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F. Finger M. Tichomirowa C. Pin P. Hanžl 《International Journal of Earth Sciences》2000,89(2):328-335
The Brno Massif in Moravia, Czech Republic, is an important exposure of Precambrian basement in central Europe. It includes
large volumes of Cadomian granitoids and a narrow fault-bounded zone with metagabbros, metadiorites, and metabasalts. This
so-called Central Basic Belt also contains some metarhyolites; one of these was dated by means of the zircon evaporation method
at 725 ±15 Ma. Chemical and isotope data show that the dated rock represents a mantle-derived magma which is cosanguinous
with surrounding MORB-type metabasites. The data suggest that the Brno Massif hosts the oldest metabasite complex currently
known in central Europe. Its formation apparently coincides with the main period of ocean-floor spreading and island-arc formation
in the Panafrican orogens. This lends further support to the theory that the Brno Massif is a Gondwana-derived element.
Received: 9 December 1999 / Accepted: 9 February 2000 相似文献
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Fengmei Chai Jingwen Mao Lianhui Dong Fuquan Yang Feng Liu Xinxia Geng Zhixin Zhang 《Gondwana Research》2009,16(2):189
The Altay orogenic belt (AOB), situated in the middle part of the Central Asian Orogenic Belt (CAOB), is one of the most important metallogenic belts in China. The Kangbutiebao Formation is a Late Paleozoic stratigraphic unit that hosts many important iron and Pb–Zn deposits. The Kangbutiebao Formation consists of intercalated volcanic and sedimentary rocks that have undergone regional greenschist to lower amphibolite facies metamorphism, and mainly outcrops in three NW-trending fault-bounded volcano–sedimentary basins, including the Maizi, Kelang, and Chonghuer basins. SHRIMP analyses of zircons from three metarhyolites of the Kangbutiebao Fm. in the Kelang Basin yield weighted mean 206Pb/238U ages of 412.6 ± 3.5 Ma, 408.7 ± 5.3 Ma and 406.7 ± 4.3 Ma, respectively, which can be interpreted as the eruption age of the Kangbutiebao silicic volcanic rocks in the Kelang Basin. These ages indicate that the Kangbutiebao Formation was formed during the Late Silurian to Early Devonian. They also demonstrate that the deposits hosted in the Kangbutiebao Formation were formed after 412–407 Ma. They play a key role in understanding the Paleozoic tectonic evolution and metallogenesis of the southern margin of the Chinese AOB. 相似文献
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