The stratigraphic imprint of a mid-Telychian (Llandovery, Early Silurian) glaciation on far-field shallow-water carbonates, Anticosti Island, Eastern Canada
DOI | 10.3176/earth.2014.20 |
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Aasta | 2014 |
Ajakiri | Estonian Journal of Earth Sciences |
Köide | 63 |
Number | 4 |
Leheküljed | 207-213 |
Tüüp | artikkel ajakirjas |
OpenAccess | |
Litsents | CC BY 4.0 |
Keel | inglise |
Id | 27428 |
Abstrakt
The near-field stratigraphic record of the Early Silurian glaciations is well documented in the literature. Data from far-field areas are, however, sparse. One of the best far-field stratigraphic records of these Llandovery glaciations is exposed on Anticosti Island in eastern Canada. Eight shallow-water paleotropical facies are present close to the mid-Telychian Jupiter–Chicotte formational boundary along the south-central coast of Anticosti Island. These can be grouped into three facies associations that include, from bottom to top: a carbonate facies association (FA-1), a mixed siliciclastic and carbonate facies association (FA-2) and an encrinitic facies association (FA-3). These mid- to outer-ramp strata represent deposition mostly from episodic, high-energy storm events as evidenced by their sharp bases, hummocky cross-stratification, large wave ripples, gutter casts and wave-enhanced sediment gravity flow deposits. Superimposed on a long-term regressive trend, one main transgressive–regressive (TR) sequence and four meter-scale TR cycles are evident, indicating a multi-order stratigraphic framework developed under the influence of glacio-eustasy. The Jupiter–Chicotte formational boundary, a regional discontinuity surface caused by a forced regression, corresponds to the onset of a far-field mid-Telychian glaciation.