Skip to Main Content
GEOREF RECORD

Calibrating the Late Ordovician glaciation and mass extinction by the eccentricity cycles of Earth's orbit

Owen E. Sutcliffe, Julian A. Dowdeswell, Robert J. Whittington, Johannes N. Theron and Jonathan Craig
Calibrating the Late Ordovician glaciation and mass extinction by the eccentricity cycles of Earth's orbit
Geology (Boulder) (November 2000) 28 (11): 967-970

Abstract

A process-based sedimentological analysis of Upper Ordovician glacial-marine rocks in Africa suggests that full glaciation of the continental shelf started in the late extraordinarius Zone of the Hirnantian. Two cycles of ice-sheet growth are represented during full glaciation. Initial terrestrial ice-sheet growth in the early extraordinarius Zone influenced the first event of the Late Ordovician mass extinction. Retreat of the ice sheet from the shelf ended by the persculptus Zone, when the second event of the Late Ordovician mass extinction began. Eccentricity controlled ice-sheet growth is assumed (periodicity 0.1 m.y.). Hence, two cycles of full glaciation lasted 0.2 m.y. The duration of the extraordinarius Zone is estimated as 0.5 m.y. Therefore, the minimum duration of the first extinction event was 0.3 m.y.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 28
Serial Issue: 11
Title: Calibrating the Late Ordovician glaciation and mass extinction by the eccentricity cycles of Earth's orbit
Affiliation: University of Wales, Centre for Glaciology, Aberystwyth, United Kingdom
Pages: 967-970
Published: 200011
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 37
Accession Number: 2000-075399
Categories: Stratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: block diag., strat. cols., sketch maps
N19°00'00" - N37°00'00", W09°00'00" - E12°00'00"
N19°30'00" - N33°00'00", E09°30'00" - E25°00'00"
N27°40'00" - N36°00'00", W13°15'00" - W01°00'00"
S35°00'00" - S22°00'00", E16°00'00" - E33°00'00"
Secondary Affiliation: University of Bristol, GBR, United KingdomUniversity of Stellenbosch, ZAF, South AfricaLASMO, GBR, United Kingdom
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 200024
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal