(Table 1) Major and trace elements at DSDP Leg 57 Holes

Several papers have recently appeared concerning the metalliferous sediments on the active oceanic ridges. The geochemistry of such sediments is reasonably well understood and the deposits generally considered to be products of volcanic processes (Boström and Peterson, 1969; Boström et al., 1969; Horowitz, 1970, 1974; Cronan et al., 1972; Cronan and Garrett, 1973; Piper, 1973). The geochemistry of trench sediments, however, is less well known. There is a great need for studies of trench inner slope sediments, particularly in view of the significance of such sediments as a record of the effects of oceanic plate subduction under the continental crust. Sampling by Glomar Challenger in the trench inner slope was therefore of utmost importance in determining the origin of trench inner slope deposits.

近期已有多项研究围绕活动洋脊上的含金属沉积物（metalliferous sediments）展开。目前学界对这类沉积物的地球化学性质已有较为充分的认知，且普遍认为此类矿床是火山作用的产物（Boström与Peterson，1969；Boström等，1969；Horowitz，1970、1974；Cronan等，1972；Cronan与Garrett，1973；Piper，1973）。然而，海沟沉积物的地球化学研究目前仍相对匮乏，相关认知较为有限。鉴于这类沉积物可作为大洋板块俯冲（oceanic plate subduction）作用波及大陆地壳（continental crust）下方的有效记录，其研究价值显著，因此针对海沟内坡（trench inner slope）沉积物开展研究的需求极为迫切。因此，借助格洛玛·挑战者号（Glomar Challenger）对海沟内坡沉积物进行采样，对于明确海沟内坡沉积物矿床的成因具有极为重要的意义。