72 SEDIMENTARY ROCKS/Deep Ocean Pelagic Oozes Figure Sources and pathways for pelagic sedimentation in the oceans Reproduced with permission from Hay WW (1974) Studies in Paleoceanography Tulsa, Oklahoma: Society of Economic Paleontologists and Mineralogists palaeoceanographic studies The Swedish Deep-Sea Expedition (1947–49) provided another fundamental advance in the study of deep-sea sediments This expedition on the Albatross deployed a new kind of coring device, called a piston corer, which was developed by Boă rje Kullenberg, a marine geologist working in Gothenburg, Sweden An innovative modification of the traditional gravity corer allowed the coring tube to fall past a stationary piston at the end of the wire, so that water was expelled from the falling tube above the piston and sediment was admitted from below This allowed retrieval of much longer (10 m or more) and much less disturbed sediment cores Acquisition of such long piston cores made possible the study of Pleistocene ocean history The era of modern deep-sea sediment sampling had begun Piston coring remains the main contemporary method of sampling the deep-sea sedimentary record, although sizing-up of the coring apparatus has led to development of giant piston corers, now capable of obtaining sediment cores up to 60 m in length A giant piston core providing a continuous 54-m-long sediment record covering million years of sedimentation was recovered from the Indian Ocean by the French ship Marion Dufresne in 1990; this is one of the longest piston cores ever recovered The advent of the Deep Sea Drilling Project (DSDP) in 1968 took deep-sea sediment sampling technology further This programme, using the dynamically positioned drillship Glomar Challenger, set to recover continuous or semicontinuous sediment records from the ocean basins and heralded another new era in the exploration of the deep-ocean sedimentary record Prior to the DSDP, the global inventory of cores recovering pre-Quaternary sediments