北海道幌加内町,天狩炭田に見出された油徴とその母層について
1966 年 31 巻 6 号 p. 250-256
詳細
1966 年 31 巻 6 号 p. 250-256
Tenkari coal-field coveres the junctional area of three counties, Uryu, Tomamae and Embetsu, and consists of the Neogene Tertiary coal-or lignite-bearing formations overlying the Cretaceous basement. Several oil indicating localities have hitherto been reported from the coal-field by several geologists. The writers newly added several localities and from which obtained oil samples for study.
As has been carried on the chemical analysis of those samples, the following facts were recognized.
(1) The oil-sand from the Cretaceous containes too small quantity of crude oil for quantitative analysis.
(2) The crude nature of the sample obtained from the seepage in the Quaternary of the Kamisekiyuzawa area [Loc. No. 1 in fig. 1] is quite different from that of one from the Tertiary formation of the Sanjussenzawa area [Loc. No. 6 in fig. 1]. As comparing with data of the nature of Japanese crude oil already known, the former belongs to the older type or the Cretaceous-Palaeogene oil type and the latter to the younger or the Neogene oil type [figs. 2-5].
Judging from the subserface geological data to the former seepage, it seems to the writers to be possible that this seepage is fed with crude oil generated in the underneath Cretaceous deposits through the conceald fault.
