Explorer Geophysical Corner
By Ritesh Sharma,Satinder Chopra
Generally, the fine-grained shale rocks are found to be composed of 50 to 70 percent clay, anywhere between 25 to 40 percent silt- and clay-sized quartz, and 5 percent of minerals including feldspars and carbonates, comprising the total rock volume. A variety of techniques such as X-ray diffraction, infrared spectroscopy and electron microscopy are available, which help us understand the type of clay minerals present in a shale sample.