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Boulders from Bengalia
This paper treats of the boulders in the Carboniferous Caney shale in the Ouachita Mountains of southeastern Oklahoma. Some of the boulders are composed of local rock, but others are composed of rock which does not crop out in the Ouachitas. As theories of long-distance transportation of the so-call...
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Published in: | The Journal of geology 1933-08, Vol.41 (6), p.590-621 |
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Main Author: | |
Format: | Article |
Language: | English |
Subjects: | |
Online Access: | Get full text |
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Summary: | This paper treats of the boulders in the Carboniferous Caney shale in the Ouachita Mountains of southeastern Oklahoma. Some of the boulders are composed of local rock, but others are composed of rock which does not crop out in the Ouachitas. As theories of long-distance transportation of the so-called exotics are considered inadequate, a theory is developed which explains the origin of the boulders from a local source. Evidence is cited which indicates that rocks like those which comprise the apparently foreign boulders underlie certain areas in the Oklahoma Ouachitas. A land, Bengalia, existed along the north side of the Ouachita area throughout most of Paleozoic time. Crustal warpings caused variations in the positions of land and sea areas, and erosion exposed the older rocks. During most of Mississippian time, Bengalia formed the north barrier of the filter-basin-like Ouachita trough in which the thick Stanley and Jackfork formations were deposited while only a few hundred feet of lower Caney shale were being laid down to the north and west. By later Caney time, Bengalia and Llanoria, the land to the south, were both lower, and straits connected the trough with seas to the north and west. Earth tremors, accompanying downwarping of the trough, caused submarine landslips of boulders from Bengalia into the upper Caney shale then being deposited in the northwest side of the trough. |
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ISSN: | 0022-1376 1537-5269 |
DOI: | 10.1086/624073 |