Holocene Paleoenvironmental Reconstruction of Depositional Environments on the Sunda Shelf , Southwest South China Sea , using a Multidisciplinary Approach
The last glacial maximum , ca. 21 , 000 years ago , caused a fall in eustatic sea level of ca. 120 m below present. The low-gradient , shallow Sunda Shelf , Southeast Asia was subaerially exposed during this sea-level lowstand and experienced rising sea level thereafter. Sea level rose to a +1.3--5...
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ftunivnorthcag:oai:libres.uncg.edu/30551 2024-02-11T10:08:03+01:00 Holocene Paleoenvironmental Reconstruction of Depositional Environments on the Sunda Shelf , Southwest South China Sea , using a Multidisciplinary Approach NC DOCKS at East Carolina University Twarog, Michael R. 2018 http://libres.uncg.edu/ir/ecu/f/0000-embargo-holder.txt English eng http://libres.uncg.edu/ir/ecu/f/0000-embargo-holder.txt 2018 ftunivnorthcag 2024-01-27T23:47:22Z The last glacial maximum , ca. 21 , 000 years ago , caused a fall in eustatic sea level of ca. 120 m below present. The low-gradient , shallow Sunda Shelf , Southeast Asia was subaerially exposed during this sea-level lowstand and experienced rising sea level thereafter. Sea level rose to a +1.3--5 m highstand ca. 6 , 500 cal yr BP , and then fell to modern sea level. The objective of this research is to characterize environmental change on the Sunda Shelf in response to the post-glacial rising eustatic sea level. To address this objective , six gravity cores were collected along a transect crossing the paleo-Chao Phraya incised river valley complex between peninsular Malaysia and southern Vietnam. Thirteen AMS radiocarbon samples , 130 bulk sediment magnetic susceptibility samples (BMS) , 66 X-ray fluorescence spectrometry (XRF) samples , and 54 samples for the analysis of foraminiferal assemblages were used to characterize change in the depositional environments of the cored sediments. BMS , XRF , and foraminiferal analysis distinguish two main units. Unit 1 is found in the lower part of the cores and typically contains more terrestrial material than sediments further up-core as shown by higher BMS values , higher % Ti , % Al , % Fe , and lower indicators of marine influence , for example , lower % Ca , % planktonic foraminifera , and percentages of deeper water benthic foraminifera such as Heterolepa dutemplei. Unit 2 is characterized by a significant increase in % Ca , % Heterolepa dutemplei and % planktonic foraminifera ca. 6 , 500 cal yr BP. Unit 1 is consistent with shallower water depths and is part of a transgressive systems tract (TST , ca. 1 m thick) that terminates ca. 6 , 500 cal yr BP. Unit 2 represents the overlying highstand systems tract (HST , ca. 1 m thick) and is characterized by an increase in % planktonics , % Ca , and shifts in benthic foraminiferal assemblages , indicating deeper water conditions than the sediments below. This shift from a TST to a HST ca. 6500 cal yr BP is consistent ... Other/Unknown Material Planktonic foraminifera University of North Carolina: NC DOCKS (Digital Online Collection of Knowledge and Scholarship) Sunda ENVELOPE(-6.982,-6.982,62.205,62.205) |
institution |
Open Polar |
collection |
University of North Carolina: NC DOCKS (Digital Online Collection of Knowledge and Scholarship) |
op_collection_id |
ftunivnorthcag |
language |
English |
description |
The last glacial maximum , ca. 21 , 000 years ago , caused a fall in eustatic sea level of ca. 120 m below present. The low-gradient , shallow Sunda Shelf , Southeast Asia was subaerially exposed during this sea-level lowstand and experienced rising sea level thereafter. Sea level rose to a +1.3--5 m highstand ca. 6 , 500 cal yr BP , and then fell to modern sea level. The objective of this research is to characterize environmental change on the Sunda Shelf in response to the post-glacial rising eustatic sea level. To address this objective , six gravity cores were collected along a transect crossing the paleo-Chao Phraya incised river valley complex between peninsular Malaysia and southern Vietnam. Thirteen AMS radiocarbon samples , 130 bulk sediment magnetic susceptibility samples (BMS) , 66 X-ray fluorescence spectrometry (XRF) samples , and 54 samples for the analysis of foraminiferal assemblages were used to characterize change in the depositional environments of the cored sediments. BMS , XRF , and foraminiferal analysis distinguish two main units. Unit 1 is found in the lower part of the cores and typically contains more terrestrial material than sediments further up-core as shown by higher BMS values , higher % Ti , % Al , % Fe , and lower indicators of marine influence , for example , lower % Ca , % planktonic foraminifera , and percentages of deeper water benthic foraminifera such as Heterolepa dutemplei. Unit 2 is characterized by a significant increase in % Ca , % Heterolepa dutemplei and % planktonic foraminifera ca. 6 , 500 cal yr BP. Unit 1 is consistent with shallower water depths and is part of a transgressive systems tract (TST , ca. 1 m thick) that terminates ca. 6 , 500 cal yr BP. Unit 2 represents the overlying highstand systems tract (HST , ca. 1 m thick) and is characterized by an increase in % planktonics , % Ca , and shifts in benthic foraminiferal assemblages , indicating deeper water conditions than the sediments below. This shift from a TST to a HST ca. 6500 cal yr BP is consistent ... |
author |
NC DOCKS at East Carolina University Twarog, Michael R. |
spellingShingle |
NC DOCKS at East Carolina University Twarog, Michael R. Holocene Paleoenvironmental Reconstruction of Depositional Environments on the Sunda Shelf , Southwest South China Sea , using a Multidisciplinary Approach |
author_facet |
NC DOCKS at East Carolina University Twarog, Michael R. |
author_sort |
NC DOCKS at East Carolina University |
title |
Holocene Paleoenvironmental Reconstruction of Depositional Environments on the Sunda Shelf , Southwest South China Sea , using a Multidisciplinary Approach |
title_short |
Holocene Paleoenvironmental Reconstruction of Depositional Environments on the Sunda Shelf , Southwest South China Sea , using a Multidisciplinary Approach |
title_full |
Holocene Paleoenvironmental Reconstruction of Depositional Environments on the Sunda Shelf , Southwest South China Sea , using a Multidisciplinary Approach |
title_fullStr |
Holocene Paleoenvironmental Reconstruction of Depositional Environments on the Sunda Shelf , Southwest South China Sea , using a Multidisciplinary Approach |
title_full_unstemmed |
Holocene Paleoenvironmental Reconstruction of Depositional Environments on the Sunda Shelf , Southwest South China Sea , using a Multidisciplinary Approach |
title_sort |
holocene paleoenvironmental reconstruction of depositional environments on the sunda shelf , southwest south china sea , using a multidisciplinary approach |
publishDate |
2018 |
url |
http://libres.uncg.edu/ir/ecu/f/0000-embargo-holder.txt |
long_lat |
ENVELOPE(-6.982,-6.982,62.205,62.205) |
geographic |
Sunda |
geographic_facet |
Sunda |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_relation |
http://libres.uncg.edu/ir/ecu/f/0000-embargo-holder.txt |
_version_ |
1790606991163392000 |