Uwagi o serpentynitach Gór Kiełczyńskich na Dolnym Śląsku

Abstract

REMARKS ON THE SERPENTINITES OF KIEŁCZYN MTS. IN LOWER SILESIA

The western part on the serpentinites zone appearing in the Sobótka massif is represented by Kiełczyn Mts. Here the author distinguishes the following serpentinites: the antigorite, the carbonate and the-chrysolite serpentinites respectively (Fig; 1). Relicts of the original rocks, i.e. diallage and tremolitic peridotite, have survived in the serpentinites in but small quantities. In dislocation zone a carbonate-talc schist appears. The actual mineral composition and the approximately reconstructed original mineral composition, in volume per cent, is presented in Table 1. The diallage peridotite and the dunite contain olivine (forsterite – 2Vγ = 86-88°), diallage (z/γ = 43-45°) and chromite spinel (picotite), while the tremolitic peridotite contains, in place of the diallage, tremolite (2Vα = 84°, z/γ = 18-21°). Antigorite is the essential mineral in all serpenitinites, whereas, chrysotile, occurs but sporadically. Carbonates appear commonly and are mainly represented by magnesite with Ca and Fe admixtures. Talc accompanies the tremolite its larger accumulations are found in the, carbonate-talc rocks. Quite commonly occurs secondary magnetite scattered in all rock varieties. Chlorite is found in small quantities.