Origin and Role of Kaolinization in Roll-Front Uranium Deposits and Its Response to Ore-Forming Fluids in the Yili Basin, China

Table 3

Gas hydrocarbon composition in host rocks within the Mengqiguer uranium deposit.

Samples	Distance from underlying coal seam (m)	Rocks	C1; (μl/kg)	C2; (μl/kg)	C3; (μl/kg)	nC4; (μl/kg)	iC4; (μl/kg)	nC5; (μl/kg)	iC5; (μl/kg)	C1/	C1/∑C
P-1	12	Coarse-grained sandstone	910.20	35.34	10.72	0.78	3.63	0.37	1.00	17.56	0.95
P-2	13	Coarse-grained sandstone	908.40	30.34	15.56	0.83	1.05	0.23	0.76	18.63	0.95
P-3	21	Conglomerate	675.21	18.61	10.01	0.33	1.56	0.17	0.44	21.70	0.96
P-4	29	Medium-grained sandstone	364.33	12.81	5.52	0.46	2.11	0.29	0.65	16.68	0.94
P-5	35	Sandy conglomerate	200.30	9.81	4.70	0.39	1.56	0.19	0.45	11.71	0.92
P-6	44	Fine-grained sandstone	194.32	6.82	4.10	0.37	1.41	0.20	0.44	14.57	0.94
P-7	49	Medium-grained sandstone	88.80	2.51	1.01	0.09	0.34	<0.05	0.09	21.98	0.96

C₁, methane; C₂, ethane; C₃, propane; nC₄, n-butane; iC₄, isobutene; nC₅, n-pentane; iC₅, isopentane; = C₂ + C₃ + nC₄ + iC₄ + nC₅ + iC₅; ∑C = C₁ + C₂ + C₃ + nC₄ + iC₄ + nC₅ + iC₅.