GSA NORTHEASTERN SECTION -

47th

ANNUAL MEETING, HARTFORD

(18–20 MARCH 2012)

POLYPHASE TECTONICS AS

A

TOOL FOR EXPLORATION OF CHROMITE ORES HOSTED BY ULTRAMAFIC ROCKS OF BULQIZA ULTRAMAFIC MASSIF, ALBANIA©

HOXHA, Lirim

-

Empire Mining Albania, Tirana,

Albania, lirimhoxha@gmail.com

Studied area

Regional geological setting showing the

External zonesExternal zones,

the western ophiolite

belt

( central Dinaride, Mirdita, Hellenic ophiolites), the Internal zones

(Korabi-Pelagonian Microcontinent = Pelagonian zone, Korab zone, Drina-Ivanjica element) and

the eastern ophiolites

(Inner Dinaric ophiolite belt and Vardar zone).

One group of authors (Mountrakis,1986; Robertson et al., 1996; Robertson and Shallo, 2000; Stampfli

and Borel, 2002; Brown and Robertson, 2004; Sharp and Robertson, 2006; Rassios

and Moores, 2006; Karamata,2006) reconstructs Pelagonian/Korabi-Pelagonian

units as a continental block that was

bordered by two Tethyan

oceanic realms

In contrast another group of authors (Mercieret al., 1975; Burchfiel, 1980; Hoxha, 2001; Bortolootti etal., 2005;Gawlick

et al. 2008; Schmid

et al., 2008) favours

asingle oceanic basin to the east, the Tethys

(Vardar/Axios)Ocean

About the displacement direction of the obducted

ophiolitesduring Middle to Late Jurassic time onto the PelagonianContinent : E-

to NE-ward direction (e.g. Robertson and Shallo, 2000; Rassios

and Dilek, 2009) or W-

to SW-ward direction (e.g. Jacobshagen

et al., 1978; Vergely, 1984; Hoxha, 2001; Gawlick

et al.,

2008; Schmid

et al., 2008 or both e.g. Mountrakis, 1986; Sharp

and Robertson 2006).

Kilias

et al. 2010 distinguishes:

Gawlick

et al. 2008

Simplified after Geological Map of Albania, 2002

The Albanian ophiolites

of the Mirdita

Zone represent remnants of Mesozoic oceanic lithosphere within the Dinaride-Albanian-Hellenide

segment of the Alpine orogenic

system.

Most recent studies (Shallo

& Dilek

2003; Dilek

and Flower 2003;Bortolotti

et al. 2005, 2006; Dilek

et al.2008)

distinguish twodifferent rock associations, formingthe Western Ophiolite

Belt (WOB) and Eastern Ophiolite

Belt (EOB).

20°00

19°3042°30

42°00

41°30

41°00

40°30

40°00 40°00

40°30

20°30 Maastrichtian to Eocene flysch

Internal Albanides

Molasse sediments andNeogene-Quaternary sediments

Ophiolites + metamorphic sole andassociated sediments, radiolaritic-ophiolitic (wilde) flysch (melange),(Bathonian-Oxfordian) andflyschoid-molasse(Kimmeridgian-Valanginian)

VLORA

External Albanides

MON

TENE

GRO

F Y R O

M

GREECE

I O N I A N S E A

Transgressive Cretaceous limestone

A D

R I A

T I C S E A

KOSOVA

SHKODRA Mirdita Ophiolite Zone

TIRANA

KORCA

WOB- Western Ophiolite Belt EOB- Eastern Ophiolite Belt

WO

B

EOB

Bulqiza

The upper mantle of WOB

includes lherzolite-harzburgite, plagioclase lherzolite, plagioclase dunite

and plutonic complex,overlain by extrusive sequence of MORB affinity whereas

the upper mantle of EOB

includes tectonized

harzburgite

and dunite,as well as ultramafic

cumulates including olivine clinopyroxenite,wehrlite, olivine websterite, and dunite

forming a transitional Mohoand plutonic complex overlain by extrusive sequence of basalts-andesites-dacites

and rhyolites

indicating SSZ affinity (Dilek

et al.2008)

A

C

B

D

ADRIA-APULIAExternal Albanides

Maastrichtian-Eocene Flysch Eastern Ophiolite Belt

Western Ophiolite Belt

Triassic-Cretaceous carbonate (Ionian)

Korab-Pelagonian Units

W EMunella Kukesi

Triassic-Jurassic carbonates (Korabi-Pelagonian)Middle Jurassic melange

Kimmeridgian-Tithonian deposits

(not to scale)

Western Ophiolite Belt Eastern Ophiolite Belt

Low Cretaceous shallowwaters carbonates

Generalized cross-section A-B

Western Ophiolite

Belt-Eastern Ophiolite

Belt (with metamorphic sole and melange) relationships After Hoxha

at Gawlick

et al..2008

47 00 000

46 80 000

46 60 000

46 40 000

46 20 000

46 00 000

45 80 000

45 60 000

45 40 000

45 20 000

45 00 000

44 80 000

44 60 000

44 40 000

44 20 000

43 80 000

44 00 000

44 20 000 44 40 000

47 00 000

46 80 000

46 60 000

46 40 000

46 20 000

46 00 000

45 80 000

45 60 000

45 40 000

45 20 000

45 00 000

44 80 000

44 60 000

Thekna

Lugu i Gjate

TernovaKrasta

Bulqiza

Batra

Qafe Burrel

Shkalla

Liqeni i Dhive

Bushtrice

Memlisht

Pojska

Katjel

Kudenisht

Gobille

Govate

Guri i Pishkashit

Hurdhat e Tolle

Rragam

Zogaj

Vlahen

Kalimash 1

PerollajKam

Kepenek

Kalimash 2,3

Tpla

Bregu i Bibes

TROPO

JA MASSIF

KU

KESI M

ASSIF

LUR

A M

ASSIF

BU

LQIZA

MA

SSIF

SHEBEN

IK-POG

RADEC M

ASSIF

10 km0

44 60 000

44 40 000

44 20 000

44 20 000

44 40 000

44 00 000

Simplified after Metalogenic

Map of Albania (ISPGJ-FGJM, 1989)showing the ultramafic

massifs of Eastern Ultramafic

Belt with main chromite

deposits

Qafe Burreli areaBulqiza-Batra- Thekna area

0

2000000

4000000

6000000

8000000

10000000

12000000

14000000

Bulqize Bater Ternove Klos Theken Kraste-LuguI Thelle

Chromite Production at Bulqiza Massif 1948-2009 (t)Chromite

Production at Bulqiza

Massif (1948‐2009)1948‐2009 (t)

Bulqize 13490323

Bater 6992843

Ternove 175301

Klos 790504

Theken 949000

Kraste‐Lugu

I 

Thelle 231296

Total 22 629 267 @ 40% Cr2 O3*

Chromite production Bulqiza-Batra-Thekna area 1948-2009 years* Albanian lump chromite

on 40% Cr2

O3 base, for 2011 year has been sold from 299 -328 $/ton (www.Ruidow.com)

Previous views for East Limb detachment at Bulqiza

and Batra

deposits

QL I

P IVL II

L I

L II-3

A) Cross-section LI, After Bulqiza

geologists, 1986

B) Cross-section -11, After Batra

geologists, 1986

NW-SE extension Bulqiza

–Batra

deposits, presumed through an extensional

tectonics

BULQIZA

Cr.-Sec. XXIIICr.-Sec. XIIICr.-Sec. IXCr.-Sec. III

Cr.-Sec. -5Cr.-Sec. -11Cr.-Sec. -15Cr.-Sec. -23

Cr.-Sec. LXVIICr.-Sec. LIX

BATRACr.-Sec. I

Extensional tectonics

first-order fold(enveloping surface)

WSWmsl(m) Z Folds

P11 Nomenclature of fold limbs

P11

P10P9

P8

P7

P6P5

P4 P3 P1

L1

Z Folds

Z Folds

second-order fold (enveloping surface)

WSW

ENE

500

1000

0 250m

P2

L 2 1

L 2 2

L 2 3

L 2 4

L 2 5

Fault

Bulqiza-Batra

Mine -

The enveloping surface to the second-order folds describes the ENE-vergent

anticlinorium

of the first-order fold structure with a normal fault in the west and an eastward directed thrust in the eastAfter Happel

et al., ERZMETALL 51 (1998) Nr. 10

2000 m

1000

0

- 1000

- 2000

WSW ENEFushe Bulqize

Quaternary

Mélange

Harzburgite and rare dunite

Harzburgite

Planar flow structure

Middle-Late Triassic limestone(Korabi Zone)

Supposed chromite structure

Coss-section C-D

New interpretationBulqiza

ultramafic

massif is a homocline

structure and the “chromite

antiform”

with easterly vergence

is a fold in plan of dip and integral part of this homocline-

meaning west as well as upward east limb extensions (Hoxha, 2007, updated)

New interpretation of chromite

horizon taking into consideration polyphase

thrusting tectonics

Mined ores

Mined ores

Mined ores

Re-interpretation of SE extension Bulqiza-Batra

deposits as a fold

and

thrustchromite

horizon affected by westward displaced polyphase

thrusting tectonic

East limb extension

West lim

b extensio

n

Mined chromite ores

Mined chromite ores

Expected “cusps”

West limb extension

West li

mb exte

nsion

Mined chromite ores

Mined chromite ores

Excpected chromite ores

Mined chromite

ores

Batra

deposit-

showing mined chromite

ores displaced by polyphase

thrusting and possible west limb and east limb extension as well as within

mined areas

Expected “cusp”

Expected “cusp

Batra

deposit-

new interpretation -

Possible exploration of the chromite

ores at hanging and thefoot walls of the westward displaced thrust

a)

b)

Mined ores

Mined ores

Structural setting of the chromite

mineralization in the Bulqiza-Batra

system-

secondary fold within west-dipping homocline

displaced by thrust faults (Hoxha, 2009)

Structural setting of the chromite

mineralization in the Bulqiza-Batra

system-

secondary fold within west-dipping homocline

displaced by thrust faults

Mined crom

iteores

Plan View (A) and) Cross-section (B)

showingthrusted

chromite

ores at Southern Batra

A)

B)

Chromite ores

Crushed and serpentinised harzburgites

Thrust at Batra

chromite

deposit

Thekna

chromite

deposit has been considered as an anticline with NE strike

Thekna

deposit showing northern and southern Thekna

as divided parallel depositswith NW strike

(EC Terra, 2009)

Exploration at Thekna

chromite

deposit (a) proved a fold in plan of dip, integral part of a homocline

structure as previously predicted (b)

2000 m

1000

0

- 1000

- 2000

WSW ENEFushe Bulqize

Quaternary

Mélange

Harzburgite and rare dunite

Harzburgite

Planar flow structure

Middle-Late Triassic limestone(Korabi Zone)

Supposed chromite structure

a) b)

Lug. Qershise

Lugu i Thelle

Pr. Prevallit

Qaf Bualli

Batra Jugore

Pylli i Zi

Moli i Lopes

Perroi i ThelleFushe Lope

BULQIZE

BATER

QQ

D

94

Luçane

94

BATRA

-BULQ

IZA W

EST LIM

B EXTENSION

BULQ

IZA-BA

TRA EA

ST LIMB E

XTENSIO

N

A

B

Fushe Kalt

Lugu i Gjate

Sheshi Kraste TERNOVE

THEKEN

Mined Ores

10 KorrikuUshtari

Bulqiza-Batra-Thekna

fold

and

thrust chromite

ore field

NW PART OF BULQIZA MASSIFSE-NW Polyphase

thrusting AT Qafe

Burreli

chromite

deposits

Conclusions

Principal chromite

horizon Bulqiza-Batra-Thekna

with easterly vergence

folds in plan of dip is integral part of Bulqiza

Homocline

Ultramafic

Massif

Principal chromite

horizon Bulqiza-Batra-Thekna

extends all over Bulqiza

Ultramafic

Massif, comprising

a fold

and

thrust chromite

ore field.

The polyphase

thrusting is a result of westward displacement of Bulqiza

Ultramafic

Massif

Exploration works performed by Empire Mining Corporation at Bulqiza-Batra-Thekna

ore field and NW at Qafe

Burreli

indicate for high developed west directed polyphase

thrusting tectonics that led to new interpretation of the structural setting and extension of the chromite

mineralization potential.

Especially, southern part of the fold

and

thrust chromite

ore field:

Bulqiza-Batra-Thekna, represent very high potential for exploration of new chromite

ores analogues in amount and grade with mined ones.

Principial

references

Happel, U., Hausberg, J., Kisters, A. & Meyer, F.M.1998: The application of digital 3-D ore body modeling to the structural analysis of the Bulqiza-Batra

chromite

mine, central Albania. Erzmetall, 51: 685-692.

Hoxha, L., 2001.The Jurassic-Cretaceous orogenic

event and its effects in the exploration of sulphide

ores, Albanian Ophiolites, Albania. Eclogae

geol Helv. 94, 339-350. Birkhauser

Verlag, Basel.

Hoxha, L. Structural control of Bulqiza

chromite

deposit: a case historyJournal of Alpine Geology, 48. S.37-

44, Wien, 2007

Gawlick, H.J., Frisch, W., Hoxha, L., Dumitrica, P., Krystyn, L., Lein, R., Missoni, S. and Schlagintweit, F.Mirdita

zone ophiolites

and associated sediments in Albania reveal Neothethys

Ocean origin. International Journal of Earth Sciences, 94, 865-881. Int

J Earth Sci

(Geol Rundsch) (2008) 97:865–881

@Springer-Verlag, 2007

Dilek, Y., Furnes, H., Shallo

M. Geochemistry of the Jurassic Mirdita

Ophiolite

(Albania)and The MORB to SSZ evolution of a marginal basin oceanic crust

.Lithos

100 (2008) 174–

209 www.elsevier.com/locate/lithos

Kilias, A., Frisch, W., Asterios, A., Dunkl, I., Falalakis, G. & Gawlick, H-J. Alpine architecture and kinematics of deformation of the northern Pelagonian

nappe

pile in the HellenidesAustrian Journal of Earth Sciences Volume 103/1 4-28 Vienna 2010

Masurenko, Ch., Tanasković, D. and Hogg, J. 2010, Potential exploration mineral resource estimate report (Bulqiza-Batra-Thekna

East) Bulqiza

Project, Albania. EC TERRA

Acknowledgment

Special thanks go to Mr. David Cliff President & CEO Empire Mining Corporation for helpful discussions over years and encouragement and permit presenting exploration data 2009-2011 years.

Addresses: 1. Rruga Kongesi I Lushnjes, Pallati 33, Ap. 134, Tirana, Albania;

2. 30 Woodland Ridge, Southwick 01077 MA. USA