Pore Structure Differentiation between Deltaic and Epicontinental Tight Sandstones of the Upper Paleozoic in the Eastern Linxing Area, Ordos Basin, China

Table 2

Relative content of clay minerals in sandstones in coal measure.

Formation		Clay (%)	K (%)	I (%)	Ch (%)	I/S (%)	/(I/S) (%)
Shanxi	Content	51-73	25-44	15-26	22-36	8-25	20-20
	Average	60.25	31.33	22.33	27.34	19	20
Taiyuan	Content	6-96	1-86	3-99	0-29	0-20	0-24
	Average	32.74	42.11	47.26	7.47	3.16	1.47

Clay: clay minerals; K: kaolinite; I: illite; Ch: chlorite; I/S: I/S mixed clay; (I/S): I/S mixed-layer rate.