Silurian K-bentonites in North America and northwestern Europe: A trans-Atlantic comparison
- Ohio State Univ., Columbus, OH (United States). Dept. of Geological Sciences
- Illinois State Geological Survey, Champaign, IL (United States)
- Univ. of Cincinnati, OH (United States). Dept. of Geology
Little published information is available about Silurian K-bentonites in North America, but a few occurrences of such beds are known from the Great lakes region and Nova Scotia. Only a small number of beds are recorded from the former area, but the Nova Scotia occurrences include about 20 beds of Llandoverian age, the most extensive sequence of Silurian K-bentonites known in North America. In contrast, more than 150 K-bentonites occur in the Silurian successions in Baltoscandia and the British Isles. Virtually all beds in North America are of Llandoverian age. There are numerous beds of that age also in Norway, Denmark (Bornholm), the British Isles, and the Swedish mainland but the successions in Estonia, Gotland, and the British Isles also include many K-bentonites of Wenlockian and Ludlovian age. Apparently, no Pridolian beds are known in North America and northwestern Europe. Many graptolite-dated collections from more than 20 sections in Baltoscandia and from many sections in the British Isles suggest that several single beds, or complexes of beds, can be traced regionally and hence have event-stratigraphic potential. The relatively few beds known from North America all occur in biostratigraphic intervals containing K-bentonites in Europe, and it is possible that some of these beds may have a common source. The much larger number of beds in northwestern Europe compared with North America may be taken as an indication that the source area of the European K-bentonites was closer to Baltica than to Laurentia, and probably located somewhere in the northern Iapetus.
- OSTI ID:
- 5025602
- Report Number(s):
- CONF-9303210-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:3; Conference: 27. annual Geological Society of America (GSA) North-Central Section meeting, Rolla, MO (United States), 29-30 Mar 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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