Ivory Coast microtektite strewn field: description and relation to the Jaramillo geomagnetic event

TY - JOUR

T1 - Ivory Coast microtektite strewn field

T2 - description and relation to the Jaramillo geomagnetic event

AU - Glass, B. P.

AU - Kent, Dennis V.

AU - Schneider, David A.

AU - Tauxe, L.

N1 - Funding Information: Ocean Drilling Program core samples were supplied with the assistance of the International Ocean Drilling Program under the guidance of William F. Ruddiman. We thank John W. King and Richard A. Muller for critical reviews of the paper. Lamont-Doherty Geological Observatory (L-DGO) core samples were provided by Rusty Lotti of the L-DGO Core Laboratory. This work was partly funded by NSF grants OCE83-14522 (BPG), OCE88-17773 (DVK, DAS) and OCE89-17252 (LT). This is Lamont-Doherty contribution 4811.

PY - 1991/10

Y1 - 1991/10

N2 - During the present study the Ivory Coast microtektite layer was found in cores from five equatorial Atlantic sites, bringing the total number of Ivory Coast microtektite-bearing cores to eleven. The strewn field appears to be restricted to between 9°N and 12°S latitude. There is a general increase in the concentration of microtektites towards the Bosumtwi crater, which is generally thought to be the source of the Ivory Coast tektites. The relationship between the onset of the Jaramillo subchron and the Ivory Coast microtektite layer has been investigated in six cores. A plot of the difference in depth between the base of the Jaramillo subchron and the microtektite layer versus sediment accumulation rate was used to determine the average post-depositional remanent magnetization (PDRM) acquisition depth and the age difference between the onset of the Jaramillo subchron and the deposition of the microtektites. Assuming that the PDRM acquisition depth does not vary with sediment accumulation rate, we find that the average PDRM acquisition depth is 7 cm and that the microtektites were deposited approximately 8 ky after the onset of the Jaramillo subchron. This indicates that the impact responsible for the Ivory Coast tektites and microtektites could not be causally related to the geomagnetic reversal at the base of the Jaramillo subchron.

AB - During the present study the Ivory Coast microtektite layer was found in cores from five equatorial Atlantic sites, bringing the total number of Ivory Coast microtektite-bearing cores to eleven. The strewn field appears to be restricted to between 9°N and 12°S latitude. There is a general increase in the concentration of microtektites towards the Bosumtwi crater, which is generally thought to be the source of the Ivory Coast tektites. The relationship between the onset of the Jaramillo subchron and the Ivory Coast microtektite layer has been investigated in six cores. A plot of the difference in depth between the base of the Jaramillo subchron and the microtektite layer versus sediment accumulation rate was used to determine the average post-depositional remanent magnetization (PDRM) acquisition depth and the age difference between the onset of the Jaramillo subchron and the deposition of the microtektites. Assuming that the PDRM acquisition depth does not vary with sediment accumulation rate, we find that the average PDRM acquisition depth is 7 cm and that the microtektites were deposited approximately 8 ky after the onset of the Jaramillo subchron. This indicates that the impact responsible for the Ivory Coast tektites and microtektites could not be causally related to the geomagnetic reversal at the base of the Jaramillo subchron.

UR - https://www.scopus.com/pages/publications/0026269601

UR - https://www.scopus.com/pages/publications/0026269601#tab=citedBy

U2 - 10.1016/0012-821X(91)90054-L

DO - 10.1016/0012-821X(91)90054-L

M3 - Article

SN - 0012-821X

VL - 107

SP - 182

EP - 196

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

IS - 1

ER -