facies, rich in quartz particles, 2)

rhodolithic floatstone/rudstone R1a facies, 3) mud-

rich, foraminiferal–Halimeda floatstone R1b1 facies,

4) mud-poor, Halimeda–floatstone facies R1b2, 5)

coral–foraminiferal–coralline algal grainstone/float-

stone R3a facies, 6) coralline algal–foraminiferal

packstone R3b facies, 7) echinoderm–coralline algal

packstone R3c facies.

In the Late Oligocene–Early Miocene from the

Malampaya buildup interior, C1a, C1b, C2, C3, M1,

M2a, M2b, and M3 facies were defined previously by

Fournier et al. (2004). Two additional facies were

defined on the basis of MA-8 rock material: 1)

foraminiferal–coralline algal–grainstone M3g1 facies,

2) coralline algal–green algal–foraminiferal packstone

M3h facies.

High-energy shelf margin facies were recognized

in the Early Miocene and are characterized by the lack

of matrix mud and the abundance of thick-walled

benthic foraminifers. Hence they are defined as

foraminiferal–coralline algal–grainstone M3g2 facies.

Fig. 3. Synthetic chart showing biostratigraphic ages, well-logs data, facies and depositional environments, and d13C profiles from wells MA-1, MA-2, and MA-5; the main

sedimentary units are reported.

F.Fournier

etal./Sedimentary

Geology175(2005)189–215

193

Table 1

A summary of the main recognized facies from the Malampaya inner shelf: sedimentologic features, skeletal components, and paleoenvironmental reconstructions

Sedimentary facies Location Dominant components Foraminiferal assemblage Large Scleractinian

remains

Paleoenvironmental

interpretation

Late Eocene Quartz-rich bryozoan–

foraminiferal–Algal packstone

facies (E1)

MA-1, MA-2,

MA-3, MA-5

–bryozoans –small discocyclina rare shallow-open shelf

–benthic foraminifers –lense-shaped Nummulities

–Halimeda –milliods

–coralline algae –Pellatispira

Rhodolithic floatstone/

rudstone (R1a)

MA-2 –coralline algae (rhodolithes) –dominant miliolids absent inner shelf slope

–Halimeda –alveolinids

–benthic foraminifers –Nummulites

–echinoderms –encrusting foraminifers

Early Oligocene Mud-rich Foraminiferal

Halimeda floatstone (R1b1)

MA-2 –benthic foraminifers –dominant miliolids rare shallow inner shelf

–Halimeda –soritids (Peneroplinae)

–coralline algae –amphisteginids

–corals –small lense-shaped Nummulites

–bryozoans –occasional heterosteginids

Mud-poor Halimeda floatstone

(R1b2)

MA-2 –Halimeda –soritids (Peneroplis) rare inner shelf sand shoal

–benthic foraminifers –miliolids

–coralline algae –amphisteginids

–corals –small lense-shaped Nummulites

–bryozoans –heterosteginids

Coral–foraminiferal–coralline

algal grainstone/Floatstone

facies (R3a)

MA-2, MA-5 –corals –miliolids frequent to abundant sand-shoal in

back-reef setting–benthic foraminifers –alveolinids

–coralline algae –thick-tested amphisteginids

–rotaliids

coralline algal–Foraminiferal

Packstone facies (R3b)

MA-1, MA-2, MA-5 –coralline algae –dominant miliolids rare shallow inner shelf

–benthic foraminifers –alveolinids

–echinoderms –amphisteginids

–coral fragments –arenaceous foraminifers

Echinoderms–coralline

algal–Packstone facies (R3c)

MA-1, MA-2, MA-5 –echinoderms –dominant miliolids absent relatively deep and

protected inner shelf–encrusting coralline algae –alveolinids

–benthic foraminifers –lense-shaped Nummulites

–rare corals and bryozoans –arenaceous foraminifers

Late Oligocene coralline algal wackestone/

packstone facies (C1a)

MA-2, MA-5 –encrusting coralline algae

(thick-layered and foliose

growth forms)

–arenaceous foraminifers absent deep inner shelf

–miliolids

–amphistegenids

–alveolinids (rare)

coralline algal–echinoderm

wackestone/packstone (C1b)

MA-1, MA-2,

MA-5, MA-10

–encrusting coralline algae –amphisteginids rare deep protected

inner shelf–echinoderms (mainly echinoids) –rotaliids

–arenaceous foraminifera

–miliolids and alveolinids

–planktonics (rare)

Coral–coralline

algal–foraminiferal

grainstone facies (C2)

MA-2, MA-5, MA-10 –small coral debris –alveolinids (Borealis pygmaeus) rare inner shelf shoal

–encrusting and geniculate –Sphaerogypsina

coralline algae –rotaliids

–benthic foraminifers –amphisteginids

F.Fournier

etal./Sedimentary

Geology175(2005)189–215

194

–miliolids (Austrotrillina)

–Heterostegina borneesis

–broken soritids and arenaceous

foraminifera

Coral–corallines

algal–foraminiferal

packstone/floatstone

facies (C3)

MA-1, MA-2,

MA-5, MA-10

–large coral debris –rotaliids frequent to abundant shallow protected

inner shelf with

seagrass

meadows and

patch-reefs

–encrusting and geniculate –Heterostegina borneensis

coralline algae –amphisteginids

–benthic foraminifers –miliolids

–alveolinids

–soritids

–lepidocyclinids

Early Miocene Echinoderm coralline algal

wackestone/packstone

facies (M1)

MA-1, MA-5,

MA-7, MA-8

–echinoderms (orphiuroids and

echinoids)

–small benthic

(Bolivina , discorbids)

rare deep open shelf

–coralline algae –planktonics

–Miogypsinoides

–lepidocyclinids, amphisteginids

and heterosteginids (occasional)

coralline algal–foraminiferal–

echinoderm packstone

facies (M2a)

MA-1, MA-5,

MA-7, MA-8

–coralline algae –arenaceous foraminifera occasional deep protected

inner shelf–benthic foraminifers –miliolids

–echinoderms (echinoids mainly) –small benthic

(Bolvina , discorbids)

–planktonics (rare)

–lepidocyclinids (rare)

Echinoderms-coralline

algal-foraminiferal

packstone facies (M2b)

MA-5 –echinoderms (ophiuroids and –arenaceous formainifera frequent to abundant moderately deep and

open shelfechinoids) –miliolids

–coralline algae –planktonics

–benthic foraminifers –lepidocyclinids

Coral-coralline algal-

foraminiferal packstone/

floatstone facies (M3)

MA-1, MA-2,

MA-5, MA-6,

MA-7, MA-8

–large coral debris –soritids frequent to abundant shallow protected

inner shelf with

seagrass meadows

and patch-reefs

–encrusting and geniculate –miliolids

coralline algae –arenaceous foraminifera

–benthic foraminifers –amphisteginids

–miogypsinids

–lepidocyclinids

Foraminiferal–coralline

algal–grainstone facies

(M3g1)

MA-1, MA-8 –benthic foraminifers –soritids absent inner shelf sand shoal

–encrusting and geniculate –miliolids

coralline algae –alveolinids

–occasional echinoderms and –miogypsinids

Halimeda plates. –encrusting foraminifers

coralline algal–Green

Algal–Foraminiferal

packstone facies (M3h)

MA-8 a–coralline algae –dominant miliolids absent shallow-water

protected inner-shelf–Halimeda

–benthic foraminifers

–common soritids and

lepidocyclinids

–occasional echinoderms and –occasional amphisteginids and

mollusks miogypsinids

Planktonic Foraminiferal

wackestone/packstone (M0)

MA-8 –planktonic foraminifers –dominant planktonic foraminifers absent drowned platform

–fragments of benthic foraminifers –heterosteginids

–coralline algae –occasional miogypsinids and

–echinoderms encrusting foraminifers

F.Fournier

etal./Sedimentary

Geology175(2005)189–215

195

Table 2

A summary of the main recognized facies from the Malampaya shelf margin, slope and flank environments: sedimentologic features, skeletal components, and paleoenvironmental reconstructions

Sedimentary facies Location Dominal components Foraminiferal assemblage Large Scleractinian

(N5 mm)

Paleoenvironmental

interpretation

Early Oligocene Coral–Algal floatstone (R1c) MA-2, MA-5 –corals –Heterostegina common reef slope

–coralline algae –Cycloclypeus

–benthic foraminifers –flat Nummulites

–Halimeda –Amphistegina

–bryozoans –occasional milliods and

arenaceous foraminifers

Coral–Foraminiferal–coralline

algal floatstone/rudstone (R2)

MA-2, MA-5 –corals –milliods abundant near reef zone

–benthic foraminifers –Amphistegina

–coralline algae –alveolinids

–echinoderms –soritids

–rare Halimeda and bryozoans –arenaceous foraminifers

Late Oligocene coralline algal–Foraminiferal

packstone (C4a)

MA-1, MA-2, MA-10 –coralline algae (algal balls) –Heterosteginids absent slope

–benthic foraminifers –Spiroclypeus

–echinoderms –rotaliids

–occasional bryozoans and corals –lepidocyclinids

coralline algal–Foraminiferal

grainstone (C4b)

MA-2 –coralline algae (algal balls) –Heterosteginids rare proximal reef slope

–benthic foraminifers –Lepidocyclinids

–corals –rotaliids

–thick-tested Amphistegina

-miliolids

-occasional Spiroclypeus

Lepidocyclinid–Rhodolithic

rudstone (C5a)

MA-2 –large benthic foraminifers –large lepidocyclinids absent flank

–coralline algae (rhodolithes) –Operculina

–Halimeda –Heterostegina

–bryozoans –Cycloclypeus

–echinoderms –Spiroclypeus

–rare milliods an amphisteginids

Halimeda rudstone (C5b) MA-2 –Halimeda –large lepidocyclinids absent flank

–coralline algae –Operculina

–large benthic foraminifers –Heterostegina

–bryozoans –Cycloclypeus

–rare miliolids and amphistegini

Early Miocene Coral–Foraminiferal–floatsone/

rudstone (M4)

MA-9 –corals (mainly Alveopora) –lepidocyclinids abundant reef flat

–benthic foraminifers –Miogypsinoides

–coralline algae –Amphistegina

–Halimeda –miliolids

–occasional bryozoans,

echinoderms and dasyclads

–soritids

Foraminiferal–coralline

algal–grainstone facies (M3g2)

MA-8 –occasional echinoderms –miogypsinids absent shelf margin sand shoal

–miliolids

–soritids

–arenaceous foraminifers

F.Fournier

etal./Sedimentary

Geology175(2005)189–215

196

ds

Fig. 4. Distribution of the depositional facies in function of the overall buildup morphology.


4.1.1.2. Perireefal facies. Floatstone/rudstone facies

containing large coral fragments and associated

benthic foraminiferal assemblages were encountered

in the uppermost part of the Early Oligocene interval

(in MA-5) and in the Early Miocene south-eastern

shelf margin (in MA-9): 1) coral–foraminiferal–coral-

line algal floatstone/rudstone R2b facies (Early

Oligocene), 2) coral–foraminiferal floatstone/rudstone

M4 facies (Early Miocene).

4.1.1.3. Slope facies. The most proximal reef slope

environments are characterized by abundant benthic

foraminifers and red algal fragments, and common

coral fragments: 1) coral–algal floatstone R1c facies

(Early Oligocene), 2) coralline algal–foraminiferal

grainstone C4b facies (Late Oligocene).

Deeper slope facies are dominated by very large

and flattened benthic hyaline foraminifers and

calcareous algae: 1) coralline algal–foraminiferal

packstone (Late Oligocene) C4a facies, 2) lepido-

cyclinid–rhodolithic rudstone C5a facies (Late Oli-

gocene), 3) Halimeda rudstone C5b facies (Late

Oligocene).

4.1.1.4. Deep carbonate shelf facies. Approximately

1 m below the top of the Nido carbonates (near the

base of the Pagasa clastics), a packstone dominated by

planktonic foraminifers, fragments of large flattened

benthic foraminifers, and coralline algae was encoun-

tered in the MA-8 well. This facies (M0), overlying

subaerially exposed shallow inner-shelf facies, is

interpreted as deposited in open-marine and deep

carbonate shelf, during a phase of major deepening

(bdrowning sequenceQ, sensu Erlich et al., 1990,

1991).

4.1.2. Diagenesis

4.1.2.1. Diagenesis in the Malampaya inner-shelf

area. Two intervals with distinct diagenetic evolu-

tion were recognised in the Malampaya inner-shelf. In

the Late Eocene–Early Oligocene interval, except in


its uppermost part, dissolution of bioclasts remained

limited. Early marine isopacheous fringes and mete-

oric to early burial drusy cements are present. Low

porosity and permeability within grainstone layers

result from early marine and meteoric and/or early

burial cementation occluding most of the primary

intergranular pores, and from weak leaching. Arago-

nitic bioclasts (corals and Halimeda) are commonly

replaced by non-ferroan mosaic calcite spar.

Diagenesis in the interval between the uppermost

Early Oligocene and the late Early Miocene is

controlled by the circulation of meteoric waters that

frequently has occurred during subaerial exposures of

the shelf (Fournier et al., 2004). Leaching of skeletal

grains, vuggy porosity, paleosoil development, and

calcite drusy cementation are the most common

meteoric features in this stratigraphic interval.

4.1.2.2. Diagenesis in the south-western flank.

Diagenesis affecting the south-western buildup flank

can be inferred from Late Oligocene MA-3 cores (Fig.

5). The very high intergranular primary porosity of

these mud-poor and coarse-grained sediments has

been almost completely occluded through successive

diagenetic phases (Fig. 5, c and d):

(A) Earlier marine precipitation of isopacheous

fibrous calcite cements alternating with geopetal

sediment infills. Geopetal infills are composed of

laminated micrite (microbial origin?), structure-

less to micro-peloidal micrite, and faecal pellets.

(B) Later cementation phases: 1) coarse-grained

drusy to mosaic calcite cements; 2) dolomite

cements; 3) coarse mosaic calcite cement

occluding fractures.

The very coarse-grained texture of cements 1) and

3) points towards a burial diagenetic environment

rather than a meteoric environment. Moreover the lack

of leaching and the highly positive values of carbon

isotope ratios (from +1.08x PDB to +2.12x PDB in

the cored interval) suggest that this interval has

probably never been subject to meteoric diagenesis.

4.1.2.3. Diagenesis in the Eastern flank. Carbonates

from the eastern flank are penetrated by well MA-2,

within the upper part of the Late Oligocene interval.

This interval was subject to weak diagenetic alteration

such as early growth of marine thin isopacheous

calcite cements and leaching of skeletal grains. Burial

calcite or dolomite cements are lacking, contrasting

with the south-western flank.

4.2. Results from the seismic interpretation

4.2.1. Seismic expression of the Malampaya buildup

The buildup is characterized seismically by medium

to high-amplitude reflections with typical spacings of

20–30 ms (Fig. 1). Reflections through the overlying

clastics are of lower amplitude with spacings of 15–25

ms. There is a sharp transition between clastics and

carbonates. This boundary is interpreted as the external

envelope of the Malampaya buildup. In the eastern

flank, reflections show abrupt changes in amplitude

and dip at its vicinity. In the western flank, particularly

to the north, the boundary is underlined by a high-

amplitude reflector. Seismic reflections in the Pagasa

clastics onlap this boundary. In the western flank,

seismic reflectors have high average dip values: 188 forinternal reflectors and 348 for the flank envelope.

The structural interpretation of the 3D seismic data

showed that the most salient structural feature is a

SW–NE-oriented fault, which forms a crest at the

western margin of the carbonate system. This fault

represents the boundary between the continuous high-

amplitude carbonate shelf reflectors and discontinu-

ous, steeply dipping, medium-amplitude ones. In the

lower part of the carbonate buildup (Late Eocene–

Early Oligocene), seismic lines clearly indicate a

normal fault (Fig. 6, d: transect EF; Fig. 7, b: transect

IJK; Fig. 8, b: transect NO). However, seismic data do

not provide clear indication on the sense of displace-

ment during the Late Oligocene–Early Miocene. This

fault was sealed by the Pagasa shales. Minor normal

faults affect the Late Eocene and Early Oligocene

deposits in the North-Eastern termination of the

carbonate system forming a short and narrow horst

structure. The Northern area was interpreted as

affected by a SW–NE-oriented fold structure (Fig.

9a and d).

4.2.2. Definition and description of unconformity-

bounded units

Unconformity-bounded units were defined, based

on the envelopes identified from seismic reflections,

combined to the vertical and lateral variations in

Fig. 5. (a) Seismic profile (transect AB: see location on Fig. 7, a), in the southernmost area of the Malampaya buildup showing a thick carbonate

succession in the western flank and a relatively narrow backstepping and aggrading shelf (location of wells MA-3 and MA-9 is indicated); b)

interpretation of the transect AB; (c) lepidocyclinid-coralline algal C5a facies (Late Oligocene, MA-3): large lepidocyclinids (Lep.) and

Halimeda plates (Hal.) are visible; the intergranular space locally is geopetally infilled with micrite (gi) and the residual porosity is occluded

completely by drusy calcite cements (dc); (d) Halimeda-rich C5b facies (Late Oligocene, MA-3): Halimeda plates (Hal.) are dominant and the

intergranular space is occluded completely by an early marine fringe of isopacheous fibrous calcite (ic) and by later meteoric drusy calcite

cements (dc); (e) close-up of core from MA-9 showing coral rudstone M4 facies (Early Miocene) with pieces of branching arborescent

Alveopora (Alv.). Colour legend for seismic sections: negative amplitudes=red, positive amplitudes=black.


depositional and diagenetic environments (Fig. 3). The

stratigraphic framework defined in this study is

summarized in Fig. 2.

4.2.2.1. Unit SR1 (Priabonian–Rupelian). Unit SR1

is bounded at base by the top of pre-Nido clastics and at

top by horizon R1 (maximum unit thickness: 100 m).

Pre-Nido clastic deposits are characterized by a chaotic

and generally low-amplitude seismic facies. The top of

the pre-Nido clastics (or base Nido limestone) repre-

sents the upper envelope of this seismic facies. The

cores extracted from well MA-4 in the uppermost part


of the pre-Nido clastics document continental fluvial

deposits of Paleocene to Eocene age.

On the seismic profiles, this unit shows diverse

onlap terminations of high amplitude reflectors over

the pre-Nido clastics (Fig. 6, c: transect CD).

Carbonates sampled in this interval in MA-1, MA-2,

and MA-5 were interpreted as very shallow-water

inner-shelf deposits. Following this, these termina-

tions can be interpreted as coastal onlaps. Mapping of

these terminations reveals a rugged exposed top-

ography at the central part of the studied area that has

been progressively buried by carbonate deposits (Fig.

6, a and c). The morphological characteristics of the

seismic reflectors and the nature of depositional facies

recognised in this interval validate the interpretation

of a relatively flat and shallow, aggrading land-

attached shelf, developing over the pre-Nido top-

ography. The lowermost SR1 unit is relatively rich in

quartz sand grains (up to 50% of the total rock

volume). The upward decreasing content in quartz

grains in the Late Eocene–Early Oligocene is believed

to be related directly to the decreasing extension of the

exposed pre-Nido clastic deposits.

In the northeastern part of the Malampaya

carbonate system, a reduced horst, sealed by the

C1.1 reflector (Fig. 6, d: transect EF), was inter-

preted from seismic data. The age of the host

formation cannot accurately be determined: downlap

terminations of westward dipping unit SC1.1 reflec-

tors onto reflector R1 indicate that the horst may

have formed coeval with or prior to the deposition of

SC1.1, but it could have been active at the time of

the SR1 unit deposition. The westward-thinning or

possibly lack of Early Oligocene deposits at the top

of the SR1 unit in MA-1 and the eastward thickening

of this unit could be related to synsedimentary

eastward tilting of the Malampaya platform and/or

to a post-SR1 and pre-SC1.1 tilting and erosion of

the uplifted crest. In the southwestern area, a thick

interval (up to 200 m) of southwestward dipping,

high-amplitude and discontinuous reflectors onlaps

the steep flank of the tilted block (Fig. 5); it

Fig. 6. (a) Paleogeographic maps of the SR1 unit (Late Eocene to Earl

Oligocene to earliest Late Oligocene); (c) seismic profile (transect CD) and

(d) seismic profile (transect EF) and interpretation in the northernmost

terminations of an intra-SC1.1 reflector; (e) seismic profile (transect GH)

Colour legend for seismic sections: negative amplitudes=red, positive am

probably represents redeposited carbonates of Late

Eocene to Early Oligocene age.

4.2.2.2. Unit SC1.1 (Rupelian–earliest Chattian).

Unit SC1.1 is bounded at base by R1 reflector and at

top by C1.1 (maximum unit thickness: 80 m).

Reflector R1 is a continuous negative high-amplitude

reflector (Fig. 6, c, d and e). It results from the

contrast in acoustic impedance between low porosity

shallow inner-shelf grainstones affected by meteoric

to burial cementation and porous inner-shelf wacke-

stone/packstone (along the western edge) to deeper

outer-shelf wackestone/packstone (along the eastern

margin).

In the northern area, a phase of eastward tectonic

tilting of the SR1 platform prior to the deposition of

the SC1.1 unit is evidenced by the following

observations: 1) the eastward deepening at the base

of the unit (Fig. 3) as suggested by the lateral facies

change between MA-1 (shallow inner-shelf R3b

facies) and MA-2 (reef slope R1c facies), 2) the onlap

terminations of C1.1 or intra-SC1.1 reflectors over R1

(Fig. 5, b: transect AB; Fig. 6, e: transect GH).

In MA-1, this unit is exclusively composed of

protected inner-shelf deposits (Fig. 3). In MA-5, a

prograding pattern is clearly expressed by the

vertical facies succession showing slope deposits

overlain by coral floatstone–rudstone from perireefal

zones, in turn, overtopped by protected inner-shelf

deposits. The same succession with a slightly thinner

inner-shelfal interval, is present in MA-2. In the

northern part of the Malampaya buildup, in the

vicinity of wells MA-1, MA-2, and MA-5, the

development of the SC1.1 unit is interpreted to

result from the eastward progradation of a reefal

platform, from an initial topographic high located

along the western edge.

High-frequency subaerial exposures are suspected

to have occurred in the uppermost part of this interval

(Fig. 3). This is based on the recurrence of calcrete

features (MA-5) and negative carbon isotope peaks

(MA-2 and MA-5). The C1.1 reflector marks the top

y Oligocene); (b) paleogeographic maps of the SC1.1 unit (Early

interpretation showing onlaps of unit SR1 over the Pre-Nido clastics;

buildup area, showing onlap of C1.1 over R1 and downlap/toplap

and interpretation showing onlaps of the SC1.1 reflectors over R1.

plitudes=black.


Fig. 7. (a) Paleogeographic map of the SC1.2 unit (Late Oligocene); (b) seismic profile (transect IJK) and interpretation showing onlap

termination of an intra SC1.1 reflector over R1, C1.2 over C1.1 and downlaps of C2.3 onto C2.2; (c) facies and sequence interpretation of the

Oligocene cored interval from MA-5 well, showing progradational and aggradational pattern of units SC1.1 and SC1.2, respectively; (d) seismic

profile (transect LM) and interpretation showing the truncation of units SR1 and SC1.2, below the base of unit SC1.2 (in MA-4, the Late

Oligocene inner-shelf deposits directly overlie the Pre-Nido clastics). Colour legend for seismic sections: negative amplitudes=red, positive

amplitudes=black.


of this interval, which is characterized by high-

frequency cyclic alternation of tightly cemented and

vuggy layers (see erratic well-log porosity response in

Fig. 3).

In the northeastern area, seismic reflections indi-

cate the presence of a very small-sized horst–graben

system. The westward dipping clinoforms with down-

lap and toplap terminations respectively against the

Fig. 8. (a) Paleogeographic map of units SC2.1, SC2.2 and SC2.3 (Late Oligocene-earliest Miocene?); (b) seismic profile (transect NO) and

interpretation displaying various downlap terminations (intra-C1.1 reflector onto R1, C2.1 onto C1.2 and C2.3 onto C2.2); (c) seismic profile

(transect PQ) and interpretation showing toplap termination of reflector C1.2 against C2.1. Colour legend for seismic sections: negative

amplitudes=red, positive amplitudes=black.


R1 and C1.1 reflectors (Fig. 6, d: transect EF) are

interpreted to represent the infill of the graben by

prograding slope deposits. There are no well data

available in this part of the buildup that could confirm

this interpretation.

4.2.2.3. Unit SC1.2 (Chattian). The base and the top

of the unit SC1.2 relate to the C1.1 and C1.2 horizons,

respectively (maximum unit thickness: 50 m). Hori-

zon C1.2 separates the top of cyclically exposed,

shallow inner-shelf deposits with numerous cemented

layers (meteoric diagenesis) from overlying unex-

posed deep-water deposits. The relatively constant

facies association below C1.2, in all of the wells that

reached this interval (MA-1, MA-2, MA-3, MA-4,

MA-5, MA-10), gives evidence of deposition on a

relatively flat inner shelf at depths less than 20 m. In

addition, in the northeastern part of the buildup,

reflector C1.2 is parallel to the underlying reflectors;

this clearly signs flat-topped shelves. The local toplap

termination of reflector C1.2 (Fig. 8, c), therefore, is

interpreted as a truncation that has resulted from a

local deformation of the carbonate platform rather

than a reef-like topography.

In MA-5, i.e. the best documented well, Fournier et

al. (2004) showed a cyclic alternation of shallow inner-

shelf facies (C1a, C1b, C2, and C3), interrupted by

subaerial exposure surfaces. The authors interpreted

this interval as an aggrading flat rimmed-shelf with

frequent exposure surfaces. The absence of significant

lateral facies changes below and above reflector C1.1

and the onlap termination of reflector C1.2 over C1.1

(Fig. 7, b: transect IJK) suggests that SC1.1 shallow

shelf deposits have been deformed tectonically prior to

Fig. 9. (a) Paleogeographic map of units SM1.1, SM1.2 and SM2, SM3 and SM4 (Early Miocene); (b) seismic profile (transect RS) and

interpretation showing a progressive backstep of a relatively narrow shelf; (c) neutron and density well-logs, facies and paleoenvironments of

side-wall samples from well MA-8 (units SM3 and SM4); (d) seismic profile (transect TU) and interpretation showing the onlap of unit SM3

over reflector M2. Colour legend for seismic sections: negative amplitudes=red, positive amplitudes=black.



and/or during the deposition of SC1.2. The resulting

topographic highs are mainly located along the west-

ern edge (Fig. 7, a). In MA-4 well, Late Oligocene

SC1.2 carbonate deposits directly overlies the pre-

Nido clastics. The seismic lines show toplap termi-

nations of R1 and C1.1 below C1.2 (Fig. 7, d: transect

LM). These terminations could reflect an eastward

tilting and truncation of SR1 and SC1.1 units below

the Late Oligocene SC1.2 deposits, or could be related

to SR1 and SC1.1 progradations.

4.2.2.4. Unit SC2.1 (Chattian). Unit SC1.2 is

bounded at the base by the C1.2 unconformity and at

the top by C2.1 (maximum unit thickness: 60 m). C2.1

reflector exhibits a flat, highly negative amplitude

segment passing into a low amplitude, westward

dipping segment that downlaps reflector C1.2 (Fig. 8,

b: transect NO). This reflector is steeply dipping

eastward and shows a decrease in amplitude. The

depositional and diagenetic patterns observed in MA-2

indicate that the high amplitude, flat segment repre-

sents a shallow shelf that has undergone subaerial

exposure; the lower amplitude and dipping segments

could represent the slopes of the small-sized buildup

which are restricted to the northeastern part of the

carbonate system. This interpretation is supported by

the occurrence of depositional facies, above C1.2,

expressing calm inner-shelf environments in MA-5

(facies M1) and deeper, open environment in MA-1

(facies C4a).

In wells MA-1 and MA-2, this interval exhibits a

shallowing-upward trend, from deep open marine

slope (C4a) to perireefal and/or inner-shelf facies

(C4b, C1b, C2). The new seismic data showed a

small-size flat-topped carbonate buildup in the north-

western part of the Malampaya carbonate system (Fig.

8). This unit results probably from aggradation and

progradation of a carbonate shelf, initially located

along a SW–NE direction, toward the SE and NW. The

local truncation of reflector C1.2 just below the high-

amplitude and flat segment of reflector C2.1 (Fig. 8, c:

transect PQ) strongly suggests that the carbonate

platform has developed on the highest area of a

tectonically deformed foundation. At the top of the

unit, the initial structure seems to be sealed completely.

4.2.2.5. Unit SC2.2 (Chattian). Unit SC2.2,

bounded at base by C2.1 and topped by C2.2, relates

to a relatively flat, aggrading shelf, deposited in a

period of relative tectonic quiescence (maximum unit

thickness: 60 m). The very erratic porosity and sonic

log responses through the whole interval may have

resulted from repeated exposure events. The seismic

profiles and well data from MA-2 provide support for

a moderate retrogradation of the eastern shelf margin

over C2.1 horizon (Fig. 8).

4.2.2.6. Unit SC2.3 (undifferentiated

Chattian–Aquitanian). Unit SC2.3 is topped by the

C2.3 horizon that displays a downlap termination onto

C2.2 (Fig. 7, b: transect IJK; Fig. 8, b: transect NO).

This unit consists of a narrow carbonate body (less

than 500 m wide) that developed along the western

edge (maximum unit thickness: 40 m). In well MA-1,

the basal deposits of SC2.3 relate to relatively deep

and open slope or outer-shelf environments (facies

C4a). They are overlain by shallower and more

protected inner-shelf deposits (facies M2a). The

chaotic porosity and sonic log records, the presence

of meteoric cements, microkarsts and the negative

carbon isotope values indicate that this unit has

undergone several exposure events during deposition.

This unit has resulted probably from southeastward

progradation of a narrow carbonate buildup that

initially developed on the top of the uplifted western

edge.

4.2.2.7. Units SM1.1 to SM3

(Aquitanian–Burdigalian). Similarly to C2.2 and

C2.3, reflectors M1.1 to M3 materialize tops of

intervals with erratic sonic and porosity log responses

that correspond to alternations of metre-thick, highly

porous, and firmly cemented layers. The recurrence of

caliche crusts, alveolar septal structures in these

intervals strongly suggest that they have been subject

to frequent subaerial exposure (Fournier et al., 2004).

These intervals are overlain by beds with small

variations in porosity and sonic that are typical for

deeper inner-shelf deposits affected by moderate

dissolution and low cementation. Such a vertical

succession is consistent with the effects of cumulative

diagenesis associated with parasequence stacking

patterns in a third-order sequence (Tucker, 1993).

The seismic reflectors that present a clear contrast

between erratic intervals, composed of alternating

porous and tightly cemented beds and intervals with


moderate to high porosity, could therefore be regarded

as third-order sequence boundaries (Fig. 10).

Units SM1.1 to SM2 have aggraded with a minor

retrograding component of the eastern margin. Unit

SM1.1 onlaps the flanks of the SC2.3 buildup (Fig. 8,

b: transect NO). The development of an aggrading

protected inner-shelf that onlaps the 40- to 50-m-thick

SC2.3 buildup implies an important relative sea-level

fall that would have occurred after deposition of the

SC2.3 unit. The subsequent relative sea-level rise has

catalysed the aggradation of the carbonate shelf

afterwards.

After deposition of the SM2 unit, tectonic folding

of the carbonate buildup along a SW–NE axis in the

northeastern part of the Malampaya carbonate system

that occurred prior to and/or during the deposition of

the SM3 unit, is evidenced by seismic records and

well data as follows: 1) onlaps of unit SM3 over

reflector M2 (Fig. 9, d: transect TU), 2) eastward

thinning of unit SM3 and 3) geometric correspond-

ence between the area of development of the fold and

that of the SM3 shallow-water carbonate deposits

(Fig. 9, a). Unit SM3 displays the same stacking

pattern, typical of inner shelf deposits, in all of the

wells reaching this interval (MA-1, -5, -7, -8). This

provides support for the onlapping nature of the

Fig. 10. Relationship between high- and lower-frequency cyclicity, deposit

tops are characterized by an increase in frequency of subaerial exposure,

energy seismic reflection takes place at the interface between erratic- and

seismic terminations over the M2 reflector. In the case

of a downlap termination, slope or open shelf

environment deposits should be expected in MA-5,

instead of shallow inner-shelf deposits. In the northern

margin of the buildup, beyond the northern termi-

nation of the SW–NE fold, the buildup is restricted to

a 700-m-wide belt located along the western edge

(Fig. 9, b: transect RS).

4.2.2.8. Unit SM4 (Upper Burdigalian). The top of

the uppermost carbonate unit is characterized by a

high-amplitude negative reflection representing the

transition between tightly cemented shallow inner-

shelf carbonates and overlying planktonic foraminifer-

bearing clastics. This reflector locally shows downlap

terminations onto reflector M3 with decrease in

amplitude in the dipping segment of the horizon.

Unit SM4 is characterized by a westward back-

stepping of the eastward margin. In the southern part

of the Malampaya buildup, a narrow reef tract,

characterized by a decreasing upward width has

developed on the eastward tilted SM1.2 platform

(Fig. 7, d; Fig. 5, a and b).

In MA-1, the presence of meteoric cement and

highly negative values of carbon isotope ratios

(�8.1x PDB at 2956.60 m, i.e. 1 m below the top

ional and diagenetic facies, well-log and seismic responses. The unit

resulting in an erratic porosity and sonic well-log response. A high-

high-porosity homogeneous intervals.


carbonates) indicates that subaerial exposure of the

buildup occurred prior to the final drowning. The

analysis of the uppermost part of the Nido Limestone

and of the lowermost Pagasa clastics from MA-8 (Fig.

11) provides new insights into the timing and forcing

of the final drowning event. The side-wall sample

extracted from 3777.50 m hole-depth (Fig. 11, a)

exhibits miliolid and soritid-dominated, shallow

inner-shelf facies (facies M3h), affected by intense

leaching and meteoric to shallow burial cementation.

The 3773.50-m-deep sample (at 0.50m below the top

of carbonates) is a planktonic foraminifer-dominated

packstone, with fragments of echinoderms, coralline

algae and large benthic foraminifers (facies M0, Fig.

9, c). This facies is indicative of a deep open marine

environment. There are no siliciclastic particles in this

sample. In addition, low gamma-ray values (b40 API)

Fig. 11. Drowning event in MA-8: (a) gamma-ray, density, and porosity

clastics; carbonate facies and paleoenvironments are indicated; (b) san

foraminifers (Pl.), and planktonic foraminifer-bearing carbonate lithoclasts

M0 with numerous planktonic foraminifers (Pl.), echinoderm fragments

recrystallised coral fragments (Cor.), Miliolids (Mil.); dissolution vugs (V

were measured, also suggesting minor terrigenous

supply (Fig. 9, a). At 3772.50 m depth (at 0.50 m

above the top carbonates), a poorly sorted sandstone

was present (Fig. 9, b). It contains common carbonate

lithoclasts, most of which are reworked from the

underlying M0 facies. Despite the relatively few data

available from the drowned interval, three observa-

tions can be made concerning the demise of the

Malampaya buildup: 1) a deepening event occurred

after an exposure episode as suggested by intense

leaching of the shallow inner-shelf facies M3h at

3777.50 m depth; 2) this deepening event is of Late

Burdigalian age as indicated by the presence of

Globigerinoides sicanus in the 3773.50-m-deep sam-

ple; 3) the oldest evidence of significant terrigenous

supply (3772.50 m depth) occurs above the clastic-

free M0 deep shelf environment facies.

well-logs from the uppermost Nido Limestone and basal Pagasa

dstone composed of sub-angular quartz grains (Qz.), planktonic

(Lith.), representing the basal Pagasa clastics in MA-8; (c) packstone

(Ech.); (d) coral-foraminiferal-coralline algal packstone M3, with

) and drusy calcite cements (dc) are visible.


5. Discussion

5.1. Controls on carbonate sedimentation

Based on seismic interpretation and rock sample

analysis, the following model for the carbonate

buildup development is proposed (Fig. 12). Initial

topography, differential subsidence at regional to local

scales, faulting, eustacy, climate, and the type of

carbonate producers influenced by varying terrige-

nous and nutrient input are known to be the main

controlling factors of carbonate platform growth (e.g.

Longman, 1981; Crevello et al., 1989; Hallock and

Schlager, 1986; Montaggioni, 2000; Masse and

Montaggioni, 2001). The effects of ocean currents

and wind circulation patterns, however, are difficult to

recognize. The high-frequency cyclicity typifying the

Late Oligocene and Early Miocene inner-shelf depos-

its could reflect a glacio-eustatic control, but episodic

tectonism could have also generated such metre-scale

cycles (Fournier et al., 2004). Possible salinity

fluctuations probably have had low impact on the

development of this system; strongly restricted or

brackish environments were not recognized in the

available rock dataset (Table 3).

5.1.1. Topographic control on carbonate growth

initiation (Late Eocene)

Numerous authors have discussed the predominant

role of topography in the initiation of carbonate

buildup development in various tectonic settings

(e.g. Longman, 1985; Fulthorpe and Schlanger,

1989; Purdy and Bertram, 1993; Wilson et al.,

2000). In the North Palawan block, the settlement

sites of carbonate buildups and associated hydro-

carbon accumulations are restricted to the crests of

tilted blocks formed during the rifting phase of the

South China Sea (Wiliams, 1997). In Malampaya, due

to the presence of exposed area on the highest points

of the tilted block, the carbonate system developed as

land-attached shelves onlapping an uneven topogra-

phy. The initial topography has not simply controlled

the location and the morphology of carbonate

systems, but has also influenced the composition of

the carbonate rocks. The basal carbonates are rela-

tively rich in quartz sand, probably derived from the

pre-Nido hinterland clastic sources. The initial pre-

Nido basement highs were buried by carbonate

deposits during the Late Eocene, within the SR1 unit.

The relatively important terrigenous supply during

this early stage of the Malampaya buildup develop-

ment may have been deleterious to coral settlement

and growth. It also explains the extreme scarcity of

coral remains in the Late Eocene carbonates, since

such continental material may have been associated to

high nutrient levels as observed in modern land-

bordering carbonate systems (Ambatsian et al., 1997;

Mc Culloch et al., 2003).

5.1.2. Subsidence and tectonic deformation of the

Malampaya buildups

Deposition and preservation of up to 600 m of

shallow-water carbonates indicate that regional sub-

sidence was the dominant control on accommodation

space. Changes in the geodynamic pattern of the

southern margin of the South-China Sea from the

Eocene to the Miocene probably induced changes in

regional subsidence rates during the Malampaya

buildup growth. In addition, variations in the lateral

unit thickness, lateral facies changes and the nature of

seismic terminations show that tectonic processes

(tilting, faulting, and local folding) operating during

the building growth has resulted in local variations in

subsidence rates or local uplifts.

During the Late Eocene to Early Oligocene, the

Malampaya shelf was controlled by two tectonic

processes (Fig. 12): 1) an eastward tilting of the

carbonate platform along the western fault and 2)

block faulting in the North-East generating a short and

narrow graben within the Malampaya shelf. The

eastward tilting promoted non-deposition and/or

erosion of the uplifted crest (during SR1 unit

deposition) and possibly controlled the prograding

pattern of the SC1.1 unit. The westward, steep dipping

clinoforms present in the north-eastern graben sug-

gests that most of the fault movement occurred prior

to and/or at the top of unit SR1; however, faults may

still have been active during the SC1.1 unit deposi-

tion. The north-eastern graben was completely filled

at the top of this unit. The end of the rifting phase

occurred at the top of the SR1 unit boundary or within

the SC1.1 unit. The small-scale internal architecture of

these syn-rift deposits cannot be determined directly

from seismic lines due to insufficient vertical reso-

lution (25 m). Bosence et al. (1998) showed that, in

syn-rift carbonate systems, the internal architecture is

Fig. 12. Model for the development history the Malampaya buildup and facies distribution, from the northern area along a MA-1–MA-5–MA-2 transect. The possible controlling

parameters are indicated.

F.Fournier

etal./Sedimentary

Geology175(2005)189–215

209

Table 3

Main expected environmental factors and their effects on the development of the Malampaya buildup

Sedimentologic, diagenetic,

and stratigraphic features of

Malampaya buildup

Main possible controlling factors

Initial

topography

Regional

subsidence

Logical tectonic

deformation/differential

subsidence

Eustatism Climate Nutrient

supplies

Wind/

currents

Type of

carbonate

producers

Buildup location x

Buildup dimensions

(extention/thickness)

x x

Type of carbonate shelf:

land attached/isolated

x x x x

Intra-inner shelf onlaps x

Development of

small-size buildups

x x x

Lateral variations of

sequence thickness

x x x

Buildup asymmetry x x

High-frequency cyclicity x x x

Protected versus open

signature of inner-shelf

environments

x

Depositional facies x x x x

Meteoric-dominated

evolution

x x x x

Buildup drowning x x


mainly governed by the interplay between fault

movement rates and carbonate production rates.

In the lower part of the Late Oligocene, prior to

and/or during the deposition of unit SC1.2, local uplift

occurred along the western fault and in the central

area (Fig. 7). This event resulted in the development

of partially land-attached shelves onlapping carbonate

islands. Episodic uplift of these topographic highs

could have caused the development of the exposure-

capped high-frequency cycles reported from this

interval.

After the deposition of unit SC1.2, a high formed

in the north-eastern part of the buildup (Fig. 12). Unit

SC1.1 was locally eroded; a carbonate platform

started to grow from this high and prograded to the

north-west and to the south-east (unit SC2.1). The

SW–NE paleo-high orientation could be related to the

reactivation of a Late Eocene–Early Oligocene syn-

rift fault.

After a period of tectonic quiescence in the

uppermost part of the Oligocene (aggrading unit

SC2.2), a narrow carbonate buildup (300 m width)

developed along the western fault (unit SC2.3). Two

interpretations can be offered to explain the prefer-

ential development of the carbonate buildup along the

Malampaya western margin: 1) a topographic high

was created along the western fault by eastward tilting

of the carbonate shelf or by local bending due to

transpressive movement along the fault. The carbo-

nate system drowned in the distal parts whereas

carbonate production kept pace with relative sea-level

in the shallower parts, 2) oceanographic conditions

(presence of currents along the western flank, water

chemistry, prevailing wind direction) created a variety

of environments more or less favourable for reef

development.

During the early Miocene (units SM2 and SM3),

differential subsidence, controlled by the reactivation

of a SW–NE-oriented high, resulted in a significant

westward thickening of the inner-shelf deposits. The

presence of shallow protected inner-shelf deposits in

the actively subsiding area (as evidenced in MA-1,

MA-7, MA-8, close to the western margin) indicates

that carbonate accumulation rates have been high

enough to fill up the main part of the accommodation

space. The high-frequency cyclicity and associated

exposure events recognized in this interval (Fournier

et al., 2004) could have been controlled by episodic


uplifts (or folding) and subsequent flooding of the

north-eastern area of the Malampaya shelf. The

asymmetry of the Malampaya buildup during the

Early Miocene between the northern (broad platform

interior) and the southern area (narrow platform

interior) is possibly related to the development of this

SW–NE oriented structure.

Concerning the last stage of buildup development

(Burdigalian unit SM4), the same interpretation as for

unit SC2.3 can explain the westward backstep of the

shallow-water carbonates.

The most conspicuous features are the asymmetric

sedimentation patterns along the flanks of the Malam-

paya system. Whereas the eastern flank and the

adjacent basin are almost completely sediment starved,

the western flank exhibits thick carbonate deposits (up

to 300 m). The cored interval of well MA-3 (Fig. 3)

represents relatively proximal part of the western

flank; deposition is probably largely autochtonous

(facies C5a and C5b), and took place in the mesophotic

zone as indicated by the dominance of large and

flattened benthonic foraminifers and coralline algae

(mainly Sporolithon). However, in the most distal part

of the western flank and in the basin, carbonate

sediments were probably in large part redeposited

(Fig. 1). Two factors can be invoked to explain this

asymmetry: 1) the western shelf margin and slope were

destabilized episodically by gravity processes and

carbonate material has redeposited in the basin. Fault

activity could have enhanced such a destabilization; 2)

redeposited material could have derived from the shelf

by winds (prevailing SW direction) or currents. A

similar asymmetrical depositional pattern was docu-

mented in the Miocene carbonate platform of the

Queensland Plateau, northeastern Australia (Betzler et

al., 1995): calciturbidite development is predominant,

respectively, on the leeward side of the reefs during the

stages of active reef growth, and on the windward side

during the stages of reef emergence.

5.1.3. Influence of climate, oceanic factors, and

composition of biological assemblages

The type of carbonate producers is an important

control on the development of the Malampaya

buildups. Although high-magnesium calcite bioclasts,

i.e. benthonic foraminifers and coralline algae are

dominant, aragonitic frame-builders, i.e. corals, are

common in the Malampaya inner-shelf deposits

during the Early Oligocene–Early Miocene. The

occurrence of coarse-grained coral rudstone facies

(facies R2 and M4: Table 2) probably indicates the

proximity of coral reefs. Fournier et al. (2004)

discussed the role played by coral-reef rims in the

nature of inner-shelf facies successions. Although the

dominance of benthonic foraminifers and coralline

algae has resulted in lower rates of carbonate

production, compared to those reported from modern

tropical coralgal associations, accumulation rates

estimated in the inner-shelf appear to be generally

sufficient to infill the accommodation space created

by structural deformation. Carbonate sedimentation

has led to form low-relief shelves.

The type of carbonate producers probably is known

to be strongly influenced by oceanographic and

climatic factors such as currents, nutrient levels, water

temperatures, and prevailing winds (Pomar et al.,

2004; Vecsei, 2004). In the Malampaya inner-shelf

environments, the green alga Halimeda is common in

the SR1 unit (Late Eocene–Early Oligocene) whereas

it is lacking completely from units SC1.2 to SM3 (late

Early Oligocene to Early Miocene). However, Hal-

imeda algae are common in the Early Oligocene to

Early Miocene slope and outer shelf environments;

they have formed Halimeda sands (Fig. 5, b).

Halimeda is known to preferentially develop in

nutrient-rich waters (Davies and Marshall, 1985;

Drew and Abel, 1985). The disappearance of Hal-

imeda in the Malampaya inner-shelf above the top of

unit SR1 could be related to changes in nutrient

concentrations and current regime in relation to the

opening of the South China Sea. The persistence or

occasional occurrence of Halimeda in the buildup

flanks could be attributed to locally active upwellings.

This interpretation was invoked to explain the

presence of Halimeda sands along the Great Barrier

Reef slopes at depths down to 100 m (Drew and Abel,

1988). The difference in buildup geometry and type

between the SR1 unit and the overlying stratigraphic

units could originate from the difference in the type of

carbonate producers (Halimeda-rich open shelf versus

coral–foraminifer-rich rimmed platform).

At diverse stages of its development, the Malam-

paya carbonate system displayed an asymmetric

morphology, particularly during the growth of narrow

buildups along the western margin (units SC2.3 and

SM4). In Cenozoic South-East Asian carbonate


systems, platform asymmetry is explained usually by

the influence of dominant paleowinds and paleocur-

rents (Cucci and Clark, 1993: Late Eocene to Miocene

Gunung Putih carbonate complex; Rudolph and

Lehmann, 1989: Miocene Natuna Platform; Grotsch

and Mercadier, 1999: Malampaya buildups). Frame-

work builders as corals have developed chiefly in

agitated and oxygenated waters at the windward side;

skeletal grains and muds were moved off the leeward

side. As discussed above (Section 5.1.3), such an

asymmetry could have resulted from the development

of carbonate buildups, during sea-level highstands, at

the top of tectonically active topographic highs along

the western fault. A similar pattern is present in the

Pedro Bank (Nicaragua Rise), where higher calcitur-

bidite supply during highstands in sea level is

documented (Andresen et al., 2003; Glaser and

Droxler, 1991).

Climate is known to strongly influence the proper-

ties of carbonate reservoirs since they control both

depositional patterns and diagenetic alteration (Sun

and Esteban, 1994). The development of reefal

environments during the Early Oligocene to Early

Miocene required warm sea surface temperatures

(humid equatorial to arid tropical conditions). In the

Late Oligocene–Early Miocene, the Malampaya shelf

has exhibited a meteoric-dominated diagenetic evolu-

tion affecting the Nido carbonates, that is more likely

related to a prevailing humid equatorial climate

favouring severe leaching and caliche development.

In contrast, the Late Eocene to Early Oligocene

Malampaya shelf is characterized by reduced meteoric

diagenetic alteration that could be related to a less

humid climate and/or few exposure events during this

interval. However, no evidence of arid conditions was

found in this interval and the sediments deposited are

totally devoid of evaporites or dolomites. Compared to

the Late Oligocene–Early Miocene interval, the Late

Eocene–Early Oligocene shelf deposits do not display

any high-frequency cyclicity. Such a change in strati-

graphic and diagenetic patterns in the mid-Oligocene

can be explained in terms of climate. The global

cooling event, penecontemporaneous to the Early–

Late Oligocene transition is recorded in the Indo-

Pacific region (Fulthorpe and Schlanger, 1989). It

could have modified the climatic regime of South-East

Asia through glacio-eustatic sea-level fluctuation,

which favoured high-frequency cyclicity and repeated

exposures on the Malampaya shelf. In addition, the

increasing upward imprint of meteoric diagenesis

through the Oligocene could be related to the south-

ward drifting of the Palawan block (from 208N at 35

Ma to 128N at 15 Ma, after Hall, 2002). This motion

could have shifted the Malampaya buildup to lower

latitudes, from tropical to equatorial conditions. As

discussed by Fournier et al. (2004), the onset of the

East Asian monsoon in the earliest Miocene has

probably influenced the nature and distribution of

barriers along the platform and therefore the lateral and

vertical distribution of the inner-shelf facies (Late

Oligocene cycles generated in protected settings

versus Early Miocene cycles originated under open-

marine conditions).

5.1.4. Drowning of the Malampaya buildup

Siliciclastic supplies from the mainland of North

Palawan, that was uplifted and exposed in the latest

Early Miocene–earliest Middle Miocene are inter-

preted as being the main control of platform drowning

in the North Palawan offshore area (Lighty et al., 1983;

Fulthorpe and Schlanger, 1989). However, in Malam-

paya, the earliest evidence of significant terrigenous

input is observed above the clastic-free M0 deep

carbonate shelf facies. This siliciclastic input occurred

subsequently to the deepening stage. Therefore, they

cannot therefore be considered to be responsible for

the drowning of the Malampaya buildup. Hence

drowning may have resulted from: 1) a rapid relative

sea level rise, related to the downward flexure of the

North Palawan Block, which outpaced carbonate

accumulation, 2) inimical waters (anoxia, excess in

nutrient level) limiting rates of carbonate production.

The second hypothesis is supported by the reappear-

ance of Halimeda in MA-8, at 6 meters below the top

of inner-shelf carbonates (Fig. 11). As mentioned

above, the growth of Halimeda beds is favoured by

high nutrient content. In Malampaya, increases in

nutrient level may have been related to the emergence

of the North Palawan Island.

5.2. Comparison with other Cenozoic tropical carbo-

nate systems

5.2.1. Buildup initiation

Many Cenozoic carbonate platforms initially have

developed on the footwall crests of tilted blocks in


extensional settings: the Eocene to Miocene Tonasa

Platform, Sulawesi (Wilson et al., 2000), the Peutra

Formation, Sumatra (Collins et al., 1996), the Liuhua

platform, South China Sea (Erlich et al., 1990),

Miocene–Pliocene Segitiga platform, east Natuna

sea, Indonesia (Bachtel et al., 2003), the Oligo-

Miocene Salalah platform, South Oman (Borgomano

and Peters, 2004). Similar to the Late Eocene–Early

Oligocene Malampaya carbonate system, the Tonasa

platform initially formed as a land-attached shelf and

comprised clastic-rich basal deposits. In the Carib-

bean region, the initiation of the Pleistocene–Hol-

ocene reefal buildup was largely controlled by

antecedent topography inherited from the tectonic

deformation of underlying siliciclastic deposits

(Esker et al., 1998; Ferro et al., 1999; Purdy et al.,

2003).

5.2.2. Influence of local tectonics

There are few published models in the literature,

documenting the tectonic control on the development

of South-East Asian Tertiary carbonate systems. The

formation of the Late Eocene to Miocene Gunung

Putih carbonate complex was influenced by differ-

ential subsidence that controlled the distribution of

carbonates on the platform and favoured the develop-

ment of small-sized buildups on structural highs

(Cucci and Clark, 1993). In the Miocene–Pliocene

Segitiga carbonate system, east Natuna sea, faulting

controlled the distribution of facies and the establish-

ment of localized buildups on structural highs,

whereas local differential subsidence caused lateral

variations in sequence stacking pattern throughout the

platform (Bachtel et al., 2003). The syn-rift develop-

ment of the Tonasa platform (Wilson et al., 2000)

could be regarded as an analogue of the Late Eocene

and Early Oligocene series from Malampaya: syn-

tilting deposition of shallow-water on the footwall,

thick successions of redeposited carbonates in the

hangingwall. Numerous other examples of syn-rift

carbonate development are documented in the Gulf of

Suez (Burchette, 1988; Bosence et al., 1998; Cross et

al., 1998).

Unlike Malampaya, the establishment and the

development of Miocene carbonate buildups, in the

offshore area of south Palawan (Rehm, 2003) and

Vietnam (Mayall and Cox, 1988), are not significantly

influenced by tectonics.

5.2.3. Platform drowning

One of the best documented drowning sequence

from the South-East Asian Cenozoic is that of the

Early Miocene Liuhua Platform, offshore People’s

Republic of China (Erlich et al., 1990, 1991). Similar

to Malampaya, the following features were reported

from the Liuhua Platform: 1) development of an

asymmetric platform prior to drowning, 2) deposition

of planktonic and flattened benthic foraminifer-rich

packstone in the uppermost section of the carbonate

series. In addition, relative sea-level rise and environ-

mental deterioration (excluding excess in clastic

supply) were invoked as possible causes for platform

drowning.

Other examples of subaerial exposure prior to

buildup drowning were documented in south-east

Asia: Middle Miocene Anepahan A-1X site, offshore

south Palawan (Rehm, 2003), Middle Miocene

Luconia Province, offshore Sarawak (Epting, 1980,

Vahrenkamp et al., 2003).

6. Conclusions

The combined analysis of rock, well-log and 3D-

seismic data shows that the Malampaya carbonate

system has recorded tectonic, climatic, eustatic,

oceanographic events and changes in benthic com-

munity structures during the Late Eocene–Early

Miocene period.

The structural relief created by block tilting, in the

late Eocene, during the rifting phase of the South

China Sea has determined the size, shape, and

location of the initial carbonate buildup.

The growth of large frame-building organisms such

as scleractinians has led to the formation of a reefal

rimmed-shelf topography during the Early Oligocene–

Early Miocene. Accumulation rates on the inner-shelf

have generally been high enough to form flat shelves

from initially uneven topography.

The active deformation during sedimentation

largely controlled the internal architecture (develop-

ment of small-sized buildups on highs, internal onlaps

in inner shelfal deposits, truncation of strata) and the

asymmetry of the buildup. The episodic reactivation

of structural highs could have been responsible for the

high-frequency cyclicity recorded in the inner-shelf,

but the role of glacio-eustacy cannot be ruled out.


Thick redeposited carbonates in the western basin are

thought to result from the episodic collapse of the

western shelf margin collapse, possibly in relation

with the western faulting activity.

The effects of oceanic currents and winds are

difficult to evaluate: they could have favoured the

development of linear buildups along the western

edge. Current-driven nutrient supplies could have

controlled the occurrence of certain skeletal compo-

nents such as Halimeda. Local nutrient excess in

oceanic water at the end of the Early Miocene is

regarded as a possible cause for final drowning of the

buildup, together with an abrupt increase in sub-

sidence rates.

Acknowledgements

This work was funded by Shell Philippines

Exploration B.V. (SPEX). Their support and approval

to publish this paper are gratefully acknowledged. We

especially thank D. Neuhaus (SPEX). This paper

significantly benefited from the experience of F.

Abbots-Guardiola (Shell International, Houston,

USA), C. Mercadier, P. Cassidy, W. Asyee, and G.

Warrlich (Shell Carbonate Team, Rijswijk, The Neth-

erlands). This manuscript was greatly improved by

reviews from J. Reijmer, C. Everts and G. Warrlich.

References

Ambatsian P, Fernex F, Bernat M, Parron C, Lecolle J. High metal

inputs to closed seas: the New Caledonian lagoon. J Geochem

Explor 1997;59:59–74.

Andresen N, Reijmer JJG, Droxler AW. Timing and distribution of

calciturbidites around a deeply submerged carbonate platform in

a seismically active setting (Pedro Bank, Northern Nicaragua

Rise, Caribbean Sea). Int J Earth Sci (Geol Rundsch)

2003;92:573–92.

Bachtel SL, Kissling RD, Martono D, Rahardjanto SP, Dunn PA,

MacDonald BA. Seismic stratigraphic evolution of the

Miocene–Pliocene Segitiga Platform, East Natuna Sea, Indo-

nesia: the origin, growth ad demise of an isolated carbonate

platform. In: Eberli GP, Massaferro J.L, Sarg JF, editors.

Seismic Imaging of Carbonate Reservoir and Systems. AAPG

Memoir, vol. 81. 2003. p. 309–28.

Betzler C, Brachert TC, Kroon D. Role of climate in partial

drowning of the Queensland Plateau carbonate platform (north-

eastern Australia). Mar Pet Geol 1995;123:11–23.

Borgomano JRF, Peters JM. Outcrop and seismic expressions of

coral reefs, carbonate platforms and adjacent deposits in the

Tertiary of the Salalah Basin, South Oman. In: Eberli GP,

Massaferro JL, Sarg JF, editors. Seismic Imaging of Carbo-

nate Reservoir and Systems. AAPG Memoir, vol. 81. 2004.

p. 251–66.

Bosence D, Cross N, Hardy S. Architecture and depositional

sequences of Tertiary fault-block carbonate platforms; an

analysis from outcrop (Miocene, Gulf of Suez) and computer

modelling. Mar Pet Geol 1998;15:203–21.

Briais A, Patriat P, Tapponnier P. Updated interpretation of magnetic

anomalies and sea floor spreading stages in the South China

Sea: implications for the Tertiary tectonics of southeast Asia.

J Geophys Res 1993;98:6299–328.

Burchette TP. Tectonic control on carbonate facies distribution and

sequence development: Miocene, Gulf of Suez. Sediment Geol

1988;59:179–204.

Collins JF, Kristanto AS, Bon J, Caughey CA. Sequence strati-

graphic framework of Oligocene and Miocene carbonates, North

Sumatra Basin, Indonesia. Proc. Indonesian Petrol. Asoc. 25th

Annu. Conv., I. 1996. p. 267–79.

Crevello P, Read JF, Sarg JF, Wilson JL. Controls on carbonate

platform and basin development. Spec Publ-SEPM 1989;44

[405 pp.].

Cross NE, Purser BH, Bosence DWJ. The tectono-sedimentary

evolution of a rift margin carbonate platform: Abu Shaar, Gulf

of Suez, Egypt. In: Purser BH, Bosence DJW, editors.

Sedimentation and Tectonics of Rift Basins: Red Sea Gulf of

Aden. London7 Chapman & Hall; 1998. p. 271–95.

Cucci MA, Clark MH. Sequence stratigraphy of a Miocene

carbonate Buildup, Java Sea. In: Loucks RG, Sarg JF, editors.

Carbonate Sequence Stratigraphy, Recent Developments and

Applications. AAPG Memoir, vol. 57. 1993. p. 291–303.

Davies PJ, Marshall JF. Halimeda bioherms—low energy reefs,

northern Great Barrier Reef. Proc 5th int coral reef symp, vol. 5.

1985. p. 1–7.

Drew EA, Abel KM. Biology, sedimentology and geography of

the vast inter-reefal Halimeda meadows within the Great

Barrier Reef Province. Proc 5th int coral reef symp, vol. 5.

1985. p. 15–20.

Drew EA, Abel KM. Studies on Halimeda: I. The distribution

and species composition of Halimeda meadows throughout

the Great Barrier Reef Province. Coral Reefs 1988;6(3–4);

195–205.

Dunn PA, Kozar MG, Budiyono B. Application of geoscience tech-

nology in a geologic study of the Natuna gas field, Natuna Sea,

Offshore Indonesia. Indonesian Petroleum Association, Pro-

ceedings 25th annual convention; 1996. p. 117–30.

Epting M. Sedimentology of Miocene carbonate buildups, Central

Luconia, offshore Sarawak. Bull Geol Soc Malays 1980;

12:17–30.

Erlich RN, Barrett SF, Guo BJ. Seismic and geologic characteristic

of drowning events on carbonate platforms. AAPG Bull

1990;74(10);1523–37.

Erlich RN, Barrett SF, Guo BJ. Drowning events on carbonate

platforms: a key to hydrocarbon entrapment? Proc. 23rd Annual

Offshore Technology Conference, Houston. 1991. p. 101–12.


Esker D, Eberli GP, McNeill DF. The structural and sedimento-

logical controls on reoccupation of quaternary incised valleys,

Belize Southern Lagoon. AAPG Bull 1998;82(11);2019–75.

Ferro CE, Droxler AW, Anderson JB, Mucciarone D. Late

Quaternary shift of mixed siliciclastic–carbonate environments

induced by glacial eustatic sea-level fluctuations in Belize. In:

Harris PM, Saller AH, Simo JA, editors. Advances in

Carbonate Sequence Stratigraphy; Applications to Reservoirs,

Outcrops and Models. SEPM Special Publication, vol. 63.

1999. p. 383–411.

Fournier F, Montaggioni LF, Borgomano J. Paleoenvironments and

high-frequency cyclicity in the Cenozoic South-East Asian

shallow-water carbonates: a case study from the Oligo-Miocene

buildups of Malampaya (Offshore Palawan Philippines). Mar

Pet Geol 2004;21(1);1–22.

Fulthorpe CS, Schlanger SO. Paleo-oceanographic and tectonic

setting of early Miocene reefs and associated carbonates of

offshore southeast Asia. AAPG Bull 1989;73:729–56.

Glaser KS, Droxler AW. High production and highstand shedding

from deeply submerged carbonate banks, Northern Nicaragua

Rise. J Sediment Petrol 1991;61(1);128–42.

Grotsch J, Mercadier C. Integrated 3-D reservoir modeling based

on 3-D seismic: the Tertiary Malampaya and Camago

buildups, Offshore Palawan, Philippines. AAPG Bull 1999;

83(11);1703–27.

Hall R. Cenozoic geological and plate tectonic evolution of SE Asia

and the SW Pacific: computer-based reconstructions, model and

animations. J Asian Earth Sci 2002;20:353–431.

Hallock P, Schlager W. Nutrient excess and the demise of coral reefs

and carbonate platforms. Palaios 1986;1:389–98.

Lighty RG, Roberts MT, Link MH, Helmold KP, Moslow TF,

Jordan DW. Alternating carbonate and siliciclastic deep-water

facies in the tectonic evolution of northwest Palawan margin

(Philippines), South China Sea. AAPG Bull 1983;67:503.

Longman MW. A process approach to recognizing facies of reef

complexes. Spec Publ-SEPM 1981;30:9–40.

Longman MW. Fracture porosity in reef talus of a Miocene

pinnacle-reef reservoir, Nido-B Field, the Philippines. In: Roehl

PC, Choquette PW, editors. Carbonate petroleum reservoirs.

New York7 Springer-Verlag; 1985. p. 549–60.

Masse J.P, Montaggioni LF. Growth history of shallow-water

carbonates: control of accommodation on ecological and

depositional processes. Int J Earth Sci (Geol Rundsch)

2001;90:452–69.

Mayall MJ, Cox M. Deposition and diagenesis of Miocene

limestones, Senkang Basin, Sulawesi, Indonesia. Sediment Geol

1988;59:77–92.

Mc Culloch M, Fallon S, Wyndham T, Hendy E, Lough J, Barnes D.

Coral record of increased sediment flux to the inner Great Barrier

Reef since European settlement. Nature 2003;421:727–30.

Montaggioni LF. Postglacial reef growth. C R Acad Sci, Paris 2000;

331:319–30.

Pomar L, Brandano M, Westphal H. Environmental factors

influencing skeletal-grain sediment associations: a critical

review from the Western Mediterranean. Sedimentology 2004;

51:627–51.

Purdy EG, Bertram GT. Carbonate concepts from the Maldives,

Indian Ocean. AAPG Stud Geol 1993;34 [56 pp.].

Purdy EG, Gischler E, Lomando AJ. The Belize margin revisited: 2

Origin of Holocene antecedent topography. Int J Earth Sci (Geol

Rundsch) 2003;92(4);552–72.

Rehm. The Miocene carbonates in time and space on- and offshore

SW Palawan, Philippines. PhD thesis, Mathematisch-Naturwis-

senschaftlichen Fakult7t der Christian-Albrechts-Universit7t,Kiel; 2003. 243 pp.

Rudolph KW, Lehmann PJ. Platform evolution and sequence

stratigraphy of the Natuna Platform, South China Sea. In:

Crevello PD, Wilson JL, Sarg JF, Read JF, editors. Controls on

Carbonate Platform and Basin Development. SEPM Special

Publication, vol. 44. 1989. p. 353–61.

Sales AO, Jacobsen EC, Morado Jr AA, Benavides JJ, Navarro FA,

Lim AE. The petroleum potential of deep-water northwest

Palawan Block GSEC 66. J Asian Earth Sci 1997;15(2–3);

217–40.

Saller A, Armin R, Ichram LO, Glenn-Sullivan C. Sequence

stratigraphy of upper Eocene and Oligocene Limestones, Teweh

area, central Kalimantan. Indonesian Petroleum Association,

21th Annual Convention; 1992. p. 69–92.

Schluter HU, Hinz K, Block M. Tectono-stratigraphic terranes and

detachment faulting of the South China Sea and Sulu Sea. Mar

Geol 1996;130(1–2);39–78.

Sun SQ, Esteban M. Paleoclimatic controls on sedimentation,

diagenesis and reservoir quality: lessons from Miocene carbo-

nates. AAPG Bull 1994;78(4);519–43.

Tucker ME. Carbonate diagenesis and sequence stratigraphy. In:

Wright VP, editor. Sedimentology Review. Oxford7 Blackwell;

1993. p. 51–72.

Vahrenkamp VC, David F, Duijndam P, Newall M, Crevello P.

rowth architecture, faulting, and karstification of a Middle

Miocene carbonate platform, Luconia Province, Offshore

Sarawak, Malaysia. In: Eberli GP, Massaferro JL, Sarg JF,

editors. Seismic Imaging of Carbonate Reservoir and Systems.

AAPG Memoir, vol. 81. 2003. p. 329–50.

Vecsei A. A new estimate of global reefal carbonate production

including the forereefs. Glob Planet Change 2004;43:1–18.

Wiliams HH. Play concepts—northwest Palawan, Philippines.

J Asian Earth Sci 1997;15(2–3);251–73.

Wilson MEJ. Prerift and synrift sedimentation during early fault

segmentation of a Tertiary carbonate platform, Indonesia. Mar

Pet 1999;16:825–48.

Wilson MEJ. Tectonic and volcanic influences on the development

and diachronous termination of a Tertiary tropical carbonate

platform. J Sediment Res 2000;70:310–24.

Wilson MEJ. Cenozoic carbonates in Southeast Asia: implications

for equatorial carbonate development. Sediment Geol 2002;

147:295–428.

Wilson MEJ, Bosence DWJ, Limbong A. Tertiary syntectonic

carbonate development in Indonesia. Sedimentology 2000;

47:183–201.

Date post:	29-Nov-2014
Category:	Documents
Upload:	quophi-gods-way-thermodynamics
View:	205 times
Download:	3 times

Development Patterns and Controlling Factors of Tertiary Carbonate

Documents