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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy >
Vol.XXIII, No.2 >
Basalts and Dolerites in the Sorachi-Yezo Belt, Central Hokkaido, Japan
| Title: | Basalts and Dolerites in the Sorachi-Yezo Belt, Central Hokkaido, Japan |
| Authors: | Niida, Kiyoaki Browse this author |
| Issue Date: | Aug-1992 |
| Publisher: | 北海道大学 |
| Journal Title: | 北海道大学理学部紀要 |
| Journal Title(alt): | Journal of the Faculty of Science,Hokkaido University. Series 4, Geology and mineralogy |
| Volume: | 23 |
| Issue: | 2 |
| Start Page: | 301 |
| End Page: | 319 |
| Abstract: | Basalts and dolerites from the late Jurassic to early Cretaceous Sorachi Group and the Cretaceous melange complex in the central axial zone of Hokkaido are classified into the following three types: high K2O type alkaline basalts, characterized by high abundance in K2O, TiO2, P2O5 and normative nepheline, low K2O type alkaline basalts with high Na2O/K2O ratio and normative nepheline, and MORB type tholeiites, poor in K2O, TiO2, P2O5. The basaltic pillow lavas, dolerite dykes and sheets, observed as autochthonous members of the Upper Sorachi Group, correspond to the low K2O type alkaline basalts. The basaltic pillow lavas in the Lower Sorachi Group are of the MORB type tholeiites. Exotic blocks of basalt and dolerite in the Cretaceous accretionary melange complexes involve both the high K2O type alkaline basalts and the MORB type tholeiites. |
| Type: | bulletin (article) |
| URI: | http://hdl.handle.net/2115/36785 |
| Appears in Collections: | Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy > Vol.XXIII, No.2
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