- Tytuł:
- Geochemical and fractal analysis of enclaves in the Dehe-Bala intrusion, (Northwestern Iran) : a new concept to the interpretation of crust-mantle interaction process
- Autorzy:
-
Gharamohammadi, Zeynab
Kananian, Ali
Eliassi, Mohsen - Powiązania:
- https://bibliotekanauki.pl/articles/2058583.pdf
- Data publikacji:
- 2019
- Wydawca:
- Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
- Tematy:
-
Dehe-Bala Granodiorites
DBG
mafic microgranular enclaves
MMEs
magma mixing
fractal dimension of enclaves - Opis:
- The Dehe-Bala intrusion is one of the remarkable intrusions of granodiorite rocks with I-type affinity and abundant mafic microgranular enclaves (MMEs) in the Buin Zahra area, Qazvin, Iran. The MMEs, composed of diorite and quartz-monzodiorites, are haphazardly widespread in the granodiorites. The Dehe-Bala Granodiorites (DBG) usually are characterized by high contents of SiO2 (64.2-66.9), Na2O (3-3.23), K2O (3.49-4), Mg# 4.84 and Th/Ta ratio (≈7.9). In comparison to the DBG, the MMEs can be distinguished by their lower value of SiO2 (52.8-58.2), K2O (1.4-3.8) and higher Mg# (0.4-0.46). All these characteristics show a different composition of the DBG and MMEs, more importantly, can argue in favor of a magma mixing/mingling origin in the DBG. The enrichment in total REEs and HFSEs in the MMEs clearly reflects a marked diffusional process from the felsic to mafic magma that could have been achieved by chemical exchange during the magma mixing/mingling process. The fractal dimensions (Dbox) of MMEs differ from 1.14 to 1.29 with the highest frequency at 1.29. The textural heterogeneity and geochemical features combined with high Dbox values in the MMEs compared with the DBG show lower degrees of mixing/mingling between mantle-derived mafic and lower crust-derived felsic magmas.
- Źródło:
-
Geological Quarterly; 2019, 63, 3; 505--521
1641-7291 - Pojawia się w:
- Geological Quarterly
- Dostawca treści:
- Biblioteka Nauki
Artykuł