- Tytuł:
- Magma mingling textures in granitic rocks of the eastern part of the Strzegom-Sobótka Massif (Polish Sudetes)
- Autorzy:
-
Domańska-Siuda, Justyna
Bagiński, Bogusław - Powiązania:
- https://bibliotekanauki.pl/articles/138640.pdf
- Data publikacji:
- 2019
- Wydawca:
- Polska Akademia Nauk. Czytelnia Czasopism PAN
- Tematy:
-
Strzegom-Sobótka Massif
granite
enclave
Variscides
magma mixing
magma mingling
textures
monazite (Ce) crystals
masyw Strzegom-Sobótka
granit
enklawa
waryscydy
miksacja magmy
mieszanie magmy
tekstury
monacyt - Opis:
- Many granitic intrusions display evidence of magma mixing processes. The interaction of melts of contrasting composition may play a significant role during their generation and evolution. The Strzegom-Sobótka massif (SSM), located in the Sudetes (SW Poland) in the north-eastern part of the Bohemian Massif of the Central European Variscides, exhibits significant evidence of magma mingling on the macro- and micro-scales. The massif is a composite intrusion, with four main varieties: hornblende-biotite granite (with negligible amount of hornblende) and biotite granite in the western part, and two-mica granite and biotite granodiorite in the eastern part. Field evidence for magma mingling is easily found in the biotite granodiorite, where dark enclaves with tonalitic composition occur. Enclaves range from a few centimeters to half a meter in size, and from ellipsoidal to rounded in shape. They occur individually and in homogeneous swarms. The mixing textures in the enclaves include fine-grained texture, acicular apatite, rounded plagioclase xenocrysts, ocellar quartz and blade-shaped biotite. The most interesting feature of the enclaves is the presence of numerous monazite-(Ce) crystals, including unusually large crystals (up to 500 μm) which have grown close to the boundaries between granodiorite and enclaves. The crystallization of numerous monazite grains may therefore be another, previously undescribed, form of textural evidence for interaction between two contrasting magmas. The textures and microtextures may indicate that the enclaves represent globules of hybrid magma formed by mingling with a more felsic host melt. Chemical dating of the monazite yielded an age of 297±11 Ma.
- Źródło:
-
Acta Geologica Polonica; 2019, 69, 1; 143-160
0001-5709 - Pojawia się w:
- Acta Geologica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł