Mineralogical Variation of Sedimentary Clay Deposit at Mae Than Mine, Ban Mae Than, Amphoe Mae Tha, Lampang Province, Thailand

The sedimentary deposit is a part of the south of Lampang basin with the age of Tertiary to present. Clays in this deposit was divided into three layers covered with red clay. Clay layers were overburden which was the clay overlying on top of coal seam; interburden was the clays lie between coal seams; and underburden was the clay lie under coal seam. The basement rock was rhyolitic tuff. Major minerals found were quartz, kaolinite, illite, potassium feldspar and montmorillonite, respectively. There was no distinct relationship of quartz content in each clay layers. However, kaolinite and illite contents slightly increased in deeper clay layers. Additionally, montmorillonite presented in basement rock sample and some of overburden clay.