leg site hole core coretype section top interval unit number sub unit pieces observer rockname color layering deformation primary mineral name (1) primary percent (1) primary size (1) primary shape (1) primary orientation (1) primary replacement (1) primary description (1) primary mineral name (2) primary percent (2) primary size (2) primary shape (2) primary orientation (2) primary replacement (2) primary description (2) primary mineral name (3) primary percent (3) primary size (3) primary shape (3) primary orientation (3) primary replacement (3) primary description (3) primary mineral name (4) primary percent (4) primary size (4) primary shape (4) primary orientation (4) primary replacement (4) primary description (4) primary mineral name (5) primary percent (5) primary size (5) primary shape (5) primary orientation (5) primary replacement (5) primary description (5) primary comments secondary percent secondary texture secondary veins secondary comments main comments more data latitude longitude depth top interval depth below sea floor 103 637 A 023 Rotary 03 037 0001 1-6. DU SERPENTINIZED PORPHYROCLASTIC HARZBURGITE. see comments see comments see comments see comments see comments Basement rock was recorved at the bottom of this core in Section 637A-23R-3, which includes 20 cm of yellow-red mud overlying about 80 cm of extreamly altered foliated harzburgite. The rock grades from a very leached yellow rock with elongated dissolution cavities along the foliation (at a angle of 30 degrees) to a more massive, strongly foliated green-gray peridotite. The rock is almost completely serpentinized and extensively replaced by calcite (>75% in the top few cm); vertical calcite veins are abundant near the bottom of the core, and calcite rims and replaces the pyroxene porphyroclasts. The freshest samples (637A-23R-3R, 37-40 cm and 46-48 cm) have a few relict mineral fragments (opx, cpx, chromite). The rocks are 75-80% olivine, 10-15% opx, 0-5% cpx and 1-2% chromium spinel. no 42.08833 -12.86333 0211.80 21217 103 637 A 024 Rotary 01 000 1-5. DU SERPENTINIZED PORPHYROCLASTIC HARZBURGITE. see comments see comments see comments see comments see comments Coarse porphyroclastic harzburgite with foliation defined by the alignment of oval-shaped orthopyroxene and chromium spinel. The rock is cut by thick (1-2.5 cm) dia gonal and vertical calcite veins which appear to become more regularly spaced downcore. The bottom of Section 637A-1 and top of 637A-2 include pink-gray mud and sand with Miocene discoasters. The rock is almost completely altered (95-100%) to serpentine. A few fragments of pyroxene porphyroclasts remain. Abundant thin calcite veins dissect the rock. The rock is a pyroxene-poor harzburgite with 90% serpentine derived from olivine, < 10% orthopyroxene, 1-2% clinopyroxene, and 1% chromium spinel. It is sheared, as shown by strong alongation of orthopyroxene pseudomorphs. no 42.08833 -12.86333 0218.40 21839 103 637 A 024 Rotary 01 060 1. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-24R-1. no 42.08833 -12.86333 0218.40 21899 103 637 A 025 Rotary 01 000 1-12. DU SERPENTINIZED PORPHYROCLASTIC HARZBURGITE. see comments see comments see comments see comments see comments The top of this core is composed of a gray-green homogeneous foliated peridotite which displays porphyroclastic textures. It is dissected by small calcite veins which are oriented at a high angle to the foliation. The calcite often contains small inclusions of magnetite. The degree of deformation, marked by the extreme elongation of orthopyroxene, increases downward to the middle of core. This is also the case for serpentinization of the peridotite, and almost no relict primary phases are preserved. Calcite veining is not as extensive, but increases again towards base of core. The bottom sections contain pyroxene-poor harzburgite which is highly serpentinized and brecciated; a lot of serpentine rubble was recorved, with large (2-3 cm) calcite veins. no 42.08833 -12.86333 0228.00 22800 103 637 A 025 Rotary 02 000 1-2. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-25R-1. no 42.08833 -12.86333 0229.50 22950 103 637 A 025 Rotary 03 000 1-11. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-25R-1. no 42.08833 -12.86333 0231.00 23100 103 637 A 025 Rotary 04 000 1-5. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-25R-4. no 42.08833 -12.86333 0232.09 23208 103 637 A 025 Rotary 05 000 1-9. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-25R-1. no 42.08833 -12.86333 0233.59 23358 103 637 A 025 Rotary 06 000 1-4. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-25R-1. no 42.08833 -12.86333 0235.04 23503 103 637 A 026 Rotary 01 000 1-5. DU SERPENTINIZED PORPHYROCLASTIC HARZBURGITE. see comments see comments see comments see comments see comments This core consists of highly altered peridotite which is variably veined by calcite. The veining is especially notable at the top and the bottom of core. The veins are thick, zoned, and are coarsely crystalline with comb structures. Serpentine veining is also pervasive. The middle of core includes massive, strongly altered and sheared, pyroxene-poor harzburgite. The orthopyroxene, which constitutes less than 10% of rock, is highly elongated and strained; the clinopyroxene is rounded and often replaced by calcite. The base of the core contains brecciated serpentinite and black serpentine rubble. Many of the cobble-sized pieces contain large calcite veins. no 42.08833 -12.86333 0237.20 23719 103 637 A 026 Rotary 02 000 1A-1H. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-26R-1. no 42.08833 -12.86333 0238.70 23869 103 637 A 026 Rotary 03 000 1-13. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-26R-1. no 42.08833 -12.86333 0239.95 23994 103 637 A 026 Rotary 04 000 1-8. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-26R-1. no 42.08833 -12.86333 0241.45 24144 103 637 A 027 Rotary 01 000 1-18. DU SERPENTINIZED PORPHYROCLASTIC HARZBURGITE. see comments see comments see comments see comments see comments This core consists of moderate to highly altered and sheared peridotite(highly altered & friable near base). Part of the recovered material includes some coarse-grained peridotite sand (a result of drilling). The top of the core includes cobble or smaller sized pieces of peridotite. This becomes more massive and less altered downward. Thin sections reveal the rock to be a pyroxene-rich harzburgite which contains more and larger fragments of the primary minerals (mostly opx and cpx). The rock is black in color in the middle of the core, but heavily veined with calcite. The rock grades into a pyroxene-poor (<10%) harzburgite with local occurrences of pyroxene-rich layers(20-25% pyroxene). Some amphibole associated with the alteration of pyroxenes is observed. Shear zones increase downward. no 42.08833 -12.86333 0246.90 24689 103 637 A 027 Rotary 02 000 1-19. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-27R-1. no 42.08833 -12.86333 0248.40 24839 103 637 A 027 Rotary 03 000 1-6. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-27R-1. no 42.08833 -12.86333 0249.90 24989 103 637 A 027 Rotary 04 040 1-8. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-27R-1. no 42.08833 -12.86333 0250.99 25139 103 637 A 027 Rotary 05 000 1-12. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-27R-1. no 42.08833 -12.86333 0252.49 25249 103 637 A 027 Rotary 06 000 1-15. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-27R-1. no 42.08833 -12.86333 0253.99 25399 103 637 A 028 Rotary 01 000 1-13B. DU SERPENTINIZED PORPHYROCLASTIC HARZBURGITE. see comments see comments see comments see comments see comments This core consists of gray-green coarse to fine-grained porphyroclastic peridotites which are pyroxene-poor(10-15% pyroxene). The apparent foliation is about 45-50 degrees at top, steepens to 75-80 degrees mid-core, and is near vertical at the base. The rock has a well-developed foliation, which is evident in thin section (extreme elongation of opx, fragmented cpx & chromium spinel crystals which are strung out along the foliation plane). The rock becomes increasingly altered and brecciated downsection, and virtually no relict fragments of primary minerals are preserved. The color changes to red-green and black downsection. The peridotite is broken into many cobble-sized pieces which have thick calcite veins and fibrous serpentine veins. no 42.08833 -12.86333 0256.60 25660 103 637 A 028 Rotary 02 000 1-14. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-28R-1. no 42.08833 -12.86333 0258.10 25810 103 637 A 028 Rotary 03 000 1-15. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-28R-1. no 42.08833 -12.86333 0259.60 25960 103 637 A 028 Rotary 04 000 1-16. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-28R-1. no 42.08833 -12.86333 0260.89 26089 103 637 A 029 Rotary 01 000 1-22. DU ALTERED PERIDOTITE. see comments see comments see comments see comments see comments Very friable and heaviliy altered peridotite was recorved in this core. It is broken up into many pieces. The color changes from red-green to black downcore. The upper part of the core contains pieces which are cut by abundant calcite veins, but this changes downwards into pieces with no calcite veins where the rock has a vertical foliation and is highly sheared. The base of the core recovered a coarse, poorly sorted peridotite sand, which is presumably the product of drilling. No shipboard thin section were made. no 42.08833 -12.86333 0266.30 26629 103 637 A 029 Rotary 02 125 23. DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-29R-1. no 42.08833 -12.86333 0267.80 26904 103 637 A 030 Rotary 01 000 n/a DU SERPENTINE MUD. see comments see comments see comments see comments see comments Only a blue-gray mud was recorved in this core. It has the composition of serpentine (chrysotile and lizardite), and is presumably drill gouge material. no 42.08833 -12.86333 0275.90 27589 103 637 A 030 Rotary 02 000 n/a DU CONTINUED. see comments see comments see comments see comments see comments See description in 103-637A-30R-1. no 42.08833 -12.86333 0276.25 27625