A B C D E F G H I J K L M N O P Q R S T U V W X Y Z #0-9

Hoedemaeker P.J. (1984) Proposals for the stratigraphic positions of the Berriasian-Valanginian and the Valanginian-Hauterivian boundaries // Bull. Of the Geol. Society or Denmark. Vol. 33. Pp. 139-146.

In two previous papers (Hoedemaeker, 1982,1983) the author proposed to draw the boundary between the Berriasian and the Valanginian at the base of the Timovella alpillensis Subzone, which he described from SE Spain. The correlation of this subzone with the published French zonation is however problematic, because the faunal association of the alpillensis Subzone is unknown from France. He correlated the alpillensis Subzone with the French Berriasella callisto Subzone. In this paper he revised his previous correlation and equated his alpillensis Subzone with the greater upper part of the callisto Subzone. He correlated the lower part of the latter subzone, which probably covers the interval assigned to the callisto Subzone in the Berriasian stratotype, with the uppermost part of his Berriasella picteti Subzone in Spain. The author also proposed (1982, 1983) to draw the Valanginian - Hauterivian boundary between the Saynoceras verrucosum and Himantoceras trinodosum Subzones. This proposal is further elucidated in this paper. The two boundaries discussed here coincide with the peaks of two successive global sea level lowstands, well marked in the Vailian global coastal onlap curve as Basal Valanginian (131) global unconformity and the Basal Hauterivian (126) global unconformity (Vail & Todd, 1981; Ziegler, 1982).