MINERALOGIA DROBNOZIARNISTYCH UTWORÓW Z KRATERU METEORYTU MORASKO

Abstract

MINERALOGY OF FINE-GRAINED SEDIMENTS FROM THE MORASKO METEORITE CRATER

Abstract. The present paper shows preliminary results of mineralogical studies of sediments in the Morasko Meteorite Nature Reserve located in the northern part of Poznań. The meteorite fell there over 5000 years ago, that left signs in the present morphology of the region in form of several craters and elevations that surround them. These forms are underlain by glacial tills and clay – silt sediments, known as the Poznań Formation. The aim of the research was to identify of the mineralogical composition of sediments, determine potential mineralogical effects of the meteorite fall, verify the impact of the meteorite fall on soft young sediments. The studies were conducted with the use of microscopic and X-ray diffraction equipment. Primary and secondary components were identified in grain fractions. Quartz, feldspar, pyroxene, clay minerals (illite, kaolinite), and pebbles of igneous rocks are the primary components of the sediment. Weathering processes resulted in the development of modern soil profiles (humus, root fragments) and aluminum silicates of vermiculite-type minerals. The secondary components are clay clasts of older rocks in younger ones, which contain components typical of the Poznań Formation (illite, kaolinite, smectite or mixed-layered smectite/ illite, very fine-grained quartz and likely feldspars). The presence of clay intercalations in tills can be associated with the meteorite fall.