A re-interpretation of the origin of sands and gravels around Banc-y-warren, near Cardigan, west Wales

Autor: D. G. Helm, B. Roberts
Rok vydání: 2007
Předmět:
Zdroj: Geological Journal. 10:131-146
ISSN: 1099-1034
0072-1050
DOI: 10.1002/gj.3350100203
Popis: The sands and gravels form part of a once more continuous succession comprising parts of three delta lobes which advanced into a deepening pro-glacial lake. Normal delta construction was accompanied by sporadic rapid mass movement of coarse sediment. This generated turbidity currents which gouged and filled remarkable channels. The deposits are cut by a very large number of normal faults which bear a strike relationship to the bedding showing they were produced by down-dip extension of the beds as a result of slope instability. The consistently southwesterly current directions, deduced from various sedimentary structures, and the constant strike orientation of faults together show that the mounds cannot be ice-contact features as was previously widely believed. The external form of the deposits is related more to subsequent erosion than to their original mode of formation.
Databáze: OpenAIRE
Externí odkaz: