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GEOREF RECORD

Compressional wave velocities of Keweenawan rock specimens from the Lake Superior region

H. C. Halls
Compressional wave velocities of Keweenawan rock specimens from the Lake Superior region
Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre (August 1969) 6 (4): 555-568

Abstract

In certain instances, formation velocities are sufficiently distinct to permit reliable geological identification of seismic refractors in the Lake Superior basin. Slightly metamorphosed volcanics, such as the Portage Lake series of the Michigan copper district, cannot be responsible for the 'upper refractor' velocities of 6.6-6.9 kmps observed at depths of about 10 km beneath Lake Superior. Amphibole-bearing volcanics, hitherto unreported, were sampled in the basal parts of the Keweenawan extrusive sequence, and represent a higher grade of regional metamorphism than commonly found in the Portage Lake Series. These must be seriously considered as the cause of the upper refractor.


ISSN: 0008-4077
EISSN: 1480-3313
Coden: CJESAP
Serial Title: Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre
Serial Volume: 6
Serial Issue: 4
Title: Compressional wave velocities of Keweenawan rock specimens from the Lake Superior region
Author(s): Halls, H. C.
Pages: 555-568
Published: 196908
Text Language: English
Publisher: National Research Council of Canada, Ottawa, ON, Canada
Accession Number: 1969-032953
Categories: Applied geophysics
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus., tables
N46°25'00" - N49°00'00", W92°15'00" - W84°19'60"
Country of Publication: Canada
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Bibliography and Index of North American Geology, U. S. Geological Survey, Reston, VA, United States
Update Code: 1969
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