Abnormal deflection in the some folded axes within Zagros fold and ...

Abnormal deflection in the some folded axes within Zagros fold and Thrust Belt, Northern Iraq, Mirawa-Mawaran synclinal axis as a case

Study

Abdalla Amir Omar

Department of Geology

College of Science-University of Salahaddin

Iraq-Arbil- North Iraq

e-mail: [email protected]

Abstract: The Mirawa-Mawaran synclinal structure was studied in order to establish the cause of

the deflection in the fold axis from one segment to another. Field data obtained from two structural

sections perpendicular to the major fold axis, one of the section located in the Mirawa segment, while

the second section located in Mawaran part. This study indicates that the attitude of the fold axis within

Mawaran segment is 300/03, with axial plane attitude 121/77, that indicate northeast vergence fold. In

the Mirawa segment, the axis of the fold is 146/11, with axial plane attitude of 328/82 that refers to

southwest vergency.

The deflection of the fold axis is attributed to presence of major lineament in the middle junction of

these two segments that coincide with a set of strike-slip, normal and reverse faults in this zone. The

model of evolution for that syncline is discussed, and assumed to be related to bending of whole

syncline at that junction part which coincide with that faults. This junction part may coincide with

boundary of basement block that manifested on the surface as lineament or as different types of the

faults.

Key word: Syncline, Mirawa, Mawaran , vergency, fold axis, deflection, lineament

Introduction:

The geographic theater of the studied area is

situated about 45 Kilometers to the northeast of

Arbil city in Iraqi Kurdistan Region. This area

occupied by a narrow, elongated, oval shape, double

plunging synclinal fold that trending northwest-

southeast parallel to the Zagros fold belt. The whole

area, which this study deals with it, is bounded by

latitude (36˚ 15` - 36˚ 30`) and longitude (44˚ 15` –

44˚ 30` ) (fig.1). Locally this synclinal

structure named Mirawa syncline, but in this study

we call it Mirawa- Mawaran syncline because it

composed of two structurally different segments, one

located at southeastern part named Mirawa, while

the northwestern part called Mawaran segment with

respect to Mawaran village.

Recent Researches in Geography, Geology, Energy, Environment and Biomedicine

ISBN: 978-1-61804-022-0 17

Tectonically, this syncline located within High

Folded Zone of the Unstable Shelf of Iraq (1)

(Fig.2A), while according to Numan (2) is located

within Forland basin of the Zagros thrust belt

(Fig.2B). The folded zone of Iraqi territory is

divided to elevate and unelevated structural subzone

(3) where the present studied area located within

elevated one (Fig.2C). According to Al-Azzawi (4)

this syncline situated in Parabolic-Semi Ellipse fold

to Sinusoidal –Parabolic fold sectors (Fig.2D).

Geomorphological setting of the studied

area closely connected and controlled by tectonic

fabric of the northern Iraq. The general

geomorphology of area can be divided onto three

main groups of Landforms: anticline ridges,

structural denudation hills and slopes, and fluvial

accumulation plains. The anticline ridges comprise

the oldest rock units cropping out in the cores of the

major anticlines which surrounding this syncline,

with a characteristic dip slope and flat Iron

topography around the cores, which defines the

shape of this synclinal fold.

The fluvial accumulation plains are mostly

developed in synclinal valleys. They cover very

wide parts of terrains; the landform is covered by

gravel, sand and mud of quaternary age. Genesis of

these sediments is connected with river flood plain,

river terraces, alluvial fans, cone deposits and recent

deposits and soil. However, the drainage network

comprehends perennial and temporary water course,

and even permanently dry valleys, but it caused the

fluvial process in the studied area is limited to the

several bigger rivers, all of them left tributaries of

the Greater Zab River, most of the rivers and stream

coming from high mountains, as this is

neotectonically active zone, even at the present days,

mountains are uplifting and rivers in effort to cancel

it are reinforcing their incising, forming deep

canyons. This occurrence is well known under the

name “antecedence”.

Fig.(1): Location map of the studied area


ISBN: 978-1-61804-022-0 18

(A) (B)

( C ) (D) Fig.(2): Tectonic position of the studied area with respect to: (A): Buday and Jassim,1987 (B): Numan,2000 (C): Maruoof,1999 (D): Al-Azawi,2003

State of the problem: Although the Mirawa-Mawaran syncline is

generally takes the same trends like Zagros Fold Belt

(i.e. NW-SE), but locally the deflection that happen

in the fold axis of this syncline is considered to be

the main structural problem which is worthwhile.

Accordingly the main purpose in this article is

related to study of structural characteristic for each

part of this syncline, in order to detect the cause of

that deflection which happens in the fold axis from

one part to another. The above purpose need

collecting data from field and previous study and

treating these data statistically in structural point of

view which is another purpose in this work.

Methodology: The work which done during the preparation of

this research can be divide in to two stages, one

concerning the field work and second is the office

work. Details of each one describe in the following

paragraphs.


ISBN: 978-1-61804-022-0 19

(A): Field work: In the present study, field measurements and

observations were carried out in 20 field stations

distributed along two structural traverses taken

perpendicularly to the Mirawa-Mawaran fold axis

trend. Two day of field work was sufficient for

collecting the required data, as well as auxiliary data

were taken from Οmar (5) such as more bedding

plane attitude and data about faults and geological

formations.

One of the traverse located in northwestern segment

of the syncline i.e. within Mawaran portion of the

syncline, while the second traverse located within

the Mirawa segment in most end of the syncline at

southeastern side. The total number of (118) reading

about bedding planes was measured using Brunton

compass. In the field the correction was done for the

magnetic declination. Each field station covered an

area of about 30-50 m2. The following important

structural elements recorded at each field station:

1- Measuring the attitude of bedding

planes.

2- Measuring attitude and type of

faults.

3- Recording layer thickness, lithology

and some mesoscopic fractures such as joints,

veins…..etc.

4- Plotting the position of the each

field station in the field on topographic base map.

(B): Office work: Schmidt equal-area net was used to analyses the

field data. The poles of bedding planes were plotted

on the pi-diagram in order to determine some

geometrical properties of that fold in different

position i.e, Mirawa and Mawaran segments of

syncline.

In order to show these data in a proper way in

the report the all data were redrawing again using

SteroWin software, which is one of the professional

software used nowadays in plotting these types of

the structural data. The pi-diagrams were used to

demonstrate the following:

1- Measuring the mean attitude of each

limb within each traverse for Mawaran and Mirawa

segments of the studied syncline.

2- Calculating and determining the fold

axes within each segment to show the variation in

direction and plunging of this syncline within the

two segments.

3- Determining the attitude of axial

plane for each segment of the fold.

4- Calculating interlimb angle for the

fold.

5- The Landsat images were also used

and interpreted for whole studied area in order to

delineate the major lineaments, which affect this

syncline; the lineaments were checked latter in the

field.

Stratigraphy of studied region:

Geological map (Fig.3), as well as columnar

section (Fig.4) for this synclinal structure are drawn

partly from the field and from the explanation notes

taken from Summer field trip manual by Omar(6), as

well as from Οmar (5),which are as follow:

Kolosh Formation:

This formation is exposed in all the

structures of the high folded zone, within the

mapped region. Generally it forms gently elevated

areas, which are dissected by dense drainage system,

due to the predominance of the soft rocks in the

formation. The formation consists of clastic rocks

that are dark gray and black in color. The rocks are

shales, claystones, sandstones, siltstone with

conglomerate. The age of this formation is

Paleocene – Lower Eocene (7).

The sandstone beds are generally dark gray or

black in color, friable, medium to coarse grain. The

thickness of the sandstone beds ranges from 0.15m

upto 0.8m. Occasionally they are pebbly, the pebbles

are small in size, not more than 2-3cm. The shales

and claystones of this formation are soft papery and

fragmented, and are weathered. The thickness of the

formation is variable and increases southeastwards.

In Shaqlawa its thickness ranges between 140 and

180m. Dolomitic limestone beds representing the

Khurmala Formation are interbedded within the

Kolosh Formation.

In Safin Anticline (SW limb of Mirawa syncline)

the appearance of thin bedded sandstone is

considered to be the contact between this formation

and underlying Shiranish Formation (8). The upper

contact of the Kolosh Formation is gradational with

the Khurmala Formation. The total thickness of the

Kolosh Formation is variable; it increases towards

southeast of the investigated region


ISBN: 978-1-61804-022-0 20


ISBN: 978-1-61804-022-0 21

Khurmala Formation: This formation, found as a series of ridges

around most of the anticlinal structures in the studied

region, belongs to the Early Paleocene – Early

Eocene time span (7). It consists of limestone which

is dolomitic, crystalline, fossiliferous. Fossils found

within this formation are some large gastropods

whose lengths reach up to 20cm. The color of the

limestone beds is yellow, in some localities creamy,

well bedded, the thickness of individual beds ranges

from 0.5-3.0m. The beds are relatively hard, because

they are overlain and underlain by soft materials

(clastics). They always form ridges and scarps over

the whole area. At the vicinity of Shaqlawa town,

one or two horizons of limestone occur. Gercus Formation:

This formation is of Middle Eocene age (9),

is exposed in all the mapped structures of the studied

region. It generally forms steep slopes below the

hard limestone of Pila Spi Formation, which forms

high and steep ridges (mostly anti-dip). Soft rocks

are the main constituents of this formation; hence it

is dissected by a dense drainage pattern, which forms

parallel rills and galleys. When the slopes are gentler

the rocks are mainly weathered and covered by red

soil. The formation consists of red clastic rocks,

which are mainly claystones, siltstones, and

sandstones with thin horizons or lenses of

conglomerate that vary vertically and laterally.

The main rock type of this formation is the

claystones, which are reddish-brown, brown and

rarely violet, soft to fairly hard and fragmented to

small chipses 3-4 cm in size. Sandstones in this

formation are less abundant than claystones and

occur as thin beds 0.5-3.5m, they are also reddish

brown and brown in color, hard, bedded, the

thickness of individual bed is 0.1 to 0.8m, fine to

medium grained.

Limestone horizons may occur within this

formation. They become thicker in the middle and

southeastern parts of the studied region. These

limestones exist as Tongues within this formation,

white, light gray in color fairly hard, well bedded,

highly fractured, its thickness ranging from 0.3to2m.

These limestone beds represent short-lived marine

incursions and are supposed to be equivalent of the

Avanah Formation of Middle Eocene (10).

The lower contact of this formation with the

underlying Kolosh or Khurmala Formation is

conformable; the contact in the field is sharp and

clear due to color difference, while the upper contact

is unconformable in all of the mapped areas with the

Pila Spi Formation. Thickness of this formation

varies from one place to another.


ISBN: 978-1-61804-022-0 22

Fig.(4): Generalized geological columnar section for studied area


ISBN: 978-1-61804-022-0 23

Pila Spi Formation: This formation belonging to Middle-Late

Eocene age (7) is exposed in the entire studied

region. It is seen as continuous high ridges

surrounding the synclinal structures with very

common flat iron morphology, while in the other

places it forms the carapace of main body of the

anticline as in case of the Pirmam Anticline.

The formation consists mainly of limestones,

which are crystalline, dolomitic, clayey or chalky

and sometime dolomitic. The color is white, creamy,

light gray, well bedded. The upper beds of this

formation contain Iron oxides and chert concretions

up to few centimeters in size, and rich in limonite

concretions.

The lowermost part of this formation

consists, of conglomerate, which marks the

unconformable contact with the underlying Gercus

Formation. This conglomerate consists of chert

pebbles, chalcedony, flint, jasper, some igneous

rocks and limestone also occur. In some areas, thin

lenticular limestone horizons may occur within

conglomerate. In northeast limb of the Safin

Anticline, green colored cement materials were

found in the conglomerate thought to be of copper

(10). The maximum thickness of the conglomerate

beds reaches up to 6m, such as near Shaqlawa City.

The thickness of the formation is highly variable.

The formation is deposited in a lagoonal

environment (7).

Fathُa Formation (Lower Fars Formation): This formation covers most of the studied

region as a continuous belt around most of the

anticlinal structures and the troughs of the synclines.

This formation is of Middle Miocene age (7).

Geomorphologically the formation forms hilly area

with continuous ridges of thick limestone forming

cuesta and hogback features around most of the

anticlines.

The formation in the studied areas consists

of cyclic deposits of claystone, limestone and marls

with the presence of lenses of gypsum as in the

southwestern limb of Mirawa-Mawaran syncline.

The main color is reddish brown with some green

and blue colors which occur in the lower parts. The

claystone is soft, fragmented into small chips,

occasionally it is silty, conchoidal fracturing is

common in the claystone. The limestone is also one

of the main constituents of the formation. It is light

gray, white, light brown, hard, well bedded, some of

beds are fossiliferous, fossils are mostly shells of

Pelecypods and gastropods up to 5cm in size. Others

are recrystallized, sandy limestones are common,

more towards the lower parts of this formation, some

of the limestone beds are underlain by green marl or

marly limestone.


underlying Pila Spi Formation is unconformable

marked by presence of basal conglomerate. Due to

the lithological difference between Pila Spi and

Fatha Formations; the contact is easily followed in

the field. It is also very clear geomorphologically

due to difference in the degree of resistance to

erosion between the two formations.

Injana Formation (Upper Fars Formation): The age of the formation is Late Miocene

according to Bellen et al (7). This formation is

exposed in the core of synclines within the studied

region. Geomorphologically, the formation forms

hilly areas with continuous strike ridges and valleys

due to alternation of hard and soft rocks.

The formation consists of cyclic deposits of

clastics, which in general coarsen upwards. The

dominant color of the clastics is red color. Each

depositional cycle consists of mudstone and

sandstone. The mudstone is occasionally silty with

some thin horizons of interbedded siltstone, which

are reddish brown, and brown in color and are 0.1-

0.5m thick. The claystone is reddish brown, grayish

brown, and rarely green and violet in color, soft to

fairly hard, weathered in some places usually

covered by soil, which is silty and sandy. The

sandstone is the second main constituent of the

formation; the main color is reddish brown to brown,

bedded, and the thickness of the individual beds

ranges from 0.1m up to 4m. Fracturing and Jointing

are well developed in the sandstone. The sandstones

are rich in sedimentary structures among them, mud

balls; cross bedding, ripple marks; and burrowings

are common.

The lower contact of the formation with the

underlying Fatha formation is conformable it is

recognized in the field by the uppermost limestone

horizon of the Fatha Formation which is always

overlain by a thick red claystone bed.

Mukdadiya Formation (Lower Bakhtiari Formation):

The formation is exposed in some synclines

of the studied region such as in the northeastern limb

of the Mirawa (Mawaran) syncline. The formation

consists of cyclic deposits of clastic material fining


ISBN: 978-1-61804-022-0 24

upwards. The cycle starts by claystone, pebbly

sandstone and thick layers of the conglomerate, in

some other places it start by pebbly sandstone, thin

beds of the claystone and thick beds of the

conglomerate. Siltstone occurs either as thin beds or

as silty materials within the claystone. The

conglomerates covers the claystones and the size of

the pebbles reaches to 25cm. The thickness of the

conglomerate beds is 20-35m. The shapes of the

pebbles within the conglomeritic beds are spherical,

bladed and rounded.


underlying formation is diachronous (9). This

contact is recognized lithologically by the first

occurrence of the pebbly sands. Pebbles usually

occur on lamination surfaces or along surfaces of the

cross bedding, they are of small size. The pebbles

may disappear laterally and reappear again along the

same bed, so the contact might be missed easily in

the field if no careful attention is paid to the

occurrence of the pebbles. The mode of the

deposition is continental, and it is the Molasse

sediments, deposited in rapidly sinking troughs (7).

Bai-Hassan Formation (Upper Bakhtiari Formation):

This formation is the youngest one in the

stratigraphic column of the studied region. The Bai-

Hassan Formation is of Middle Pliocene age. It

consists of molasses sediments represented by

deposition of conglomerates and claystone with

some sandstone and siltstones beds. Variations from

claystone to siltstone and sandstone, horizontally and

vertically were observed. The conglomerates are the

first main constituent of the formation, especially in

the upper parts in which they from more than half of

the thickness of this formation. Conglomerates

consist mainly of limestones, silica and some

igneous and metamorphic rocks. The shape of

conglomeratic pebbles is spherical, bladed and rod

shape, the size varies from less than 1cm up to

15cm, sand and calcareous materials poorly cement

the pebbles. Lenses of sandstone are common in the

conglomerates.

The thickness of the formation is difficult to

measure due to wide covered areas of the formations

outcrop. The top of the formation is always

weathered. The lower contact of the formation with

underlying Mukdadiya Formation is diachronous (9);

it is recognized lithologically by the appearance of

the first thick (more than 1m) conglomerate horizon

(10).

The depositional environment of the

formation is continental fluviatial, molasses

deposition which is the product of erosion of the

mountain ranges, deposited in one or more sinking

troughs in front of those ranges.

Quaternary sediments:

Quaternary sediments covered large parts of

the studied area, especially in the south,

southwestern parts of the studied regions. These

sediments represent; River terraces, slope sediments,

valley filling sediments and soil. They differ widely

depending on the type of the mother rocks and on

the order of the valleys that exist in the mountains,

as well as on weathering process.

Structural Analysis of the Mawaran- Mirawa Syncline:

This syncline is relatively narrow and long

one. Extends from Sarqant village at NW plunge,

towards north of the Nazanin town it called wadi

Balessan, it is about 30km length measured on aerial

photographs, all parts of this syncline located within

studied area. The trough of the syncline consist

upper Fars formation with river deposit. The axis

trend N55W from up to near Hasara village, then the

axis deflected to take a direction N35W. In order to

analysis this structure it divided in to two segment

one located at northwestern side which we called it

Mawaran segment and the second portion located at

southeast called Mirawa. Each part has its own

structural characteristic differs from each other;

accordingly we divided in to two part.

A): Mawaran segment of the Syncline:

One of the field traverses located at this part

of this syncline, the stereographic projection for

bedding planes (Fig.5) show different structural

characteristics. The attitude of the southwestern limb

of this syncline is 299/59, while the northeastern

limb have attitude of 124/33, this indicate that the

south western limb is steeper than the northeastern

limb accordingly the vergency of the fold in this

segment is toward northeast direction. The fold axis

(B-axis) in this part measured from stereographic

projection as 300/3. The axial plane attitude is

121/77 and the interlimb angle is measured as 95.

The geological map of this portion of

syncline also show that the amount of the dip in


ISBN: 978-1-61804-022-0 25

southwest limb show higher angle than the

northeastern side, so that the axial plane directed

toward gentler limb that is northeastern limb.

B): Mirawa segment of the syncline:

This part of the major synclinal fold located

towards southeastern side, in this portion also one

traverse is taken, and all bedding plane data were

plotted on the stereographic projection (Fig.6). The

total of 48 bedding planes shows that the attitude of

the southwest limb is 343/32, while the attitude of

the northeast limb of the same syncline in this

segment is 138/51. The axial plane attitude is

328/82, which coincides with the direction of the

south west limb, this means that this syncline in this

portion has vergency towards southwest, which is

differs from the Mawaran segment, as well as the

fold axis has an attitude of 146/11, and the interlimb

angle is about 77. The geological map of this

synclinal fold also shows that the values of dip of

beds are higher in northeast limb rather than the

southwest limb.


ISBN: 978-1-61804-022-0 26

NE Limb of the Mirawa Syncline

SW Limb of the Mirawa Syncline

B-axis

B-axis

SW Limb of the Mawaran Syncline

NE Limb of the Mawaran Syncline

SW limb attitude

NE limb attitude

pi- plane attitude

Attitude of Axial plane

interlimb angle = 86

Fig ( ) : Sterographic projection for bedding planes in MAWARAN section

Fig ( ) : Sterographic projection for bedding planes in MIRAWA section

SW limb attitude

NE limb attitude

attitude of pi- plane

attitude of Axial plane

Interlimb angle=72º

Fig.5

Fig.6


ISBN: 978-1-61804-022-0 27

C): Structure of the Middle part of the Mawaran-

Mirawa Syncline:

(Junction part of the two segments)

The middle part at which the Mawaran segment

changed to Mirawa segment has a characteristic

structural important. This part which is the junction

coledorie between the above two segment are

described in many structural reports and thesis.

Travaglia and Dainelli, (11) Described that a major

lineament pass through this junction, more over

Οmar (5) describe this major lineaments and he

considered to be as one of the regional lineament

which passes through this area, his description are

listed below:

This Lineament (Fig.7) is long regional lineament,

was first delineated on the Landsat mosaic of

Kurdistan region on the basis of aligned northeast

trending topographic and tonal features (11). The

most notable geomorphological and structural

features, which characterize this lineament, are from

southwest to northeast as follow:

Fig.(7): Landsat image show the regional lineament C passing through the studied syncline ( after Omar,2005)

1- Deflection of the Qarachuq

anticlinal fold axis coincides in this part with the

position of a known fault delineated on the

geological map of this anticline (12).

2- Lineament (C) passes

northeastwards through the Kirkuk anticlinal

structure causing culmination and depressions in the

axis of this structure leading to the so-called

Khurmalah, Baba and Avanah domes in the jargon

of local petroleum geologists.

3- In the Arbil plain this Lineament

coincides with straight segments of the surface

drainage pattern as well as, tonal variation is also

noticed along this lineament in this locality.

4- A spectacular topographic

manifestation of lineament is seen in the steep cliffs

of Sara-Rash locality where the Pirmam anticlinal

axis ends abruptly.

5- Deflection of the Mirawa -Mawaran

synclinal axis due to this lineament from the

direction of 320 to 295.

6- Northeastwards, this lineament cuts

a cross the southwestern limb of Shakrok Anticline

where a 35m long dextral strike-slip fault can bee

seen in the field.


ISBN: 978-1-61804-022-0 28

7- The northeastern extension of this

lineament cut a cross successive anticlines of Shikh-

Wasanan and Korak anticlines causing collapse,

gorges and displacements within the different

geological formation

This lineament divides the area into two sub-blocks

(5) , one of the block located to the southeast which

Mirawa part of this synclinal structure is consist,

while the second block located to northwest and

Mawaran segment is a part of it. This major

lineament may be a surface manifestation of the

basement block boundary. The subdivisions of

folded zone into a blocks by basement faults is

propounded by coworkers such as; Numan,(13),

Doski(14).

Our study in the field in this area of that

syncline indicates that this major lineament coincide

with two faults of strike-slip type, one of them

located at NE limb of the synclinal structure which is

of sinistral type and the second one located at SW

limb of same type and on the same extend. The fist

one shows displacement in outcrops for about 10m,

while the second one displaced the beds for about

15m. Moreover some normal and reverse faults of

small displacement ranging 5-7m are present in same

positions. These faults occurs parallel to the

synclinal fold axis, especially in junction part of the

two segments (i.e. Mawaran segment and Mirawa

segment). The normal faults occurs mostly in this

area parallel to bedding planes, so it form bedding

faults, while reverse faults makes an angle to the

bedding plane (see geological map).

Interpretation and Discussion of the results: Previous field observation and data analysis

indicates that this elongate, narrow synclinal

structure made up of two segments, which they are

Mawaran and Mirawa segments. Each segment has

its own structural properties differs from the other

part. One of the most worthwhile points in the

structural analysis is concerning the trend of the fold

axis. The axis of this syncline in Mawaran part has a

trend of 301˚, while Mirawa part of this syncline has

fold axis that trend 146˚ (i.e. 326˚). This indicates

that the same syncline has two different fold axes

direction. The variation between these two trends is

about 26˚, which means that the Mawaran segment

(i.e. fold axis) deflected from Mirawa segment (i.e.

fold axis) by 26˚.

One another notable exception that must take

into consideration is concern the vergency of this

fold. The axial plane of the Mirawa synclinel

segment directed towards northeast, while the axial

plane of the Mawaran synclinal segment directed

towards southwest. This indicates that the axial

plane of this syncline is flip-flopped nearly in the

middle part (i.e. junction part).

The junction between these two segments

appears on landsat image as a major regional type

lineament which has a long length with a direction

nearly N45E. In the field the position of this

lineament occupied by a number of strike-slip,

normal and reverse faults. The two strike slip faults

are considered to be of traversal fault type that cut

the middle part, while the normal and reverse faults

are two longitudinal faults type. All of these faults

seem to be of local occurrence and of restricted

elongation.

Moreover, it seem that the response of each segment

for a regional stresses was different, so reflect

different geometrical characters for each segment.

The hinge closer for Mirawa segment is much tight

than the hinge of the Mawaran segment; this can

obviously appears from two interlimb angles.

The structural model, which is applicable for the

above situation is during regional stress, which acted

on this syncline bending, occurs along a middle part,

which was occupied by a major lineament. This

lineament may relate to a basement fault. The

bending of the syncline create a space in one limb,

and in order to avoid this space problem a set of

strike-slip, normal and reverse fault appears (Fig.8).

These situations obey the model that proceeded by

Twiss and Moores (15). The basement fault may be

a basement block boundary, accordingly each block

behaviors separately with respect to a regional

stresses which acting on them, one of them (such as

Mirawa segment) became much more tighter due to

it located between two rigid cretaceous obstruction

one of them in north which represented by uplifting

of cretaceous succession in Shakrok Anticline, and

another obstruction located in south represented by

Safin cretaceous successions which was uplifted in

that time. Concerning Mawaran segment there are no

any criteria tell about presence of any obstruction

body around this part, so that the syncline in this part

rotated anticlockwise by amount of 26˚, through a

middle part which is the location of major lineament.

This model seems to be a convenient about the area

of the study many coworker in low propounds

especially subdivision of the area into sub-blocks

and high folded zone of the Iraqi territories (14).


ISBN: 978-1-61804-022-0 29

References 1-Buday, T. and Jassim, S. Z., 1987. The Regional

geology of Iraq: tectonic, Magmatism and

Metamorphism. Vol. 2, S.E. Geol. Survy. Min.

Invest., Baghdad, Iraq, 352p.

2-Numan, N. M. S., 2000. Major Cretaceous tectonic

events in Iraq. Ref. Jour. Sci., 11 (3), pp. 32- 52.

3-Marouf, N.Z., 1999. Dynamic evolution of

sedimentary basin in northern Iraq and hydrocarbon

formation, migration and entrapment. Unpub. Ph.D

thesis, University of Baghdad, Iraq.

4-AL- Azzawi, N.K., 2003. The structural

development of folds shape in the Foreland Belt of

Iraq,and its tectonic implication. Unpub.Ph.D.thesis,

University of Mosul (in Arabic), 163P

5-Omar,A.A,2005, An integrated structural and

tectonic study of the BinaBawi-Safin-Bradost region

in Iraqi Kurdistan, Ph.D thesis,Salahaddin

university,293P.

6-Omar,A.A. 2006, Notes about the geology of the

Shaqlawa area, field manual,12p.

7-Bellen, V.R.C., Dunnington, H.V., Wetzel, R. and

Morton, D.M., 1959. Lexique stratigraphique

International. Fasc.10a,Iraq, Paris, 333p.

8-Hanna, M.T. 1993. Palynology of the Cretaceous-

Tertiary boundary in Hijran area, Northeastern Iraq.

Unpub. M.Sc. thesis, university of Salahaddin, (in

Arabic), 93 p.

9-Buday, T., 1980. The regional geology of Iraq,

Stratigraphy and paleogeography, Dar AL-Kuttib

Pub. House. University of Mosul, Iraq. 445p.

10-Sissakian, V. K. and Youkhana, R., 1978. Report

on regional geologic mapping of Erbil-Shaqlawa-

Koisanjaq- Raider area. D.G. Geol. Surv. Min.

Invest., Baghdad, Iraq, Unpub. Report, No. 975.

SOM Library.

11-Travagalia, C. and Dainelli, N., 2003. Lineament

map for Northern Iraq ( KurdistanRegion) from

Landsat images. FAO/ GWU, map scale 1:250000.

12-Fouad, S. F., 1983, Structural geology of

Qarachuq folds, Unpub. M.Sc. thesis, unive. of

Baghdad, (in Arabic), 201p.

13-Numan, N. M. S., 1984. Basement controls of

stratigraphic sequences and structural patterns in

Iraq. Jour. Geol. Soc. Of Iraq, 16, pp.8-28.

14-Doski, J.A.H., 2002. Structural study along

selected sections across Safin Anticline (Kurdistan–

Iraq). Unpub. M.Sc. thesis, University of salahaddin,

129p. 15-Twiss, R. J. and Moores, E. M., 1992.

Structural geology. W.H. Freeman, USA, 532


ISBN: 978-1-61804-022-0 30

Date post:	10-Feb-2017
Category:	Documents
Upload:	lamdan
View:	217 times
Download:	4 times

Abnormal deflection in the some folded axes within Zagros fold and ...

Documents