The thermoluminescence of the limestones of the Meramecian and Chesteran series (middle and upper Mississippian) of the Illinois basin was studied in an attempt to develop the thermoluminescence of limestones into a useful research tool in subsurface geology.

A powder method of sample preparation is described which makes accurate quantitative measurement of thermoluminescence possible. The apparatus used in measuring and recording thermoluminescence is described briefly.

The analysis of patterns of variation in intensity of thermoluminescence and in glow-curve shapes vertically through a formation appears to have some usefulness in subsurface stratigraphy in (a) identifying and characterizing a formation, (b) assisting in recognizing tops and bottoms of limestone formations where lithologic breaks are not present, (c) splitting thick carbonate rock sequences into small units useful in correlation, and (d) recognizing erosion or non-deposition of zones by the absence of parts of the typical pattern of variation.

Within certain limitations, the variations in radioactivity of the limestones appear to be the dominant factor in the cause of variations in thermoluminescence.