108., Tertiary Foraminifera from the Amaze Oil Field

Abstract

The Amaze Oil Field is situated in Izumozaki-mati, Niigata-ken and eight samples collected therefrom constitute the material of this research., More precisely, three of them were collected from the Haizume-Formation, one from the Nisiyama Formation, three from the Siiya Formation, and one from the Teradomari Formation., Fig., 1 shows these fossil localities., The significant Foraminiferas of the faunas contained are listed in Table 2., Haizume Formation: Loc., 55 and Loc., 57 are situated nearly in the same horizon., Loc., 58 is somewhat upper in horizon than the former two localities., The leading members of the Foraminiferan fauna from Loc., 55 and Loc., 57 are Textularia sagittula, Quinqueloculina vulglaris, Cassidulina japonica, Globigerina bulloides and Cibicides lobatulus, Cibicides refulgens is predominant in Loc., 58, but Cassidulina japonica is not found in it., The Foraminiferan fauna from Loc., 55 and, Loc., 57 reveals a close affinity with that of Kutta which YABE and HANZAWA reported in 1923., Here I suggest the Kutta assemblage to designate this fauna in the Amaze and the Nisiyama Oil Fields., Nisiyama Formation: Only one sample was collected, and the Foraminiferan fauna is very small in the number of species and individuals., Siiya Formation : Three samples were at hand., Haplophragmoides subgrobosum and Goesella sp., 1 are dominant in the one from Loc., 66 and a few species of Nonionides, Buliminidae and Rotaliidae are contained in the two others, but the predominant species in the Haizume Formation can not be found in this., Teradomari Formation : Cyclamina pauciloculata is common., In order to show the relative abundance of different families in the three localities, Loc., 58, Loc., 55 and Loc., 57, in the Haizume Formation, a value is arbitrarily assigned to each letter in the cheek list : R=1, C=10, A=20., Table 3 shows the number of abundance for each family based on these approximate figures and the percentage of abundance for each family in the three localities when the total number of abundance in Loc., 57 was taken as 100., Fig., 2A is a graphic interpretation of this table., Fig., 2B shows the relationship of the families in twelve localities in the Higasiyama and Araya Formations of the Higasiyama Oil Field.,