Early Diagenesis Records and Pore Water Composition of Methane-Seep Sediments from the Southeast Hainan Basin, South China Sea

Table 1

Major mineral components and their semiquantification results in sediments from the Southeast Hainan Basin (%).

No.	Depth (cm)	Illite	Gypsum	Kaolinite	Brucite	Witherite	Barite	Anhydrite	Quartz	Microcline	Albite	Ba-calcite	Calcite	Mg-calcite	Siderite	Magnesite	Vaterite	Pyrite	Maghemite
T1-44	20	24.2		11.9			22.3		13.1		2.3		7.9			3.5	3.4	11.5
T1-46	35	25.4		13.4	7.0	1.3	22.5	3.5	12.0		2.7		8.9			3.5
T1-36	85	28.7		14.2			25.9		13.8		2.6	5.8	6.0			3.0
T1-38	100	25.2		9.1			30.2		14.6		2.5		8.7		1.9	3.3		4.5
T1-28	200	30.3		11.7	9.6		25.0		10.4			4.4	3.7					4.9
T1-30	216	20.8		13.4	3.8		28.0		10.7			5.4	5.9			3.7		8.3
T1-32	230	26.4		13.4	10.0		28.9		9.1			3.0	5.3					3.9
T1-20	320	27.4		16.2			28.2		14.5		4.0		9.6
T1-22	336	24.5		10.7	11.6		27.1		10.5		2.3		3.7			4.6		5.1
T1-24	355	19.7		11.1	10.4	16.0		2.5	13.4		1.6		11.7	2.3		3.1		3.3	5.0
T1-12	380	24.41	3.08	11.37				2.94	26.50		3.27		25.16	2.51				0.76
T1-14	395	43.1		16.7	7.1		15.3		6.4		2.3		3.3	1.8				4.0
T1-16	415			16.6			37.8	6.6	13.5		6.2		7.6	2.7				9.0
T1-2	440	20.8		17.9				2.8	29.4		3.4		19.9	3.1		2.7
T1-4	450	26.1	4.3	15.0					26.4		3.6		19.0	2.9		2.6
T1-6	465	20.3		14.8			1.7		30.0	9.9	3.3		18.2					1.8
T1-8	475	22.1		11.3				3.2	29.8	8.0	3.8		15.1	2.3		2.6		1.7