Budowa i geneza pokryw ochrowych w Karpatach na przykładne wystąpienia w Czerwonkach Hermanowskich k. Rzeszowa -

Janusz Kotlarczyk, Tadeusz Ratajczak

Abstrakt


THE STRUCTURE AND GENESIS OF OCHRECOVERS IN THE CARPATHIANS AT THE EXAMPLE OF THE CZERWONKI HERMANOWSKIE OCCURRENCE N. RZESZÓW (SE POLAND)

Summary

During field work carried out in 1982-1988 within the Skole Unit of the Polish Carpathians a number of small ochre covers was recorded. Their occurrence in Czerwonki Hermanowskie (the village of Hermanowa, Rzeszow Voivodship), represents a typical example (Fig. 1). The authors have made complex geological and geomorphological (Figs 1-4) as well as mineralogical and petrographical (Figs 5-14, Table 1) investigations and determined some chemical (Table 2 and 3) and technological properties of the ochres. The covers in question were formed during the Holocene hypergenesis of flysch rocks, and the outcrops of the Menilite Beds were particularly favoured, as they usually contain from some to almost twenty percent of disseminated iron compounds and are strongly fractured. The formation of the ochre covers is controlled by geomorphology and hydrological regime, and the iron compounds are leached in specytic cases from the hypergenic zone onto the surface (Fig. 15). Initially they occur in the colloidal form but, with the progress of time, grade successively into ferrhydrite and goethite, the mineral phases with better and better order internal structure. The leaching is followed by the surface washing of the iron compounds and, as the result, the ochres are contamined by siliciclastic material, derived from weathered Carpathians rocks. If the volume of a hypergenic zone is large enough and the process of leaching lasts long, an ochre cover with the thickness of above 1 m may be formed The high Fe 203 content (30-55 wt. %) of these sediments increases their economic potential, particularly in the case of bigger occurrences. The cover of iron oxides from Czerwonki Hermanowskie represents the most typical ochres as its chemical composition is concerned (Fig. 16).

Pełny tekst:

PDF