苏北盆地玄武岩地质年龄及地层时代

本文以快中子活化（39Ar／40Ar）法、K—Ar法为主要手段．通过16个玄武岩样品地质年龄的测定和分析．首次建立了苏北盆地泰州组—盐城组玄武岩喷发年代时间剖面，并对各级段的界线年龄进行了修正。提出了白垩系和第三系的界线在泰州组与阜宁组之间．古新统与始新统界线在阜宁组—～二段和三～四段之间、始新统与渐统界线在三垛组一段和二段之间，本区缺失上渐新统地层。

THE GEOLOGICAL TIME OF BASALT AND STRATA IN NORTH JIANGSU BASIN

The main subject uf this paper is to revise the geulugical tin1e accurding to the results of basalt age determination. The authors used fast neutron activatiun method and K-Ar dilution metering as major measures and ensured the reliability of the results of determination. The basalt eruptive time scale has been established fur the first time, based on the determination of 16 samples. After a composite induction, the ages of the each formation boundary in North Jiangsu Basin have been revised, and a chronostratigraphic sequence was established. The au-thors propose that the boundary between Cretaceuus and Tertiary is lucated between Tatihou Formation and Funing Formatiun, the buundary between Palaeocene and Eocene is at the in-terface between lst Member-2nd Menlber and 3rd Member-4th Member of Funing Forma-tion, the boundary between Eocene and Oligocene is at the interface between lst Member and 2nd Member of Sanduo Formation, and strata of Upper Oligucene are absent from this area.