Unknown
PANGAEA
In:
Supplement to: Sergeev, K F; Krasnii, M L; Neverov, Yul; Ostapenko, V F (1983): Composition of crystalline basement of the southwest end of the Zenkevich swell (Hokkaido uplift). Tikhookeanskaya Geologiya (Pacific Geology), 2(2), 3-8
Publication Date:
2023-05-12
Description:
Geological and geophysical investigations carried out within the Hokkaido Rise showed that intrusives composing outcrops of the crystalline basement on the ocean floor form a continuous series from monzonites and diorite-monzonites to granites with prevalence of granodiorites with stable mineralogical association: biotite - hornblende - K-feldspar. Acidic volcanic rocks are characterized by a similar mineralogical association with almost complete absence of plagioclase-pyroxene species. It seems that the Hokkaido Rise, as well as the marginal oceanic Zenkevich swell as a whole are not primary oceanic structural formations and have undergone a complex and long history of geological development with intense orogenic movements that occurred in Middle Cretaceous and preceded subalkaline basalt outpouring during postorogenic subsidence of the Earth crust.
Keywords:
Archive of Ocean Data; ARCOD; Dredge; DRG; Northwest Pacific; Pegas-80-2143; Pegas-80-2145
Type:
Dataset
Format:
application/zip, 2 datasets
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