The impact of eustatic sea-level fluctuations, temperature variations and nutrient-level changes since the Pliocene on tropical carbonate platform (Xisha Islands, South China Sea)

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doi: 10.1016/j.palaeo.2018.10.013
Author(s): Wu Feng; Xie Xinong; Betzler, Christian; Zhu Weilin; Zhu Youhua; Guo Laiyuan; Ma Zhaoliang; Bai Huaqing; Ma Benjun
Author Affiliation(s): Primary:
China University of Geosciences at Wuhan, College of Marine Science and Technology, Wuhan, China
Universität Hamburg, Germany
China National Offshore Oil Corporation, China
Chinese Academy of Sciences, Nanjing Institute of Geology and Palaeontology, China
Chinese Academy of Sciences, Institute of Deep-sea Science and Engineering, China
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Vol.514, p.373-385. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 76 refs.; illus., incl. sketch map
Summary: Sedimentological, paleontological, and geochemical data from core XK-1 in the Xisha Islands, South China Sea, allow a detailed documentation of the evolution of the reef-bank system from the early Pliocene to the late Pleistocene and of the aeolianite deposits from the late Pleistocene to the Holocene. A bank characterized by heterozoan carbonates occurred until 1.7 Ma. Between 1.7 and 0.2 Ma, the system turned into a reef dominated by photozoan carbonates. After 0.2 Ma, the aeolianite deposits, composed of heterozoan skeletal grains, occupied this area. A Pliocene to Pleistocene decrease in the abundance of planktonic foraminifera and some benthic foraminifer species generally associated with deep water settings indicates a long-term shallowing-upwards trend, resulting from the large-scale eustatic sea-level falls. Seven exposure horizons are recorded in core XK-1, due to high-frequency sea-level changes. The thickness of the reef body in the individual cycles increased after the Middle Pleistocene transition. This is interpreted as a consequence of the increase in duration of the short-term sea-level highstands. The formation of heterozoan aeolianite deposits after 0.2 Ma is probably caused by climate cooling, related with the intensification of East Asian winter monsoon. The rapid increase in coral abundance at ∼1.7 Ma correlates well with a sharp decline in nutrient level, recorded by decreases in geochemical nutrient indexes values, declines in bryozoan and red algae (rhodolith) abundance, and decreases in the abundance of foraminifer species indicative of elevated nutrient-level. This correlation indicates that the carbonate factory turnovers were also affected by nutrient-level fluctuations, which could be linked to a paleoceanographic reorganization. These results demonstrate that together with sea-level fluctuations, also paleoceanographic changes had a significant effect on the Pliocene-Holocene tropical carbonate system.
Year of Publication: 2019
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Algae; Alkaline earth metals; Anthozoa; Asia; Atolls; Barium; Benthic taxa; Biofacies; Carbonate platforms; Carbonate sediments; Cenozoic; China; Clastic rocks; Cnidaria; Copper; Cores; Eolianite; Eustasy; Far East; Foraminifera; Holocene; Leg 184; Metals; Microfossils; Neogene; North Pacific; Northwest Pacific; Nutrients; ODP Site 1143; Ocean Drilling Program; Pacific Ocean; Paleo-oceanography; Paleotemperature; Planktonic taxa; Pleistocene; Pliocene; Productivity; Quaternary; Reef environment; Reefs; Rhodophyta; Sea-level changes; Sedimentary rocks; Sediments; Shallow-water environment; South China Sea; Tertiary; Titanium; Tropical environment; West Pacific; Xisha Islands; Xuande Atoll; Yongle Atoll
Coordinates: N161500 N170500 E1123000 E1113000
Record ID: 2019026748
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands