Extracting a detailed magnetostratigraphy from weakly magnetized, Oligocene to early Miocene sediment drifts recovered at IODP site U1406 (Newfoundland margin, Northwest Atlantic Ocean)

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doi: 10.1002/2017GC007185
Author(s): van Peer, Tim E.; Xuan, Chuang; Lippert, Peter C.; Liebrand, Diederik; Agnini, Claudia; Wilson, Paul A.
Author Affiliation(s): Primary:
University of Southampton, National Oceanography Centre Southampton, Southampton, United Kingdom
Other:
University of Utah, United States
University of Padova, Italy
Volume Title: Geochemistry, Geophysics, Geosystems - G<sup>3</sup>
Source: Geochemistry, Geophysics, Geosystems - G>3`, 18(11), p.3910-3928. Publisher: American Geophysical Union and The Geochemical Society, United States. ISSN: 1525-2027
Note: In English. 56 refs.; illus., incl. 2 tables, sketch map
Summary: Fine-grained magnetic particles in deep-sea sediments often statistically align with the ambient magnetic field during (and shortly after) deposition and can therefore record geomagnetic reversals. Correlation of these reversals to a geomagnetic polarity time scale is an important geochronological tool that facilitates precise stratigraphic correlation and dating of geological records globally. Sediments often carry a remanence strong enough for confident identification of polarity reversals, but in some cases a low signal-to-noise ratio prevents the construction of a reliable and robust magnetostratigraphy. Here we implement a data-filtering protocol, which can be integrated with the UPmag software package, to automatically reduce the maximum angular deviation and statistically mask noisy data and outliers deemed unsuitable for magnetostratigraphic interpretation. This protocol thus extracts a clearer signal from weakly magnetized sediments recovered at Integrated Ocean Drilling Program (IODP) Expedition 342 Site U1406 (Newfoundland margin, northwest Atlantic Ocean). The resulting magnetostratigraphy, in combination with shipboard and shore-based biostratigraphy, provides an age model for the study interval from IODP Site U1406 between Chrons C6Ar and C9n (∼21-27 Ma). We identify rarely observed geomagnetic directional changes within Chrons C6Br, C7r, and C7Ar, and perhaps within Subchron C8n.1n. Our magnetostratigraphy dates three intervals of unusual stratigraphic behavior within the sediment drifts at IODP Site U1406 on the Newfoundland margin. These lithostratigraphic changes are broadly concurrent with the coldest climatic phases of the middle Oligocene to early Miocene and we hypothesize that they reflect changes in bottom water circulation. Abstract Copyright (2017), . The Authors.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Canada; Ceara Rise; Cenozoic; Clastic sediments; Continental margin; Drift; East Pacific; Eastern Canada; Equatorial Atlantic; Equatorial Pacific; Expedition 320; Expedition 342; Expeditions 320/321; IODP Site U1334; IODP Site U1406; Integrated Ocean Drilling Program; Leg 154; Leg 177; Leg 199; Leg 208; Lower Miocene; Magnetic properties; Magnetization; Magnetostratigraphy; Marine sediments; Miocene; Neogene; Newfoundland; Newfoundland and Labrador; North Atlantic; North Pacific; Northeast Pacific; Northwest Atlantic; ODP Site 1090; ODP Site 1218; ODP Site 1264; ODP Site 1265; ODP Site 1266; ODP Site 929; Ocean Drilling Program; Ocean floors; Oligocene; Pacific Ocean; Paleogene; Paleomagnetism; Sediments; South Atlantic; Stratigraphy; Tertiary; Walvis Ridge
Coordinates: N402059 N402100 W0513859 W0513900
Record ID: 2018022357
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom, Reference includes data supplied by, and/or abstract, Copyright, American Geophysical Union