Commune: Strzelin (pow. strzeliński, woj. dolnośląskie)
Framework element or context represented:
Contact metamorphism in the Sudety Mts.
Primary geological/geomorphological interest:
Contact of the Upper Carboniferous granite intrusion with the metamorphic mantle.
Comparative assessment justification:
Large variety of the rock of contact metamorphism.
Protection status and accessibility:
Due to importance of the outcrop in the field of stratigraphy, mineralogy and petrography it is proposed to be a protected geosite.
Character of site: Abandoned quarry.
Area: about 0.5 ha
Altitude: 200 m a.s.l.
Lithology: granitoids, other metamorphic rocks, limestones
Discipline: Petrography, Stratigraphy of Proterozoic
Process Age: *all periods
Bedrock Age: Carboniferous, *all periods
Description of primary interest:
The abandoned quarry is divided into two casts: western and eastern ones, and crop out the contact between the granitoid body and its mantle. Within the former, the granitoid intrusion of Strzelin contacts with the heavily weathered, partially migmatised mica schists characterised by well-developed ptygmatic folds. The schists belong to the metamorphic mantle of the granitoid intrusion forming the Wzgórza Strzelińskie structure. Within the schists series there are numerous, about 12 centimetres thick, veins of aplogranite following the foliation surfaces. Underneath calcium and silica rich rocks occur with the inserts of feldspar, quartz, garnet and diopside rich rocks. The inserts are sometimes composed of almost only garnet crystals concentrated especially within the cavities. The whole formation overlies the series of crystalline limestones, which were extensively mined in the past. In the eastern quarry there is an outcrop of fine-grained quartzites and the underlying calcium and silica rich rocks.
Literature:
BEREŚ B., 1969 — Petrografia granitu Strzelina i okolicy. Archiwum Mineralogiczne, 28/2: 69-76. BOBIŃSKI W., GAWLIKOWSKA E., KŁONOWSKI M. 1999 - Important geosites of the Polish Sudetes. Pol. Geol. Inst., Spec. Papers, 2: 19-25