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Tropical shoreline ice in the late Cambrian: Implications for earth's climate between the Cambrian Explosion and the Great Ordovician Biodiversification Event

GSA Today

By:
, , ,
DOI: 10.1130/GSATG84A.1

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Abstract

Middle to late Cambrian time (ca. 513 to 488 Ma) is characterized by an unstable plateau in biodiversity, when depauperate shelf faunas suffered repeated extinctions. This poorly understood interval separates the Cambrian Explosion from the Great Ordovician Biodiversification Event and is generally regarded as a time of sustained greenhouse conditions. We present evidence that suggests a drastically different climate during this enigmatic interval: Features indicative of meteoric ice are well preserved in late Cambrian equatorial beach deposits that correspond to one of the shelf extinction events. Thus, the middle to late Cambrian Earth was at least episodically cold and might best be considered a muted analogue to the environmental extremes that characterized the Proterozoic, even though cooling in the two periods may have occurred in response to different triggers. Such later Cambrian conditions may have significantly impacted evolution preceding the Ordovician radiation.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Tropical shoreline ice in the late Cambrian: Implications for earth's climate between the Cambrian Explosion and the Great Ordovician Biodiversification Event
Series title:
GSA Today
DOI:
10.1130/GSATG84A.1
Volume
20
Issue:
11
Year Published:
2010
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
GSA Today
First page:
4
Last page:
10
Number of Pages:
7