{"title":"Geochronology of a sedimentary core in the northwest of South China Sea and regional paleoenvironmental changes over the last million years","authors":"","doi":"10.1016/j.csr.2024.105322","DOIUrl":null,"url":null,"abstract":"<div><p>The South China Sea (SCS) is ones of the largest marginal seas on the Earth. Apart from IODP/ODP sites, limited progress has been made in establishing chronostratigraphy for long-term geological sequences spanning millions of years. In this study, we present findings from a sediment core (NH-01) collected from the eastern part of Hainan Island, northwest SCS, in terms of magnetostratigraphy and sedimentary/paleoenvironmental changes in the past 1 Myr. The main findings are as follows: (1) Two magnetic polarity zones in core NH-01 can be preliminarily correlated with the upper part of the intervening Matuyama chron and the Brunhes normal chrons, respectively. (2) By tuning the color indices of core NH-01 to the stacked benthic δ<sup>18</sup>O record, the age-depth model was refined, and the sediment accumulation rates are estimated as 10–30 cm/kyr (3) The sedimentary processes in the study area display a dominant 100-kyr cycle, with contributions from precession and obliquity bands, underscoring the influence of regional sea-level changes and monsoonal evolution. Comparisons between the NH-01 sedimentary record and various global climate proxies indicate a significant shift in regional sedimentary processes around 430 kyr, which can be attributed to the pronounced impact of the</p><p>Mid-Brunhes event, potentially linking it to climatic changes in the Southern Hemisphere. Consequently, sedimentary records from the northwest SCS not only capture regional environmental history but also provide insights into potential connections between different climatic systems.</p></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":null,"pages":null},"PeriodicalIF":2.1000,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Continental Shelf Research","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0278434324001523","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"OCEANOGRAPHY","Score":null,"Total":0}
引用次数: 0
Abstract
The South China Sea (SCS) is ones of the largest marginal seas on the Earth. Apart from IODP/ODP sites, limited progress has been made in establishing chronostratigraphy for long-term geological sequences spanning millions of years. In this study, we present findings from a sediment core (NH-01) collected from the eastern part of Hainan Island, northwest SCS, in terms of magnetostratigraphy and sedimentary/paleoenvironmental changes in the past 1 Myr. The main findings are as follows: (1) Two magnetic polarity zones in core NH-01 can be preliminarily correlated with the upper part of the intervening Matuyama chron and the Brunhes normal chrons, respectively. (2) By tuning the color indices of core NH-01 to the stacked benthic δ18O record, the age-depth model was refined, and the sediment accumulation rates are estimated as 10–30 cm/kyr (3) The sedimentary processes in the study area display a dominant 100-kyr cycle, with contributions from precession and obliquity bands, underscoring the influence of regional sea-level changes and monsoonal evolution. Comparisons between the NH-01 sedimentary record and various global climate proxies indicate a significant shift in regional sedimentary processes around 430 kyr, which can be attributed to the pronounced impact of the
Mid-Brunhes event, potentially linking it to climatic changes in the Southern Hemisphere. Consequently, sedimentary records from the northwest SCS not only capture regional environmental history but also provide insights into potential connections between different climatic systems.
期刊介绍:
Continental Shelf Research publishes articles dealing with the biological, chemical, geological and physical oceanography of the shallow marine environment, from coastal and estuarine waters out to the shelf break. The continental shelf is a critical environment within the land-ocean continuum, and many processes, functions and problems in the continental shelf are driven by terrestrial inputs transported through the rivers and estuaries to the coastal and continental shelf areas. Manuscripts that deal with these topics must make a clear link to the continental shelf. Examples of research areas include:
Physical sedimentology and geomorphology
Geochemistry of the coastal ocean (inorganic and organic)
Marine environment and anthropogenic effects
Interaction of physical dynamics with natural and manmade shoreline features
Benthic, phytoplankton and zooplankton ecology
Coastal water and sediment quality, and ecosystem health
Benthic-pelagic coupling (physical and biogeochemical)
Interactions between physical dynamics (waves, currents, mixing, etc.) and biogeochemical cycles
Estuarine, coastal and shelf sea modelling and process studies.