Table 1. Physicochemical variables from shallow and deep sediment samples.

		Geographical location		Physicochemical variables
Site	Sample	Longitude	Latitude	Depth (m)	Redox ↑ (mV)	TS ↑ (µM)	TOM (%)	TOC (µM)	Sand (%)	Lime ↑ (%)	Clay ↓ (%)
Shallow	E10	97°13′48″W	25°15′N	20	−131.0	0.05	0.80	0.45	34.5	51.2	14.4
	E11	96°56′24″W	25°15′N	75	−174.4	0.05	1.10	0.61	26.5	57.3	16.3
	E12	96°43′12″W	25°15′N	100	−204.0	0.05	1.02	0.56	20.5	51.2	28.4
	E13	96°27′36″W	25°15′N	200	−131.7	0.05	0.83	0.46	22.5	51.2	26.4
	E14	96°18′36″W	25°15′N	600	−192.9	0.05	1.02	0.56	23.7	68.2	8.1
Deep	E121	95°30′W	25°00′N	2,800	230	0.10	1.22	0.68	33.75	60.3	6.0
	E122	95°00′W	25°00′N	3,600	233	0.10	0.59	0.33	27.75	66.3	6.0
	E123	94°00′W	25°00′N	3,700	225	0.11	0.44	0.25	25.7	66.3	8.0
	E124	93°00′W	25°00′N	3,700	215	0.11	0.85	0.47	29.8	64.3	5.9
	E125	92°00′W	25°00′N	3,500	236	0.12	0.81	0.45	23.9	70.3	5.9
	E126	91°00′W	25°00′N	3,700	215	0.12	0.92	0.51	25.8	68.2	6.0

Notes.

TS, total sulfur; TOM, total organic matter and TOC, total organic carbon. Physicochemical variables measured with no replicates. Pearson coefficient showed significant correlation at a p-value <0.01 among TS (r² = 0.98), redox potential (r² = 0.98), and the percentages of lime (r² = 0.78) and clay (r² = −0.78) particles with depth.

↑ Variables with positive correlation with depth.

↓ Variables with negative correlation with depth.