气候变化领域集成服务门户(CCPortal): Depositional environments beneath the shelf-edge slopes of the Great Barrier Reef; inferred from foraminiferal assemblages: IODP Expedition 325

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DOI	10.1016/j.palaeo.2018.10.033
	Depositional environments beneath the shelf-edge slopes of the Great Barrier Reef; inferred from foraminiferal assemblages: IODP Expedition 325
	Yagioka N.; Nakada C.; Fujita K.; Kan H.; Yokoyama Y.; Webster J.M.
发表日期	2019
ISSN	0031-0182
起始页码	386
结束页码	397
卷号	514
英文摘要	To understand sea-level changes since the Last Glacial Maximum (LGM) and their effects on coral reef systems, the shelf-edge slopes of the Great Barrier Reef (GBR) were cored during the Integrated Ocean Drilling Program (IODP) Expedition 325. Recovered unconsolidated sediments beneath the submerged shelf edge reefs contain abundant foraminiferal tests, which record changes in depositional environments and paleo-water depths. A total of 177 sediment samples were collected from 17 holes along three transects located within two geographical areas (Noggins Pass and Hydrographers Passage), and were analyzed to determine stratigraphic changes in foraminiferal assemblages (2–0.5 mm size fraction). Results show that four foraminiferal assemblages (A, B, C and D) are delineated by multivariate analyses (Q-mode cluster analysis and non-metric multidimensional scaling: NMDS), and these assemblages correspond to a back-reef to reef margin zone (0–10 m deep; Assemblage A), an upper photic zone (10–30 m deep) associated with hard substrates (Assemblage B), an intermediate to lower photic zone (30–90 m deep) characterized by soft substrates (Assemblage C), and a lower photic zone (90–130 m deep) only found in modern shelf slopes (Assemblage D). Gradual shifts in these four foraminiferal assemblages superimposed on a two-dimensional NMDS ordination mainly reflect water-depth gradients and the relative dominance of two substrate types (hard and soft substrates). Pre-LGM (older than Marine Isotope Stage 3: ≥MIS3) sediments along transects at Hydrographers Passage were deposited at intermediate to lower photic zones. In contrast, relatively shallow-water sequences found in ≥MIS3 deposits at Noggins Pass likely owe their origin to either turbidite and/or land slide processes. The lack of Assemblage D in ≥MIS3 deposits from all transects could be related to lowering temperature and/or increasing terrestrial influences (i.e. more light attenuation). Shallowing upward sequences found in LGM (MIS 2) deposits at Hydrographers Passage are likely related to stepwise sea-level falls to the full extent of the LGM. These foraminifer-based paleoenvironmental interpretations suggest that the GBR shelf edge slopes have changed their depositional environments continuously in response to sea-level fluctuations during the last glacial cycle. © 2018 Elsevier B.V.
英文关键词	Last Glacial Maximum; Marine Isotope Stage 3; Multivariate analysis; Sea-level change
语种	英语
scopus关键词	biostratigraphy; continental slope; coral reef; depositional environment; foraminifera; fossil assemblage; geographical region; Last Glacial; Last Glacial Maximum; marine isotope stage; marine sediment; multivariate analysis; Ocean Drilling Program; paleoenvironment; sea level change; shelf break; Australia; Coral Sea; Great Barrier Reef; Queensland; Anthozoa; Foraminifera
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151144
作者单位	Physics and Earth Sciences Course, Graduate School of Engineering and Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan; Department of Physics and Earth Sciences, Faculty of Science, Tropical Biosphere Research Center, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan; Graduate School of Integrated Sciences for Global Society, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan; Atmosphere and Ocean Research Institute, Department of Earth and Planetary Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8564, Japan; Geocoastal Research Group, School of Geosciences, The University of SydneyNSW 2006, Australia
推荐引用方式 GB/T 7714	Yagioka N.,Nakada C.,Fujita K.,et al. Depositional environments beneath the shelf-edge slopes of the Great Barrier Reef; inferred from foraminiferal assemblages: IODP Expedition 325[J],2019,514.
APA	Yagioka N.,Nakada C.,Fujita K.,Kan H.,Yokoyama Y.,&Webster J.M..(2019).Depositional environments beneath the shelf-edge slopes of the Great Barrier Reef; inferred from foraminiferal assemblages: IODP Expedition 325.Palaeogeography, Palaeoclimatology, Palaeoecology,514.
MLA	Yagioka N.,et al."Depositional environments beneath the shelf-edge slopes of the Great Barrier Reef; inferred from foraminiferal assemblages: IODP Expedition 325".Palaeogeography, Palaeoclimatology, Palaeoecology 514(2019).