Clay mineralogy of Gulf of Papua Shelf and Pandora Trough deposits constrains sediment routing during the last sea‐level cycle

Sedimentology ◽  
2020 ◽  
Vol 67 (5) ◽  
pp. 2502-2528 ◽  
Author(s):  
Emily A. Wei ◽  
Neal W. Driscoll
Keyword(s):  
Sea Level ◽  
Clay Mineralogy ◽  
Sediment Routing ◽  
Gulf Of Papua

Chemical weathering response to extreme global warming during Paleocene-Eocene Hyperthermals, Southern Pyrenees, Spain

2021 ◽  
Author(s):  
Rocio Jaimes-Gutierrez ◽  
Thierry Adatte ◽  
Emmanuelle Puceat ◽  
Jean Braun ◽  
Sebastien Castelltort
Keyword(s):  
Climatic Change ◽  
Chemical Weathering ◽  
Numerical Models ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Foreland Basin ◽  
Isotopic Analysis ◽  
Feedback Mechanism ◽  
Horizon 2020 ◽  
Sediment Routing

<p>The Paleocene and early Eocene were periods yielding multiple hyperthermal events. The most pronounced of them was the Paleocene-Eocene Thermal Maximum (PETM), which was characterized by an abrupt increase in global temperature (5–8 °C) over a short time (20 ka). A negative carbon isotope excursion marks the onset of the PETM, which resulted in the fast injection of CO<sub>2</sub> into the ocean-atmosphere system, triggering global climatic changes. Geochemical, mineralogical, and sedimentological markers record the resulting increase in continental weathering. This is important, as enhanced chemical erosion influences both the CO<sub>2</sub> concentration in the atmosphere and ocean acidity, generating a feedback mechanism. Hence, constraining the rates and intensity of weathering response can further clarify the causes for the PETM and Eocene hyperthermals. This study focuses on the well-preserved Pyrenean foreland basin and intends to assess the continental chemical weathering response of the sediment routing system during the PETM. Clay mineralogy is a climate-sensitive proxy, which records changes in continental erosion. Therefore, clay mineral proportions will be analyzed using X-ray diffraction and major element chemistry on clay-rich samples from the entire source-to-sink system (continental to deep marine deposits). Kaolinite and smectite will be separated from the detrital clay fraction and further subjected to δ<sup>18</sup>O and δD isotopic analysis for paleoclimatic reconstruction. The combined Lu-Hf and Sm-Nd isotope systems in the clay fraction of the sediments will be used to track the evolution of chemical weathering intensity. The outcome of this project will serve to validate numerical models to understand erosion as a function of rapid climatic change. This topic is of keen interest, as the PETM and its sedimentological signal work as a natural analog for anthropogenically-induced climatic change. The project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No 860383.</p>

scholarly journals How do basin margins record long-term tectonic and climatic changes?

Geology ◽  
2020 ◽  
Vol 48 (9) ◽  
pp. 893-897
Author(s):  
Jinyu Zhang ◽  
Zoltán Sylvester ◽  
Jacob Covault
Keyword(s):  
Sea Level ◽  
Numerical Models ◽  
Source Area ◽  
Climatic Changes ◽  
Steady States ◽  
Sediment Supply ◽  
Relative Sea Level ◽  
Continental Scale ◽  
Sediment Routing ◽  
Basin Margin

Abstract A long-standing goal of sedimentary geoscience is to understand how tectonic and climatic changes are reflected in basin fill. Here, we use 14 numerical models of continental-scale sediment-routing systems spanning millions of years to investigate the responses of sediment supply and basin sedimentation to changes in uplift and precipitation in the source area. We also investigate the extent to which these signals can be altered by relative sea level (the sum of subsidence and eustasy). In cases of constant relative sea level, sediment supply and margin progradation have similar responses because nearly all of the sediment is transported beyond the coastal plain and continental shelf to the basin margin. Thus, margin progradation can be used as a proxy for sediment supply. However, changes in uplift and precipitation result in different erosional patterns in the source area and different basin-margin depositional patterns. Changes in uplift result in gradual (over several million years) adjustment to new steady states of source-area erosion and margin progradation, whereas changes in precipitation result in abrupt changes in erosion and progradation followed by a return to the initial steady states. In cases of changing relative sea level, sediment storage on the shelf attenuates signals of uplift, but signals of precipitation change can be interpreted in the basin-margin record because climate-induced sediment supply changes are large enough to influence margin progradation. Understanding the relationship between sediment supply and basin-margin progradation, and their linked responses to forcings, improves our ability to interpret signals of environmental change in the stratigraphic record.

scholarly journals Benthic Foraminiferal response to sea level change in the mixed siliciclastic-carbonate system of southern Ashmore Trough (Gulf of Papua)

2008 ◽  
Vol 113 (F1) ◽  
Author(s):  
Brooke E. Carson ◽  
Jason M. Francis ◽  
R. Mark Leckie ◽  
André W. Droxler ◽  
Gerald R. Dickens ◽  
...  
Keyword(s):  
Sea Level ◽  
Sea Level Change ◽  
Carbonate System ◽  
Level Change ◽  
Gulf Of Papua

scholarly journals Doomed to drown? Sediment dynamics in the human-controlled floodplains of the active Bengal Delta

Elem Sci Anth ◽  
2017 ◽  
Vol 5 ◽  
Author(s):  
Kimberly G. Rogers ◽  
Irina Overeem
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Land Surface ◽  
Sediment Dynamics ◽  
Transport Processes ◽  
Sediment Dispersal ◽  
Bengal Delta ◽  
Delta Plain ◽  
Sediment Routing ◽  
The Impact

The Ganges-Brahmaputra-Meghna (Bengal) Delta in Bangladesh has been described as a delta in peril of catastrophic coastal flooding because sediment deposition on delta plain surfaces is insufficient to offset rates of subsidence and sea level rise. Widespread armoring of the delta by coastal embankments meant to protect crops from flooding has limited natural floodplain deposition, and in the tidally dominated delta, dikes lead to rapid compaction and lowered land surface levels. This renders the deltaic floodplains susceptible to flooding by sea level rise and storm surges capable of breaching poorly maintained embankments. However, natural physical processes are spatially variable across the delta front and therefore the impact of dikes on sediment dispersal and morphology should reflect these variations. We present the first ever reported sedimentation rates from the densely populated and human-controlled floodplains of the central lower Bengal Delta. We combine direct sedimentation measurements and short-lived radionuclides to show that transport processes and lateral sedimentation are highly variable across the delta. Overall aggradation rates average 2.3 ± 9 cm y–1, which is more than double the estimated average rate of local sea level rise; 83% of sampled sites contained sediment tagged with detectable 7Be, indicating flood-pulse sourced sediments are widely delivered to the delta plain, including embanked areas. A numerical model is then used to demonstrate lateral accretion patterns arising from 50 years of sedimentation delivered through smaller order channels. Dominant modes of transport are reflected in the sediment routing and aggradation across the lower delta plain, though embankments are major controls on sediment dynamics throughout the delta. This challenges the assumption that the Bengal Delta is doomed to drown; rather it signifies that effective preparation for climate change requires consideration of how infrastructure and spatially variable physical dynamics influence sediment dispersal on seasonal and decadal time scales.

Implications for Provenance since the Last Glaciations in Southeastern Andaman Sea Sediments by Clay Mineralogy

2019 ◽  
Vol 10 (1) ◽  
pp. 140
Author(s):  
Suratta BUNSOMBOONSAKUL ◽  
Penjai SOMPONGCHAIYAKUL ◽  
Zhifei LIU ◽  
Akkaneewut CHABANGBORN ◽  
Anond SNIDVONGS
Keyword(s):  
Sea Level ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Clay Mineralogy ◽  
Andaman Sea ◽  
Interglacial Period ◽  
Provenance Analysis ◽  
Geological Time ◽  
Core Mass ◽  
Fine Grained

This study presents high-resolution clay mineralogy of Core MASS-III-10, located in the southeastern Andaman Sea. The study aimed to investigate terrigenous sedimentary input from various potential provenances throughout different periods of geological time. The clay mineral assemblages of MASS-III-10 reveal a high amount of smectite at 73% (65-79%), a moderate kaolinite at 12% (10-17%), and a low illite and chlorite content(<15%) over the last 45 ka. Provenance analysis suggests the most fine-grained terrigenous sediments originated from the Irrawaddy Delta Shelf (IDS), with minor sediments deriving from the Andaman Islands, the East Continental Shelf (ECS), and Sumatra provenance. The results show that IDS were predominantly smectite (~44%) while the ECS largely produced kaolinite (47%). The provenance interpretation based on the smectite content revealed that over time there has been no change in the main source of sediment in the Andaman Sea, despite changes in the volume of sedimentary input. Since the last glaciation, the Myanmar provenance (including IDS) has always contributed clay minerals, while other sources made up only minor contributions to the Andaman Sea. The clay minerals from the Myanmar provenance increased when the sea level was at a low stand (MIS 2), potentially due to shoreline retreat which enabled easier transportation of sediment from other sources. During the interglacial period (MIS 1 and 3), the study found a decrease in Myanmar-sourced clay minerals, which may be because the higher sea level made clay mineral deposition more difficult.

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