Strontium isotope ratios of planktonic foraminifera from sediment samples acroos the K/T boundary

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Hauptverfasser: Martin, Ellen E, MacDougall, J Douglas
Format: Dataset Open Access
Sprache:en
Veröffentlicht: PANGAEA 1991
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_version_ 1867167661286227968
author Martin, Ellen E
MacDougall, J Douglas
author_facet Martin, Ellen E
MacDougall, J Douglas
collection Datos científicos de ciencias marinas y ambientales
contents Seawater 87Sr/86Sr values increase abruptly by 28 * 10**-6 across the Cretaceous/Tertiary boundary (KTB). This small, but rapid shift is superimposed on the larger scale structure of the seawater Sr isotope curve. The time scale of radiogenic Sr addition appears to be too rapid to reconcile with sources associated with volcanism, and we show that the amount of Sr required to produce even this small increase is too large to be derived from: (1) a KT bolide of the size constrained by the Ir anomaly, (2) continental crust ejecta from the impact of such a bolide, (3) soot from global wildfires initiated by an impact, or (4) any combination of these sources. The probable source of the radiogenic Sr is enhanced continental weathering, but the high rate of increase appears to rule out processes such as sea level regression, glaciation or tectonism. A plausible mechanism for rapid addition of radiogenic Sr to the oceans is enhanced weathering associated with globally distributed acid rain (pH c. 1) which is a proposed by-product of a bolide impact (Prinn and Fegley, 1987, doi:10.1016/0012-821X(87)90046-X).
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_712154
institution PANGAEA
language en
publishDate 1991
publisher PANGAEA
record_format pangaea
spellingShingle Strontium isotope ratios of planktonic foraminifera from sediment samples acroos the K/T boundary
Martin, Ellen E
MacDougall, J Douglas
39-356; 43-384; 74-528; 86-577A; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg39; Leg43; Leg74; Leg86; North Atlantic/RIDGE; North Pacific Ocean; South Atlantic/PLATEAU; South Atlantic/RIDGE
Seawater 87Sr/86Sr values increase abruptly by 28 * 10**-6 across the Cretaceous/Tertiary boundary (KTB). This small, but rapid shift is superimposed on the larger scale structure of the seawater Sr isotope curve. The time scale of radiogenic Sr addition appears to be too rapid to reconcile with sources associated with volcanism, and we show that the amount of Sr required to produce even this small increase is too large to be derived from: (1) a KT bolide of the size constrained by the Ir anomaly, (2) continental crust ejecta from the impact of such a bolide, (3) soot from global wildfires initiated by an impact, or (4) any combination of these sources. The probable source of the radiogenic Sr is enhanced continental weathering, but the high rate of increase appears to rule out processes such as sea level regression, glaciation or tectonism. A plausible mechanism for rapid addition of radiogenic Sr to the oceans is enhanced weathering associated with globally distributed acid rain (pH c. 1) which is a proposed by-product of a bolide impact (Prinn and Fegley, 1987, doi:10.1016/0012-821X(87)90046-X).
title Strontium isotope ratios of planktonic foraminifera from sediment samples acroos the K/T boundary
topic 39-356; 43-384; 74-528; 86-577A; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg39; Leg43; Leg74; Leg86; North Atlantic/RIDGE; North Pacific Ocean; South Atlantic/PLATEAU; South Atlantic/RIDGE
url https://doi.org/10.1594/PANGAEA.712154