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Research output: Contribution to specialist publication › Article
Research output: Contribution to specialist publication › Article
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TY - GEN
T1 - A geomagnetic polarity timescale for the Carboniferous
AU - Hounslow, Mark W
N1 - © 2021 The Author(s). Published by The Geological Society of London. All rights reserved.
PY - 2021/3/9
Y1 - 2021/3/9
N2 - The geomagnetic polarity pattern for the Carboniferous is incompletely known, but with the best resolved parts in the Serpukhovian and Bashkirian. Hence, data from both igneous and sedimentary units are also used in an additional polarity bias evaluation. In the Tournaisian to mid Visean interval polarity is mainly derived from palaeopole-type palaeomagnetic studies, allowing identification of polarity bias chrons. Seven polarity bias chrons exist in the Mississippian (MI1nB to MI4nB) with an additional 33 conventional magnetochrons and submagnetochrons (MI4r to MI9r). The Moscovian and Gzhelian polarity is best resolved in magnetostratigraphic studies from the Donets Basin and the southern Urals. Dispute about the reliability of these data is ill-founded, since an assessment of supporting data from palaeopole-type studies suggests that these datasets currently provide the best magnetic polarity data through the Pennsylvanian. Polarity bias assessment indicates a normal polarity bias zone in the Kasimovian. In the Pennsylvanian there are 27 conventional magnetochrons and submagnetochrons (PE1n to CI1r) and one normal polarity bias chron (PE8nB). The Kiaman Superchron begins in the mid Bashkirian, with clear data indicating brief normal polarity submagnetochrons within the Superchron. The magnetochron timescale is calibrated using 31 U-Pb zircon dates and a quantitative Bayesian-based age-scaling procedure.
AB - The geomagnetic polarity pattern for the Carboniferous is incompletely known, but with the best resolved parts in the Serpukhovian and Bashkirian. Hence, data from both igneous and sedimentary units are also used in an additional polarity bias evaluation. In the Tournaisian to mid Visean interval polarity is mainly derived from palaeopole-type palaeomagnetic studies, allowing identification of polarity bias chrons. Seven polarity bias chrons exist in the Mississippian (MI1nB to MI4nB) with an additional 33 conventional magnetochrons and submagnetochrons (MI4r to MI9r). The Moscovian and Gzhelian polarity is best resolved in magnetostratigraphic studies from the Donets Basin and the southern Urals. Dispute about the reliability of these data is ill-founded, since an assessment of supporting data from palaeopole-type studies suggests that these datasets currently provide the best magnetic polarity data through the Pennsylvanian. Polarity bias assessment indicates a normal polarity bias zone in the Kasimovian. In the Pennsylvanian there are 27 conventional magnetochrons and submagnetochrons (PE1n to CI1r) and one normal polarity bias chron (PE8nB). The Kiaman Superchron begins in the mid Bashkirian, with clear data indicating brief normal polarity submagnetochrons within the Superchron. The magnetochron timescale is calibrated using 31 U-Pb zircon dates and a quantitative Bayesian-based age-scaling procedure.
U2 - 10.1144/SP512-2020-102
DO - 10.1144/SP512-2020-102
M3 - Article
VL - 512
JO - Geological Society Special Publications
JF - Geological Society Special Publications
SN - 0305-8719
PB - Geological Society of London
ER -