Geologic Time(23 slides) $46

Several slides illustrate the historical development of geologic time concepts. Estimates of earth ages from the 18th to the 20th century are compared. Several slides develop the origin of the geologic column in 19th century Europe through the presently accepted timtable. The remaining slides develop dating concepts through sedimentary rock correlations, igneous intrusives and radioisotopic methods.

Copyright 1999 by Pan Terra Inc., PO Box 556, Hill City, SD, USA 57745.

All rights reserved.......Tel or fax 605-574-4760