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GEOREF RECORD

Global mafic magmatism at 2.45 Ga; remnants of an ancient large igneous province?

Larry M. Heaman
Global mafic magmatism at 2.45 Ga; remnants of an ancient large igneous province?
Geology (Boulder) (April 1997) 25 (4): 299-302

Abstract

Radiometric dating, including numerous high-precision U-Pb baddeleyite and zircon ages, of Paleoproterozoic flood basalts, dike swarms, and layered mafic intrusions worldwide, indicates that a substantial volume of mafic magma was produced on Earth ca. 2.45 Ga. New U-Pb data presented here for the 2473 Ma Matachewan and 2446 Ma Hearst diabase dike swarms in North America establish a critical temporal link with ancient flood-basalt volcanism in Karelia and constrain the timing of a very ancient magnetic field reversal on Earth. The potential volume, magnitude, and extent of this magmatism may approach many of the better-known Mesozoic flood-basalt provinces and represent the oldest recognized large igneous province. The initiation and subsequent proliferation of flood-basalt and associated magmatism near the Archean-Proterozoic boundary may reflect a fundamental change in heat flux at the core-mantle boundary that heralded the breakup of a Late Archean supercontinent.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 25
Serial Issue: 4
Title: Global mafic magmatism at 2.45 Ga; remnants of an ancient large igneous province?
Author(s): Heaman, Larry M.
Affiliation: University of Alberta, Department of Earth and Atmospheric Sciences, Edmonton, AB, Canada
Pages: 299-302
Published: 199704
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 35
Accession Number: 1997-041006
Categories: Igneous and metamorphic petrologyGeochronology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, sketch maps
N43°00'00" - N79°00'00", W124°00'00" - W56°00'00"
N42°00'00" - N57°00'00", W95°00'00" - W74°00'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 199715
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