This pdf file contains all figure pages in the dissertation:

Fig

ure

1.1

Him

alay

as-T

ibet

an P

late

au T

opog

raph

y (f

rom

http

://w

ww

.geo

.cor

nell.

edu)

.T

his

imag

e is

a f

alse

-col

or, s

hade

d re

lief

imag

e w

ith il

lum

inat

ion

from

the

nort

hwes

t. T

he s

hado

win

g gi

ves

an in

dica

tion

of lo

cal r

elie

f w

hile

col

or in

dica

tes

elev

atio

n as

fol

low

s: m

agen

ta=

sea-

leve

l; bl

ue=

1000

m; c

yan=

2000

m; g

reen

=30

00m

; ye

llow

=40

00m

; red

=50

00m

; whi

te=

6000

m a

nd a

bove

.

2

Kat

awaz

Koh

ista

nLa

dakh

Zan

skar

Lha

sa B

lock

BN

S

Indi

a

IYZ

S

Gam

ba

Tin

gri

Mal

la J

ohar

Haz

ara

30N

25N

30N

25N

70E

80E

90E

70E

80E

90E

HF

Indi

an P

late

Les

ser

Him

alay

a

Hig

h H

imal

aya

Cry

stal

lines

Koh

ista

n-L

adak

h A

rc C

ompl

ex

Tet

hyan

Him

alay

a

Lha

sa B

lock

Indo

-B

urm

an R

ange

MC

T

STD

S

Inne

r-bu

rman

Bas

in

Qia

ngta

ng B

lock

Figu

re 1

.2 R

egio

nal g

eolo

gica

l m

ap o

f T

ethy

an H

imal

aya

(mod

ifie

d af

ter

Row

ley,

199

6)B

NS:

Ban

ggon

g-N

ujia

ng S

utur

e IY

ZS:

Indu

s-Y

arlu

ng-Z

angb

o-Su

ture

, MC

T:M

ain-

Cen

tral

-Thr

ust,

STD

S:So

uthe

rn-T

ibet

-Det

achm

ent-

Syst

em

Xig

aze

Lha

sa

Gya

ngze

4

India

Shelf Rise Trench

Asia

Gangdese Arc

Ophiolites

TuffFlysch

(1)

(2)

(3)

Figure 1.3 Schematic cross-sections of the India-Asia convergence up to the initiation of collision (modified after Rowley and Kidd, 1981). (1) Cretaceous; (2) Paleocene; (3) Eocene.

5

Qt

F L

Con

tinen

tal B

lock

Pro

vena

nce

Magmatic Arc Provenance

Recycled OrogenProvenance

Qm

F Lt

Con

tinen

tal B

lock

Pro

vena

nce

Magmatic Arc Provenance

Recycled O

rogen

Provenance

Mixed

Figure 1.4 Detrital mode distribution in three major tectonic settings. After Dickinson et al. (1983).Qt: monocrystalline quartz+polycrystalline quartz; Qm:monocrystalline quartz; F: feldspar, L:rock fragments; Lt: rock fragments+polycrystalline quartz.

8

Gy rong-Kangmar Thrust

Lhasa Block

Indus-Yarlung Tsangpo-Suture

High Himalaya

NepalBhutan

Yadong

KangmarTianba

Gyangtse

Xigaze

Gamba

Tingri

Lhaze

100 km

India

Tethyan Himalaya - N

Tethyan Himalaya - S

TibetIYZS

Figure 2.1 Simplified geologic map of Tingri-Gyangtse area, southern Tibet (modified after Willems et al., 1996). The inset map shows this region located in the Himalaya system.

17

Gamba E1-2

E1-2

K2

K2

K2

K2

K1

K1

K1

K1

K1

Q

Q

Q

J3 J3

J3

J3

J3

J3

J3

J3

J1-2

J1-2

T

Tatsang

10 km

Figure 2.2 Simplified geologic map of the Gamba region (modified after geologic map (1:1,500,000) in Xizang BGMR, 1992).

18

Figu

re 2

.3 G

eolo

gic

map

of

the

Zhe

pure

Sha

n M

ount

ain

(bas

ed o

n fi

eld

obse

rvat

ions

and

imag

e in

terp

reta

tion

(Kid

d)).

Geo

grap

hic

coor

dina

tes

in d

egre

es, m

inut

es.

27

86 4

686

50

86 4

2

28 4

2

28 4

4

28 4

6

28 4

0

28 3

8

28 3

6

28 3

4

86 3

886

54

86 5

887

02

Peng

qu R

iver

Nep

al-L

hasa

Roa

d

To

Old

Tin

gri

Shek

ar D

zong

Shen

keza

Y

ouxi

a

Gon

gza

Sect

ion

Zhe

pure

Sha

n R

ange

Shen

keza

FM

You

xia

FM.

Zhe

pure

Sha

n FM

.

Jidu

la F

M

Pre-

Jidu

la F

M

Faul

t

Kat

awaz

Koh

ista

nL

adak

h

Zan

skar

Lha

sa B

lock

BN

S

Indi

a

IYZ

S

Gam

ba

Tin

gri

Mal

la J

ohar

Haz

ara

30N

25N

30N

25N

70E

80E

90E

70E

80E

90E

Raj

mah

al

Indi

an P

late

Les

ser

Him

alay

as

Hig

h H

imal

ayas

Cry

stal

line

Koh

ista

n-L

adak

n A

rc C

ompl

ex

Tet

hyan

Him

alay

as

Lha

sa B

lock

Indo

-B

urm

an R

ange

MC

T

STD

S

Inne

r-bu

rman

Bas

in

Qia

ngta

ng B

lock

Xig

aze

Lha

sa

Figu

re 2

.

Figu

re 3

.1 R

egio

nal g

eolo

gica

l m

ap o

f T

ethy

an H

imal

aya

(aft

er R

owle

y, 1

996)

. BN

S: B

angg

ong-

Nuj

iang

Sut

ure

IYZ

S:In

dus-

Yar

lung

-Zan

gbo-

Sutu

re, M

CT

:Mai

n-C

entr

al-T

hrus

t, ST

DS:

Sout

hern

-Tib

et-D

etac

hmen

t-Sy

stem

.

45

Nepal im BhutanYadong

100 km

Tethyan Himalaya - S

Tethyan Himalaya - N

High Himalaya

Lhasa Block

Xigaze

Kangmar Tianba

Gamba

Tingri

Lhaze Gyangtse

Indus-Yarlung-Zangbo-Suture

Gyirong-Kangmar Thrust

Figure 3.

Figure 3.2 Simplified tectonic map of the study area (after Willems et al, 1996)

46

5 km

89.80 89.90

Gyangtse-Lhasa roadJiabula

Grey shales, quartzites and marls

Black cherts and shales

Tianba Flysch and overlying shales

Melange (area of pink limestone blocks shown)

Nieru V

alley

Tianba28.70

28.80Fault

Fault

Figure 3.3 Sketch geologic map at Tianba showing three measured sections 1-3.Note: Rivers are traced from the 1:100,000 topographic map

48

3

1 2

Figu

re 3

.4. T

ianb

a cr

oss-

sect

ion

(sec

tion

2, s

ee f

igur

e 3.

3 fo

r lo

catio

n) H

oriz

onta

l sca

le=

vert

ical

sca

leSe

e Fi

gure

3.1

1 fo

r ex

plan

atio

n of

lith

olog

ic u

nits

and

orn

amen

ts.

4300

m

4400

m

4500

m

4600

m

N

7

6

5

43

2

1

8

49

Figu

re 3

.5 V

iew

to n

orth

of

Tia

nba

sect

ion.

Dar

k gr

ey s

hale

s an

d ch

erts

are

of

earl

y C

reta

ceou

s se

dim

ents

in th

e ri

ver

valle

y an

d th

e lo

wer

slo

pes

of th

e hi

lls b

eyon

d; ta

n-or

ange

ban

d is

the

Tia

nba

Flys

ch; p

ink-

purp

le r

ocks

abo

ve th

is a

re f

ault-

juxt

apos

ed la

te C

reta

ceou

s lim

esto

nes

and

shal

es.

[The

aut

hor,

Bin

Zhu

, in

this

pic

ture

]

Mea

sure

d se

ctio

n2T

ianb

a Fl

ysch

50

(1)

(2)

Figure 3.6 Sedimentary structures in the Tianba Flysch(1) Ripple marks; (2) Sole marks.

51

Figure 3.7 Well-bedded turbidite sandstones with shale interbeds in the center part of the Tianba Flysch. View to east, section youngs to north (left).

52

Figu

re 3

.8 T

op o

f th

e T

ianb

a Fl

ysch

, nor

th o

f T

ianb

a vi

llage

. The

upp

erm

ost t

hick

-bed

ded

sand

ston

e of

the

Tia

nba

Flys

ch is

on

the

righ

t. V

iew

to E

NE

, sec

tion

youn

gs to

nor

th (

left

).T

he d

ark

grey

sh

ales

con

form

ably

ove

rlie

the

Tia

nba

flys

ch.

54

Figu

re 3

.9 S

ider

itic

sand

ston

e be

d sh

owin

g gr

aded

-bed

ding

. Abu

ndan

t Cr-

rich

spi

nels

are

fo

und

in th

ese

sand

ston

es.

55

Figu

re 3

.10

Out

size

d (u

p to

1 m

acr

oss)

cal

care

ous

nodu

les

in th

e gr

eeni

sh-g

rey

shal

es,

nort

h of

Tia

nba

villa

ge. V

iew

to N

E. O

ne s

mal

l nod

ule

(10

cm a

cros

s) y

ield

ed a

n am

mon

ite. [

Dr.

B. Z

hang

in th

is p

ictu

re]

56

7. Melange .

0

50

100

150

200

250

300

350

400m

-50

-100

-150

m

limestone

sandstone

coarse sandstone

siltstone

shale

mudstone

chert

melange

marlstone

Figure 3.11 Measured Section (2), north of Tianba village. See Figure 3.3 for location.

TB-5

TB-6

TB-7

TB-12

TB-13

TB-14

B

A

TB-33

Tia

nba

Flys

ch

sandstone with spinel sandstone without detected spinel

TB-11

DB-1

D4

Fault

8. Purple, medium-bedded and blocky siliceous limestone with lenses of red shale (late Cretaceous)

5. Grey-green burrowed shale, heavily pencilled with 3 lenticular siderite sandstones beds

6. Dark grey and green shales with large carbonate nodules in the upper part.Ammonite (A) and Belemnite (B)

4. Grey to green, medium- to thick-bedded siltstone and sandstone, interbedded with shale (one 30 cm black limestone).

3. Yellowish-green micaceous siltstones

2. Black chert, siliceous mudstones and shales, and minor marlstones.

1. Black shales and minor mudstones and cherts.

Minor Fault

57

?

100

200

300

400

-100

-200

-300

-400

0

500m

Tia

nba

Fly

sch

Fault Fault

Fault

Section 3 Section 1 Section 2

Figure 3.12 Measured stratigraphic sections at Tianba. Section locations are shown in Figure 3.3 See Figure 3.11 for explanation of the lithologic ornaments.

59

300

um

Figu

re 3

.13

Phot

omic

rogr

aph

(cro

ssed

pol

ars)

of

quar

tz-r

ich

sand

ston

e in

the

basa

l par

t of

wes

tern

se

ctio

n (s

ectio

n 3

in F

igur

e 3.

3). Q

uart

z gr

ains

are

mos

tly m

onoc

ryst

allin

e,an

d th

e ro

ck is

wel

l-so

rted

.

60

30 u

m

Figu

re 3

.14

Phot

omic

rogr

aph

(cro

ssed

pol

ars)

of

a m

etam

orph

ic r

ock

frag

men

t in

the

quar

tz-r

ich

sand

ston

es in

the

basa

l par

t of

wes

tern

sec

tion

(sec

tion

3, s

ee f

igur

e 3.

3 fo

r lo

catio

n.

61

Qt

LF

Chulung La Arenite (Garzanti, et al., 1987)

Giumal sandstone (Garzanti, et al., 1987)

Greywackes

Quartz arenites

Recycledorogen

Qm

LtF

Recycled

orogen

Figure 3.15 Detrital mode plot of sandstones in the Tianba sections. Tectonic fields from Dickinson and Suczek, 1979. Giumal sandstones and Chulung La Arenite from Zanskar are shown for reference on the QtFL plot.

62

300

um

Figu

re 3

.16

Phot

omic

rogr

aph

(pla

ne p

olar

s) o

f gr

eyw

acke

s in

the

Tia

nba

mea

sure

d se

ctio

n.N

ote

angu

lar

quar

tz g

rain

s ar

e po

orly

-sor

ted,

and

ther

e ar

e so

me

feld

spar

gra

ins

(dus

ty/d

irty

lo

okin

g co

mpa

red

with

cle

arer

qua

rtz

grai

ns).

63

100

um

Figu

re 3

.17

Phot

omic

rogr

aph

(cro

ssed

pol

ars)

of

feld

spar

(pe

rthi

te)

in th

e gr

eyw

acke

s of

the

Tia

nba

sect

ion

2 (s

ee f

igur

e 3.

3 fo

r lo

catio

n).

65

30 u

m

Figu

re 3

. 18

Phot

omic

rogr

aph

of a

vol

cani

c ro

ck f

ragm

ent c

ompo

sed

of p

lagi

ocla

se

phen

ocry

sts

with

in f

ine-

grai

ned

grou

nd m

ass.

Thi

s in

dica

tes

that

ther

e w

as a

sig

nifi

cant

vo

lcan

ic s

ourc

e fo

r th

e T

ianb

a Fl

ysch

.

66

30 u

m

Figu

re 3

.19

Phot

omic

rogr

aph

(cro

ssed

pol

ars)

of

a ro

ck f

ragm

ent w

ith tr

achy

tic te

xtur

e in

T

B6

sam

ple

in th

e T

ianb

a se

ctio

n 2

(see

fig

ure

3.3

for

sect

ion

loca

tion)

.

67

Figu

re 3

.20

His

togr

am s

how

ing

the

diff

eren

t det

rita

l mod

es b

etw

een

quar

tzite

and

gre

ywac

kes

in th

e T

ianb

a se

ctio

ns. T

hese

san

dsto

nes

have

sim

ilar

quar

tz c

onte

nts,

whi

le th

ere

are

mor

e m

atri

x, f

elds

par,

vol

cani

c lit

hics

and

le

ss m

etam

orph

ic li

thic

s in

the

grey

wac

kes

com

pare

d to

the

quar

tzite

s. M

onoq

uart

z: m

onoc

ryst

allin

e qu

artz

; Pol

yqua

rtz:

pol

ycry

stal

line

quar

tz; P

lag:

pla

gioc

lase

; K-s

par:

K-f

elds

par;

V

-lith

ic: v

olca

nic

lithi

cs; M

-lith

ic: m

etam

orph

ic li

thic

s; S

-lith

ic: s

edim

enta

ry li

thic

s; o

paqu

e: o

paqu

e m

iner

als.

68

Gre

ywac

kes

Qua

rtz

aren

ites

Figu

re 3

.21

Che

mic

al c

ompo

sitio

ns o

f de

trita

l Cr-

rich

spi

nels

usi

ng p

airs

plo

t fro

m S

-plu

s

TiO

2

Al2

O3

Cr2

O3

MnO

MgO

NiO

FeO

Fe2O

3

74

Figure 3.22 Backscattered electron images of melt inclusions in the

detrital spinels from Tianba Flysch.

a.

b.

c.

76

Mg/(Mg+Fe2+)

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

V2O

5

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Mg/(Mg+Fe2+)

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

MnO

0.15

0.20

0.25

0.30

0.35

0.40

0.45

Tianba Flysch spinels Hawaii Disko

Mg/(Mg+Fe2+)

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 N

iO

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

Mg/(Mg+Fe2+)

0.2 0.3 0.4 0.5 0.6 0.7

ZnO

0.05

0.10

0.15

0.20

0.25

0.30

Figure 3.23 Covariation of minor elements with Mg/(Mg+Fe2+) in spinel

(For comparision, data from Hawaii and Disko are also shown):

a. MnO vs. Mg#; b. NiO vs. Mg#; c. ZnO vs. Mg#; d. V2O5 vs. Mg#.

a b

c d

78

0.2

BoninitesIsland-arc basalts

Intra-plate basalts

Back arc basin

MORB

TiO

2 w

t%

Flysch

DiskoHawaii

Figure 3.24 Major element contents of spinels and tectonic setting discriminant plot:a. Cr/(Cr+Al) vs. Mg/(Mg+Fe2+) after Barnes and Roeder, 2001; b. TiO2 vs. Cr/(Cr+Al) after Arai, 1992.

Mg/(Mg+Fe2+)

Isopleths of olivine Fo (dashed lines) from Kamenetsky et al, 2001

OIB

Arc

Boninites

Flysch

DiskoHawaii

Fo80

-81

Fo85

-86

Fo87

-88

Fo89

-90

MORB

Hawaii

a

b

Cr/(Al+Cr)

Cr/

(Al+

Cr)

80

0.01

0.1

1.00

10.0

10 20 30 40

CFB OIB

MORB

ARCWest Greenland

Al2O3%

FlyschDiskoHawaii

Fe3+/(Al+Cr+Fe3+)

Flysch

DiskoHawaii

Intra-plate basalt

MORBARC

TiO

2 w

t%T

iO2 w

t%

c

d

Figure 3.24(continued) Major element contents of spinels and tectonic setting discriminant plot:c. TiO2 vs. Fe3+/(Al+Cr+Fe3+) after Arai, 1992; d. TiO2 vs. Al2O3 after Kamenetsky et al, 2001.

81

100

Zanskar

Figure 3.25 Comparison of lithostratigraphy between Tianba, Zanskar (after Garzanti, 1993), Thakkhola (Garzanti, 1999) and Wolong (Jadoul, et al. 1998).

Chikkim Fm.

Pingdon La Fm.

Takh Fm.

Spiti Fm.

Thakkhola Wolong

Spiti Fm.

Dangardzong Fm.

Kagbeni Fm.

Dzong Fm.Wolong Fm.

Tianba Flysch

0

200

300 m

-100

-200

-300

-400

Volcaniclastic sandstones

Quartz arenites

Shales and cherts

Limestones

Shales

Jiabula Fm.

Tianba

Fault

85

(a)

(b)

94

Gy

rong

-Kan

gmar

Thr

ust

Lha

sa B

lock

Indu

s-Y

arlu

ng T

sang

po-S

utur

e

Hig

h H

imal

aya

Nep

alB

huta

nY

adon

g

Kan

gmar

Tia

nba

Gya

ngts

e

Xig

aze

Gam

ba

Tin

gri

Lha

ze

100

km

Ind

ia

Tet

hyan

Him

alay

a -

N

Tet

hyan

Him

alay

a -

S

Tib

etIY

ZS

Figu

re 4

.2 S

impl

ifie

d te

cton

ic m

ap o

f th

e st

udy

area

(aft

er W

illem

s et

al,

1996

).T

he in

set m

ap s

how

s th

e T

ingr

i-G

yang

tse

area

in th

e H

imal

ayan

sys

tem

.

95

a. b.

c. d.

98

Figure 4.4 Major element contents of spinels and tectonic setting discriminant plots:a.TiO2 vs. Al2O3 after Kamenetsky et al[14]. Studies of Cr-rich spinel compositions from different tectonic settings show that TiO2 and Al2O3 contents of spinel form a linear trend for those from Continental Flood Basalts (CFB), OIB, DI (Disko Island, W. Greenland), and MORB. Our data mostly plot in the middle of this trend, mainly in the OIB field.b.Cr-Al-Fe3+ ternary plot. 95% of the detrital spinels plot in the 90th percentile contours of OIB field. Different fields are from Barnes and Roeder[33]: 1-MORB; 2-OIB; 3-Island Arc; 4-Boninites.

b.

0.01

0.1

1.00

10.0

10 20 30 40

TiO

2 w

t%

Al2O3 wt%

CFB

Arc

MORB

OIB

Al1

2

3

4

a

DI

101

Figure 4.5 Elemental maps of a melt inclusion quenched from 1250C, showing the homogenised melt inclusion.a. Backscatter image of the melt inclusion; b. X-ray image of Al distribution;c. X-ray image of Cr distribution; d. X-ray image of Mg distribution;e. X-ray image of Fe distribution; f. X-ray image of Ti distribution.

a. b.

c. d.

e. f.

102

Figure 4.6 Major-element compositions of melt inclusions in the detrital spinels from Tianba Flysch. Note K2O, TiO2, Al2O3, P2O5, and Na2O are increasing with dereasing MgO, showing relative enrichment of incompatible elements consistent with the crystallization of olivine and spinel.

105

BasaltPicro-basalt

TephriteBasanite

Phono-tephrite

Trachy-basalt

BasalticAndesite

Andesite

Dacite

Basaltictrachy-andesite

Trachy-andesite

Trachyte

Tephri-phonolite

RhyoliteFoidite

Alkalic

Tholeiitic

Figure 4.7 Total alkalis vs silica plot after Le Bas et al. [34]. The Macdonald-Katsura line that divides the tholeiitic series from the alkalic series is from Macdonald and Katsura[35]. In our glass data, there are 13 analyses with Na2O content >1 wt%, and only one plots in the tholeiitic area, hence the parental magma of these melt inclusions must be alkali basalt.

107

Figure 4.8 Positive correlation between Al2O3 and TiO2 contents in melt inclusions and hosted spinels (the best fit lines and fields are from Kamenetsky et al., 2000). Continuous line in a. is a power law best fit through published data; Continuous and dashed lines in b. are best fit through the high-Al (Al2O3 in melt >14 wt%) and low Al (Al2O3 in melt<14 wt%) data, respectively. Our data are either close to, or aligned with their best fit lines. The relatively narrow range of our data and proximity to the OIB point suggest a single tectonic provenance for these detrital spinels.

Spinel Al2O3 wt%

Mel

t Al 2

O3 w

t%

spinel TiO2 wt%

mel

t TiO

2 wt%

OIB

ARC

MORB

ARC

OIB

MORB

a

b

109

Figure 4.9 TiO2-MnO-P2O5 plot (after Mullen, 1983). CAB: Calc-Alkaline basalts; IAT: Island Arc Tholeiites; OIA: Ocean Island Alkali basalt or Seamount Alkali Basalt; OIT: Ocean Island Tholeiites. 13 of data (Na2O>1 wt%) plot in, or very close to, the OIA field. Therefore the melt of the spinel melt inclusions was most like oceanic island basalt. R represents the field of Rajmahal Traps (data from Storey et al., 1992).

110

CAB

IAT

MORB

OIT

OIA

MnO*10 P2O5*10

TiO2

R

Arc

MO

RB

Hot

spot

Figu

re 4

.10

Dis

crim

inan

t fun

ctio

n pl

ot o

f ba

salt

from

thre

e te

cton

ic s

ettin

gs.

The

com

posi

tions

of

basa

lt (S

iO2:

40-

55 w

t%)

from

Izu

Isl

and

Arc

(50

), A

ndea

n A

rc(5

0), M

aria

nia

Arc

(50

), H

onsh

u A

rc(5

0), M

OR

B(2

00),

H

awai

i(50

), I

cela

nd(5

0), K

ergu

elen

Isl

and

(50)

, and

Can

ary

Isla

nd (

50)

are

used

to d

evel

op th

is p

lot u

sing

line

ar

disc

rim

inan

t fun

ctio

n(ld

a) in

Spl

us [

29].

11

of 1

3 m

elt i

nclu

sion

s in

Tia

nba

Flys

ch p

lot i

n H

otsp

ot b

asal

t fie

ld, a

nd

no p

oint

s pl

ot in

arc

fie

ld. R

ajm

ahal

dat

a fr

om K

ent e

t al.,

1997

; Sto

rey

et a

l., 1

992.

D1=

2.02

*log

(SiO

2/T

iO2)

-2.1

5*lo

g(A

l 2O3/

TiO

2)-3

.14*

log(

FeO

/TiO

2)+

0.82

*log

(CaO

/TiO

2)+

0.41

*log

(MgO

/TiO

2)-1

.07*

log(

K2O

/TiO

2)-0

.37*

log(

Na 2

O/T

iO2)

+0.

53*l

og(P

2O5/

TiO

2)D

2=1.

69*l

og(S

iO2/

TiO

2)-2

.88*

log(

Al 2O

3/T

iO2)

-0.0

9*lo

g(Fe

O/T

iO2)

+0.

85*l

og(C

aO/T

iO2)

-0.4

9*lo

g(M

gO/T

iO2)

-1.1

5*lo

g(K

2O/T

iO2)

+3.

48*l

og(N

a 2O

/TiO

2)-0

.17*

log(

P 2O

5/T

iO2)

Raj

mah

al

111

Figure 4.11 Reconstruction map at about 117 Ma (modified after Besse and Courtillot, 1988). MAD, Madagascar block; S.TIB, southern Tibet; RT, Rajmahal Traps; TF, Tianba Flysch. The red line is the major subduction zone.

Eurasia

ArabAfrica

Australia

S.TIB

Neo-Tethys

India TF

RT

Antarctica

115

K2O

Al2O3

CaO*+Na2ONatural Waters

Plagioclase K-Feldspar

Muscovite

Illite

Kaolinite,Gibbsite, Chlorite

Pred

icte

d w

eath

erin

g tre

nd

TB5

TB6TB7

TB1

TB13

TB14

TB8

TB4, TB10, TB11

Figure 5.1 CIA ternary plot of the Tianba Flysch. Modified after Bock et al. (1998). The enrichment in Al2O3 and depletion of CaO+Na2O+K2O reflect the degree of chemical weathering to which the materials have been subjected. Four analyses (TB1, TB7, TB13, TB14) defined a linear trend encompassed in the predicted weathering trend for the average upper crustal composition. Four shales do not follow the predicted weathering trend, indicating processes in addition to the weathering have affected these sediments. TB6 and TB5 plot close to the Al2O3-CaO+Na2O join, which may indicate a signficant volcanic input.

Shales

Sandstones

Siltstone

Upper crust

120

Figure 5.2 SiO2-Al2O3 plot of the Tianba Flysch. TB5 (based on CaO and LOI-free recalculation) is not in the linear trend formed by the rest of analyses in Tianba Flysch.PAAS from Taylor and McLennan (1985), average basalt composition from Condie (1993).

122

Figure 5.3 MgO-FeOt plot of the Tianba Flysch.TB14 (siltstone) has high Fe content falling off the Fe-Mg trend of the other analyses. PAAS from Taylor and McLennan (1985), basalt from Condie (1993).

124

125

Figure 5.4 Al2O3-TiO2 plot of the Tianba Flysch.There is a approximate linear relationship between Al2O3 and TiO2 in the analyses from the Tianba Flysch. PAAS from Taylor and McLennan (1985), basalt from Condie (1993).

Shales

Siltstone

Sandstones

TB5

Sediment Recycling (Zircon addition)

Compo

sitio

nal

varia

tions

Active margin

Passive margin

Figure 5.5 Th/Sc-Zr/Sc plot of the Tianba Flysch.Passive margin and Active magin fields, and trends of compositional variations and sediment recycling are from McLennan et al. 1990. PAAS from Taylor and McLennan (1985), average basalt composition from Condie (1993).There is a signficant enrichment of Zircon (high Zr/Sc) in passive margin setting resulting from sedimentary sorting and recycling.

128

PAAS

Basalt

Figure 5.6 Th/U-Th plot of the Tianba Flysch. Arrow indicates a weathering trend.Note analyses (except TB5) from the Tianba Flysch follow the weathering trend, similar to Australian Shales with cratonic provenance (McLennan et al., 1990). PAAS from Taylor and McLennan (1985), average basalt and granite compositions from Condie (1993).

130

Weathering Trend

Figure 5.7 Cr/V-Y/Ni plot of the Tianba Flysch.Note Cr/V ratios of the Tianba Flysch are constantly low with the increase in Y/Ni ratios.Mafic-ultramafic sources tend to have high Fe, Cr, Ni abundances with low Y/Ni and high Cr/V ratios. TB5 has high Cr and Ni abundances indicating a volcanic provenance. PAAS and Upper Crust from Taylor and McLennan (1985), average basalt composition from Condie (1993).

132

Oph

ioli

tic

inpu

t

Figu

re 5

.8 C

hond

rite

-nor

mal

ized

RE

E p

lot o

f th

e T

ianb

a Fl

ysch

, nor

th o

f T

ianb

a vi

llage

.A

ll an

alys

es e

xcep

t TB

5 sh

ow L

RE

E e

nric

hmen

ts a

nd n

egat

ive

Eu

anom

alie

s, s

imila

r to

PA

AS,

in

dica

ting

a co

mm

on c

rato

nic

prov

enan

ce. R

elat

ivel

y fl

atte

n R

EE

tren

d of

TB

5 po

ints

to a

sig

nfic

ant

volc

anic

sou

rce.

PA

AS

from

Tay

lor

and

McL

enna

n (1

985)

.

134

Quartzose SedimentaryProvenance

Mafic igneousprovenance

Intermediateigneousprovenance

Felsic igneousprovenance

Siltstone

Figure 5.9 Tectonic discriminant diagram for the Tianba Flysch.Tectonic setting fields are from Roser and Korsch (1988).F1=-1.773TiO2+0.607Al2O3+0.76Fe2O3-1.5MgO+0.616CaO+0.509Na2O-1.224K2O-9.09F2=0.445TiO2+0.07Al2O3-0.25Fe2O3-1.142MgO+0.438CaO+1.475Na2O+1.426K2O-6.86Data from Roser and Korsch (1988).

135

0.1TB6

Arc

ACM

PM

Figure 5.10 K2O/Na2O-SiO2 (a) and SiO2/Al2O3-K2O/Na2O (b) plots of the Tianba Flysch.Tectonic setting: PM-passive margin, ACM-active continental margin, ARC-volcanic arc, A1-Arc setting, A2-evolved arc setting (from Roser and Korsch, 1986).Most samples from the Tianba Flysch plot in the passive margin area while TB5 plots in arc or active continental margin, indicating a volcanic source for the upper Tianba Flysch. PAAS from Taylor and McLennan (1985).

138

K2O/Na2O

SiO

2/A

l 2O

3

Shales

Sandstones

TB5

Siltstone

PAAS

A1

A2

ACM

PM

ShalesSandstonesTB5SiltstonePAASK

2O/N

a 2O

SiO2 wt%

a

b

Gy

rong

-Kan

gmar

Thr

ust

Lha

sa B

lock

Indu

s-Y

arlu

ng T

sang

po-S

utur

e

Hig

h H

imal

aya

Nep

alB

huta

nY

adon

g

Kan

gmar

Tia

nba

Gya

ngts

e

Xig

aze

Gam

ba

Tin

gri

Lha

ze

100

km

India

Tet

hyan

Him

alay

a -

N

Tet

hyan

Him

alay

a -

S

Tib

etIY

ZS

Figu

re 6

.1 S

ketc

h ge

olog

ic m

ap o

f T

ingr

i reg

ion,

sou

ther

n T

ibet

. The

inse

t map

sho

ws

this

reg

ion

loca

ted

in th

e H

imal

ayan

sys

tem

. M

odif

ied

afte

r W

illem

s et

al.(

1996

).

Figu

re 2

142

Shenkeza

Youxia

Gongza

Section

28 42

28 44

28 40

86 42 86 44 86 46

Gongza

Shenkeza FM

Youxia FM.

Zhepure Shan FM.

Jidula FM

Pre-Jidula FMFault

Zhepure Shan Range

(1)

1 km

Figure 6.2 Simplified geologic map showing the location of the studied sections in the Tingri region on the western flank of Zhepure Shan Mountain. Note: (1) is measured section at Shekeza.Geographic coordinates in degrees, minutes.

144

Jidula Fm.: Calcareous and glauconitic sandstones intercalated with shales.

Zhepure Shanpo Fm.: grey and black marlstone, shale, and sandy limestones.

Zhepure Shan Fm.: Thick-bedded to massive limestones with abundant foraminifera, intercalated with calcareous marls and marls.

0 m

200 m

0 m

100 m

185 m

Shenkeza Fm.:Red mud rocks, siltstones and sandstones.

Youxia Fm.:Green shales and thin-bedded sandstones with rare limestones.

Zhepure Shan Fm.Limestones and marlstones.

Figure 6.3 Stratigraphic columns of lower Tertiary sequence in the Tingri region. The Shenkeza section was measured by us in 2000, and the Gongza section is from Willems et al. (1996). Section locations are shown in Figure 2. Sample locations are indicated by "Sxxx" at Shenkeza section and "Julxxx" at Gongza section.

Gongza Section Shenkeza Section

S87

S88

S90

S94

S95

Unconformity

marlstonequartzose sandstone/siltstone limestone shale

Jul75

600 m

800 m

Zhepure Shanbei Fm.: Well-bedded limestones interbedded with thin layers of calcareous marls.

Gamba Group: pelagic and hemi-pelagic marls and caclareous marls.

Jul2

Jul1

S138

S141

S145

S148

lithic arenites

50 m

S150, 151

150 m

145

Figure 6.4 View to E of the upper part of the Youxia Formation in the head of the Shenkeza valley, made up of green shales and sandstones. The shales conformably overlie the Zhepure Shan limestones. The section of the upper Youxia Formation was measured up the gully on the left side of the photo.

Youxia Formation

149

Zhepure Shan Formation

Shenkeza Formation

Figure 6.5 View to N of Shenkeza Formation of red shales and occasional intercalations of fine-grained sandstones. The Zhepure Shan limestones above are in thrust contact with this unit.

150

151

Figure 6.6 View to NW of the unconformity between the Youxia and Shenkeza Formations. Note there is abrupt change in color from green to red. Excavation of the contact at the location of the hammer in this photo revealed a 1 m thick soil horizon of the base of the red unit, and a rubbly regolith of green sandstone fragments below it. [Professor W. Kidd stands on the unconformity, 21 Oct 2000]

Figure 6.7 Hummocky cross-stratification in the top sandstones of the Youxia Formation, indicating a depostional environment of storm waves during the late Youxia Formation.

153

Qt

F L

Con

tinen

tal B

lock

Pro

vena

nce

Magmatic Arc ProvenanceR

ecyc

led

Oro

gen

Prov

enan

ceA Stumpata/Dibling

B Balakot Fm.

C Subathu Fm.

D Siwalik (Nepal)

B

Figure 6.8 Detrital mode plot of lower Tertiary sandstones in the Tingri regionTectonic fields from Dickinson, 1985. Fields of other related Himalayan sandstones shown are from Garzanti et al. (1996)

Qm

F Lt

Con

tinen

tal B

lock

Pro

vena

nce

Magmatic Arc Provenance

Recycled O

rogen

Provenance

Mixed

Jidula Sandstone Youxia Green Sandstone Shenkeza Red Sandstone

A

C

D

156

300 um

Figure 6.9 Photomicrograph (crossed polars) of quartz-rich sandstone (Jul2) in the Jidula Formation, Gongza section. Note: most quartz grains are well-sorted, unit extinguishing.

159

Figure 6.10 Photomicrograph of well-rounded monocrystalline quartz gains with calcite cement in the Jul 75 sandstone of Jidula Formation, Gongza Formation. Opaque minerals are magnetite or ilmenite.

300 um

160

100 um

Figure 6.11 Photomicrograph (crossed polars) of a metamorphic rock fragment in Jul 75 sandstone of Jidula Formation, Gongza section.

161

300 um

Figure 6.12 Photomicrograph (crossed polars) of lithic-rich sandstone (Shen88) in the Youxia Formation, Shenkeza section. Note most quartz grains are angular in shape.

162

100 um

Figure 6.13 Photomicrograph (crossed polars) of volcanic rock fragments in the Shen88 sandstone of the Youxia Formation, Shenkeza section.

Volcanic lithic

Volcanic lithic

164

Calcite

100 um

Plagioclase

Volcanic lithic

Figure 6.14 Photomicrograph (crossed polars) of Shen94 sandstone in the Youxia Formation, Shenkeza section. Note there are calcite, volcanic lithic and plagioclase grains.

Calcite

165

chertvolcanic lithics

100 um

Figure 6.15 Photomicrograph (crossed polars) of volcanic and sedimentary rock fragments in the Shen87 sandstone of the Youxia Formation, Shenkeza section.

166

QuartzCalcite

100 um

Plagioclase

Figure 6.16 Photomicrograph (crossed polars) of a plagioclase grain in the Shen94 sandstone of the Youxia Formation, Shenkeza section.

167

Quartz

Calcite

100 um

plagioclase

metamorphic lithic

Figure 6.17 Photomicrograph (crossed polars) of a broken plagioclase and a metamorphic rock fragment in Shen88 sandstone of the Youxia Formation, Shenkeza section.

168

Quartz

Figure 6.18 Photomicrograph (crossed polars) of angular-subangular greywackes (Shen145) of Shenkeza Formation, Shenkeza section.

200 um

169

200 um

Figure 6.19 Photomicrograph (crossed polars) of angular quartz grains and a plagioclase in the Shen148 sandstone of Shenkeza Formation, Shenkeza section.

170

Natural Waters

Plagioclase K-Feldspar

Muscovite

Illite

Kaolinite,Gibbsite, Chlorite

Pred

icte

d w

eath

erin

g tre

nd

Figure 6.20 CIA ternary plot of lower Tertiary clastics in the Tingri region. Modified after Bock et al. (1998). The enrichment in Al2O3 and depletion of CaO+Na2O+K2O on this plot reflects the degree of chemical weathering to which the materials have been subjected. Three analyses of the Jidula Fm. defined a linear trend encompassed in the predicted weathering trend for the average upper crustal composition while those of the Youxia Fm. do not follow the predicted weathering trend, indicating processes in addition to the weathering have affected the Youxia sediments.

Upper crust

Youxia ShalesYouxia/Shenkeza Sandstones

Jidula Sandstone

176

0

2

4

6

8

10

12

14

16

18

20

30 50 70 90

1

10

100

0.1 1.0 10.0

Figure 6.21 Geochemical plot of the lower Tertiary clastics in the Tingri region. a. Al2O3 vs. SiO2 plot; b. SiO2/Al2O3 vs. K2O/Na2O plot; c. Al2O3 vs. TiO2 plot; d. K2O/Na2O vs. SiO2 plot. Tectonic setting fields are from Roser and Korsch (1986) for Figure 6.21 d and PM is passive margin field from McLennan et al. (1990). Note in Fig 6.21d, Jul1 and Jul75 are recalcualted to 100% CaO and volatile-free because of signifcantly high CaO contents. PAAS from Taylor and McLennan (1985), basalt from Condie (1993).

Al 2

O3

SiO2

Youxia-Shales Youxia/Shenkeza-Sands

SiO

2/A

l 2O

3

K2O/Na2O

Jidula-Silt

Jidula-Sand

ba

c

Al2O3

TiO

2

SiO2

K2O

/Na 2

O

ARC

Active Margin

Passive Margin d

PM

Jul75Jul1

177

Basalt PAAS

Cho

ndri

te n

orm

lized

RE

E p

atte

rns

Youxia-Shale95

Youxia-Shale90

Youxia-Sand94

Shenkeza-Sand148

Jidula-Silt1

Jidula-Sand2

Jidula-Sand75

F1

F2

Quartzose SedimentaryProvenance

Mafic igneousprovenance

Intermediateigneousprovenance

Felsic igneousprovenance

Figure 6.21(continued). Geochemical plot of the lower Tertiary clastics in the Tingri region. e. Provenance discrimination diagram; f.Chondrite-normalized REE patterns, chondritic values are those of Taylor and McLennan (1985). Tectonic setting fields are from Roser and Korsch (1988) for Figure 6.21e. Note in Figure 6.21e, Jul1 and Jul75 are recalculated to 100% CaO and volatile-free because of signficantly high CaO contents.

e

f

Jul1

Jul75

178

A

B

CD

PM

Figure 6.22 Tectonic discrimination plots from Bhatia and Crook (1986): a. La-Th-Sc ternary plot; b. Th-Sc-Zr/10 ternary plot. Fields are A-oceanic island arc, B-continental island arc, C-active continental margin, D-passive margin. PM is the Passive margin field from McLennan et al. (1990).

Youxia/Shenkeza-Sands Jidula-Silt Jidula-Sand

a

Th

Zr/10Sc

b

PM

184

Continentalflood Basalt

Alaska-type

OphioliteOphiolites

Al2O3

TiO

2

S148 S94 S87 S88

CFBOIB

MORB

ARC

SSZ Peridotite

MORBPeridotite

20

30

40

50

60

70

0 10 20 30 40Al2O3

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.00.10.20.30.40.50.60.70.8Mg/(Mg+Fe2+)

Cr/

(Cr+

Al)

Fore-arc Peridotites

Xigaze Ophiolites

Luobusa Ophiolites

AbyssalPeridotites

JijalPeridotites

Ladakh Peridotites

Figure 6.23 Geochemical plot of Cr-rich spinels from the Youxia and Shenkeza sandstones. a. Al2O3 vs. Cr2O3 plot, b. Cr# (Cr/(Cr+Al)) vs. Mg# (Mg/(Mg+Fe2+)) plot, fields displayed are: Abyssal peridotites from Brindzia and Wood (1990), Fore-arc peridotites from Parkinson and Pearce (1998), Jijal Peridotites and Ladakh peridotites from Rolland et al. (2002), Luobusa ophiolites from Zhou et al. (1996), and Xigaze ophiolites from Wang et al. (2000). c. TiO2 vs. Al2O3 plot, fields displayed are from Kamenetsky et al. (2001): CFB-continental flood basalt, OIB-oceanic island basalt, MORB-mid-ocean ridge basalt, ARC-volcanic island arc, SSZ-suprasubduction zone. d. Cr-Al-Fe3+ ternary plot, fields displayed are from Cookenboo et al.(1997).

Cr 2

O3

Cr Al

Fe3+

a b

c d

188

Figure 6.24 Comparison of stratigraphic columns of the Himalayan foreland basin, from Hazara-Kashmir (Bossart and Ottiger, 1989, which is modified by Najman et al. (2002)), through Zanskar (Garzanti et al., 1987, 1996), Himachal Pradesh (Najman and Garzanti, 2000), to Tingri, southern Tibet (this study). Timescale after Berggren et al. (1995).

Yellow-mature clastics of Indian passive margin; blue-carbonates of the Indian passive margin; green-marine orogenic clastics; red-non-marine redbeds.

193

Thanetian

Ypresian

Lutetian

Bartonian

Priabonian

Selandian

Danian

61.0

57.9

54.7

49.0

41.4

36.9

33.7

Pale

ocen

eE

ocen

e

Epoch StageAge

(Ma)

Hazara-

Kashmir

Balakot Fm.

Lockhart Fm.

Patala Fm.

Zanskar

Chulung La Fm.

Dibling Fm.

Stumpata Fm.

Zhepure Shan Fm.

Jidula Fm.

Subathu Fm.(sandstones)

Subathu Fm.(limestones)

Himachal Pradesh (N. India)

Tingri

Youxia Fm.

Shenkeza Fm.?

?

?