LAYER SILICATES FROM SERPENTINITE-PEGMATITE CONTACT (WIRY, LOWER SILESIA, POLAND)

Highly tectonized contact between serpentinite and younger pegmatite i n the magnesite mine of Wiry contains various layer silicates. Vermicu lite, chlorite, smectite, and interstratified mica-vermiculite were re cognized by means of routine XRD examination. Two three component inte rstratifications of mica-vermiculite-chlorite and chlorite-swelling ch lorite-smectite were identified by a combined procedure of deconvoluti on of the XRD patterns and simulation of XRD tracings. A mineral with large diffraction maxima, displaying ''chlorite intergrade'' character istics, appeared to be a mixture of chlorite, mixed layer chlorite-sme ctite, and vermiculite. Polytypes of phyllosilicates were determined b y the X-ray transmission method. Due to the heritage of parent mineral polytype structure by transitional products of alteration, two distin ct sequences of layer silicates were observed: one formed from triocta hedral mica (vermiculite, mixed layer mica-vermiculite); and one evolv ed from chlorite (e.g., mixed layer chlorite-swelling chlorite-smectit e). A tentative scheme of the primary contact zone structure, not obsc ured by subsequent brittle tectonics either by transformation of layer silicates, is proposed.