Introduction

Studies on the geology of Barbados go back to the last century with the first account of the Oceanic Formation sediments being given by Jukes-Browne & Harrison (1892). They recognized that what they called the basal Globigerina marls had been deposited at a water depth of 900 m to 1800 m while the radiolarian earths were evidence of a depth from 3600 m to 5400 m. These were unusual findings as it was thought at that time to be highly unlikely that such deep sea sediments would be found on land.

The first modern comprehensive study of the sediments grouped as the Oceanic Formation of Barbados was carried out by Alfred Senn at the time that he was also producing a map of the pre-Pleistocene rocks of the island. His publications (Senn 1940, 1947) gave field information on the outcrops of the Oceanic Formation but no detail of the foraminiferal faunas, though these were used by him for dating. Beckmann (1953) used Senn's samples for a detailed analysis of the foraminiferal fauna and this has been the basis on which the ranges of the benthics have been plotted here (Fig. 86).

The earlier studies were hampered by a lack of understanding of the nature of accretionary prisms and their relationship to subduction zones at plate boundaries. The new generation of work undertaken by R. C. Speed and his co-workers (Speed 1981,1988; Torrini 1988) has provided a sound framework in which to place rock sequences, the dating of which by the help of microfossils has, in return, been essential for the understanding of the structural complexities.