Triassic plutonism in southern California: Southward younging of arc initiation along a truncated continental margin
Earliest Cordilleran magmatism in the southwestern United States is recorded by a belt of Triassic plutons that intrude Proterozoic basement of the Mojave crustal province and its cratonal/miogeoclinal cover.' The belt extends from the western Mojave Desert through the Transverse Ranges to the Colorado River trough. Triassic plutons are predominantly alkali-calcic, Fe- and Sr-enriched quartz monzodiorites and monzonites. The northern part of the belt is composed of two older plutonic suites (241-231 Ma) which are high K to shoshonitic; the southern part of the belt is a younger (218-213 Ma), sodic-alkalic suite. The plutonic record in southern California suggests a short-lived, southward younging continental margin arc setting for emplacement of Triassic plutons, superimposed on a continental margin modified by sinistral transform faulting Triassic plutonism in this region was followed by a magmatic lull prior to the onset of voluminous Middle to Late Jurassic Cordilleran arc magmatism.
Citation Information
Publication Year | 1997 |
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Title | Triassic plutonism in southern California: Southward younging of arc initiation along a truncated continental margin |
Authors | A. P. Barth, R. M. Tosdal, J. L. Wooden, K. A. Howard |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Tectonics |
Index ID | 70019905 |
Record Source | USGS Publications Warehouse |