- Tytuł:
- The Baga-Gazriin Chuluu A-type granites of Central Mongolia compared with other igneous bodies nearby : a geochemical approach
- Autorzy:
-
Machowiak, K.
Stawikowski, W. - Powiązania:
- https://bibliotekanauki.pl/articles/2059389.pdf
- Data publikacji:
- 2012
- Wydawca:
- Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
- Tematy:
-
Central Mongolia
Baga-Gazriin Chuluu pluton
A-type granites
geochemistry
Hotont area granitoids - Opis:
- The subject of the study are the relationships between the Late Triassic A-type granites of the Baga-Gazriin Chuluu pluton in Central Mongolia and the magmatic bodies located either adjacent to or a short distance from this intrusion. We compare new geochemical data from the most representative samples of the Baga-Gazriin Chuluu pluton with published data from the Mesozoic granitoids of the Egiindavaa complex and T sagduul massif in the Hotont area. The geochemical analyses of all these granitoids are also compared with the geochemical characteristics of trachyandesites of unknown age which neighbour the Baga-Gazriin pluton. The Baga-Gazriin granites, most of the Tsagduul granites and a few samples from Egiindavaa are A-granites with strong crustal affinity. By contrast, most of the Egiindavaa granitoids include considerable mantle-derived material and thus seemingly formed in different conditions, with a higher water content in the magma. The trachyandesites adjacent to the Baga-Gazriin Chuluu pluton have been referred to a Permian volcano-sedimentary complex, making them distinctly older than the granitoids. All the A-type granites discussed were emplaced in extensional conditions, which developed after cessation of the compressional regime resulting from the closure of the Mongol-Okhotsk Ocean. The shallow-lying source for their generation was connected with slab break-off or the presence of a hot spot. The granitoids, in the late stage of crystallisation, were enriched in complex ions that were REE carriers, as shown by a distinct “tetrad effect”.
- Źródło:
-
Geological Quarterly; 2012, 56, 3; 457--474
1641-7291 - Pojawia się w:
- Geological Quarterly
- Dostawca treści:
- Biblioteka Nauki
Artykuł