Timing of ore deposition and sill intrusion at Site 856: evidence from stratigraphy, alteration, and sediment pore-water composition

Abstract

A major objective of drilling at Site 856 was to determine the relationship, if any, between the large massive sulfide deposit there and the adjacent small, circular hill called Bent Hill. Bent Hill, like several nearby hills, is cored by a bright seismic reflector inferred to be an intrusion, probably consisting of sills similar to the three penetrated in Holes 856A and 856B. These intrusions are believed to have uplifted the hills. Stratigraphic relationships and other evidence suggest that the massive sulfide body began to form in the Pleistocene, whereas Bent Hill was uplifted in the Holocene. The deposit is therefore not genetically related to the hill. -from Authors