Mineralogical and petrological characteristics of mudrocks from the Upper Palaeozoic Turony Formation (Slavonia–Drava unit)

Abstract

In this paper, the results of mineralogical and petrological studies of very low-grade metapelitic sedimentary rock types
(i.e. slate and metasiltstone) of the Upper Palaeozoic Turony Formation from southern Transdanubia (western flank of the
Villány Mountains, SW Hungary) are presented. The studied Turony samples are predominantly composed of albite, quartz,
illite±muscovite, chlorite (mixed chlorite–smectite) and haematite. Additionally, calcite, dolomite and rare albitized Kfeldspar and smectite also occur. Moreover, there are some accessory minerals such as opaque grains (e.g. pyrite),
tourmaline, zircon, monazite, rutile and apatite. The mineralogical composition of these rocks suggests a relatively felsic
provenance area and reflects the cumulative effects of the early and subsequent burial diagenetic processes (such as
albitization) in an open system, illitization and chloritization during warm and arid climatic conditions in a playa lake.