ABSTRACT

Misinterpretations of modes of arenites containing framework grains of both intrabasinal and extrabasinal origin lead to unreliable reconstructions of paleobasins and paleosource areas. A satisfactory scheme for the classification of such hybrid arenites is needed to provide an adequate framework for basra analysis. Criteria for the definition of the chief classes of arenites must distinguish between extrabasinal and intrabasinal detritus and minimize the dependence of arenite nomenclature on grain size. Four main groups of arenaceous grain types are recognized: 1) noncarbonate extrabasinal, 2) carbonate extrabasinal, 3) noncarbonate intrabasinal, and 4) carbonate intrabasinal. Their three dimensional configuration establishes a first-level classification o the main types of arenites. Two more groups of arenaceous modes, neovolcanic and carbonate particles of extra- or intrabasinal undetermined origin, are required for a practical scheme. The practicability of the suggested approach can be demonstrated in paleogeographic and paleotectonic reconstructions.