Infra-supra structure relations of a microcline-granite dome in the Somero area, Svecofennides, SW Finland
Internal structure and deformational history of two granite domains with markedly distinct tectono-metamorphic evolutions occur in the Somero area, SW Finland. The Ruostejärvi dome, located NW of Somero, is characterized by a gently dipping core-mantle contact. The grade of metamorphism in this dome...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Geological Society of Finland
1989-12-01
|
| Series: | Bulletin of the Geological Society of Finland |
| Subjects: | |
| Online Access: | http://www.geologinenseura.fi/bulletin/Volume61/sgs_bt_061_2_pages_131_141.pdf |
| Summary: | Internal structure and deformational history of two granite domains with markedly distinct tectono-metamorphic evolutions occur in the Somero area, SW Finland. The Ruostejärvi dome, located NW of Somero, is characterized by a gently dipping core-mantle contact. The grade of metamorphism in this dome increases towards the core and migmatites have the character of injection veins. In contrast, in the Halkjärvi domain (SW of Somero) all structural elements are (sub)vertical and the rocks are of high metamorphic grade over the entire domain. In this case, migmatization resulted from in situ melt generation. The two domains are separated by a WNW-ESE striking lineament. This lineament represents a zone of intense shearing that caused an upward block movement of the southern domain. The Halkjärvi domain represents the infra-structure, while in the Ruostejärvi domain a supra structure of a granite dome is exposed. The variation in supra-infra structure is discussed in relation to the mechanism of diapirism in granite domes. |
|---|---|
| ISSN: | 0367-5211 1799-4632 |