Paleomagnetic and 40Ar/39Ar results from mafic dikes and sills in northwestern Wyoming and western Montana yield similar virtual geomagnetic poles and isotopic dates. In combination with paleomagnetic and geochronologic data from elsewhere in the western Cordillera, these data provide evidence for a regional mafic magnetic event at 780 to 770 Ma that affected a large area of western North America.
Citation Information
Publication Year | 1997 |
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Title | Paleomagnetic and 40Ar/39Ar geochronologic data from late Proterozoic mafic dikes and sills, Montana and Wyoming |
DOI | 10.3133/pp1580 |
Authors | Stephen S. Harlan, John William Geissman, Lawrence W. Snee |
Publication Type | Report |
Publication Subtype | USGS Numbered Series |
Series Title | Professional Paper |
Series Number | 1580 |
Index ID | pp1580 |
Record Source | USGS Publications Warehouse |