Původ spessartinem bohatých granátů v drobách Drahanské vrchoviny

ČOPJAKOVÁ, Renata, Milan NOVÁK and Jiří OTAVA. Původ spessartinem bohatých granátů v drobách Drahanské vrchoviny (The origin of spessartine-rich garnets in graywackes of the Drahany Upland). In Moravskoslezské Paleozoikum 2003. Olomouc, 2003, p. 6-7.

Basic information

Original name

Původ spessartinem bohatých granátů v drobách Drahanské vrchoviny

Name (in English)

The origin of spessartine-rich garnets in graywackes of the Drahany Upland

Authors

ČOPJAKOVÁ, Renata, Milan NOVÁK and Jiří OTAVA

Edition

Olomouc, Moravskoslezské Paleozoikum 2003, p. 6-7, 2003

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Other information

Type of outcome

Stať ve sborníku

Confidentiality degree

není předmětem státního či obchodního tajemství

Organization unit

Faculty of Science

Keywords in English

spessartine rich garnets; provenance; Drahany Culm; Czechoslovakia

Tags

Czechoslovakia, Drahany Culm, provenance, spessartine rich garnets

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Abstract

In English

Studies of garnet geochemistry by electron microprobe is widely applicable in solving problems of provenance. Spessartine-rich garnet is rather less common then other main garnet species which makes it a provenance sensitive indicator. This paper presents example that show the value of spessartine-rich garnets in provenance study of Lower Carboniferous sediments of Drahany Upland. Polymict garnet assemblages of Drahany Upland (Protivanov-, Rostání- and lower part of Myslejovice Formation, Goniatite zones Peg a Goa) with various mixture of garnet geochemistry contain more than 20% of spessartine-enriched garnets. The change into pyrope-almandines predominant oligomict assemblages (upper part of Myslejovice Formation, Goniatite zones Gob a Gog) is characteristic among others by a sudden decrement of spessartine-rich garnets below 5% and reflects changes in provenance. It is commonly believed that the clastic material originates from crystalline terrains situated West of Culm sedimentary basin. The study of spessartine-enriched garnet geochemistry in polymict garnet assemblages provides cogent evidence of supply clastic material from northern situated geological units (Silesicum and Orlice-kladsko Crystalline Unit). The youngest sediments (polymict garnet assemblages) were not ever supplied by the Silesicum and Orlice-kladsko Crystalline Unit but material came from West. Certain part of spessartine-enriched garnets can arise from recycled older Culm sediments.