Browsing by Subject "eclogite facies"

Now showing 1 - 1 of 1

Access status: Restricted ,
Skały facji eklogitowej kompleksu metamorficznego Richaddalen, NW Spitsbergen, Svalbard
(Data obrony: 2017-09-26) Serafin, Małgorzata
Wydział Geologii, Geofizyki i Ochrony Środowiska
The purpose of the study was to trace the history of the metamorphic transformation of rocks of eclogite facies belonging to the Richarddalen metamorphic complex originating in the Biskayerhalvoya area of NW Spitsbergen within the Svalbard archipelago. The retail conditions of the eclogitic composition and its mineral paragenesis, transformations and structures formed after retrogression of lower metamorphic phases have been described in detail. The research also outlines the geography and geological structure of Svalbard, including the Caledonian Structural Floor and the Richarddalen Complex, part of it. Among the ten samples taken for the study in 2013 during a cruise on Horyzont II and field geological conference „Geological Workshop Geology of Svalbard Basement 1 - 8 September 2013, Svalbard”, were three samples of retrograded eclogites (amphibolites), five gneisses samples and two metaaplite samples. A field study was carried out to describe the exposures from which samples were taken, the photographic documentation of the said exposures and their location with a GPS receiver. Subsequently, macrophotographs and photographs of the cut and „witnesses” of ten samples were collected, as well as microphotographs and microscope descriptions using a polarization microscope in the Laboratory of Optical Microscopy, Department of Mineralogy, Petrography and Geochemistry, Faculty of Geology and Environmental Protection, AGH University of Science and Technology in Cracow. On the basis of macro- and microscopic investigations of structural and textural features and mineral paragenesis and literature (including the PT path for metamorphism of eclogites by Elvevold and Ravna (2014)), the approximate PT paths of metamorphism (passing through three metamorphic fecies: eclogite, amphibolite and greenschist) have been sketched for each of the three types of rocks by locating recognized mineral parageneses and textural features on specific sections of these paths. Three stages of gneiss evolution, two stages of the evolution of retrograde eclogites (amphibolites) and two stages of metaaplite genesis, have been identified and presented with the metamorphic episodes associated with them and their age in a summary graph of PT paths of all three types of rocks.