Jadeitic pyroxene found as pebbles in lower Cretaceous formation of the Kanto Mountains, central Japan.

Abstract

Jadeitic pyroxene has recently been found as pebbles of sandstone beds in lower part of lower Cretaceous formation of the Kanto Mts. This fact as well as previous discovery of lawsonite and pumpellyite-bearing rocks as clastic materials in the same horizon clearly show that the Sanbagawa metamorphism of the Kanto Mts. must have occurred before the deposition of lower Cretaceous formation of the Kanto Mts.