Permalink : http://hdl.handle.net/2115/36680

The Tokoro Belt, a tectonic unit of the Central Axial Zone of Hokkaido, is characterized by the preponderant Jurassic effusive rocks of geosynclinal phase of so-called Hidaka Orogenic Movement. As a large scale feeder dyke consisting of perpendicularly arranged pillows of diabase associated with perlite textured sericite rock has been found there in the Tokoro Belt, mode of occurrence, rock properties and chemistry of the feeder dyke are outlined in this paper. Mass of arfvedsonite diabase which has not been known in the Central Axial Zone of Hokkaido was discovered closely related to the dyke. From the mode of occurrence of the mass, it is considered that this peculiar rock mass might have been taken up from a basement of the Tokoro Belt.