Expanded Provenance Analysis (EPAn) of Clastic Deposites. Five-part coordinated analysis of clastic rocks

Abstract

It is well known, that clastic rocks have great economical and scientific importance as for example they are hydrocarbon- and water reservoires and remnants of totally eroded, disappeared mountains. The precise mineralogical-petrological determination (petrography) of their detrital grains and identification of their source area can be important research direction for both areas. Traditionally, two main trends have been developed for the provenance examination of unconsolidated clastic sequences: The petrography of the larger pebbles, which performs the macroscopic determination and thin-section examination of the   individual pebbles larger than a few centimetres and the examination of the heavy minerals, which deals with the sandy size minerals of the layer. Both methods have serious deficiencies. To eliminate some of these deficiencies, fine-grained pebble examination (FPE) method have been introduced into the petrographic examinations in the last few years. But it didn’t resolve the problem to connect surely the different heavy minerals with source rock types. With this work, our aim is to present such a grain determination procedure that allows to determine and identify more accurately and certainly the source rock types for clastic deposites, and with the help of which the deficiences of separately used methods can be eliminated. The system of research we call Expanded Provenance Analysis (EPAn) is a coordinated joint application of five different grain determination methods on clastic deposites. It includes previously used and newly presented methods as well.  In this article, we present in detail the method description, the conditions of use, advantages and disadvantages of each steps of the „EPAn” method, and the role and the usefulness of the test ranks. At the end of the presentation, we will discuss the evaluation of the „EPAn” test series.