Table T1. Compilation of deep (>50 m) drill holes into in situ ocean basement drilled by the Deep Sea Drilling Project and the Ocean Drilling Program (1968–2006).

Leg	Hole	Latitude	Longitude	Ocean	Water depth (m)	Age (Ma)	Sediment thickness (m)	Basement penetration (m)	Recovery (%)	Spreading Rate S/I/F 40/80	Comments	Lithology
24	238	11°09.21'S	70°31.56'E	Indian	2845	30	506	81	50	S/I	Projection of Chagos-Laccadive Plateau	Basaltic lavas
26	257	30°59.16'S	108°20.99'E	Indian	5278	120	262	65	50	S/I	Wharton Basin off Perth, Australia	Basalt and breccia
34	319A	13°01.04'S	101°31.46'W	Pacific	4296	16	98	59	25	F	Bauer Deep, 13°S East Pacific Rise	Basaltic lavas
37	332A	36°52.72'N	33°38.46'W	Atlantic	1851	3.5	104	331	10	S	Mid-Atlantic Ridge 36–37°N	Basalt, basalt breccia, interlayered sediments
37	332B	36°52.72'N	33°38.46'W	Atlantic	1983	3.5	149	583	21	S	Mid-Atlantic Ridge 36–37°N	Basalt, basalt breccia
37	333A	36°50.45'N	33°40.05'W	Atlantic	1666	3.5	219	310	8	S	Mid-Atlantic Ridge 36–37°N	Basalt, basalt breccia
37	335	37°17.74'N	35°11.92'W	Atlantic	3188	15	454	108	38	S	Mid-Atlantic Ridge 36–37°N	Basaltic lavas
45	395A	22°45.35'N	46°04.90'W	Atlantic	4485	7.3	111	577	18	S	Mid-Atlantic Ridge 23°N	Basaltic lavas and breccia
45	396	22°58.88'N	43°30.95'W	Atlantic	4450	9	126	96	33	S	Mid-Atlantic Ridge 23°N	Basaltic lavas
46	396B	22°59.14'N	43°30.90'W	Atlantic	4459	13	151	255	23	S	Mid-Atlantic Ridge 23°N	Basalt and breccia
49	410A	45°30.53'N	29°28.56'W	Atlantic	2987	9	331	49	38	S	Mid-Atlantic Ridge 45°N	Basaltic lavas
49	412A	36°33.74'N	33°09.96'W	Atlantic	2626	1.6	163	131	18	S	Mid-Atlantic Ridge 33°N	Basalt flows and intercalating limestone
51–53	417A	25°06.63'N	68°02.48'W	Atlantic	5478	110	208	209	61	S	Western Atlantic	Basaltic lavas
51–53	417D	25°06.69'N	68°02.81'W	Atlantic	5489	110	343	366	70	S	Western Atlantic	Basaltic lavas
51–53	418A	25°02.10'N	68°03.44'W	Atlantic	5519	110	324	544	72	S	Western Atlantic	Basaltic lavas
54	428A	09°02.77'N	105°26.14'W	Pacific	3359	2.3	63	53	39	F	9°N East Pacific Rise	Basaltic lavas
63	469	32°37.00'N	120°32.90'W	Pacific	3803	17	391	63	34	I	Off California coast	Basaltic lavas
63	470A	28°54.46'N	117°31.11'W	Pacific	3555	15	167	49	33	I	Off California coast	Basaltic lavas
65	482B	22°47.38'N	107°59.60'W	Pacific	3015	0.5	137	93	54	I	Off Gulf of California	Massive basalt and interlayered sediment
65	482D	22°47.31'N	107°59.51'W	Pacific	3015	0.5	138	50	50	I	Off Gulf of California	Massive basalt and interlayered sediment
65	483	22°53.00'N	108°44.90'W	Pacific	3084	2	110	95	40	I	Off Gulf of California	Massive basalt and pillow basalt with interlayered sediments
65	483B	22°52.99'N	108°44.84'W	Pacific	3084	2	110	157	47	I	Off Gulf of California	Massive basalt and pillow basalt with interlayered sediments
65	485A	22°44.92'N	107°54.23'W	Pacific	2997	1.2	154	178	51	I	Off Gulf of California	Massive basalt and interlayered sediments
68	501	01°13.63'N	83°44.06'W	Pacific	3467	6.6	264	73	60	I	South flank of Costa Rica Rift	Basaltic lavas
82	559	35°07.45'N	40°55.00'W	Atlantic	3754	35	238	63	37	S	West flank of Mid-Atlantic Ridge 35°N	Basaltic lavas
82	562	33°08.49'N	41°40.76'W	Atlantic	3172	12	240	90	45	S	West flank of Mid-Atlantic Ridge 33°N	Pillow basalt and massive basalt
82	564	33°44.36'N	43°46.03'W	Atlantic	3820	35	284	81	43	S	West flank of Mid-Atlantic Ridge 34°N	Pillow basalt and minor massive basalt
91	595B	23°49.34'S	165°31.61'W	Pacific	5615	80	70	55	28	F	Central South Pacific	Vesicular aphyric basalt
92	597C	18°48.43'S	129°46.22'W	Pacific	4164	30	53	91	53	F	West flank South East Pacific Rise 18°S	Massive basalt flows
106/109	648B	22°55.320'N	44°56.825'W	Atlantic	3326	0	0	51	12	S	Mid-Atlantic Ridge 23°N	Pillow basalt
123	765D	15°58.560'S	117°34.51'E	Indian	5714	140	948	271	31	F	Argo Abyssal Plain	Normal–Enriched MORB basaltic lavas
129/185	801C†	18°38.538'N	156°21.59'E	Pacific	5674	170	462	414	47	F	Western North Pacific	Pillow basalt, basalt flows, breccias
129	802A	12°5.778'N	153°12.63'E	Pacific	5980	120	509	51	33	F	Western North Pacific	Basaltic lavas
136	843B	19°20.54'N	159°5.68'W	Pacific	4418	95	243	71	37	F	West of Hawaii	Basaltic lavas
69/70/83 /111/137 /140/148	504B	1°13.611'N	83°43.818'W	Pacific	3474	6.6	270	1841	20	I	South flank of Costa Rica Rift	Basalt, stockwork, diabase
148	896A	1°13.006'N	83°43.392'W	Pacific	3459	6.6	200	269	27	I	South flank of Costa Rica Rift	Basaltic lavas
185	1149D	31°18.79'N	143°24.03'E	Pacific	5818	133	307	133	17	F	Western North Pacific	Pillow basalt, basalt flows, breccias
187	1162B	44°37.9'S	129°11.3'E	Indian	5464	18	333	59	17	I	Australian-Antarctic Discordance	Basaltic lavas and breccia
187	1163A	44°25.5''S	126°54.5'E	Indian	4354	17	161	47	33	I	Australian-Antarctic Discordance	Basaltic lavas
187	1164B	43°45.0'S	127°44.8'E	Indian	4798	18.5	150	66	16	I	Australian-Antarctic Discordance	Basaltic lavas
191	1179D	41°04.8'N	159°57.8'E	Pacific	5564	129	377	98	44	F	Western North Pacific	Basaltic lavas
200	1224F	27°53.36'N	141°58.77'W	Pacific	4967	46	28	147	26	F	Central Pacific	Basaltic lavas
203	1243B	5°18.07'N	110°04.58'W	Pacific	3868	11	110	87	25	F	Western flank of East Pacific Rise 5°N	Basaltic lavas
206	1256C	6°44.18'N	91°56.06'W	Pacific	3635	15	251	89	61	F	Cocos plate eastern flank East Pacific Rise	Basaltic lavas
206	1256D	6°44.16'N	91°56.06'W	Pacific	3635	15	251	502	478	F	Cocos plate eastern flank East Pacific Rise	Basaltic lavas

Notes: The holes listed here sampled normal mid-ocean-ridge basalt (N-MORB) crust formed at bare rock mid-ocean ridges and were initiated in lavas. We have not included holes from arc settings or holes spudded into plutonic rocks at tectonic windows or transform faults. Table adapted from separate compilations of hard rock drill holes by W. Bach, J. Alt, and D. Teagle. † = 60.2 m of alkali basalt sills that were intruded at the sediment/basement boundary some 20 m.y. after the formation of the crust in Hole 801C have been subtracted from the basement penetration in that hole.

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