SEDIMENTARY ROCKS/Deep Ocean Pelagic Oozes 71 Figure Distribution of the main sediment types on the ocean floor Reproduced with permission from Davies TA and Gorsline DS (1976) Oceanic sediments and sedimentary processes In: Riley JP and Chester R Chemical Oceanography, vol 5, 2nd edn., pp 80 London: Academic Press Phipps, on HMS Racehorse, bought up ‘‘fine soft blue clay’’ from a depth of 1250 m, the first recorded successful deep-sea sounding The sample was taken in water on the southern edge of the Voring Plateau in the Norwegian Sea In 1818, Sir John Ross recovered lb (2.7 kg) of greenish mud from a depth of 1920 m in Baffin Bay, offshore Canada, using a deep-sea grab, representing one of the first recorded successful substantial deep-sea sediment recoveries The laying of the first functioning submarine telegraph cable across the Straits of Dover in 1851 led to rapid expansion in the collection of deep-sea soundings and samples, driven by the prospect of the new means of intercontinental communication However, it was not until the voyage of HMS Challenger (1872–76) that enough deep-sea samples were recovered to produce the first global seafloor sediment map The voyage of HMS Challenger, led by Professor Charles Wyville Thomson, professor of natural history at the University of Edinburgh, was the first large-scale expedition devoted to oceanography A wealth of seafloor samples were recovered from 362 observing stations, spaced at uniform intervals, along the 128 000-km track traversed during the voyage John Murray, a naturalist on the Challenger expedition, oversaw the initial analysis of the recovered samples; Murray later edited the Challenger Reports, following the death of Wyville Thomson in 1882 The milestone Challenger Report on ‘Deep-Sea Deposits’ represented the first comprehensive volume on sediments of the deepocean seafloor Published in 1891 with the assistance of Murray’s co-worker AF Renard, this volume introduced many of the descriptive terms used today, such as ‘red clay’ and ‘Globigerina ooze’, and provided the basis for further deep-ocean sediment studies Murray also correctly related the distribution of shell-bearing plankton in the surface waters to the calcareous and siliceous sediments of the deep-ocean seafloor A major step forward in the investigation of seafloor sediments was the invention of the gravity corer by German researchers; the corer allowed continuous samples of extended lengths of sediment to be collected (but generally restricted to 1–2 m in length) The German South Polar Expedition (1901–03) collected several 2-m cores that were described by E Philippi in 1910 These cores showed that some deep-water sediments were stratified During the period 1925–38, Germany ran a series of oceanographic expeditions using the ship Meteor, which recovered several 1-m-long cores from the southern Atlantic and Indian oceans These cores, studied by Wolfgang Schott, showed changes in foraminifer species with depth and initiated the first