- GeoRef, Copyright 2008, American Geological Institute. Reference includes data from Bibliography and Index of North American Geology, U. S. Geological Survey, Reston, VA, United States
Smoothed slabs of limestone, observed and recorded by different methods, reveal sedimentary structures with different degrees of success. Sedimentary structures only dimly visible in ordinary light are made conspicuous by transmitted infrared. Fluorescent dyes penetrate defects in the rocks and reveal little of primary structures. Carbonates respond so uniformly to X-rays that structures are not revealed. Transmitted infrared is thus preferred for carbonates.