KALCIT-BARYTOVÉ KONKRECE Z TĚŠAN, OKR. BRNO-VENKOV: NÁLEZ, DATA A MOŽNÉ DŮSLEDKY

Roč.16,(2009)

Abstrakt

Unique calcite-barite concretions from Těšany (district Brno-country) have been found and studied in detail. These concretions and large limestone boulders are considered to represent material from the Jurassic period and present the only material and opportunity to improve knowledge about these unussual rocks in the studied area. EPMA has been used to constrain complex mineralogy. Results in this study are supplemented by LA-ICP-MS microanalysis. The increased precision is related to combination of different methods (PL, CL and BSE imaging) to distinguish compositionaly different calcites as a separate groups investigated by scans of multi-point analyses. Based on microtextural observations and chemical analyses 3 calcite groups are distinguish. This study provides new information for widespread sulphates (5–20 %) and fi ne-grained quartz (5–35 %) too.


Klíčová slova:
Těšany, Jurassic carbonate-sulphate concretions, REE, EPMA and LA-ICP-MS data
Reference

Adámek, J. (2005): The Jurassic floor of the Bohemian Massif in Moravia – geology and paleography. – Bull. Geosci., 80, 4, 291–305. Praha.
Bosák, P. (1978): Rudická plošina v Moravském krasu – část III. Petrografie a diageneze karbonátů a silicitů jurského reliktu u Olomučan. – Čas. Mor. muzea, Vědy přír., 63, 7–28. Brno.
Boyton, W. V. (1984): Cosmochemistry of the rare earth elements: meteorite studies. In: Henderson, R. (ed.): Rare Earth Element Geochemistry – Developments in Geochemistry 2, 89–92, Elsevier. Amsterdam.
Eliáš, M. – Eliášová, H. (1984): Facies and paleogeography of the Jurassic in the western part of the Outer Flysch Carpathians in Czechoslovakia. – Sbor. geol. Věd, Geol., 39, 105–170. Praha.
Petránek, J. (1995): Sedimentární acháty. – Bull. min. – petr. odd. NM v Praze, Vol. 3, 100–103. Praha.
Losos, Z., Přichystal, A., Richterová, D. (2000): Uzavřeniny anhydritu a barytu v jurských konkrecích z Moravy a jejich genetický význam. – Geol. výzk. Mor. Slez. v r. 1999, 66–68. Brno.
Mejzlík, Z. (1977): K rozšíření a genezi jurských konkrece ve střední části Moravského krasu. – Sbor. Okr. vlastivěd. Muz. Blansko, VI–VII (1974–75), 137–146. Blansko.
Tucker, E. M. (1976): Quartz replaced anhydrite nodules (Bristol diamonds) from the Triassic of the Bristol District. – Geol. Mag. 113 (6), 569–574. Cambridge.

Metriky

334

Views

453

PDF views