Heavy minerals from Oligocene sandstones of the Menilite Formation of the Skole Nappe, SE Poland: a tool for provenance specification

摘要

Heavy minerals from sandstones belonging mostly to the Boryslav Sandstone and Kliva Sandstone members of the lower part of the Menilite Formation (Oligocene) in the northern part of the Skole Nappe, Polish Carpathians are characterized. In the study area, the sediments were deposited in the Rzeszow and Lancut channel zones running from the northern margin of the basin. The most frequent heavy minerals in the sandstones examined include zircon, tourmaline, rutile, staurolite, kyanits and garnet. Single grains of andalusite, sillimanite, apatite, epidote, brookite and chrome spinel occur in some samples. The very small content of apatite is related to long, continental weathering in the source area, which is referred to the Paleozoic sedimentary cover of Ihe MaJopolska Block and the easternmost part of the Upper Silesian Block. Different preservation states, morphology, degree of roundness and colour varieties suggest that the heavy minerals studied derive from various petrographic types including metamorphic, igneous and sedimentary rocks. However, the Carboniferous and Permian conglomerates and sandstones seem to be the most probable source rocks.