Miocene volcanic rocks in MITI "Kanazawa-Oki" well: A description of syn-rifting volcanism.

Abstract

Abstract:Thick Miocene basaltic pile has been confirmed in the MITI "Kanazawa-Oki" well which was drilled in the Hokuriku Basin upon the eastern part of Southwest Japan back arcshelf.

Seismic evidence of divergent rifting and subsequent deformation in the southern Japan Sea, and a Cenozoic tectonic synthesis of the eastern Eurasian margin

“…The MITI Kanazawa-oki borehole penetrated a basaltic seamount erupted within one of the depocenters. Its chemical composition is suggestive of thinned lithosphere during deposition of Unit E (Itoh et al, 1994). Paleobathymetric data on the borehole imply that the basin rapidly subsided 1000 m simultaneously with the igneous activity (Itoh et al, 1997).…”

“…In the figure, the bent structure of the geologic zones of southwest Japan is Table 2 on the basis of drilling survey of MITI Kanazawa-oki ( Fig. 3; Itoh et al, 1994Itoh et al, , 1997 and another exploration borehole (Itoh and Arato, 1999). restored, as shown by the straight MTL and a gap around the northern Japan Sea coast, according to an estimation of the middle Miocene differential rotation in the eastern part of the rifted sliver (Itoh, 1988).…”

“…3 and 4. As some exploration boreholes have been drilled within the area (Itoh et al, 1994(Itoh et al, , 1997, seismic units/horizons can be assigned to geologic periods as listed in Table 2. This offshore basin is characterized by a rapid subsidence and thick accumulation of the Unit E, the lowermost part of the marine succession, during the late early Miocene.…”