Global geologic processes and their practical significance

Abstract

During the past decade or so geoscientists have learned, mainly from study of the ocean floor, that such earth processes as earthquakes and volcanic eruptions are part of a geodynamic system of processes that, over time, literally move the continents and shape the ocean basins. The new theory of global plate tectonics holds that great fractures divide the Earth's crust into a mosaic of large plates, each of which is in motion independently of adjacent plates. The seven primary plates are: the Eurasian, African, South American, North American, Pacific, Australian, and Antarctica. In some places the plates are diverging, as at mid-ocean ridges where the ocean floor is spreading; at other places they are converging and one plate is overriding another; and in still other places the plates are sliding past each other. From the standpoint of scientific implications, the global tectonics concept provides a unifying plan for studying a group of seemingly unrelated geoscientific phenomena that may in reality be but different manifestations of a single geoprocess. The new understanding of the Earth's geoprocesses will help us decipher the origin and history of mountain systems and related geologic features on all the continents. Understanding of the processes that continually remold the Earth's outer crust is to be found primarily by concerted examination of the sea floor. The practical significance of the plate tectonics concept is that understanding the processes involved and the continuing mobility of the Earth's crust by study of the sea floor and land areas adjacent could well lead us to understand the origin of ore deposits, the genesis of hydrocarbons in structural basins, the chemistry of manganese nodule formation, and the predictability of earthquakes and volcanic eruptions — problems of great importance to men of all nations. The complex processes involved in the global tectonics concept are yet fully understood, and in all fairness, the concept must be called a working model. The observations on which it is based have come in large part from investigations that are reconnaissance in nature, and the highly generalized tenets of the concept must now be studied in the depth and scope of detail necessary to establish validity and to relate an understanding of the processes involved to the needs and concerns of mankind. The scope of the problems is global, and to understand them and apply our knowledge to man's needs likewise will require a scientific effort of international scale involving participants of all nations. Three international research programs have already been initiated to attack some of the problems: (1) the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES); (2) the International Decade for Ocean Exploration (IDOE); and (3) the International Geodynamics project. The wisdom of the doctrine of freedom of research that has prevailed up until now is more than demonstrated in the rich return of scientific advance described. If our understanding of global geologic processes and of the geology of ocean basins as a basis for seabed resource development is to advance, the UN Seabeds Committee must plan a regime that encourages research and international cooperation.