Mafické enklávy z granitoidů vystupujících v širším okolí Blanska
| Title in English | Mafoc enclaves from granitoids exposed in the vicinity of Blansko |
|---|---|
| Authors | |
| Year of publication | 2006 |
| Type | Article in Periodical |
| Magazine / Source | Geologické výzkumy na Moravě a ve Slezsku v roce 2005 |
| MU Faculty or unit | |
| Citation | |
| Field | Geology and mineralogy |
| Keywords | granitoids - enclaves - petrology - chemistry - xenocryst |
| Description | Mafic micro granular enclaves (MME) and matching host rocks which occur in the east granodiorite part of the Brno massif were studied petrology and geochemistry to establish their origin and to investigate the processes involved in their differentiation. Macroscopic and microscopic features indicate that the MME are products mixing between a basic end member and host rocks of granodiorite to tonality composition. Many of them show obvious similarities to the matching host rock: they contain the identical mineral phases as their host rock, nevertheless the content of mafic minerals (biotite and hornblende) and opaque minerals is somewhat higher. Zoned plagioclase megacrysts in some enclaves contain anhedral cores jacketed by euhedral rim. These plagioclase could represent xenocrysts of early crystallised host rock phases mechanically accreted inward the liquid of enclaves. Acicular crystals of apatite are indicative of rapid crystallization of the enclaves liquid. Host rocks display intermediate to acid composition, while the enclaves are more basic. |
| Related projects: |