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IODP Expedition 335
Superfast Spreading Rate Crust 4
Daily Science Report for 31 May 2011
LOCATION: Underway from Site 1256 to Panama
SCIENCE UPDATE: Underway to Panama with ETA of 3 June, 0700 h. The scientific party has completed all sampling activities and is completing the Expedition reports.
Daily Science Report for 30 May 2011
LOCATION: Underway from Site 1256 to Panama
SCIENCE UPDATE: Rig operations at Hole 1256D ended at noon and the vessel is underway to Panama with ETA of 3 June, 0700 h. The scientific party is completing sampling and report writing activities.
Daily Science Report for 29 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: When the coring bit reached the bottom of the hole in the early morning, a core barrel was deployed and coring resumed. The barrel was recovered after advancing 1.4 m, from 1520.2 to 1521.6 mbsf, and yielded 10 large pebble size rollers with a nominal total length of 0.5 m (36% recovery). The recovered material was in all likelihood not freshly drilled and consisted mostly of gravel that had been rounded during previous bit runs in the hole, and a few angular pieces. Time for coring had expired and cementing operation began at noon. The first cement plug was emplaced at 1521 mbsf (15 bbls) and the second plug was placed from ~940-910 mbsf (60 bbls). These are intended to stabilize the two problem regions in the hole to facilitate reaching the bottom of the hole to core on a future expedition. The scientific party started to sample the cores, rocks, and cuttings recovered during Expedition 335.
Daily Science Report for 28 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The drill string was tripped to the rig floor and the rescued FMS-sonic tool string removed from the logging bit. Given the lack of evidence of debris from the destroyed drill bit at the bottom of the hole, the absence of metal on the magnet fishing tool, and the very reduced level of soft fill, it was decided to reenter Hole 1256D for the 24th time this Expedition with a C9 hard formation coring bit. This bit offers the greatest gauge protection to open the bottom-most constriction of the hole. An integrated sampling plan for the rock material recovered during Expedition 335 was completed and investigators staked out their samples. Expedition reports are nearing completion.
Daily Science Report for 27 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The first logging run with triple combo successfully reached the bottom of Hole 1256D (1520 mbsf). The caliper didn't open in the lowermost ~14 m of the log, but provided an estimate of the hole size for the remainder of the open hole (1488-270 m). All three bow springs of the upper centralizer were damaged during the logging run and were replaced in preparation for the second run. When the FMS tool string was deployed it was unable to exit the logging shoe. The tool was retrieved and the stabilizer springs examined. It was decided that the new springs were stiff but in good order. One of the springs in the lower centralizer was also replaced as a precautionary measure before the tool string was deployed again. The tool again could not freely exit the logging bit and pumping was utilized to assist its exit. Unfortunately the tool became stuck in the logging bit, neither able to exit or be retrieved back in the drill pipe. Wire cutting procedures were initiated. The drill string will be pulled shortly, with the logging tool extending ~20 m beneath it. In the shipboard laboratory, all cores and other rock material recovered during Expedition 335 were laid out on five tables and preliminary decisions on archiving part of each sample were made in preparation of full shipboard sampling.
Daily Science Report for 26 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The fishing magnet arrived back on the rig floor in the morning with only very minor metal debris. A logging bit was made up and deployed, and re-entered Hole 1256D in the afternoon. The triple combo logging string was deployed and logging is imminent. Expedition 312 scientists started to revise their precruise sample request in preparation for sampling the core and rock material recovered during Expedition 312.
Daily Science Report for 25 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The reverse circulating junk basket (RCJB) arrived back on the rig floor in the morning with only a few gravel-size pieces of rock. This led to the decision to postpone the logging program and attempt to recover metal debris using the fishing magnet. Expedition 312 cores from the plutonic sequence were sampled in a coordinated effort that will result in scientific studies based on Hole 1256D material recovered on multiple expeditions.
Daily Science Report for 24 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The reverse circulating junk basket (RCJB) deployed for the fourth time with bit run #19 contained ~5 kg of angular cobble-sized rocks, two granoblastic dikes and one spectacular gabbro. The angularity of the rocks indicated that they were freshly deposited with a suspected origin somewhere in the bottom 7 m of the hole. The external junk baskets contained the usual gravel sized and smaller cuttings. The RCJB assembly was made up and deployed one more time (the fifth and presumably the last time on this expedition) with bit run #20. The science party held a sampling party for a coordinated sampling approach to the Expedition 312 working section halves.
Daily Science Report for 23 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The reverse circulating junk basket (RCJB) with three stacked external junk baskets was run into the hole one more time (bit run #19) to clear rocks from the bottom of the hole and is on its way back to the rig floor. Scientists submitted draft site reports, analyzed the latest rocks recovered in the RCJB of bit run #18, and prepared for sampling.
Daily Science Report for 22 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The reverse circulating junk basket (RCJB) with three stacked external junk baskets was recovered in the afternoon. It contained four granoblastic dike cobbles: one rounded (tumbled by the drilling or milling process) displaying a spectacular 1-cm wide diorite vein, and three angular, with a total weight of ~8 kg. The external junk baskets contained relatively small amounts of sand-sized cuttings. The lack of significant metal in the recovery lead to the decision to run the RCJB assembly one more time. Henry Dick gave a talk at the continuing science seminar.
Daily Science Report for 21 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The second milling bit was recovered at noon. A fishing configuration was made up consisting of the reverse circulating junk basket at the bottom and three stacked external junk baskets above. The drill string was rigged into the hole to recover rocks and metal junk at the bottom of the hole. The science party discussed sampling plans.
Daily Science Report for 20 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The mill was recovered in the early morning. It was undergauge and heavily worn. The bit was unable to ream the very bottom of the hole. A narrower diameter flat bottomed mill was mounted to the drill string and deployed to continue to mill the junk and rocks at the bottom of the hole for ~6 h. This will be followed with reaming and cleaning runs until the metal fragments are removed. The science party discussed the end of cruise activities, including report writing and the coordinated sampling of rocks recovered from Hole 1256D on expeditions 312 and 335.
Daily Science Report for 19 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: Milling at the bottom of the hole ended in the early afternoon and the rig has been in tripping mode since. The plan is to change to a second milling bit and conduct another milling run before fishing for the junk. Marguerite Godard and Benoit Ildefonse gave presentations at the science seminar.
Daily Science Report for 18 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The drill pipe was recovered in the morning. The bit was in gauge, showed the expected abrasion on the peripheral teeth and very little wear to the frontal inserts, except for a few missing, indicating that it fulfilled its objective. The drill string was equipped with a flat bottomed mill with an external junk basket. The objective is to grind the coring bit fragments at the bottom of the hole into smaller pieces that can be circulated out of the hole, caught by the junk basket, or snared by the fishing magnet that will follow the mill. Jeremy Deans gave a presentation at the science seminar.
Today's re-entry with the mill exceeded 100 miles of pipe trip on this expedition, testament to the determination of the rig floor teams to fulfill the deepening of this critical reference site for the study of the accretion of fast-spread ocean crust.
Deep Earth Academy staff and former School of Rock participants introduced 85 teachers to scientific ocean drilling and Deep Earth Academy curricular materials during a 90 minute presentation at the NSF. These kindergarten through 6th grade teachers are recipients of the prestigious 2010 Presidential Award for Excellence in Mathematics and Science Teaching (PAEMST). The highlight of the session was a live ship-to-shore broadcast with several members of the IODP Expedition 335 science party who gave the teachers a virtual tour of the research vessel and answered questions from the teachers about the science, engineering, and planning aspects of the expedition.
Daily Science Report for 17 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: More than 12 h were spent reaming ~2 m of tight formation down to where the metal junk is believed to cover the bottom of the hole. The drill pipe is being tripped to the surface. Benedict Abily gave a presentation at the science seminar.
Daily Science Report for 16 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: After about 10 h of working the hole from 1519~1521 mbsf, the drill string was tripped back to the surface. The cutting teeth on the drill bit showed little wear. However, the overall bit structure showed severe wear on the outside, including grooves thought to be created by metal, and the legs were slightly bent inwards to the point where the roller cones could not be rotated by hand, indicating that the bottom of the hole is under gage. The junk basket was beaten and bevelled. A new, armored bit with a more aggressive cutting structure around its periphery was made up and deployed to open up the bottom of the hole and the drilling assembly was run into the hole (bit run 16 of the expedition). Damon Teagle gave a presentation at the science seminar.
Daily Science Report for 15 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: A tricone drilling assembly was run into the hole (bit run 15 of the expedition) in an attempt to wash and ream the last ~2 m of remaining hard fill covering the presumed bit fragments on the bottom of the hole. Betchaida Payot gave a presentation at the science seminar.
Daily Science Report for 14 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The reverse circulation junk basket of bit run 14 arrived on the drill floor in the early evening. It contained two cobbles in the main basket and some gravel and sand-sized material in the external bit sub-baskets. Most of the rocks are granoblastic dike material, with a few exceptional pieces exhibiting coarser crystal sizes. Given the persistence of cobble-sized material near the bottom of the hole, a tricone drill bit was made up and run to the seafloor for re-entry #15 with the goal of grinding up the remaining loose rock. The science party further examined the rocks recovered in the various junk basket deployments. Scientific illustrator Sarah McNaboe presented her work. The core description teams presented their observations from thin sections made of Cores 335-1256D-235R to 238R.
Daily Science Report for 13 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The reverse circulation junk basked arrived on the drill floor at noon. It contained two cobbles and a few pebbles of granoblastic dike material and the drill collars were once more replete with fine basaltic cuttings. The ball used to trigger reverse circulation was found in its proper position and the loss of circulation must therefore have been due to clogged jets rather than the reasons speculated about the night before. The drill string was this time equipped with a flow-through catcher-type junk basket expected to have a greater potential to capture the gravel at the bottom of the hole. The science party further examined the rocks recovered in the various junk basket deployments. Johan Lissenberg gave a talk at the science seminar.
Daily Science Report for 12 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The drill string was again equipped with the reverse circulating junk basket and lowered into the hole. In the evening, the bit reached within a couple of meters from bottom and the circulation reversing ball was dropped down the pipe. The initial pressure rise expected as the ball approached its destination was observed on the rig. However, that signal was not followed by the expected pressure drop, indicating that the ball had failed to shear the pins and was not properly seated. Without adequate circulation in either direction, it was not possible to advance and the trip back to the rig floor began. The science party cut and examined the rocks recovered the previous day from the junk basket. Eric Ferre gave a talk at the science seminar.
Daily Science Report for 11 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The drill string equipped with the reverse circulating junk basket reached the bottom of the hole in the morning and returned to the rig floor late night. Almost 50 m of pipe fill consisting of cleanly washed sand-sized cuttings were serendipitously retrieved from the pipe above the junk basket, resulting in what appears to be a significant hole cleaning action. The junk basket itself was tightly packed with sand and gravel, including several fist to small head sized cobbles. Thin sections will be made to examine the recovered material. The science party continued the shipboard seminar with a presentation by Parijat Roy.
Daily Science Report for 10 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The drill string with the tricone bit was retrieved at noon after extensive washing, reaming and flushing in the hole. The junk basket contained abundant gravel to sand sized cuttings of different rock types, including gabbroic rocks with textures hitherto unseen in cores recovered from Hole 1256D. Among the cuttings were a few tens of pieces of steel ~1 cm in size and countless mm-size pieces. The string was equipped with the reverse circulating junk basket in an attempt to retrieve the larger pieces of hardware at the bottom of the hole and lowered to the seafloor.
Daily Science Report for 9 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The day was spent washing, reaming, and flushing Hole 1256D to within a few meters of the bottom of the hole (~1520 mbsf) using a tricone bit.
Daily Science Report for 8 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: While running in the hole with the fishing magnet and junk baskets, circulation was lost at ~73 m above bottom of hole. Attempts to pull back and regain circulation were not successful. The drill string was pulled all the way to the surface where the bit sub, junk baskets, and magnet were found to be packed with sand-sized cuttings of basalt with metal shavings and some cement grains. It was decided to re-enter the hole with a tricone bit and wash, ream and flush the debris out of the hole to within a few meters of the expected hardware at the bottom of the hole. The science party continued the shipboard seminar with presentations by Mark Kurz.
Daily Science Report for 7 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The bit arrived on deck in the early morning and showed severe abrasion, with cones, legs, guides, and jets missing and only a smoothly ground stump left. This properly explained the lack of advance as well as the abrasion on the core barrel shoe observed the previous day. The drill string was equipped with a fishing magnet and junk baskets and run into the hole to recover the remains of the bit. The science party continued the shipboard seminar with presentations by Jeff Alt and Michelle Harris.
Daily Science Report for 6 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: Coring was very slow, advancing only 2 m in 16 h. Core 1256D-238R consisted of three dolerite roller pieces. The core barrel shoe displayed significant and unusual abrasion (~2 cm) indicating a mechanical problem. The drill string is being recovered to assess and change the bit. A science meeting was held with presentations by the geochemistry group on planned shipboard analyses and feasibility of the shipboard handheld XRF system. The science meeting was followed by the first sampling party on Expedition 335.
Daily Science Report for 5 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The first day of coring in the target formation in Hole 1256D advanced the hole from 1507.1 to 1518.2 mbsf (Cores 1256D-235R through 237R). Total recovery was 0.94 m of rock consisting of dikes intruded by tonalite dikelets. Scientist submitted reports of their laboratory group analysis of Expedition 312 cores and data.
Daily Science Report for 4 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: Coring of the cemented interval in Hole 1256D continued from 942.5 - 980.9 mbsf and yielded a few rollers in each of the core catchers. One of the recovered pieces, ~4 cm in size, contained cryptocrystalline sparsely plagioclase-phyric basalt (sheet flow?) with a circumference of prominent 5-mm black haloes indicating a closely spaced orthogonal low-temperature vein, consistent with the rock recovered on Expedition 312 from the cemented interval. The drill pipe was advanced by washing and reaming and reached the bottom of the hole by midnight. After spending 16 days opening, cleaning, and stabilizing the hole, using a consistent approach and experiencing no serious operational problems, the fourth stage of coring in Hole 1256D has finally begun. A science meeting was held to present and discuss the findings of the paleomagnetics and physical properties groups based on their analysis of Expedition 312 cores.
Daily Science Report for 3 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The drill pipe was run in the hole with a coring bit to core throughout the cement plug deployed the previous day, and then into the formation at 1507 mbsf. The first two attempts at coring the cement plug between 924.0-942.5 mbsf returned a few small (<5 cm) pieces of cement, indicating that the firm mudstone-like material was ground up under the weight of the bit. A science meeting was held to present and discuss the findings of the alteration petrology and structural geology groups from their analysis of Expedition 312 cores.
Daily Science Report for 2 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: The drill pipe was run in the hole with a cementing bit configuration. Sixty barrels of cement were pumped into the problematical interval with the bit at 960 mbsf. The drill string was pulled up, flushed with water, and pulled to the surface in preparation for coring. A science meeting was held to present and discuss the findings of the igneous petrology group from their analysis of Expedition 312 cores.
Daily Science Report for 1 May 2011
LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)
SCIENCE UPDATE: Washing and reaming Hole 1256D continued swiftly, except for a 2-h period of stuck pipe at ~1162 mbsf. In the early morning, hard fill was encountered ~6 m above the bottom of the hole. After grinding and flushing the fill out of the hole, the target depth at ~1507 mbsf was finally reached. The drill pipe was pulled and 60 barrels of heavy mud were spotted in the problematic interval at 920-960 mbsf. The pipe was then pulled to the surface to prepare for a cementing job in the same interval. The science party continued the shipboard seminar with a presentation by Natalia Zakharova. Lab teams continued writing reports about their measurements and descriptions of Expedition 312 samples.
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