The nature of the Clay Pebble-beds and associated rocks of South-West Ecuador

Resumen

Summary Previous literature on the Clay Pebble-bed of Ancon is reviewed and earlier theories of its origin by thrusting, sliding under gravity and sub-aerial mudflows are discussed in detail. Evidence is produced to show that the rock must be a sedimentary deposit and that none of the previous theories can be accepted. It is re-interpreted as having been deposited by submarine sliding. Sedimentary structures from the overlying Socorro Beds are also discussed and it is concluded that these are turbidity current deposits. Brief mention is made of similar rocks in north-western Peru and in Trinidad.