Complexity in Matuyama-Brunhes polarity transitions from North Atlantic IODP/ODP deep-sea sites

Online Access: Get full text
doi: 10.1016/j.epsl.2017.03.019
Author(s): Channell, J. E. T.
Author Affiliation(s): Primary:
University of Florida, Department of Geological Sciences, Gainesville, FL, United States
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, Vol.467, p.43-56. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. Includes appendix. 50 refs.; illus., incl. sketch map
Summary: Integrated Ocean Drilling Program (IODP) Expedition 303 to the North Atlantic provided 16 records of the Matuyama-Brunhes polarity transition (MBT), based on u-channel and discrete samples, from holes drilled at three sites (Sites U1304, U1305 and U1306) that have mean Brunhes sedimentation rates of 16-18 cm/kyr. The MBT occurs during the transition from marine isotope stage (MIS) 19c to MIS 18e, with mid-point at ∼773 ka, and a transition duration of ∼8 kyr. Combining the new MBT records, including one new record for the top Jaramillo, with previously published North Atlantic MBT records (ODP Sites 983, 984 and 1063) yields a total of more than 20 high-sedimentation-rate polarity transition records. The MBT yields a repetitive pattern of transitional field states as virtual geomagnetic poles (VGPs) move from high southern latitudes to loop over the Pacific, group in NE Asia, and transit into the mid-latitude South Atlantic before reaching high latitudes in the Northern Hemisphere. The VGPs for the top Jaramillo transition feature a loop over the Pacific, then a NE Asia group before transit over the Indian Ocean to high southerly latitudes. The North Atlantic MBT records described here contrast with longitudinally-constrained VGP paths for the MBT, indicating that relatively low sedimentation rate (∼4 cm/kyr) records of the MBT are heavily smoothed by the remanence acquisition process and do not adequately represent the MBT field. The VGPs at the MBT and top Jaramillo, as measured in the North Atlantic, have similarities with excursion (Iceland Basin) VGP paths, and were apparently guided by maxima in downward vertical flux similar to those seen in the modern non-dipole (ND) field, implying longevity in ND features through time.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; Bermuda Rise; Brunhes Chron; Cenozoic; East Pacific; Expedition 303; Expeditions 303/306; IODP Site U1304; IODP Site U1305; IODP Site U1306; Integrated Ocean Drilling Program; Jaramillo Subchron; Leg 162; Leg 172; Lower Pleistocene; Magnetic declination; Magnetic inclination; Magnetic susceptibility; Matuyama Chron; North Atlantic; Northeast Atlantic; Northwest Atlantic; ODP Site 1063; ODP Site 983; ODP Site 984; Ocean Drilling Program; Pacific Ocean; Paleomagnetism; Pleistocene; Quaternary; Reykjanes Ridge; Sedimentation rates; South Atlantic; Upper Quaternary; Virtual geomagnetic poles
Coordinates: N530300 N530300 W0333200 W0333200
N572800 N572900 W0483200 W0483200
N581400 N581400 W0453800 W0453900
N602412 N602412 W0233826 W0233826
N612532 N612532 W0240457 W0240457
N334111 N334111 W0573654 W0573654
Record ID: 2017045992
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands