Glauconite dates from the Upper Jurassic and Lower Cretaceous

Abstract
Few dates are available from stratigraphically well-documented igneous materials of late Jurassic and early Cretaceous age. Glauconite dates therefore have a special interest despite the geochronological limitations of the mineral. Evidence from the Albian and Cenomanian, moreover, shows that some Mesozoic glauconites give results only slightly lower than the probable correct dates.