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1
Tracing the source to sink patterns of river sediments in East Asian marginal seas by using geochemical methods
Shouye YANG, Yanguang DOU, Chao LIState Key Laboratory of Marine Geology, Tongji University, Shanghai, China Zhenxia LIU, Hua YUThe First Institute of Oceanography, SOA, Qingdao, China
International Sediment Trap Workshop and Symposium on Sediment Transport and Sediment on Asian Margins, 23-27 March, 2009 Taiwan
2
Research background How to identify the river sediments? Case study: — Discriminations of sediment sources of
the Okinawa Trough during the late Quaternary
Talk outlineTalk outline
3
Tibet uplift Monsoon evolution & river evolution
Key questions: Provenance weathering, Chemical flux, Sediment recycling at present and in the geological past
Source to sink
Changjiang R.
Source to sink
East
China
Sea
Yellow Sea
?Cheju Strait
Japan
Sea
Okinaw
a Tro
ugh
Huanghe R.
Huge sediments derived from mega-rivers dominate the sedimentation of the western Pacific marginal seas.
5
2004.7 primary
productivity
Asanuma et al., 2005
Freshwater transport from the Changjiang to the Japan Sea could significantly affect the primary production & deep circulation in the Japan Sea.
Senjyu, T et al. (2006, [email protected])
Suspended particles?
6
The S2S pattern of river sediments in the Yellow Sea is very complex and much variable during the late Quaternary, which is a big challenging problem for the paleoenvironmental reconstruction.
Yang et al. (2003)Earth-Science Review
Unit: 108
ton/yr
Sediment flux in Sediment flux in the Yellow Seathe Yellow Sea
7
Potential sediment provenances in the shelf and open sea
Siliciclastic sediments: S2S
River Basin Estuary Open Sea
River inputVolcanic ash
SE
DGKS9604
Aeoliandust
hydrothermalsource
lateral transportof terrestrial matter
KuroshioCurrent?
8
Sediment samples and analytic methods
9
Samples from the Changjiang (Yangtze River) (suspended, bed, floodplain)
Upper reaches Lower
reaches
Middle
reaches
10
The first bend of the Changjiang at Shigu
Wujiang River Daduhe and Minjiang Rivers
NW NE
Field work in the Changjiang, 2003-2007
11
The Upper Reach:Jinshajiang River at Lijiang, Yunnan Province
The Lower Reach
12
Huanghe: Yellow River
13
Case study: Okinawa Trough
Core DGKS9604:
Location: west slope of the middle Okinawa Trough
Water depth: 766 m
Core length: 10.76 m (~30 Cal Ka)
Recovery: about 95%
200
38°
30°
26°
34°
1000
200
1000
100
200
DGKS9603
DGKS9604
Yellow Sea
East Chi
na S
ea
0 200km
100
Sea of Japan
120° 124° 128° 132°
Korea
Changjiang
Old HuangheJapan
Kyushu
China
Taiwan
36°
32°
28°
24°122° 126° 130°
Tokara Strait
Ryukyu Islands
CDWAira
AtaKikai
Kurosh
io c
urre
nt
Coas tal current
Cheju Is.
Sediment S2S pattern of the Okinawa Trough during the late Quaternary
14
• Sample pre-treatment :<0.063mm fine-grained samples (elements)
1 N HCl leaching experiment (element & Sr-Nd-Pb isotopes)
• REE and elements : ICP-MS/ES• Sr-Nd-Pb isotopes : — TIMS ( modern sediments ) — MC ICP-MS ( Core sediments )• Mineral chemistry (zircon, garnet, apatite, monazit
e)
Analytic methods
15
Geochemical proxies of sediment provenance discrimination
— REE fractionation pattern and parameters including (La/Yb)UCC, (Gd/Yb)UCC, (La/Sm)U
CC, δCe, δEu
— Ratios of conservative elements such as La/Sc, Th/Sc, Ti/Nb, Cr/Th, Ti/Al…..
— Sr-Nd-Pb isotopic systematics
— Mineral chemistry of detrital zircon, monazite, Ti-Fe oxides and garnet grains
16
Research background How to identify the river sediments? Case study:
— Discriminations of sediment sources of the Okinawa Trough during the late Quaternary
Talk outlineTalk outline
17
Rare earth elemental compositions in the Changjiang sediments
UCC: upper continental crust, T & M, 1985
residual fraction
1N HCl leaching
Yalongjiang
JinshajiangFujiang
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The Korean river sediments are relatively more enriched in LREE than Chinese river sediments, suggesting different source rock compositions in their drainage basins.
Yang, et al. (2002) EPSL
19
Characteristic REE parameters and elemental ratios can be treated as reliable geochemical proxies to trace the river sediment sources.
Chinese Rivers
Chinese Rivers
Yang et al., Earth-Science Review, 2003; Chinese Sci Bull., 2004
Korean rivers
Korean rivers
20
Korean rivers
Chinese rivers
Korean rivers
Chinese rivers
Yang et al., Earth-Science Review, 2003; Chinese Sci Bull., 2004
Geochemical proxies for discriminating Chinese and Korean river sediments
21
Sr-Nd isotopic compositions of the Changjiang suspended sediments
Yang et al., Sci in China, 2007
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Comparison of Sr-Nd isotopes
0.5100
Missi.
Nile
143 144Nd/ Nd
0.5110 0.51300.5120
UCC
AmazonGanges Indus
Mekong
0.700 0.710 0.720 0.730 0.740 0.750 0.760
Missi.
Nile
G/B
World River
87 86Sr/ Sr
Weathered UCC
Loess
Australian shale Huanghe
Changjiang
ChangjiangHuanghe
PAAS
XiangjiangYuanjiang
Ganjiang
23
Distinct isotopic compositions exist between East Asian river sediments
24
1N HCl-leached fractions of the river sediments show good discrimination results between Chinese and Korean river end-members.
Choi et al. 2007. Marine Chemistry
25
Detrital zircon grains from the Changjiang river sediments
26
Mineral chemistry of detrital zircon grains from the Changjiang sediments
27
Zircon ages of the Changjiang sediments
28
Monazite age spectrum of the Changjiang sediments
29
Controls of sedimentary geochemical compositions
• Provenance rocks character : age, type, outcrop area, weathering rate
• Chemical fractionation of minerals during chemical weathering
• Hydrodynamic sorting during transport and deposition : grain size effect, SPM representative
• Sediment recycling : complex but important • Sample treatment : 1 N HCl, residual fraction
30
金
沙
江
雅
砻
江
大
渡
河
岷
江沱
江
涪
江
嘉
陵
江
汉
江
赣
江
湘
江
资
江
沅
江
澧水
乌
江
赤水河
横
江牛
栏
江攀枝花
宜宾
重庆
万县
长沙
武汉
南京
CJ-1CJ-2丽江 CJ-3CJ-4
CJ-6CJ-5
CJ-7
CJ-8
CJ-9
CJ-10
CJ-13
CJ-11
CJ-12
N
铜陵三峡大坝
Samplingsite
Metamorphic rocksIgneous rocksSedimentary rocks
Granite Ultrabasic-basicrocks
BasaltSiliciclasticsediments
Carbonaterocks & clasticsediments
Low-grademeta. Rocks
High-grademeta. Rocks
Source rocks in the Changjiang drainage basin
31
Increasing ages
Sr isotopic compositions in the source rocks of the Changjiang drainage basin
0.700 0.710 0.720 0.730 0.740 0.750 0.760
87 86Sr/ Sr
0.700 0.710 0.720 0.730 0.740 0.750 0.760
Upper reaches
Mid-Lower reaches
Changjiang
Changjiang
Igneous rock and crystallinebasement in south Himalaya
Carbonate in themiddle-upper valley
Himalayan granite
Late Yesannian granite in Tibet
Emeishan Basalt
River water in thesource area
Archean metamorphic complex
Sinnian-Cambrian silicalite in Hunan and Jiangxi Metamorphic rockin the middle-lower valleyJiangxi
Mesozoic granite
Changjiangestuarine water
Mesozoic igneous rock in lower valley
Cenozoic basaltin the lower valley Ganjiang
YuanjiangXiangjiang
32
Nd isotopic compositions in the source rocks of the Changjiang drainage basin
0.5100
143 144Nd/ Nd
0.5110 0.51300.5120
Changjiang
0.5100 0.5110 0.51300.5120
Upper reaches
Mid-Lower reaches
Changj iang
Himalayan graniteEmeishan BasaltKongling
amphibolite
Late Yesannian granite in Tibet
Kongling meta-sedimentary rock
Shoshonite in east Tibet
Igneous rock and crystallinebasement in south Himalaya
Kongling gneiss
Jiangxi Mesozoic granite
Meso-high grade metamorphicrock in central Jiangxi
Mesozoic-Cenozoic basaltin the middle-lower valley
Sedimentary rockin SE Yangtze Block
Alkaline rockin the lower valley
33
Acidic igneous rocks dominant in the Korean river basins.
Different climate regimes result in variable weathering intensities.
34
Case study Sediment provenances of the middle Okinawa Trough during the last 30 Cal ka
20 0
38°
30°
26°
34°
100 0
200
DGKS9603
DGKS9604
Yellow Sea
East China Sea
100
120° 124° 128° 132°
Korea
Changjiang
Old Huanghe
Japan
Kyushu
ChinaTa
iwan
36°
32°
28°
24°
122° 126° 130°
Tokara Strait
Ryukyu I
slands
CDW AiraAta
Kikai
ODP1202
N
E
Huanghe
YS
CC
ZF
CC
TWC
Kurosh
io Curre
nt
0 200km
N
1000
2 00100
YSWC
Core DGKS9604:
Location: west slope of the middle Okinawa Trough
Water depth: 766 m
Core length: 10.76 m (~30 Cal Ka)
Recovery: about 95%
35
Large changes occur in the deglacial periodÄêÁä (C
al a)
TN(%)
.1 .2 .3 .4Éî
¶È(m
)0
1
2
3
4
5
6
7
8
9
10
11
TOC(%)
.5 1.0 1.5 2.0
CaCO3(%)
0 6 12 18 24 30
TOC/TN
0 2 4 6 8 10
OIS 1
OIS 2
OIS 3
37010
33264
30800
27620
21456
16334
12339
35721827
5799
13C
-24 -23 -22 -21 -20δ
36
δCe(n)
.88 .96 1.04
δEu(n)
.60 .68 .76
(Gd/Yb)ucc
.90 1.26 1.62
(La/Yb)ucc
.6 1.0 1.4.12 .24 .3680 160 2400 14 28
δ18O (‰, PDB)
-3-11
Mz (phi)
6.25 6.75 7.250
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
∑ REE (ppm) ∑ REE-flux
OIS1
OIS2
OIS3
Unit 1
Unit 2
K-Ah
AT
Ag
e (
ka
BP
)
CaCO (%)3
REE: abrupt changes occur at ca. 8 ka
37
La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu.5
1.0
1.5
2.0
2.5Uni t 1 : < 7.1 ka
Abonormi ty 1: 7.6 kaUni t 2 : 3-8.2ka
Abonormi ty 2 : 25.8 ka
7.6 ka BP< 7.1 ka BP
31-8.2 ka BP
25.8 ka BP
Uni t 1:
Uni t 2:
Sam
ple
/UC
C
REE
REE fractionation patterns
Tephra layer
Sr-Nd isotopes
abrupt changes occur at 8 ka
Unit 2
Unit 1
39
Different sediment sources
Aira caldera data after Arakawa et al. (1998); Volcanic rocks data after Shinjo and Kato (2000)
.6 .8 1.0 1.2 1.4.6
.8
1.0
1.2
1.4
1.6
Changjiang
Taiwan sediments
Huanghe
Volcanic rocks
Aira volcanic source
25.8 ka
7.6 ka
Unit 1Unit 2
(La
/Sm
) ucc
(Gd/Yb)u cc
Unit 1Unit 2
ChangjiangHuanghe
Aira volcanic sourceVolcanic rocksTaiwan sedimentstwo tephra layers
Unit 1: 0~ 7.1 ka
Taiwan Source?
Unit 2: 8.2~31 ka
Changjiang-sediments dominated
Dou et al., submitted
40
~150 Mt/yr
Shuh-Ji Kao, et al., 2005. TAO
41
Variable sediment sources with time
~ LGM
200
38°
30°
26°
34°
1000
200
1000
100
200
DGKS9603
DGKS9604
Yellow Sea
EastChinaSea
0 200km
100
Sea of Japan
120° 124° 128° 132°
Korea
Changjiang
Old Huanghe
Japan
Kyushu
China
Taiwan
36°
32°
28°
24°122° 126° 130°
Tokara Strait
Ryukyu Islands
AiraAta
Kikai
Kurosh
io current
paleo-coastalline at LGM
0~7 ka BP
200
38°
30°
26°
34°
1000
200
1000
100
200
DGKS9603
DGKS9604
Yellow Sea
East China Sea
0 200km
100
Sea of Japan
120° 124° 128° 132°
Korea
Changjiang
Old Huanghe
Japan
Kyushu
China
Taiwan
36°
32°
28°
24°122° 126° 130°
Tokara Strait
Ryukyu Islands
CDWAira
AtaKikai
Kurosh
io c
urre
nt
42
Thanks!