IODP Expedition 335

Superfast Spreading Rate Crust 4

Daily Science Report for 30 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: Hole 1256D was washed and reamed from 943 mbsf to 1379 mbsf and steady progress continues towards the target at ~1507 mbsf. The science party continued the shipboard seminar with a presentation by Tony Morris. Lab teams began writing reports about their measurements and descriptions of Expedition 312 samples.

Daily Science Report for 29 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: The drill string, equipped with a tricone bit, re-entered Hole 1256D in the early morning and proceeded to work the tight interval at ~922 mbsf for several hours. Progress was eventually indicated when the bit reached a depth of 943 mbsf by the end of the day. The science party continued the shipboard seminar with a presentation by Ryo Oizumi, followed by an operational progress and context presentation by the co-chiefs. Lab teams submitted draft methods sections and continued descriptions of cores from Expedition 312.

Daily Science Report for 28 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: At 0600 h the bit was still at ~922 mbsf and a pipe round trip began to change the bit. The tandem junk basket deployed above the tricone bit yielded coarse basalt sand with several basalt pebbles and fragments of breccia, quartzite, and cement. By the end of the day the drill pipe had reached the seafloor, ready to re-enter Hole 1256D. The science party continued the shipboard seminar with a presentation by Jessica Till. Lab teams continued descriptions and measurements of cores from Expedition 312.

Daily Science Report for 27 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: Drilling with the tricone and varying drilling parameters continued throughout the day without any advancement past 921 mbsf. The science party continued the shipboard seminar with a presentation by Marie Python. Lab teams continued descriptions and measurements of cores from Expedition 312.

Daily Science Report for 26 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: The drill string was retrieved, equipped with a tricone bit configured for drilling operations, and re-deployed into Hole 1256D for the sixth time. In the early evening, the bit tagged bottom at ~882 mbsf, indicating that the 50-barrel cement plug extended ~40 m above the problematic surface at 922 mbsf. Drilling proceeded quickly through the cemented interval, however, the drill again did not advance past 921 mbsf. The science party continued the shipboard seminar with a presentation by Henry Dick. Lab teams continued descriptions and measurements of cores from Expedition 312.

Daily Science Report for 25 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: The drill string was retrieved, equipped with a tricone bit modified for cementing operations, and re-deployed into Hole 1256D for the fifth time. In the early evening, ~50 barrels of cement slurry were pumped into the problem zone and chased with drill water. The drill pipe is now being recovered and will be redeployed with a tricone bit configured to make hole. The science party continued the shipboard seminar with a presentation by Endo. Lab teams continued to configure their core description schemes based on their descriptions of cores from Expedition 312. Imaging and other core logging measurements began as well on the Expedition 312 cores.

Daily Science Report for 24 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: The bit arrived on the rig floor in the early morning and the cementing equipment was rigged down. A new tricone bit was mounted and by late afternoon the drill string was run into Hole 1256D for the fourth time during this cruise. The same obstruction was encountered at ~922 m depth, indicating that a cement plug had not built up above the compromised interval. High torque indicated that the bit was again getting stuck in the presumed gravel interval. The decision was made to retrieve the string and prepare for a second cementing operation using a larger amount of cement. The science party continued the shipboard seminar with a presentation by Miyashita, enjoyed the first Sunday BBQ on deck, and continued describing cores from Expedition 312.

Daily Science Report for 23 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: The drill bit reached the drill floor in the early morning and both boot baskets contained a few kilograms of angular basaltic gravel ranging in size from coarse sand to large pebbles. Most material is consistent with material cored in this interval during Expedition 309. Given the assumption that the drill bit had been bouncing on a gravelly obstruction for days, it was decided to deploy a cement plug at the problematic interval to bind the gravel sufficiently to allow subsequent drilling through the plug. The drill string was equipped with a tricone bit adapted for cementing and re-entered Hole 1256D in the afternoon. Four hours later, five barrels of 15 ppg cement slurry were pumped into the troubled interval and chased with 5 barrels of drill water. In the meantime, the science seminar continued with presentations by Harris and Adachi, and scientists continued describing cores from Expedition 312.

Daily Science Report for 22 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: Reaming and cleaning operations in Hole 1256D resumed in the morning using a tricone bit with a more aggressive cutting structure and a tandem set of boot baskets to recover rock fragments. By late evening, no progress had been made in passing the obstruction at 922 m depth. Retrieval of the drill string began and preparations are being made to deploy a coring bit, with decisions contingent on the examination of the bit and cuttings when they arrive on the rig floor. The science seminar continued with a presentation by Kim. Scientists are describing cores from Expedition 312 that were shipped to the vessel for that purpose.

Daily Science Report for 21 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: Reaming and cleaning operations in Hole 1256D were suspended in the morning after no progress was made in passing the obstruction at 922 m depth. The pipe was retrieved and the drill bit changed to a more aggressively cutting bit. The pipe was then deployed again for re-entry into Hole 1256D. The science seminar continued with presentations by Abe and Baines. Scientists received training with the DESClogik core description software while implementation of extensive, carefully reviewed core description templates began. All lab groups continued preparation of the methods section of the expedition report.

Daily Science Report for 20 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: Reaming and cleaning operations in Hole 1256D continued throughout the day. Unfortunately the bit could not pass the obstruction at 922 m depth so far. The science seminar continued with presentations by France and Koepke. Scientists also received lab training and continued preparations of analytical methods.

Daily Science Report for 19 April 2011

LOCATION: Hole 1256D (6°44.163' N, 91°56.061' W)

SCIENCE UPDATE: The vessel arrived at Hole 1256D at 01:15. The drill pipe was deployed near the seafloor, equipped with a tricone bit with a mechanical bit release. The VIT deep sea camera was lowered to find the re-entry cone. Repair of a flooded cable caused a delay of ~3 h before Hole 1256D was successfully re-entered at ~18:00. The pipe was lowered without rotation or circulation with the objectives of reaching ~1100 m depth, conducting an equilibrium temperature logging run, and taking a fluid sample near the bottom of the hole. Unfortunately the bit couldn't pass an obstruction at 924 m, the same depth at which Expedition 312 spent several days washing and reaming. Late in the night, the top drive was picked up and rotation (with limited circulation) began.

Daily Science Report for 18 April 2011

LOCATION: Underway from Puntarenas (Costa Rica) to Site 1256 (6°44.2' N, 91°56.1' W)

SCIENCE UPDATE: Senior USIO and Transocean personnel met for a final clarification of operations at Hole 1256D. The science party received presentations by Guerin, Tominaga, and Morris on the use of downhole logging data from Hole 1256D as well as a presentation on the shipboard computing systems and network. All laboratory teams met for further laboratory training and preparations. The estimated time of arrival at Site 1256 is 0100h on 19 April.

Daily Science Report for 17 April 2011

LOCATION: Underway from Puntarenas (Costa Rica) to Site 1256 (6°44.2' N, 91°56.1' W)

SCIENCE UPDATE: The vessel left Puntarenas at 04:20. The estimated time of arrival at Site 1256 is 02:00 on 19 April. Senior scientists, staff scientists, and operations superintendent met to discuss the details of initial operations. The science party received presentations by Teagle, Ildefonse, and Wilson on the background and objectives of Expedition 335. All laboratory teams met for training and/or specification of scientific methods.

Daily Science Report for 16 April 2011

LOCATION: Berth 4, Puntarenas Pier, Costa Rica

SCIENCE UPDATE: The final science party member arrived at the JR. The science party received presentations about the expedition project and general work flows, which concluded the settling-in phase of the cruise. The science conference then proceeded to start defining the detailed methods for the scientific activities of the cruise. A major emphasis is on the specification of macroscopic and microscopic description of core material, including igneous petrology, alteration petrology, and structural geology observations.

Daily Science Report for 15 April 2011

LOCATION: Berth 4, Puntarenas Pier, Costa Rica

SCIENCE UPDATE: All Expedition 335 scientists transferred from the San Jose hotel to Puntarenas and moved onto the vessel the previous day except for one whose travel was delayed by three days. The science party received introductory safety and life on board information upon arrival. This morning, the co-chief scientists engaged in a press conference at a Universidad National Costa Rica locality near the vessel. The science party received science laboratory tours. Regional visitors toured the ship in the afternoon.