IODP Expedition 340

Lesser Antilles Volcanism and Landslides

Daily Science Report for 31 March 2012

LOCATION: Site U1399 (CARI-08B, 14°23.24'N 61°42.96'W, water depth 2901 mbsl)

SCIENCE UPDATE: During the last 24 hours we retrieved Cores U1399B-2H to -27H with 177 m of material (101% recovery) reaching 183 m into the formation. The cored material consists of alternating layers of hemipelagic mud, volcaniclastic fine sand and tephra. The proportion of coarse grained material, especially in the lower parts of Hole U1399B, is much higher than in Hole U1399A.

Daily Science Report for 30 March 2012

LOCATION: Site U1399 (CARI-08B, 14°23.24'N 61°42.96'W, water depth 2901 mbsl)

SCIENCE UPDATE: We retrieved Cores U1399A-22H to -36X with 50 m of material (47% recovery) reaching 275 m into the formation. We decided to terminate this hole because of time constraints and the poor XCB recovery. We offset the vessel to the northeast and spudded Hole U1399B at 2310 h. Core U1399B-1H recovered 6 m of material (101% recovery) reaching 6 m into the formation. The cores recovered today still consist of the chaotic unit we have drilled since the beginning of this site. It is composed of alternating layers of hemipelagic mud, volcaniclastic fine sand and tephra, being in parts deformed.

Daily Science Report for 29 March 2012

LOCATION: Site U1399 (CARI-08B, 14°23.24'N 61°42.96'W, water depth 2901 mbsl)

SCIENCE UPDATE: We started coring Hole U1399A at 0145 hrs and retrieved Cores U1399A-1H to -22H with 170 m of material (101% recovery) reaching 167 m into the formation. The cored material consists of hemipelagic mud and fine sand with interbedded tephra and volcaniclastic sand layers. The sediments are highly deformed in parts, indicating remobilization after initial deposition probably caused by debris avalanche.

Daily Science Report for 28 March 2012

LOCATION: Site U1399 (CARI-08B, 14°23.24'N 61°42.96'W, water depth 2901 mbsl)

SCIENCE UPDATE: After a number of unsuccessful tries to log Hole U1398B we started to prepare the ship for its ~12 nmi transit to Site U1399 at 1030 hrs. Logging was impossible because the hole most likely collapsed. At 2215 hrs we arrived on Site U1399 and started to prepare the drilling tools for our next coring operation.

Daily Science Report for 27 March 2012

LOCATION: Site U1398 (CARI-09B, 14°16.70'N 61°53.34'W, water depth 2935 mbsl)

SCIENCE UPDATE: We finished coring Hole U1398B at 2145 hrs. Cores U1398B-31X to -34X penetrated 263 m into the formation and recovered 9 m (23%). The cored material consists of hemipelagic sediments with interbedded tephras. Afterwards we displaced Hole U1398B with heavy mud in preparation of downhole logging.

Daily Science Report for 26 March 2012

LOCATION: Site U1398 (CARI-09B, 14°16.70'N 61°53.34'W, water depth 2935 mbsl)

SCIENCE UPDATE: We finished coring Hole U1398A retrieving Cores U1398A-28X to -30X with 8 m of material (27% recovery) reaching 269 m into the formation. At 0723, we spudded Hole U1398B and by midnight we had retrieved Cores U1398B-1H to -15H with 116 m of material (101% recovery) extending to 115 m into the formation. The cored material still consists of a succession of volcaniclastic and hemipelagic sediments as well as tephra layers of varying thickness and composition. Some of the tephra layers, especially at the top of the section are rich in large pumice particles.

Daily Science Report for 25 March 2012

LOCATION: Site U1398 (CARI-09B, 14°16.70'N 61°53.34'W, water depth 2935 mbsl)

SCIENCE UPDATE: During the last 24 hours we retrieved Cores U1398A-8H to U1398A-27X with 76 m of material (40% recovery) reaching 240 m into the formation. The cored material consists of volcaniclastic and hemipelagic sediments as well as tephra layers of varying thickness and composition.

Daily Science Report for 24 March 2012

LOCATION: Site U1398 (CARI-09B, 14°16.70'N 61°53.34'W, water depth 2935 mbsl)

SCIENCE UPDATE: At 0245 we started the 46 nmi long transit to Site U1398 (CARI-09B) and were positioning over this site at 0700. After assembling the drill string and picking up the bottom hole assemblage we started coring Hole U1398A at 1551 hrs. Cores U1398A-1H to -7H penetrated 51 m into the formation and recovered 31 m of material (62%). The cored material consists of mainly volcaniclastic sediments composed of dark, ash-sized particles and variably large andesitic pumice and lava clasts.

Daily Science Report for 23 March 2012

LOCATION: Site U1397 (CARI-10B, 14°54.41'N 61°25.35'W, water depth 2482 mbsl)

SCIENCE UPDATE: At 0630 we started our logging operations in Hole U1397B with the triple combo tool string. After two passes through the hole, we finished logging with the triple combo at 1015 and prepared for logging with the FMS-sonic tool string. At 1330 we started logging with the FMS-sonic and conducted two logging passes. Our logging operations at this site were finished at 1800. The reminder of the evening was spent preparing the rig floor and the ship for our transit to Site U1398.

Daily Science Report for 22 March 2012

LOCATION: Site U1397 (CARI-10B, 14°54.41'N 61°25.35'W, water depth 2482 mbsl)

SCIENCE UPDATE: We finished Hole U1397B and started to prepare the drill floor for logging operations. We retrieved Cores U1397B-24X to U1397B-33X and recovered 11 m (14%) reaching a total depth of 254 mbsf. Drilling conditions became problematic below ~220 mbsf. Nonetheless we were able to retrieve material from the debris flow itself. This material consisted partly of large pieces of fresh to hydrothermally altered andesite. It appears that we probably have cored through some large debris flow blocks typical in deposits like this.

Daily Science Report for 21 March 2012

LOCATION: Site U1397 (CARI-10B, 14°54.41'N 61°25.35'W, water depth 2482 mbsl)

SCIENCE UPDATE: We spudded Hole U1397B at 02:52 and retrieved Cores U1397B-1H to U1397B-23X with an average recovery rate of 72% (120 m of material) reaching ~171 mbsf. The material cored is similar to the material cored in Hole U1397A and consists of alternating sequences of volcanic fallouts, volcaniclastic turbidites and hemipelagic sediments with a high content of volcanic, ash-sized particles.

Daily Science Report for 20 March 2012

LOCATION: Site U1397 (CARI-10B, 14°54.41'N 61°25.35'W, water depth 2482 mbsl)

SCIENCE UPDATE: In the last 24 hours we retrieved Cores U1397A-21X to U1397A-35X with an average recovery rate of 18% (26 m of material) reaching ~266 mbsf. After Core U1397A-35X at 23:00 was on deck we terminated Hole U1397A for scientific reasons and prepared for spudding Hole U1397B. The material cored mainly consists of tephra and debris flow deposits of variable composition and grain size.

Daily Science Report for 19 March 2012

LOCATION: Site U1397 (CARI-10B, 14°54.41'N 61°25.35'W, water depth 2482 mbsl)

SCIENCE UPDATE: We started coring Hole U1397A at 04:25. By midnight we retrieved Cores U1397A-1H to U397A-20H to 122 mbsf with an average recovery rate of 101% (118 m of material). The cores recovered are really beautiful and consist of tephra layers intercalated in a coarse sand grained background sediment. The number of tephra layers is enormous, averaging about 50 per core (counting only the ones being above ~ 0.5 cm in thickness). The tephra layers consist of ash and pumice, the pumice being andesitic in composition.

Daily Science Report for 18 March 2012

LOCATION: Site U1396 (CARI-01C, 16°30.49'N 62°57.09'W, water depth 787 m)
and Site U1397 (CARI-10B, 14°54.41'N 61°25.35'W, water depth 2482 mbsl)

SCIENCE UPDATE: We competed Site U1396 with the retrieval of Cores U1396C-11H to U1396C-15H reaching 139 mbsf. The material cored consists of marine sediments of varying grain size with intercalated, variable thick tephra horizons consisting of ash and pumice particles. The oldest sediments retrieved at this site date as far back as ~4.5 Ma based on bio- and magneto-stratigraphic information. At 09:45 we started the 113 nm transit to Site U1397 (CARI-10B) and arrived on site at 19:45. For the reminder of the day the bottom whole assembly was prepared for the drilling operations at this site.

Daily Science Report for 17 March 2012

LOCATION: Site U1396 (CARI-01C, 16°30.49'N 62°57.09'W, water depth 787 m)

SCIENCE UPDATE: We started coring Hole U1396A at 03:40 and finished coring at 16:15 after retrieving Cores U1396A-1H to U1396A-15H with a total of 141 m of material (average recovery rate of 104%) reaching 135 mbsf.. We started coring Hole U1396B at 16:50, drilled down to a depth of 5 mbsf and retrieved one single core to 15 mbsf to get complete recovery of interval, which was heavily disturbed in Hole U1396A because of a shattered core liner. We started coring Hole U1396C at 18:10 and retrieved Cores U1396-1H to U1396-10H with an average recovery rate of 105%. The material cored consists of marine sediments of varying grain size with intercalated, variable thick tephra horizons consisting of ash and pumice particles.

Daily Science Report for 16 March 2012

LOCATION: Site U1396 (CARI-01C, 16°30.49'N 62°57.09'W, water depth 787 m)

SCIENCE UPDATE: We finished coring Site U1395 at 01:15 and prepared the hole for the logging operations by pumping a 25-barrel sweep of high viscosity mud and displacing the hole with 85 barrels of 10.5 ppg mud. Afterwards we rigged up the logging tools and started logging with the triple combo tool string at 05:25. Logging operations concluded at 15:00 after running the FMS-sonic tool string. We secured the vessel for the 28.6 nm transit to Site U1396 (CARI-01C) and arrived on site at 22:48. We switched into DP mode and started to pick up the bottom hole assembly in preparation for coring Hole U1396A.

Daily Science Report for 15 March 2012

LOCATION: Site U1395 (CARI-04D, 16°29.60'N 61°57.09'W, water depth 1191 m)

SCIENCE UPDATE: In the last 24 hours we retrieved Cores U1395B-8H to U1395B-25X with an average recovery rate of 53% (75 m of material), reaching 197 mbsf. We cored volcanic turbidites, turbidites as well as marine sediments in different consolidation stages consisting mainly of calcareous material.

Daily Science Report for 14 March 2012

LOCATION: Site U1395 (CARI-04D, 16°29.60'N 61°57.09'W, water depth 1191 m)

SCIENCE UPDATE: At 16:30 we finished coring Hole U1395A reaching 231 mbsf. We recovered another 12 cores (U1395A-17X to U1395A-28X) with 20 m of material at an average recovery rate of 19%. We cleared the seafloor and offset the ship 20 m to the east and started coring Hole U1395B at 19:32. By midnight we retrieved Cores U1395B-1H to U1395B-7H with an average recovery rate of 103% (64 m of material), reaching 62 mbsf. We cored volcanic turbidites, turbidites composed of marine sediments as well as marine sediments in different consolidation stages.

Daily Science Report for 13 March 2012

LOCATION: Site U1395 (CARI-04D, 16°29.60'N 61°57.09'W, water depth 1191 m)

SCIENCE UPDATE: After logging we cleared the seafloor and prepared the ship for the roughly ten-mile transit to Site U1395. We arrived on site at 03:00 and started coring Hole U1395A at 08:55. By midnight we had retrieved Cores U1395A-1H to U1395A-16X with an average recovery rate of 99% (124 m of material) reaching 126 m into the formation. We cored a succession of several volcanic turbidites, turbidites composed of marine sediments and normal deposited marine sediments.

Daily Science Report for 12 March 2012

LOCATION: Site U1394 (CARI-03C, 16°38.43'N 62°02.29'W, water depth 1126 m)

SCIENCE UPDATE: We finished coring in Hole U1394B with Cores U1394B-19H to 1394B-21H to a total depth of 181.4 mbsf. We recovered 28 m of alternating layers of marine and volcaniclastic sediment (average recovery of 100%). Afterward we prepared the hole for logging, sweeping it with high viscosity mud and displacing it with heavy mud. We started logging at 07:15 with the triple combo tool string, measuring natural gamma radiation, porosity, resistivity and hole size. After the triple combo we tried unsuccessfully to run the VSI tool for the seismic experiments. Our last logging run was the FMS-sonic tool string, which records acoustic velocities and produces a resistivity image of the borehole walls.

Daily Science Report for 11 March 2012

LOCATION: Site U1394 (CARI-03C, 16°38.43'N 62°02.29'W, water depth 1126 m)

SCIENCE UPDATE: We spudded Hole U1394B at 02:55 and retrieved Cores U1394B-1H to U1394B-18H from 0 to 154 mbsf. In total we retrieved 113 m of material at an average recovery rate of 74%. In the upper part of the hole we cored volcaniclastic sediments, below the volcaniclastic material we recovered marine sediments.

Daily Science Report for 10 March 2012

LOCATION: Site U1394 (CARI-03C, 16°38.43'N 62°02.29'W, water depth 1126 m)

SCIENCE UPDATE: For the last 24 hours we did not retrieve any cores because we encountered highly unfavorable drilling conditions and had to abandon Hole U1394A. We moved 20 m to the north at 16:35 and started to pick up the bottom hole assembly in preparation of the coring operations at Hole U1394B.

Daily Science Report for 9 March 2012

LOCATION: Site U1394 (CARI-03C, 16°38.43'N 62°02.29'W, water depth 1115 m)

SCIENCE UPDATE: Drilling proceeded steadily for the last 24 hours. We retrieved Cores U1394A-5X to U1394A-27X with an average recovery rate of 15%, a total of 33.21 meters of material. The cores contained turbiditic, volcaniclastic, and clayey sediments.

Daily Science Report for 8 March 2012

LOCATION: Site U1393 (CARI-02C, 16°43.13'N 62°05.06'W, water depth 914 m)
and Site U1394 (CARI-03C, 16°38.43'N 62°02.29'W, water depth 1115 m)

SCIENCE UPDATE: Drilling proceeded rather slowly, with relatively steady progress until 05:15, when we broke a core barrel and lost it in the hole. At this time we had to abandon Hole U1393A. Because of the rather unfavorable conditions for coring, trying to retrieve unconsolidated, heterogeneous material, the decision was made to move on to the next site U1394 (CARI-03C). We reached Site U1394 at 1230 hrs, ran a camera survey of the seafloor, tagged the seafloor at 17:05 and started drilling Hole U1394A. We retrieved Cores U1394A-1H to U1394A-4H with an average recovery rate of 101%. The cores contained basaltic scoria and a mixture of variably grained volcaniclastic and biogenic sediment.

Daily Science Report for 7 March 2012

LOCATION: Site U1393 (CARI-02C, 16°43.13'N 62°05.06'W, water depth 914 m)

SCIENCE UPDATE: The day started with a 20-minute camera survey of the seafloor at 00:20, which was necessary due to the rough seafloor morphology around Site U1393. The main target at this site is the most recent debris avalanche deposit of Soufrière-Hills volcano on Montserrat. After finding a smooth area we tagged the seafloor at 00:43 and started drilling Hole U1393A. We retrieved Cores U1393-1H to U1393-7X with an average recovery rate of 11%. The cores contained mainly fresh tephra and cut up pieces of andesite.

Daily Science Report for 6 March 2012

LOCATION: Transit from San Juan, Puerto Rico, to Site U1393 (CARI-02C)

SCIENCE UPDATE: The day started with the technical and scientific pre-site meeting for Site U1393. The rest of the day was mainly dedicated to last fine tuning of our analytical methods, sampling training, and finalization of our templates for capturing descriptive data. The JOIDES Resolution arrived at Site U1393 at 18:00. After switching into DP mode and picking up the bottom hole assembly, tripping the drill string continued throughout the remainder of the evening.

Daily Science Report for 5 March 2012

LOCATION: Transit from San Juan, Puerto Rico, to Site U1393 (CARI-02C)

SCIENCE UPDATE: The JOIDES Resolution departed San Jose at 08:48 and started the 25-hour transit to the first drill site CARI-02C, SE of Montserrat. Science meetings, shipboard orientations and core description training continued. Scientists started writing the "Methods" chapter for the cruise report, met with their respective lab technicians for training on analytical instruments and continued working on the templates for core description. In the afternoon Teresa Greely, education officer, introduced the science party to the education and outreach program planned for this expedition. Afterwards the sampling plan for personal samples that have to be collected on the ship (water, microbiology, technological testing) was finalized.

Daily Science Report for 4 March 2012

LOCATION: San Juan, Puerto Rico

SCIENCE UPDATE: Scientists and technical staff began intensive shipboard science orientation. Core describers and paleontologists received their first detailed introduction to the DeskLogic application for capturing descriptive data in the database. DESCLogik templates prepared before the expedition were distributed to the core description team for further review. In the afternoon, Co-Chief Scientist Anne Le Friant gave an overview of the expedition science objectives. Following this presentation, all of the scientists met to develop and finalize a shipboard sampling plan.

Daily Science Report for 3 March 2012

LOCATION: San Juan, Puerto Rico

SCIENCE UPDATE: IODP Lesser Antilles Volcanism and Landslides Expedition (340) started with the first line on shore at 1150 on 02 March. Expedition scientists boarded the ship at 0845 on 03 March and started to explore their new home. Scientist orientation (ship and lab safety, life on board) started immediately after the science party finished a guided tour of the laboratories and accommodations.