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IODP Expedition 351

Izu Bonin Mariana Arc Origins

Daily Science Report for 29 July 2014

LOCATION: In transit to Yokohama, Japan

SCIENCE UPDATE: We are underway for Yokohama, Japan. We expect to arrive ~0830 h on 30 July (tomorrow).


Daily Science Report for 28 July 2014

LOCATION: In transit to Yokohama, Japan

SCIENCE UPDATE: We departed Site U1438 at 0115 h and are underway for Yokohama, Japan. We expect to arrive ~0830 h on Wednesday (30 July). The science party finalized and submitted all of their reports for Site U1438 and Expedition 351.


Daily Science Report for 27 July 2014

LOCATION: Hole U1438F (27°23.0167′N, 134°19.0905′E)

SCIENCE UPDATE: We finished recovering the drill string by 1030 h, thus ending operations at Site U1438. The remainder of the day was spent preparing the ship for transit. We anticipate departing the site at ~0100 h on 28 July. The science party continued working on their reports for Site U1438.


Daily Science Report for 26 July 2014

LOCATION: Hole U1438F (27°23.0167′N, 134°19.0905′E)

SCIENCE UPDATE: The triple combo was recovered on deck at 0330 h and the second logging tool, the vertical seismic imager (VSI), was prepared at 0425 h. The VSI was run to 691 mbsf (~9 m above the bottom of the hole) and then recovered at 1210 h. The final tool string, FMS-sonic, was deployed at 1400 h and reached 689 mbsf (~11 m above the bottom of the hole). It was recovered at 2040 h, which concluded logging operations in Hole U1438F. Following the logging operations, we began recovering the drill string. The science party continued working on their Site U1438 reports.


Daily Science Report for 25 July 2014

LOCATION: Hole U1438F (27°23.0167′N, 134°19.0905′E)

SCIENCE UPDATE: After releasing the bit at the bottom of the hole, we pulled the pipe up to logging depth (95 mbsf). However, once we reached logging depth, anomalous pump pressure readings seemed to suggest the bit had not released. Therefore, we ran the pipe back down to 700 mbsf and performed the bit release operation again. We then pulled the pipe back up to logging depth. The first of three planned logging tool strings, the triple combo, was made up and deployed at 1855 h. The triple combo ran down to 700 mbsf with no problems. On the uplog, the triple combo indicated a borehole diameter of ~10 inch. The science party continued working on their reports for Site U1438.


Daily Science Report for 24 July 2014

LOCATION: Hole U1438F (27°23.0167′N, 134°19.0905′E)

SCIENCE UPDATE: We finished drilling Hole U1438F at 1915 h to a total depth of 700 mbsf. We then conducted a sepiolite mud sweep and a wiper trip to prepare the hole for logging operations. We plan to run three logging tool strings: the triple combo, the FMS-sonic, and the vertical seismic imager (VSI). The science party continued working on their reports for Site U1438.


Daily Science Report for 23 July 2014

LOCATION: Hole U1438F (27°23.0167′N, 134°19.0905′E)

SCIENCE UPDATE: We spent the beginning of the day tripping the drill string to the seafloor for our dedicated logging hole. Hole U1438F was spudded at 1203 h. We plan to drill a 9.875 inch hole to ~700 mbsf and then deploy three logging tool strings. As of midnight, the bit had reached 375 mbsf. The remaining laboratory measurements for paleomagnetics, physical properties, geochemistry, and micropaleontology were nearly completed.


Daily Science Report for 22 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: The first logging run with the triple combo achieved a depth of 1186 mbsf. The triple combo was unable to pass below this depth, so we collected log data from there up to the end of the 10.75 inch casing at 604 mbsf. The borehole diameter was wider than the caliper could measure (>18 inch). As both the FMS-sonic and VSI tool strings require good contact with the borehole wall, we decided not to run these. The GBM, a borehole magnetometer, was run as the second and final tool string in Hole U1438E. It was deployed at 0355 h and was able to reach 1186 mbsf. After the GBM tool was recovered (1235 h), we pulled the pipe out of the hole (2315 h), offset the ship 10 m north and 20 m west of Hole U1438A, and began tripping the drill string. Our final operation for this expedition will be to drill a dedicated logging hole (Hole U1438F). The science party completed their Methods sections for the Proceedings volume and finalized their post-expedition research plans. The remaining laboratory measurements for paleomagnetics, physical properties, geochemistry, and micropaleontology are ongoing.


Daily Science Report for 21 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: After recovering Core U1438E-88R we began preparations for downhole logging, which included raising the end of the drill pipe to a logging depth of 190 mbsf, well inside the 10.75 inch casing that extends to 604 mbsf. While raising the pipe, tight hole conditions were encountered between 1600–1591 mbsf and 1418–1340 mbsf; in the latter interval, we briefly lost circulation. The end of the pipe reached logging depth at 1245 h. The rig up for the triple combo tool string began at 1515 h and it was deployed at 1655 h. The triple combo tool string reached a total depth of 1189 mbsf. Core U1438E-88R was described. It consists of light gray basalt with rare altered olivine and pyroxene phenocrysts. In total, we cored 150 m of basement and recovered just over 44 m (29% recovery). Additional laboratory measurements for paleomagnetics, physical properties, geochemistry, and micropaleontology are still ongoing.


Daily Science Report for 20 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-86R (18% recovery), 87R (33%), and 88R (16%) to 1611 mbsf. Core U1438E-88R was the last core recovered for Expedition 351. Overall recovery for Hole U1438E was 61%. After recovering the final core, we began preparations for downhole logging. Cores U1438E-85R through 87R were described. They consist of medium to light gray basalt with olivine and pyroxene phenocrysts, which are often replaced by chlorite and oxide. Multiple chlorite, carbonate, and sulfide veins are present.


Daily Science Report for 19 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-83R (27% recovery), 84R (10%), and 85R (25%) to 1585 mbsf. Cores U1438E-83R and 84R were described. They consist of gray fine-grained basalt with patchy chlorite and oxide alteration. Multiple serpentine, carbonate, and sulfide veins are present.


Daily Science Report for 18 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-81R (16% recovery) and 82R (33% recovery) to 1560 mbsf. After recovering Core U1438E-82R at 1315 h, we raised the bit up to 1380 mbsf to conduct a wiper trip. While working the bit back down, it was initially unable to pass the sediment-basement contact at ~1460 mbsf. The remainder of the day was spent trying to work it back down into basement, and to the bottom of the hole, which was eventually reached shortly before the end of the day (2305 h). Approximately 3 m of fill was encountered so a mud sweep was conducted. Cores U1438E-80R to 82R were described. They consist of medium-grained basalt with patchy chlorite alteration. Multiple serpentine, carbonate, and sulfide veins are present.


Daily Science Report for 17 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-76R (87% recovery) to 80R (19% recovery) to 1543 mbsf. In general, our penetration rates in basement have been slow (1.6 m/h) and our overall recovery has been variable. Cores U1438E-76R to 79R were described. They consist of dolerite and basalt with remarkably fresh minerals. Sulfide and calcite veins are also present.


Daily Science Report for 16 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-72R to 74R. While drilling Core U1438E-75R, the drill pipe experienced excessive harmonic vibration and we terminated coring after only advancing 3 m. We recovered Core U1438E-75R and by the time it was on deck the vibrations stopped. We then cut and recovered Core U1438E-76R to 1510 mbsf. Cores U1438E-72R to 75R were described. They consist of holocrystalline dolerite and basalt. Core U1438E-75R is more coarse-grained than previous cores.


Daily Science Report for 15 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-70R and 71R to 1474.7 mbsf. After recovering Core 71R, the drill pipe became stuck for a short period of time with maximum torque of 800 amps, pump pressure of 2000 psi, and 60–70 klb of overpull. Therefore we spent the majority of the day conducting hole cleaning operations. At 1830 h, RCB coring resumed and we recovered Core U1438E-72R. Cores U1438E-68R to 71R were described. Cores U1438E-68R and the upper part of Section U1438E-69R-1 consist of red mudstone with poorly preserved radiolaria. The sediment-basement contact was identified in Section U1438E-69R-1 at ~17 cm. The rest of Core 69R, as well as Cores 70R and 71R, consist of holocrystalline dolerite and basalt with multiple inclined oxide and carbonate veins.


Daily Science Report for 14 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-63R to 69R to a total depth of 1475 mbsf. We switched to recovering half length cores (4.7 m instead of 9.5 m) after Core U1438E-66R to try to improve core recovery and quality because the material tends to be moderately to severely fractured. After recovering Core U1438E-69R the drill pipe became stuck for a short period of time despite mud sweeps after every core. This suggests some trouble with flushing the cuttings out of the hole. Cores U1438E-62R to 67R were described. Cores U1438E-62R and 63R consist of red mudstone, tuffaceous sandstone, breccia conglomerate (mixed volcanic and sedimentary clasts), and a basalt interval in Core U1438E-62R. Cores U1438E-64R to 67R consist of sequences of grayish black and brownish black tuffaceous mudstone, siltstone, and fine sandstone. Core U1438E-67R also contains a prominent calcite vein. Radiolaria are commonly present but are poorly preserved, so age control is absent.


Daily Science Report for 13 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-58R to 60R to a depth of 1405 mbsf. We then spent 2.5 h reconfiguring the uppermost part of the drill string and cleaning the hole. RCB coring resumed at 1530 h and we recovered Cores U1438E-61R and 62R. Cores U1438E-58R to 61R were described. They consist of red mudstone with ash, red mudstone with radiolaria, and rare intervals of tuffaceous sandstone. Core U1438E-61R contains a 19-cm-thick porphyritic basalt cobble. Radiolaria are commonly present, but are poorly preserved so age control remains a challenge.


Daily Science Report for 12 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: The bit was lowered to the depth at which we halted coring before the typhoon (~1319 mbsf) and RCB coring recommenced at 0215 h. We recovered Cores U1438E-51R to 57R to 1386 mbsf. Cores U1438E-51R to 55R were described. There is an increasing proportion of finer-grained material with the cores now consisting primarily of mudstone, mudstone with ash, tuffaceous mudstone, and intervals of tuffaceous siltstone. Bioturbation is slight to moderate in the mudstones. Microfossils are still absent.


Daily Science Report for 11 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We finished tripping the drill bit to just above seafloor and the reentry cone (~4643 mbsl) by 0645 h. At that time, the heave of the ship was still too high to attempt to deploy the subsea camera system and reenter the hole, so we decided to wait for the weather to further attenuate. At 1345 h, we deployed the subsea camera system and reentered Hole U1438E at 1655 h. After recovering the subsea camera system, the drill bit was lowered into the hole; the conditions of the hole are excellent. At midnight the bit had reached 1282 mbsf, about 38 m above the bottom of Hole U1438E. The science party continued working on report and methods drafts and participated in a seminar entitled “Ancient melting and rejuvenation processes at passive margins, OCTs: The Jurassic-Permian paradox of Alpine peridotites.”


Daily Science Report for 10 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: Our transit back to Site U1438 was completed at 0830 h. We spent the majority of the day waiting for the sea state conditions to attenuate. From 1900 h, we began making up a RCB bottom-hole assembly and tripping drill pipe back down to the reentry cone at Hole U1438E. At midnight, the bit had reached ~568 m below sea level. The science party worked on their report drafts and participated in a seminar on the geochemistry of mid-ocean ridge basalts (MORB) through time.


Daily Science Report for 9 July 2014

LOCATION: Midnight position (27°25.8′N, 135°24.8′E)

SCIENCE UPDATE: We continued to wait at a safe standby location and observed the progress of Typhoon Neoguri for the majority of the day. As a result of weather reports indicating the conditions at Site U1438 were safe for us to return, we began the transit back at 1800 h. The science party worked on their report drafts and a subset participated in a discussion regarding postcruise analyses of material from Hole U1438D.


Daily Science Report for 8 July 2014

LOCATION: Standby location (27°21.9′N, 136°44.9′E)

SCIENCE UPDATE: We are waiting for Typhoon Neoguri to pass before transiting back to Site U1438. The science party worked on their report drafts and participated in a discussion regarding lithologic interpretation of the volcaniclastic sediments recovered thus far.


Daily Science Report for 7 July 2014

LOCATION: Standby location (27°21.9′N, 136°55.8′E)

SCIENCE UPDATE: We concluded our transit to a safe standby location at 0600 h and are currently waiting for Typhoon Neoguri to pass before transiting back to Site U1438. The science party worked on their report drafts and participated in a seminar entitled “Adakites, Aleutian magmas, and subduction initiation.”


Daily Science Report for 6 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E) and in transit (midnight position 27°36.7′N, 136°28.4′E)

SCIENCE UPDATE: We finished recovering the drill string at 0110 h and started transiting away from the typhoon at 1230 h. We were still transiting to a safe location at midnight and expect to reach it by 0600 h on 7 July. Cores U1438E-49R and 50R were described. Core recovery was drastically reduced to 23% and 14%, respectively. The cores were clay rich and more lithified with numerous nodules. Microfossils are still absent.


Daily Science Report for 5 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-44R to 50R to 1319 mbsf. Due to impending severe weather, coring was terminated at 1825 h. We then began to recover the drill string in preparation for transit to a site east of the typhoon. Cores U1438E-41R to 48R were described and consist mainly of finer grained lithologies, such as tuffaceous siltstone and mudstone. Microfossils are still absent, making age determination challenging.


Daily Science Report for 4 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We continued RCB coring and recovered Cores U1438E-37R to 44R to 1265 mbsf. The hole conditions are good, but core recovery has dropped below 70%. Cores U1438E-33R to 40R were described. Cores U1438E-33R to 37R consist mainly of tuffaceous sandstone, siltstone, and breccia-conglomerate, while Cores U1438E-38R to 40R consist of tuffaceous sandstone, siltstone, and mudstone; bioturbation is moderate in the siltstones and mudstones. A prominent gypsum/quartz vein is present in Core U1438-38R. Microfossils are absent, making age determination challenging.


Daily Science Report for 3 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-27R to 36R to 1187 mbsf. The hole conditions are good and core recovery is excellent. Cores U1438E-20R to 32R were described. The cores continue to consist mainly of tuffaceous sandstone, siltstone, and mudstone. Cores U1438E-21R and 28R contain tuffaceous matrix-supported polymict conglomerate; the majority of clasts are mud and andesite. No microfossils were present in the respective core catcher samples, so an age determination was not possible.


Daily Science Report for 2 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-18R to 26R to 1090 mbsf. The hole conditions are good and core recovery is excellent. Cores U1438E-12R to 19R were described. Most of the cores consist mainly of tuffaceous sandstone (with gravel) and siltstone (with sand). Cores U1438E-13R, 16R and 19R also contain breccia and breccia-conglomerate. Calcareous nannofossils indicate the material is of Eocene age.


Daily Science Report for 1 July 2014

LOCATION: Hole U1438E (27°23.0153′N, 134°19.0898′E)

SCIENCE UPDATE: We recovered Cores U1438E-10R to 17R to 1002 mbsf by 1800 h. The remainder of the day was spent on conditioning the hole with mud sweeps and a wiper trip. Cores U1438E-6R to 11R were described. They consist mainly of tuffaceous sandstone (with gravel) and siltstone (with sand). Bioturbation is moderate on average in the siltstones. Calcareous nannofossils are present and indicate the material is of Eocene age.


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Modified on Wednesday, 30-Jul-2014 22:05:11 CDT.