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Upper Llandoverian Grogal Sandstones and Aberystwyth Grits in the New Quay area, Central Wales: A possible upwards transition from contourites to turbidites

✍ Scribed by J. M. Anketell; J. P. B. Lovell


Publisher
John Wiley and Sons
Year
2007
Tongue
English
Weight
650 KB
Volume
11
Category
Article
ISSN
0072-1050

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✦ Synopsis


Abstract

The lower boundaries of the Aberystwyth Grits Formation and the underlying Grogal Sandstones Formation (new name) in the New Quay area are defined. The Grogal Sandstones Formation is described, and interpreted as a contourite deposit on a continental rise; we believe these are the first rocks in the British Isles to be identified as contourites. The transition within a few tens of metres from Grogal Sandstones Formation contourite facies, displaying bimodal current directions, to Aberystwyth Grits Formation turbidite facies, with unimodal current directions, can be seen well in two places on the coast southwest of New Quay. Regionally, an upward transition from finegrained contourites to turbidites of varying facies can be recognised. Our results are compatible with Ziegler's interpretation of early Upper Llandoverian palaeogeography.