Progress in Exploration of the Wulagen Pb-Zn deposit,

Xinjiang, NW China

Beijing Non-ferrous Metals Exploration Center

2007/11

1. Discovery History

2. Geological Characteristics

3. Enlightenment of Exploration

4. Outlook

Contents

1 、 Discovery History of the Deposit

The Wulagen Pb-Zn deposit is located on about 6km to the south of Kangsu, Wuqia county, Xinjiang, and there is a highway to the camp.

•In 1943, the mineralized outcrop was discovered in the Wulagen district, whic

h was recorded as a Pb-Zn occurrence in the map of regional geology and reso

urces at scale of 1:1,000,000.

•1951-1961, this occurrence had been evaluated by the Kashi Mining Manage

ment Office, and the 702 Geological Party of Non-ferrous Resources. The mai

n goal at that time was to prospect the breccia-type Pb-Zn ore deposit hosted

by carbonate rocks in the northern ore zone, and the metal reserves of No.1 o

rebody are as follows: 11,300 tons Pb @ 5.8%, 17,400 tons Zn @ 7.43%.

•1958-1963, the deposit had been mined at small scale.

•1962-1998, there was no further prospecting in this area due to the restricted

understanding of this deposit as a small hydrothermal deposit.

Discovery History

•1999-2000, Xinjiang Xinhui Geology and Mining Corporation (the predecessor of the Xinjiang Institute of Geological Survey, the China Geological Survey Center for Non-ferrous Resources) had carried out geological survey in the Wulagen district and adjacent area, and the deposit was thought to be possessing the characteristics of strata-bounded ore deposit, which was similar to that of the Jinding large Pb-Zn deposit in Yunnan province, and then, the sandstone-type ores were determined to be of good potentiality.

•2001-2002, a project from the China Geology Survey, named as “the Resource Potentiality Assessment of Pb-Zn Polymetal Minerals in the Wuqia area, Xinjiang”, had been carried out by the Xinjiang Institute of Geological Survey, the China Geological Survey Center for Non-ferrous Resources. Based on the surface survey, a drill hole (ZK0-1) had been finished in the southern ore zone, discovering the large-sized orebody with apparent thickness of 254m (true thickness of 194.10m), and the average grades are of 0.53% for lead, and 4.34% for zinc, implying a good perspective as a large deposit.

Discovery History

Ore thickness is 48.94m on surface ， with grades of 0.38 ％ Pb, and 3.13 ％Zn.

Depth is 70m (tunnel), thickness is 84.56m, with grades of 0.30 ％ Pb, and 3.76 ％ Zn.

Drill hole ZK0-1: apparent thickness is 254m, and 194.10m for true thickness, with average grades of 0.53%Pb, and 4.34%Zn.

The profile of No.0 prospecting line in the southern ore zone

•2004-2007, a project from the China Geology Survey, named as “the Resource Inves

tigation and Assessment of Pb-Zn-Cu Minerals in the Wuqia-Atushi area, Xinjiang”,

has being carried out by the Xinjiang Institute of Geological Survey, the China Geol

ogical Survey Center for Non-ferrous Resources. The perspective of Wulagen Pb-Zn

deposit has been preliminary controlled, and some investigation and assessment wor

ks have also been carried out in the adjacent area.

•So far, the proved reserve of Pb+Zn is of 4Mt at class of 333+3341, which is expected

to be over 5Mt after further prospecting work in the Wulagen mine site. Besides, so

me new occurrences are discovered in the adjacent area, such as Kangxi, Wudong,

Yangbei, Jiang’ejie’er and Tuopa, and so on.

Discovery history

The south limb of the Wulagen syncline

E1w

Ore-bearing strata

2. Geological Characteristics

(1) Strata ： The host rocks are light grey sandstone and pebbled sandstone of Palaeocene Wulagen Formantion (E1w).

Proterozoic metamorphic clastic rocks

Cretaceous pelitic siltstone

Fault Fault

E1W1

E1W2

E1W3

The Wulagen Formation is divided into three parts:

Part 1 (E1W1) is ore-b

earing glutenite.

Part 2 （ E1W2 ）

is the hanging wall consisting of mudstone and marl sandwiched with gypsum.

Part 3 (E1W3) cons

ists of marl and limestone with fossil of brachiopods, which shows the transgression sequence.

康

苏

河

Geological Characteristics

(2) Structure ： The deposit is controlled by the Wulagen syncline, which is divided into two ore zones, the northern zone and the southern zone.

The northern ore zone is 3000m long, consisting of three orebodies.

The southern ore zone is 3500m long, consisting of three orebodies.

Kangsu River

Outlook of the Wulagen synclineThe dip of north limb is steeper than that of the south limb. The syncline is unconformable overlaid by the Quaternary (Q) Xiyu conglomerate.

E1w

Q

The second part of the No.2 orebody is located on prospecting lines of 47-71 ,which is 800m in length and 9.62m in thickness, and grades are of 0.47%Pb, 1.75%Zn, and 2.22%(Pb+Zn).

(3)Orebody ： The stratiform, stratiform-like orebodies are accordant with the host strata.

No.1 orebody is 3500m in length with average thickness of 15.80m, and average grades of 0.70% Pb, 3.55%Zn, and 4.25%( Pb+Zn).

No.3 orebody is located on prospecting lines of 0-8, which is 400m in length and 27.07 in thickness, and grades are of 0.55%Pb, 4.13%Zn, and 4.68%(Pb+Zn).

SZK7-1

Inclined depth controlled : 510m;Orebody elevation: 1860m;Horizontal thickness: 52.35m; Pb average grade: 0.75%Zn average grade: 2.50%Pb+Zn grade: 3.25%

Maximum of single sample:Pb: 1.70%Zn: 2.54%Pb+Zn: 4.24%

Metal mineral assemblage is simple, and the main minerals are sphalerite, galena and pyrite.

The profile of prospecting line 7 in the southern ore zone

A

B C

(4) Ore types:

A: the oxidized sandstone (containing gravel) type ore on surface.

B, C ： the primary sandstone (containing gravel) type ore.

Sandstone type ore mainly consists of sphalerite.

Breccia type ore :

Locally occurred in the brecc

iated marl on the top of sand

stone type ore, which is relat

ively rich in lead.

A

B C

A ： the massive galena vein is occurred locally on the north limb.

B ： the bedded gypsum occurred in the hanging layer of the ore-bearing strata is distributed extensively in mine site.

C ： the brecciaed gypsum layer.

B

A

I II III

(5) Host Rock AlterationA ： the fading in footwall strata of northern ore zone

I-ore-bearing sandstone; II-fading alteration of Cretaceous mudstone in the footwall; III- Cretaceous claret mudstone (country rock).

B ： the dolomitization of hanging wall marl on the top of ore-bearing glutenite in the southern ore zone.

Up to 2006

The table of evaluated resources reserve

Orezone

Number of orebody

Reserve type

Reserve of Pb-Zn ore (ten thousands ton)

Metal reserve (ton)

Reserve of Pb+Zn (ton)

Average grade(×10-2) Mark

Southern oreZone

Northern orezone

total

total

Two parts

The drilling in 2007 shows that orebodies within two limbs are combined with each other at depth, so that the resource potential is expanded remarkably.

The proved reserve (333+3341) is over 4 Mt, and the

perspective reserve is over 5 Mt.

The profile of drilling hole ZK1 in the core of the Wulagen syncline

SZK0-1

SZK15-1

SZK0-2SZK0-3

NZK24-1

SZK7-1

NZK56－1

SZK70－ 1

SZK39-1

ZK1

There is still great prospecting potential in the Wulagen camp

Distribution map of drilling project

The Wulagen deposit is characterized by large scale and steady minerli

zation.

•Based on the geological characteristics, a two-stage mineralization m

odel is suggested:

•From Later Mesozoic to Early Cenozoic, this area experienced sedime

ntary processes from continental facies to shallow marine facies in the

regional extension regime, resulting in the extensive hot brine activity.

•In Later Paleocene, affected by the collision between India plate and E

urasian plate, the ore-bearing hot brine was extracted and moved to th

e favorable site to form the Pb-Zn deposit, and the pebbled sandstone l

ayer of Wulagen Formation within impermeable layers (mudstone) bec

ame the favorable site for mineralization of ore-bearing hot brine by wa

y of infiltration and replacement.

2. Geological Characteristics

3. Enlightenment of Exploration

There are many ages （ Pt ， D ， C ， E ） and many types of Pb-Zn mineralization in the western margin of the Tarim basin, where there are the features of the large-scale ore concentration area. However, the geological work in this area is still poor now, so that further work should be carried out to discover large Pb-Zn deposits.

(1) To reasonably select the target area is the base for ore prospecting

(2) It is the key to ore prospecting that to exactly understand the ore deposit type, and choose the right technique method (combination).

•In the past, the Wulagen deposit was accounted as a small hydrothermal dep

osit with little perspective. After our survey, we recognize that the deposit ha

s the similar characteristics to that of Jinding strata-bounded deposit, and ha

s the favorable ore-forming conditions of large deposit.

•In the past, the prospecting mainly focused on the mineralization of breccia t

ype ore at small scale. Through geology and geochemistry survey on the profi

le, we have discovered the large-scale mineralization of sandstone type that is

not easy to recognized on surface, and put this ore type as the main prospecti

ng object.

•Due to the natures of precipitous topography, low content of sulfide ， and t

he ore-bearing layer together with gypsum layer, we choose the method of pri

mary halo exploration to quickly block out the enriching section of ore-bearin

g strata. We employ the geological mapping, geochemical exploration and eng

ineering verification as the main evaluation means.

(3) Strengthening the study on minerogenetic (ore controls) regulations, and c

hoosing the key engineering for verification, are the effective ways to enhance

our confidence of ore prospecting, and expand the resource reserve.

•Based on the knowledge of the mineralization and the thickness of ore-bearing

sandstone (conglomerate) layer in Wulagen deposit, we chose the key position to

drill a core (ZK0-1) for verification with the annual appropriation of only 0.6

million Yuan. The core reveals the orebody of 194m in thickness, with average

grade of 4.87% for Pb+Zn, showing large perspective of the Wulagen deposit (>

0.5Mt).

•Based on the knowledge of the orebody controlled by a syncline, we verify our i

dea at the rising ends of the syncline, and the orebodies of north and south ore z

ones are proofed to be combined with each other at depth, which expands rema

rkably the resource reserve and the space for searing new orebody.

(4) Persistent support and effective guidance from the China Geology Survey guarantee the achievement of ore-searching breakthrough in this area.

(5)Public geology work promotes the business geology work,whcich is an important approach to accelerate the transformation of exploration results.

Gate of mine site

Mine office building

A large-scale Pb-Zn mine is in accelerating construction

WULAGEN mine site

4. Outlook

To the west region of the Wulagen Pb-Zn deposit, there are same ore-bearing layers and similar mineralization characteristics. Three Pb-Zn ore belts have been discovered, including KANGXI section (the west extending part of the northern zone), (the southern zone )XIYAN section and WUDONG section( subsidiary anticline of the synclinorium ), which have a great potential for prospecting.

Geological map of Wulagen Pb-Zn deposit in Wuqia county, Xinjiang

The length of the middle part mineralized body is about 3200 meters and average thickness is 32.54 meters. Average grades are of 0.23%Pb,and 1.24%Zn.

Kangxi is located at western e

xtending part of the northern

zone , and there occurred the

same strata.

The length of the mineralizati

on zone is about 8 kilometers

and the width is 150 meters.

Mineralization mark have be

en discovered on surface, and

this area has a large prospect

ing potential.The length of the south mineralized body is about 1600 meters and average thickness is 16.23 meters. Average grades are of 0.

50%Pb, and 2.76%Zn.

The length of the northern mineralized body is about 1200 meters and average thickness is 10.50 meters. Average grades are of 0.36%Pb, and 1.41%Zn.

KANGXI lead-zinc occurrence

Transgression range

There extensively exist the similar mineralization conditions to those of the Wulagen deposit in the western of Tarim basin.

The Kashi depression in the west fringe of Tarim basin was formed in late Mesozoic–early Cenozoic extension regime, which is a compound rejuvenated basin at the continental margin. The length is 300 kilometers and width is 50-150kilometers. In Paleocene epoch, the intrusion of Tethys seawater formed vast semi-hermetical -hermetical marine basin and provide condition to form widely thermal brine activity. Subsequently, during the conversion period from compression to extension, ore-bearing hydrothermal brine had been extracted and transported to be deposited.

The sketch map of the Kashi depression

In the Kusilapu Pb-Zn belt,

located on the piedmont zon

e of West Kunlun in the sout

hwestern margin of Tarim

Basin, the MVT mineralizat

ion are developed extensivel

y. In recent years, with the s

upport of projects on resour

ces survey, five concentrate

d areas have been discovere

d, and the primary reserve i

s about 1.5Mt.

Tuiopa Pb-Zn deposit

Huosibulake Pb-Zn deposit

立项依据

Wulagen Pb-Zn deposit

Shalitashi Pb-Zn deposit

Qiongkuer Pb-Zn deposit

Kangxi Pb-Zn depo

sit

Baishibulake Pb-Zn deposit

Kada Pb-Zn deposit

Northwestern margin of Tarim basin-(southwest Tianshan) Huoshibulake lead-zinc metallogenic belt

The Pb-Zn resources base in the western margin of Tarim basin

The ore concentrating area in west margin of Tarim basin include:

Wulagen Pb-Zn metallogenic belt in the basin formed in Mesozoic-Cenozoic;

Kusilapu MVT Pb-Zn metallogenic belt in the southwestern margin of Tarim basin;

Huoshibulake SEDEX Pb-Zn metallogenic belt in southwestern of Tianshan. formed in Devonian

The western margin of Tarim basin will become the important Pb-Zn resource base with huge prospecting potential (>10Mt).

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