FLUORESCENCE OF LIMESTONES AND LIMESTONE COMPONENTS

The fluorescence of a series of limestones has been investigated; the relative fluorescence intensities of these limestones differ by a fact or of 10. With UV excitation, the fluorescence spectra of these limest ones exhibit two distinct peaks, one blue and one red; the relative ma gnitude of the blue peak is larger for more fluorescent limestone. The limestones were digested, allowing for isolation of different limesto ne components, which are acid-extractable organics, bitumen, and kerog en. With the correlation of fluorescence spectra and intensities, it h as been established that the acid extract fraction produces the blue p eak in the rocks. Concentrated bitumen produces red fluorescence, cont ributing to the red peak of the rock. Generally, the limestone kerogen s are found to possess very low fluorescence, in contrast to carbonace ous shale kerogens, and probably do not contribute to rock fluorescenc e.