A 750-kyr detrital-layer stratigraphy for the North Atlantic (IODP Sites U1302-U1303, Orphan Knoll, Labrador Sea)

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doi: 10.1016/j.epsl.2011.11.029
Author(s): Channell, J. E. T.; Hodell, D. A.; Romero, O.; Hillaire-Marcel, C.; de Vernal, A.; Stoner, J. S.; Mazaud, A.; Röhl, U.
Author Affiliation(s): Primary:
University of Florida, Department of Geological Sciences, Gainesville, FL, United States
University of Cambridge, United Kingdom
Universidad de Granada, Spain
Université du Québec a Montreal, Canada
Oregon State University, United States
Laboratoire des Sciences du Climat et de l'Environnement, France
University of Bremen, Germany
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, Vol.317-318, p.218-230. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 71 refs.; illus., incl. 1 table, sketch map
Summary: Integrated Ocean Drilling Program (IODP) Sites U1302-U1303, drilled on the SE flank of Orphan Knoll (Labrador Sea), preserve a record of detrital layers and other proxies of hydrographic change that extend the record of ice-sheet/ocean interactions through most of the Brunhes Chron. The age model is built by tandem matching of relative paleointensity (RPI) and oxygen isotope data (δ18O) from Neogloboquadrina pachyderma (sin.) to reference records, indicating a mean Brunhes sedimentation rate of 14 cm/kyr. Sedimentation back to marine isotope stage (MIS) 18 is characterized by detrital layers that are detected by higher than background gamma-ray attenuation (GRA) density, peaks in X-ray fluorescence (XRF) indicators for detrital carbonate (Ca/Sr) and detrital silicate (Si/Sr), and an ice-rafted debris (IRD) proxy (wt.% >106µm). The age model enables correlation of Site U1302/03 to IODP Site U1308 in the heart of the central Atlantic IRD belt where an age model and a similar set of detrital-layer proxies have already been derived. Ages of Heinrich (H) layers H1, H2, H4, H5 and H6 are within ∼2 kyr at the two sites (H0, H3 and H5a are not observed at Site U1308), and agree with previous work at Orphan Knoll within ∼3 kyr. At Site U1308, Brunhes detrital layers are restricted to peak glacials and glacial terminations back to marine isotope stage (MIS) 16 and have near-synchronous analogs at Site U1302/03. Detrital layers at Site U1302/03 are distributed throughout the record in both glacial and most interglacial stages. We distinguish Heinrich-like layers associated with IRD from detrital layers marked by multiple detrital-layer proxies (including Ca/Sr) but usually not associated with IRD, that may be attributed to lofted sediment derived from drainage and debris-flow events funneled down the nearby Northwest Atlantic Mid-Ocean Channel (NAMOC). The prominent detrital layers at Sites U1302/03 and U1308 can be correlated to millennial scale features in the Chinese speleothem (monsoon) record over the last 400 kyr, implying a link between monsoon precipitation and Laurentide Ice Sheet (LIS) instability. The detrital-layer stratigraphy at Site U1302/03 provides a long record of LIS dynamics against which other terrestrial and marine records can be compared. Abstract Copyright (2012) Elsevier, B.V.
Year of Publication: 2012
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Alkaline earth metals; Asia; Atlantic Ocean; Brunhes Chron; Calcium; Cenozoic; China; East Asian monsoon; Expedition 303; Expeditions 303/306; Far East; Foraminifera; Glacial environment; IODP Site U1302; IODP Site U1303; IODP Site U1308; Ice rafting; Integrated Ocean Drilling Program; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; Labrador Sea; Metals; Microfossils; Mid-Atlantic Ridge; North Atlantic; Northeast Atlantic; Northwest Atlantic; O-18/O-16; Orphan Knoll; Oxygen; Paleoclimatology; Protista; Quaternary; Sedimentation rates; Si/Sr; Silicon; Speleothems; Sr/Ca; Stable isotopes; Strontium; Upper Quaternary
Coordinates: N495300 N495300 W0241400 W0241400
N501200 N501200 W0454100 W0454100
N501000 N501000 W0453800 W0453800
Record ID: 2012051980
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands