Table T4. Summary of Leg 202 geochemistry.

	Region	Site	Water depth (m)	Sulfate concentration minimum (mM)	Depth (mcd)	Alkalinity concentration maximum (mM)	Depth (mcd)	Phosphate concentration maximum (M)	Depth (mcd)	Ammonium concentration maximum (mM)	Depth (mcd)	Methane concentration maximum (mM)	Shallowest Depth (mcd)	Calcium concentration minimum (mM)	Depth (mcd)
Limited to no sulfate reduction
	Nazca Ridge	1236	1323	<26	170–191	2.2	—	2	3	<0.005	—	none detected		increases with depth
		1237	3212	<26	5–63	>5	9–20	9	5	>0.25	9–33	8	42–63	increases with depth
	Cocos Rise	1241	2027	little depletion	—	>5	63–95	5	3	>0.4	53–106	13	189	increases with depth
Intermediate sulfate reduction
	Carnegie Ridge	1238	2203	<10	75	>17	83–93	>15	10–64	3	82–386	<100		6.1	54
	Panama Basin*	1240	2921	<15	135–200	>17	147–190	>30	147–190	>2	147–200	57	147	<3.5	104–179
Complete sulfate reduction
	Chile Basin	1232	4072	<2	26	>30	26–159	>50	throughout	>2	37	>10,000	>60	<6	27
														<4	93–105
	Chile Margin	1233	838	BDL	21	>60	21–44	>210	11–55	>5	11–77	High	23	<2	5–11
		1234	1015	BDL	10	>63	18–52	>120	10–52	>11	40–88	High	9	<2	10–112
		1235	489	BDL	20	>60	31–42	>200	20–42	>8	31–42	High	20	<2	20–109
	Carnegie Ridge	1239	1414	BDL	71	>28	92–123	>20	61–113	>6	133–378	Moderate–high	100	5.5	71–82
	Cocos Rise	1242	1364	BDL	23	>25	23–94	60	34	>7.5	94–170	High	35	2.5	34

Notes: * = Site 1240 is influenced by fluid flow in the underlying basalt, and its geochemistry is discussed separately in the text as a consequence. BDL = below detection limit. Sulfate detection limit was typically 1 mM or lower.