Features of ice-rafted debris (IRD) at IODP Site U1312 and their palaeoenvironmental implications during the last 2.6 Myr

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doi: 10.1016/j.palaeo.2018.09.002
Author(s): Liu Jingyu; Fang Nianqiao; Wang Feng; Yang Fengfan; Ding Xuan
Author Affiliation(s): Primary:
China University of Geosciences-Beijing, School of Ocean Sciences, Beijing, China
State Oceanic Administration, China
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Vol.511, p.364-378. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 84 refs.; illus., incl. 1 table, sketch map
Summary: In this paper, we build an age model by tuning the G. ruber δ18O curve to the LR04 stack and U1308 benthic δ18O curve with the aid of the high-resolution lightness parameter L*, which mirrors the marine oxygen isotope stages, and we analyse the major palaeoenvironmental events indicated by different proxies, particularly the >250 µm fraction and the 150-250 µm fraction of ice-rafted debris (IRD) at IODP Site U1312. In general, the input of IRD at Site U1312 can be divided into two stages. In Stage 1, ranging from ∼2.6 Ma to ∼1 Ma, the number of lithic grains was small, the frequency of ice rafting events was low, and the components were diverse and mainly comprised quartz, feldspar and clasts. In Stage 2, ranging from ∼1 Ma to the present, the number and frequency of lithic grains considerably increased and were accompanied by detrital carbonate additions derived from the Hudson Strait after ∼650 ka. Regarding the IRD features in the study area, the distinctive layers are as follows. IRD did not occur until 2.52 Ma at Site U1312, implying that icebergs discharged by the Northern Hemisphere glaciers bearing lithic grains were involved in pelagic sedimentation for the first time. Interestingly, a monotonic component of debris, magnetite with some ilmenite and quartz, was observed in a single layer at approximately 1.4 Ma. The source of this component may simply be the erosion of volcanic formations in Iceland during the glacial period. Detrital carbonate played an important role in the IRD component after ∼650 ka, and the input and frequency of IRD increased dramatically, revealing glacier enhancements and the instability of the Laurentide ice sheet. The IRD characteristics at Site U1312 during MIS 22, MIS 12 and MIS 6 were different from those at other sites near the IRD belt and may be closely related to the European ice sheets. During MIS 10-8, the input of IRD was high, the dominant warm species G. ruber was too rare for the isotope test to be conducted, and the abundance of planktonic foraminifera severely declined, which may indicate that extreme conditions occurred at Site U1312 during this interval.
Year of Publication: 2018
Research Program: DSDP Deep Sea Drilling Project
IODP Integrated Ocean Drilling Program
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; Benthic taxa; C-13/C-12; Calcium carbonate; Carbon; Cenozoic; DSDP Site 610; DSDP Site 611; Debris; Deep Sea Drilling Project; Depth; Expedition 303; Expedition 306; Expeditions 303/306; Foraminifera; Glaciation; Globigerinacea; Globigerinidae; Globigerinoides; Globigerinoides ruber; Granulometry; Heinrich events; IODP Site U1308; IODP Site U1312; IODP Site U1313; IPOD; Ice rafting; Integrated Ocean Drilling Program; Isotope ratios; Isotopes; Latitude; Leg 162; Leg 94; Lower Pleistocene; Magnetite; Marine environment; Marine sediments; Mid-Atlantic Ridge; Middle Pleistocene; Neogloboquadrina; Neogloboquadrina pachyderma; North Atlantic; Northeast Atlantic; Northern Hemisphere; O-18/O-16; ODP Site 984; Ocean Drilling Program; Oxides; Oxygen; Paleo-oceanography; Paleoclimatology; Pleistocene; Quaternary; Reykjanes Ridge; Rockall Trough; Rotaliina; Ruddiman Belt; Sediments; Stable isotopes
Coordinates: N425000 N425012 W0230500 W0230515
Record ID: 2019021196
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands