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Article: Development of glacial Llyn Teifi, west Wales: Evidence for lake-level fluctuations at the margins of the Irish Sea ice sheet
- Article from:
- Journal of the Geological Society
- Article date:
- March 1, 1998
- Author:
CopyrightCopyright Geological Society Publishing House Mar 1998. Provided by ProQuest LLC. (Hide copyright information)
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C. J. N. FLETCHER1 & H. J. SIDDLE2
Abstract: A thick sequence of Quaternary laminated silt and clay, sand, gravel, and diamict has recently been proven at Llandudoch (St Dogmaels), west Wales. Most of these deposits accumulated in a tributary valley of Afon (River) Teifi, that formed prior to the last glaciation. The laminated silt and clay occur up to 103 m above present sea level, and are considered to have been deposited in Llyn (Lake) Teifi-a large ice-dammed lake that developed in the Teifi valley as the Irish Sea ice sheet impinged onto the Welsh mainland during the late Devensian. Rhythmic units are interpreted as annual varves, whose composition was determined by the distance ...