Journal of The School of Marine Science and Technology,Vol.3 No.3
On Miocene Coenothecalia Heliopora Coerulea (Pallas)of Coral Reefs from
The Tanzawa Mountains, Southern Kanto Mountains, Central Japan
Masahito KADOTA and Yoshifumi MISAWA
Abstract
Miocene Tanzawa Group is distributed in the Tanzawa Mountains of the southern Kanto,central Japan,and is
composed of thick green tuff strata.
Limestone lenses in the strata are intercalated in multiple sizes, in thichness from a few meters to 50meters.
Fossil of coral reef creatures yielded in the limestone.
We found a couple of very interesting fossils in one of these limestones in the Hitoto area, Yamakita Mati,
Ashigarakami Gun,Kanagawa Prefecture.These fossils are Heliopora coerulea (Pallas)colonies.Recent,Heliopora
coerulea inhabits around the coral reefs at southern Amamioshima (Island), Kagosima prefecture. Therefore, the
colony of Tanzawa area in the middle Miocene age would be to assume a kind of tropical to sub-tropical palaeoclimate.