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IODP Expedition 351
Izu Bonin Mariana Arc Origins
Daily Science Report for 30 June 2014
LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)
SCIENCE UPDATE: We finished drilling without coring in Hole U1438E to 867 mbsf at 0715 h. We then began RCB coring and recovered Cores U1438E-4R to 9R to 925 mbsf. Cores U1438E-4R and 5R were described and are similar in composition to cores recovered from the lower part of Hole U1438D. They consist mainly of tuffaceous sandstone (with gravel) and siltstone (with sand). Calcareous nannofossils indicate the material is of Eocene age.
Daily Science Report for 29 June 2014
LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)
SCIENCE UPDATE: We reentered Hole U1438E at 0115 h and then recovered the subsea camera system. After a mud sweep, we began drilling ahead in the hole, which continued for the rest of the day. By midnight we reached ~760 mbsf. Our intention is to drill to a total depth of ~870 mbsf and then begin coring. The science party finalized their results from Holes U1438A and U1438B, and worked on their results from Hole U1438D, as well as revising their methods sections for the Proceedings volume.
Daily Science Report for 28 June 2014
LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)
SCIENCE UPDATE: We finished recovering the drill string and had disassembled the underreamer and mud motor assembly by 1200 h. A rotary core barrel (RCB) bottom-hole assembly (BHA) was then made up and we started lowering the drill string at 1630 h. The subsea camera system was deployed at 2200 h to guide reentry into Hole U1438E. The science party continued working on their results from Holes U1438A, U1438B, and U1438D, as well as revising their methods sections for the Proceedings volume. They also participated in a seminar on subduction initiation in the Tonga-Kermadec Arc.
Daily Science Report for 27 June 2014
LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)
SCIENCE UPDATE: The 10.75 inch casing string was installed by 1225 h with the casing shoe at 605 mbsf. The drill string was then pulled clear of the hole, as observed with the subsea camera system, at 1805 h. By midnight the drill string had been recovered to a depth of ~3150 m below sea level. The science party continued working on their findings from Holes U1438A, U1438B, and U1438D, as well as revising their methods sections for the Proceedings volume. The Co-chief Scientists, Staff Scientist, and Publications Specialist continued meeting with individual laboratory groups to discuss their report drafts.
Daily Science Report for 26 June 2014
LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)
SCIENCE UPDATE: We deployed the 10.75 inch casing string and the assembly of mud motor, underreamer, and 9.875 inch tricone bit that will be used to install the casing. The subsea camera system was also deployed to guide the reentry into Hole U1438E. The seafloor was observed at 2225 h and reentry was achieved in 10 min (2235 h) after which the subsea camera system recovery began. The science party continued working on their findings from Holes U1438A, U1438B, and U1438D, as well as revising their methods sections for the Proceedings volume. The Co-chief Scientists, Staff Scientist, and Publications Specialist began meeting with individual laboratory groups to discuss their report drafts.
Daily Science Report for 25 June 2014
LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)
SCIENCE UPDATE: We finished recovering the drill string at 1250 h. The remainder of the day was spent preparing the 10.75 inch casing string and the assembly of mud motor, underreamer, and 9.875 inch tricone bit that will be used to install the casing into the pre-drilled borehole. The science party continued working on their findings from Holes U1438A, U1438B, and U1438D, and participated in another science seminar on subduction initiation in the Permian of southern California.
Daily Science Report for 24 June 2014
LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)
SCIENCE UPDATE: We continued drilling the 14.75 inch hole for the 10.75 inch casing and reached the final depth (613 mbsf) at 1440 h. Cleaning of the borehole with mud sweeps and a wiper trip were completed by 2215 h. No overpull, drag, or fill was identified, indicating that the borehole is in good condition. We then began to recover the drill string and were at 368 mbsf at midnight. The science party continued working on their findings from Holes U1438A, U1438B and U1438D.
Daily Science Report for 23 June 2014
LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)
SCIENCE UPDATE: We deployed the subsea camera system at 0230 h and subsequently reentered Hole U1438E at 0455 h. We then recovered the subsea camera system and began drilling a 14.75 inch hole for the 10.75 inch casing at 0930 h, which continued for the remainder of the day. By midnight we had reached a depth of 371.79 mbsf. The science party participated in a seminar on subduction initiation models and continued working on their findings from Holes U1438A, U1438B and U1438D.
Daily Science Report for 22 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We finished recovering the drill pipe at 1200 h. We then changed the bottom-hole assembly to one containing a 14.75 inch drill bit that will allow us to drill a hole to ~600 mbsf for the 10.75 inch casing. At 1815 h, we began deploying the drill pipe again and the bit had reached ~3700 mbsl by midnight. The science party submitted draft reports with their findings from Holes U1438A, U1438B and U1438D.
Daily Science Report for 21 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We continued installation of the Hole U1438E reentry cone and casing system. Hole U1438E was spudded at 1415 h, and the jet-in of the reentry cone and 16 inch casing to 60.1 mbsf was completed at 1800 h with no problems. We then recovered the subsea camera system and had begun recovering the drill pipe at 2200 h. The science party had a second science meeting to continue discussions about the data collected thus far. They also continued catching up on remaining analyses from Hole U1438D and writing their findings from Holes U1438A, U1438B and U1438D.
Daily Science Report for 20 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We finished recovering the drill string at 1130 h, and began installation of the Hole U1438E reentry cone and casing system. The reentry cone was deployed at 2235 h and the drill pipe had been lowered to ~572 m below sea level by midnight. The science party continued catching up on remaining analyses from Hole U1438D and writing their findings from Holes U1438A, U1438B and U1438D. We also had a science meeting to discuss the data generated thus far.
Daily Science Report for 19 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: After recovering the subsea camera system used to reenter Hole U1438D, the triple-combo tool string (density, neutron porosity, resistivity, natural gamma) was assembled and lowered into the hole at 0355 h. The triple combo was unable to pass below ~314 mbsf and log data were collected from this depth up to the end of the drill string (95 mbsf). We lowered the end of the drill string down to ~330 mbsf and attempted to log again below the borehole obstruction. This time the logging tool string could not pass below 368 mbsf, so we decided to retrieve the logging tool string and finish Hole U1438D operations. While pulling the drill pipe out of the hole, significant overpull was encountered, but after two hours (2030–2230 h) the pipe was worked free. Once we finish recovering the drill string, we intend to begin installation of the Hole U1438E reentry cone and casing system. The science party continued catching up on remaining analyses from Hole U1438D and began writing their findings from Holes U1438B, U1438B and U1438D.
Daily Science Report for 18 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We offset 20 m north and dropped the drill bit on the seafloor before moving back over Hole U1438D and attempting reentry. Several unsuccessful attempts were made in the morning (0600–1130 h) before the black and white long-range camera on the subsea camera system failed. After fixing the camera system, we successfully reentered Hole U1438D at 2135 h and set the drill pipe to logging depth (~95 mbsf). Final preparations were being made for wireline logging at midnight. The remainder of the cores were described (Cores U1438D-63R to 72R) and are composed of tuffaceous siltstone and sandstone with consolidated breccia and, in one core (U1438D-66R), limestone. Calcareous and siliceous microfossils are mostly absent, but calcareous nannofossils in Section U1438D-65R-CC suggest an Eocene age.
Daily Science Report for 17 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We recovered Cores U1438D-65R to 72R after which coring of this hole finished with a final depth of 897.8 mbsf. During the rest of the afternoon and evening, preparations were made to maintain the hole for contingency operations. A free-fall funnel was dropped and the subsea camera system was deployed just before midnight. The next steps before wireline logging will involve dropping the drill bit outside of the hole and then reentering Hole U1438D. Cores U1438D-52R to 62R were described and are composed of tuffaceous mudstone, siltstone and sandstone. Calcareous and siliceous microfossils are absent except for Section U1438D-62R-CC, where species indicate an Eocene age.
Daily Science Report for 16 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We recovered Cores U1438D-54R to 64R (to 818 mbsf). The hole conditions continue to be good and interstitial water is still extractable from the cores. Cores U1438D-43R to 51R were described and are composed of tuffaceous medium to coarse sandstone, tuffaceous clast-supported polymictic consolidated breccia-conglomerates, and tuffaceous mudstone with nannofossils and micronodules. Calcareous nannofossils in Section U1438D-62R-CC indicate the material is of Eocene age.
Daily Science Report for 15 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We recovered Cores U1438D-41R to 53R (to 714 mbsf). The hole conditions continue to be excellent and interstitial water is still extractable from the cores. Cores U1438D-34R to 42R were described and are similar in composition to previous cores with fining upwards cycles of distinct layers containing tuffaceous mudstone with strong bioturbation and tuffaceous fine sandstone. Calcareous nannofossil and foraminifer species indicate we are in the earliest Oligocene.
Daily Science Report for 14 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We recovered Cores U1438D-30R to 41R (to 597 mbsf). The hole conditions continue to be excellent. Cores U1438D-24R to 33R were described and are similar in composition to previously described cores. There appears to be a slight trend towards finer grain sizes and less thick alternating sequences. Bioturbation is moderate in the tuffaceous mudstones, and calcareous nannofossils indicate we are in the earliest Oligocene (~33 Ma).
Daily Science Report for 13 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We recovered Cores U1438D-18R to 29R (364–481 mbsf). The hole conditions thus far have been excellent. Cores U1438D-13R to 23R were described and show thick (decimeter-scale) alternating sequences of tuffaceous mudstone, siltstone and/or sandstone with tuffaceous matrix-supported polymictic medium to coarse sandstone. Cores U1438D-19R and 21R contain tuffaceous matrix-supported polymictic consolidated breccia conglomerates that transition to coarse sandstone. The dominant clasts are pumice. Bioturbation has largely disappeared and microfossils are scarce, so age control has become more challenging. However, calcareous nannofossil species indicate we are still in the Early Oligocene.
Daily Science Report for 12 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: We continued RCB coring Hole U1438D, recovering Cores U1438D-6R to 9R (248–280 mbsf). Due to a tropical storm, we had to cease operations from 0430–1045 h. Upon resuming, we recovered Cores U1438D-10R to 17R (286–365 mbsf). Cores U1438D-2R to 12R were described and primarily consist of tuffaceous mudstones, siltstones and sandstones. These tuffaceous sedimentary rocks show fining upward cycles with the tuffaceous mudstones usually exhibiting evidence of bioturbation. Calcareous nannofossils are abundant and foraminifers are present; however, siliceous microfossils (radiolarians) are absent. Biostratigraphic markers indicate that the core material is from the Early Oligocene.
Daily Science Report for 11 June 2014
LOCATION: Site U1438 (27°23.0218′N, 134°19.1023′E)
SCIENCE UPDATE: After preparing for our RCB pilot hole (Hole U1438D), we spudded in at 1330 h and drilled down (without coring) to 219 mbsf. This depth is ~40 m above where we terminated Hole U1438B. We then resumed coring and recovered Cores U1438D-2R to 5R (to ~240 mbsf), which provided some overlap with the XCB cores recovered in Hole U1438B. Those cores exhibited increased drilling disturbance with depth, particularly biscuiting. Today, we described Cores U1438B-20F to 30X (174–257 mbsf). The change in lithology first seen in Cores U1438B-18H and 19H (159–169 mbsf) persisted with tuff, tuffaceous siltstone and tuffaceous sandstone dominating. Ash layers are coarser and calcareous microfossils are abundant. The base of Core U1438B-30X is middle to early Oligocene.
Daily Science Report for 10 June 2014
LOCATION: Site U1438 (27°23.0108′N, 134°19.1020′E)
SCIENCE UPDATE: We continued coring with the XCB system and recovered Cores U1438B-27X to 30X (average recovery ~75%) after which we terminated Hole U1438B at 0525 h. After offsetting 20 m, we conducted a jet-in test (Hole U1438C) which finished at 1005 h. The remainder of the day was spent bringing the drill pipe back up to the rig floor to change the bottom-hole assembly and preparing for drilling/coring operations at the first of two holes using the rotary core barrel (RCB) system. During these operations, the description of cores from Hole U1438B continued with the major lithologies similar to previous cores from this hole (mud and tuffaceous mud), until Core U1438B-18H (166.7 mbsf; late Oligocene). This core and Core U1438B-19H exhibit a sharp change in lithology and contain silty sandstone and tuffaceous sandstone.
Daily Science Report for 9 June 2014
LOCATION: Site U1438 (27°23.0108′N, 134°19.1020′E)
SCIENCE UPDATE: We continued coring Hole U1438B, recovering Cores U1438B-7H to 19H. These cores are primarily composed of mud and tuffaceous mud. The ash layers became less frequent from Core U1438B-8H onwards and those present are more diffuse. Age control continued to be difficult as most samples are devoid of microfossils. Tentative ages suggest the base of Core 14H is Miocene and the base of Core 18H is late Oligocene. After recovering Core 19H, we decided to change to the half-length advanced piston corer (HLAPC) with which we recovered Cores U1438B-20F to 22F (to 180 mbsf). At this point, we experienced incomplete strokes and significant overpull, so we decided to switch to the extended core barrel (XCB) system. Using the XCB system, we recovered Cores U1438B-23X to 26X. Overall, core recovery has been ~90% in Hole U1438B.
Daily Science Report for 8 June 2014
LOCATION: Site U1438 (27°23.0108′N, 134°19.1020′E)
SCIENCE UPDATE: Before beginning the first hole at Site U1438, we conducted a seafloor survey with our camera system in the early morning (0215–0415 h). There were no features observed during the survey. We spudded Hole U1438A at 1045 h and recovered Cores U1438A-1H to 3H (0–26.5 mbsf). This hole was planned to enable high-resolution sampling of the upper section and will provide overlap with subsequent Hole U1438B. The cores consisted mainly of mud and tuffaceous mud with some discrete ash layers. There was one distinct foraminiferal ooze in Core U1438A-2H, but age control was difficult as most of the samples were barren of both calcareous microfossils and radiolarians. The most reliable age constraint suggests the recovered material is no older than 3.2 Ma. Hole U1438A was terminated at 1400 h; we then offset 10 m to the east and spudded Hole U1438B at 1510 h. Cores U1438B-1H to 6H extended to ~55 mbsf. All cores were oriented with the FlexIT tool and in situ temperature measurements with the APCT-3 were made before recovering Cores 3H to 6H. The upper three cores of this hole (Cores U1438B-1H to 3H) were quite similar to those from Hole U1438A. The lithology of Cores U1438B-3H to 6H is also similar, but with coarser ash layers. No age constraints are available as the material was barren of microfossils.
Daily Science Report for 7 June 2014
LOCATION: Arrived at Site U1438 (IBM-1)
SCIENCE UPDATE: We arrived at Site U1438 (IBM-1) at 0245 h. The remaining joints of borrowed drill pipe were made up into stands and put in the pipe racker. To prepare for coring the first hole, an advanced piston corer (APC)/extended core barrel (XCB) coring bottom-hole assembly (BHA) was made up and lowered to the seafloor. The subsea camera system was deployed at 2230 h and will survey the seafloor around our site. Each laboratory group finalized preparations for receiving core tomorrow (~midday). The Sample Allocation Committee concluded their meetings with small groups and individuals.
Daily Science Report for 6 June 2014
LOCATION: In transit to Site U1438 (IBM-1)
SCIENCE UPDATE: We are still in transit to Site U1438 (IBM-1) and estimate arrival at 0400 h on 7 June, depending on the weather. The science party finished transitioning onto their shifts and each laboratory group submitted their methods drafts. The Sample Allocation Committee finalized the shipboard sampling plan and continued meeting with small groups and individuals. The tentative expectation is to have the first core on deck around midday on 8 June.
Daily Science Report for 5 June 2014
LOCATION: In transit to Site U1438 (IBM-1)
SCIENCE UPDATE: We are currently in transit to IBM Arc Origins Site U1438 (IBM-1) with an estimated arrival time of 0400 h on 7 June. The science party transitioned to their shifts and continued working on their methods. The Sample Allocation Committee continued with small group meetings and discussed personal sampling strategies. It was decided to first core a short (20 mbsf) hole with the APC for high-resolution sampling, and then core until APC refusal in the second hole. Representatives from the operations, science and technical personnel met for a pre-spud meeting. The tentative expectation is for the first core to be on deck around midday on 8 June.
Daily Science Report for 4 June 2014
LOCATION: Honmoku B3 (Yokohama, Japan) and in transit to site IBM-1
SCIENCE UPDATE: We departed Yokohama at 0552 h and began our ~2 day transit to IBM Arc Origins Site IBM-1. The science party continued working in their lab groups on equipment setup and methods, and the Imaging Specialist began microscope setup with the paleontologists and petrologists. The Sample Allocation Committee continued with small group meetings to prepare shipboard and personal sampling schemes. The Education and Outreach officers gave a presentation about their plans for educational broadcasts to shore and the development of several videos. We had a short detour at 1800 h back towards Yokohama to correct a visa documentation issue, but the ship was back on course at 2308 h. Our expected time of arrival at site IBM-1 is now 1400 h on 7 June depending on currents and weather.
Daily Science Report for 3 June 2014
LOCATION: Honmoku B3 and 4 berth, Yokohama, Japan
SCIENCE UPDATE: The science party received ship tours from the Operations Superintendent, as well as a wireline logging introduction and tours of the logging facilities/equipment by the Logging Staff Scientist and Schlumberger engineer. They continued working in their lab groups on equipment setup and methods, while the Sample Allocation Committee began small group meetings to prepare shipboard and personal sampling schemes. The loading of all freight was completed and the remaining port call activities are in their final stages. We are still scheduled to leave port at 0600 h on 4 June.
Daily Science Report for 2 June 2014
LOCATION: Honmoku B3 and 4 berth, Yokohama, Japan
SCIENCE UPDATE: The science party discussed their personal research interests with the entire group with the result of some important collaborations forming. They then broke into their laboratory groups and spent the rest of the morning becoming acquainted with the equipment and workflow. The remainder of the day was spent in the labs working on their Methods sections. Several VIP tours were conducted for the U.S. Ambassador to Japan, the embassy staff, and MEXT personnel, including the Deputy-Director General. Additional tours included CDEX/JAMSTEC personnel and students. The new fiber optic cable replacement was completed and tested well. The loading of most other freight was completed with the exception of the remaining borrowed CDEX drill pipe. We are scheduled to leave port at 0600 h on 4 June 2014.
Daily Science Report for 1 June 2014
LOCATION: Honmoku B3 and 4 berth, Yokohama, Japan
SCIENCE UPDATE: The science party began the day with a presentation on the expedition science background and objectives from the Co-chief Scientists, which was followed by a presentation on the mechanics of documenting the expedition science, given by the Staff Scientist. Core flow laboratory tours were conducted with the science party as well. We continued our port call activities, which included loading surface freight, stowing supplies and equipment, and replacing the subsea camera system’s fiber optic cable. A service call to the XRD was completed and it is now fully functional.
Daily Science Report for 31 May 2014
LOCATION: Honmoku B3 and 4 berth, Yokohama, Japan
SCIENCE UPDATE: The science party arrived and settled into their cabins before noon, except for one scientist whose flight was delayed and arrived at midnight. We also continued our port call activities, including the ship’s crew change, loading of freight, and off loading of drill pipe for inspection. Additionally, legacy cores from Leg 195, Site 1201 from the IODP Kochi Core Center were loaded. These cores were requested by the science party to help in preparing for core description.
Daily Science Report for 30 May 2014
LOCATION: Honmoku B3 and 4 berth, Yokohama, Japan
SCIENCE UPDATE: The IODP Izu-Bonin-Mariana (IBM) Arc Origins Expedition 351 officially began with the first line ashore at 1106 h. We began our port call activities, including customs and immigration, IODP-USIO crew change and crossover, boarding of Co-chief Scientists, and the installation of a replacement fiber optic cable. Scientists are scheduled to board the ship on 31 May.
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