| Abstract: | We evaluated 193 K-Ar ages (10 newly determined) of basaltic and differentiated rocks of the Serra Geral (Parana??) flood-basalt province for indications of magmatism occurring systematically with progressive rifting and complete separation ( ???130-105 Ma) of South America from Africa. The K-Ar ages represent basalt emplacement between 35?? and 19??S covering about 1,200,000 km2. We note that volcanism appears ubiquitous across the province between about 140 and 115 Ma, and that there are no significant age differences within that relate directly to progressive south-to-north tectonism. On the other hand, the oldest samples, about 140-160 Ma, are among those nearest the Brazil coastline (rift margin), perhaps suggesting migration of activity away from the rift with time. Studies of other flood-basalt provinces now indicate short (<3 m.y.) eruption periods, thereby pointing to the need for re-examination of Serra Geral ages by 40Ar-39Ar incremental heating techniques. ?? 1989. |
| Genre: | Article |
| ProdID: | 70015336 |
| Citation Author: | Fodor, R. V.; McKee, E. H.; Roisenberg, A. |
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| Citation End Page: | 349 |
| Citation Issue: | 4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of South American Earth Sciences |
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| Citation Number Of Pages: | 7 |
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| Citation Search Results Text: | Age distribution of Serra Geral (Parana??) flood basalts, southern Brazil; 1989; Article; Journal; Journal of South American Earth Sciences; Fodor, R. V.; McKee, E. H.; Roisenberg, A. |
| Citation Start Page: | 343 |
| Citation Volume: | 2 |
| Citation Year: | 1989 |
| Type: | citation/reference |
| Text: | Age distribution of Serra Geral (Parana??) flood basalts, southern Brazil; 1989; Article; Journal; Journal of South American Earth Sciences; Fodor, R. V.; McKee, E. H.; Roisenberg, A. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sun, 1 Jan 1989 00:00 -0600 |
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