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IODP Expedition 323

Bering Sea Paleoceanography

Daily Science Report for 31 August 2009

LOCATION: In transit to Yokohama, Japan (40°41.59'N, 151°05.16'E)

SCIENCE UPDATE: Site U1345 reports are nearly completed and works continues on the expedition summary. Scientists continue editing their sample requests and research plans, preparing abstracts and/or presentations for the INVEST Meeting and AGU. We are also reparing data and personal boxes for shipping. We are predicted to pass tropical storm Krovanh on our starboard side tomorrow afternoon. Our local time was retarded 2 hrs (GMT +10).
Our local time was advanced 24 hrs at midnight.


Daily Science Report for 29 August 2009

LOCATION: Southeast of the Sea of Okhotsk in transit to Yokohama, Japan

SCIENCE UPDATE: Scientists continue uploading core description and paleontological data to the ship's database, processing data, discussing results and postcruise research, editing their sample requests and research plans, preparing abstracts and presentations for the INVEST Meeting. Site U1344 reports are mostly finished; Site U1345 reports and expedition summary are in progress. The JR's Captain continues to monitor tropical storm Krovanh as it continues to move toward us. At 19:40 hr, the ship's course was deviated to the south as Krovanh was predicted to squeeze us out of sea room close to the Kuril Islands.
Our local time was advanced 24 hrs at midnight.


Daily Science Report for 28 August 2009

LOCATION: Southeast of the Peninsula of Kamchatka in transit to Yokohama, Japan

SCIENCE UPDATE: We held the science meeting for Site U1345 to present and discuss our scientific results. This was followed by two more meetings to discuss postcruise research and sampling strategies. Scientists continue uploading core description data to the ship's database, processing data, discussing results, and preparing site reports. Site U1344 reports are nearly finished; Site U1345 reports and the expedition summary are in progress. The Expedition Logo was selected with Tats Sakamoto's (Stratigraphic Correlator) design becoming the winner. We are monitoring the predicted path of typhoon/tropical storm Krovanh to take the appropriate preventive course in the next day or so.


Daily Science Report for 27 August 2009

LOCATION: East of the Peninsula of Kamchatka, 51°52.23'N, 159°55.33'E, in transit to Yokohama, Japan

SCIENCE UPDATE: All hard rock core sections from Hole U1342D on the Bowers Ridge have been imaged and described, and measured for paleomagnetic properties. The rocks consist of basalt at the top with interbedded gray, green, and red volcanoclastic breccias and sandstones below. Breccias are mostly polymictic, but also monomictic. Some sandstones exhibit layering, and most clasts in the breccias are basalt of varying textures. Scientists are processing data, discussing results, preparing presentations for the science meeting, and working on site reports. The laboratories are being prepared for cleaning.


Daily Science Report for 26 August 2009

LOCATION: West of Commander Islands, southwest Bering Sea, in transit to Yokohama, Japan

SCIENCE UPDATE: All core sections from Hole U1345E have been measured for physical properties on the laboratory track systems and described. The remaining unsplit hard rock core sections from Site U1342 are being split into working and archive halves and prepared for core description, imaging and measuring of paleomagnetic properties. Routine samples continue to be measured in the Chemistry lab for interstitial water chemistry and solid phase geochemistry. The End of Cruise Meeting was held in the afternoon to provide information on end of expedition activities and schedule, as well as the postcruise publications deadlines. Scientists continue working on data processing and site reports.


Daily Science Report for 25 August 2009

LOCATION: In transit to Yokohama, Japan

SCIENCE UPDATE: Scientists continue processing core and samples from Site U1345 and working on site reports. The last cores from Hole U1345E are being measured for physical properties on the whole-round multisensor logger (WRMSL) and all archive sections from Hole U1345D have been imaged, measured for color reflectance and described. The sedimentary section remains unchanged, except for a ~15-20 cm long pumice rock that was encountered in Core U1345C-16H. The age of the stratigraphic sequence recovered at Site U1345 spans 0 to ~440 ka based on biostratigraphic markers. Routine samples continue to be measured for interstitial water chemistry and sediment bulk geochemistry. Hard rock cores from Site U1342 are being brought back to the Core Lab to continue their curation and preparation for lithologic description.


Daily Science Report for 24 August 2009

LOCATION: In transit to Yokohama, Japan

SCIENCE UPDATE: We completed APC coring of Holes U1345D and U1345E to a total depth of 150 m DSF. Recovery at both holes was 103%. This ended coring operations at our last site. The total amount of core recovered for the entire expedition is 5743 m. The sedimentary section at Site U1345 consists predominantly of alternating silty clay and diatom bearing silty clay with sand layers, diatom rich laminated intervals, finely disseminated authigenic carbonates, occasional ash layers, mollusk shells debris and clasts. All cores from Hole U1345D and U1345E have been measured on the fast track and down to Core U1345D-7H on the whole-round multisensor logger (WRMSL). All cores from Hole U1345B and down to Core U1345C-13H have been split into working and archive halves. The working halves have been boxed and stored away, and the archive halves have been measured for color reflectance, imaged and described and are currently been measured for paleomagnetic properties. The age of the stratigraphic sequence recovered at Site U1345 is estimated to be younger than 440 ky based on biostratigraphic markers. Routine samples continue to be measured for sediment moisture and density, interstitial water chemistry and sediment bulk geochemistry. Scientists presented results from Site U1344 at the science meeting and are working on site reports. We departed Site U1345 a few minutes before 0100 hrs on 25 August.


Daily Science Report for 23 August 2009

LOCATION: At Site U1345 (NAV-1B), 60°09.19'N, 179°28.20'W (1129 mbsl)

SCIENCE UPDATE: We started APC coring operations at Site U1345. We have completed Holes U1345A to 146.9 m DSF, U1345B to 36.7 m DSF, and U1345C to 148.5 m DSF. Sediment recovery has been 103%, 104.2%, and 102.9%, respectively. We are currently APC coring Hole U1345D. The sedimentary section at Site U1345 consists predominantly of alternating silty clay and diatom bearing silty clay with sandy layers, diatom rich laminated intervals, finely disseminated authigenic carbonates and clasts. Cores U1345A-1H to 16H, U1345B-1H to 4H, and U1345C-1H to 14H have been measured on the fast track; and down to Core U1345C-2H on the whole-round multisensor logger (WRMSL). All cores from Hole U1345A have been split into working and archive halves. The archive halves have been measured for color reflectance, imaged and described. The working halves have been sampled in low resolution for postcruise research and for shipboard physical properties measurements, and Cores U1345A-1H to 4H measured for formation factor. The age at the bottom of Hole U1345A is estimated at ~0.3-0.4 Ma based on radiolarian biostratigraphy. Cores sections from Hole U1345B were carefully sampled for methane gas directly on the catwalk, then measured on the fast track logger before being taken down to the microbiology cold room for high-resolution microbiological sampling. Routine samples are being measured for sediment moisture and density and interstitial water chemistry and sediment bulk geochemistry. Furthermore, scientists are preparing presentations for the science meeting and working on site reports.


Daily Science Report for 22 August 2009

LOCATION: At Site U1345 (NAV-1B), 60°09.19'N, 179°28.20'W (1129 mbsl)

SCIENCE UPDATE: We arrived at Site U1345 and began dynamic positioning at 20:06 hr local time (-11 hr GMT). The ships crew started assembling and lowering the drill string to the seafloor, the scientists continue processing data and preparing reports, and the technical staff prepares the lab for the new cores from this last site of our expedition. All core sections from Hole U1344E have been measured on the whole-round and section half loggers. Routine samples continue to be measured for sediment moisture and density and interstitial water chemistry and sediment bulk geochemistry.


Daily Science Report for 21 August 2009

LOCATION: At Site U1344 (GAT-3C), 59°3.0'N, 179°12.2'W (3220 mbsl)

SCIENCE UPDATE: We successfully completed APC coring of Hole U1344E, the last hole at Site U1344. The total cored length at this hole was 199.8 m, recovering 202.68 m of sediments in Cores U1344D-1H to 23H (101% recovery). All core sections from Hole U1344E have been measured on the fast track logger and down to Core U1344E-15H on the whole-round multisensor track. Cores U1344E-1H to 12H have been split, measured on the section half loggers and described. The lithology remains unchanged: alternating diatom-bearing silty clay to diatom-rich sandy silt with occasional ash layers and shelly intervals. Archive halves of all APC cores are being measured on the cryogenic magnetometer. An age of ~400 to 500 ka has been assigned to the base of Core U1344E-18H based on radiolarian biostratigraphic markers. Whole-round samples continue to be analyzed for interstitial water chemistry and sediment bulk geochemistry. Expedition scientists are analyzing their data, preparing science reports and presentations for the science meeting, and designing the expedition logo. The day ended with a beautiful sunset that unveiled a clear and impressive view of the optical phenomenon known as 'green flash.'


Daily Science Report for 20 August 2009

LOCATION: At Site U1344 (GAT-3C), 59°3.0'N, 179°12.2'W (3220 mbsl)

SCIENCE UPDATE: We successfully completed APC coring of Hole U1344D recovering Cores U1344D-6H to 32H. The total depth reached was 286.5 m DSF, with a recovery of 286.1 m of sediment (or 100%). The aim at this hole was to recover a duplicate record of the upper part of the stratigraphic section at Site U1344 down to the Brunhes/Matuyama boundary. We will begin APC coring of Hole U1344E in the next few hours to a total depth of ~200 m. All core sections from Hole U1344D have been measured on the fast track logger and down to Core U1344D-24H on the whole-round multisensor track. Cores U1344D-6H to 20H have been split, measured on the section half loggers and described. The lithology remains the same as in Hole U1344C, alternating diatom-bearing silty clay to diatom-rich sandy silt. Archive halves of all APC cores are being measured on the cryogenic magnetometer. An age of ~280 to 320 ka has been estimated for the base of Cores U1344D-12H and 13H based on radiolarian and diatom biostratigraphic markers; and an age of 410 to 510 ka has been estimated for the base of Core U1344D-17H based on radiolarian markers. Whole-round samples continue to be analyzed for interstitial water chemistry and sediment bulk geochemistry.


Daily Science Report for 19 August 2009

LOCATION: At Site U1344 (GAT-3C), 59°3.0'N, 179°12.2'W (3220 mbsl)

SCIENCE UPDATE: We successfully completed wireline logging of Hole U1344A using the triple combo and the FMS sonic tools recovering good quality data. Soon after the logging tools were pulled out of the hole and rigged down, Hole U1344B, a microbiology dedicated hole, was started recovering 4.8 m of sediment in Core 1H. The core liner was cracked upon recovery, compromising the viability of using the sediment for microbiological sampling because of contamination. Therefore, we reshot Core 1H starting Hole U1344C and reaching the target depth of 35.6 m (Cores U1344C-1H to 4H). Cores were split and sampled for methane gas directly on the catwalk. All core sections were measured on the fast track logger before being taken down to the microbiology cold room for high resolution microbiological sampling. Hole U1344D was started immediately after and by midnight we had recovered Cores U1344D-1H to 5H. All cores recovered at Hole U1344D have been measured in the whole-round loggers and are being sampled using rhyzons. Cores U1344D-1H and 2H have been split, imaged, measured for color reflectance and described. The main lithology is diatom-bearing silty clay to diatom-rich sandy silt. An age of 0.05 Ma has been estimated for the base of Core U1344D-4H based on radiolarian biostratigraphy. Interstitial water samples are being analyzed for chemistry and sediment bulk geochemistry.


Daily Science Report for 18 August 2009

LOCATION: At Site U1344 (GAT-3C), 59°3.0'N, 179°12.2'W (3220 mbsl)

SCIENCE UPDATE: We completed XCB coring Hole U1344A to a total depth of 745 m DSF and recovered 648.1 m of sediment (87% recovery). Wireline logging preparations started soon after and by midnight, Hole U1344A was fully logged using the Triple Combo tool. A second run using the FMS sonic tool is currently underway. The main lithology in the lowermost section of Hole U1344A remains the same, dark greenish gray diatom-bearing silty clay to diatom-rich sandy silt, with occasional sandy layers, pebble size clasts, authigenic carbonate layers, and rare diatom ooze. All cores sections and section halves have been measured for physical sediment properties and IW samples are being analyzed for interstitial water chemistry and sediment bulk geochemistry. Biostratigraphic markers have been elusive in Hole U1344A, but a preliminary age of >1.7-1.9 Ma has been estimated for the base of Core 63X based on radiolarians. Early in the afternoon, Expedition Scientists, IODP Technical Staff and the Transocean Crew shared a relaxing time during the expedition's kite contest. A number of winners were selected in a range of inspiring categories.


Daily Science Report for 17 August 2009

LOCATION: At Site U1344 (GAT-3C), 59°3.0'N, 179°12.2'W (3220 mbsl)

SCIENCE UPDATE: We continue XCB coring of Hole U1344A. The current hole depth is 675.7 m DSF (Core U1344A-71X) with 580.73 m of sediment recovered (86 %). Whole-round core sections are flowing continuously through the fast track and WRMSL loggers, and thermal conductivity measurements. All cores down to Core U1344A-67X have been split into working and archive halves. Working halves are being sampled in low resolution for postcruise research and routine shipboard physical properties. Archive halves are being imaged, described and measured for color reflectance and paleomagnetic properties. No major lithological changes have been observed in the deeper part of the sedimentary section and no definite biostratigraphic markers have been found below Core U1344A-44X (0.9-1.5 Ma). Catwalk samples are being analyzed for interstitial water chemistry and sediment bulk geochemistry. The Teacher at Sea is actively blogging about his experience on the expedition, and participating in many of the shipboard scientific activities with the expedition scientists and the IODP Technical Staff.


Daily Science Report for 16 August 2009

LOCATION: At Site U1344 (GAT-3C), 59°3.0'N, 179°12.2'W (3220 mbsl)

SCIENCE UPDATE: We continue XCB coring of Hole U1344A. The current depth stands at 560.5 m DSF (Core U1344A-59X) with 503.83 m of sediment recovered (88.89%). Whole-round core sections are flowing continuously through the core loggers (fast track and WRMSL) and thermal conductivity measurements. All cores down to Core U1344A-50X have been split. The working halves have been sampled in low resolution for postcruise research and routine shipboard physical properties. The archive halves have been imaged, measured for color reflectance and described before continuing their core flow to the ship's cryogenic magnetometer. The sediment in the deeper section at Hole U1344A continues to be dark greenish gray diatom-bearing silty clay to diatom-rich sandy silt, with occasional sandy layers, pebble size clasts, authigenic carbonate layers, and rare diatom ooze. The sediment is moderately bioturbated. The bottom of Core U1344A-44X is estimated to be 0.9-1.5 Ma according to radiolarian biostratigraphy. The Brunhes/Matuyama boundary (0.781 Ma) was identified in Section U1344-31X-2. Catwalk samples are being measured for DIC, alkalinity and sulfate content. Expedition scientists are working on the site reports.


Daily Science Report for 15 August 2009

LOCATION: At Site U1344 (GAT-3C), 59°3.0'N, 179°12.2'W (3220 mbsl)

SCIENCE UPDATE: We continue XCB coring of Hole U1344A. The current depth stands at 330.4 m DSF (Core U1344A-35X) with 323.57 m of sediment recovered (97.93%). The maximum depth reached with the APC system at this hole was 255.1 m DSF (Core U1344A-27H). Recovery with the APC system averaged 103.65%. Whole-round core sections are been measured with the track systems for magnetic susceptibility, natural gamma radiation, thermal conductivity and density and down to Core U1344A-26H have been split, the working halves sampled in low resolution for postcruise research and routine shipboard physical properties; the archive halves imaged, measured for color reflectance and described. Subsequently, the archive halves are being measured for paleomagnetic properties using the ship's cryogenic magnetometer. The sediment at Hole U1344A is predominantly dark greenish gray diatom-bearing silty clay to diatom-rich sandy silt, with occasional sandy layers, sponge spicule aggregates and pebble size clasts. The sediment is moderately bioturbated. Core catcher samples have not produced any distinct biostratigraphic markers for the sedimentary section below Core U1344A-13H (~0.3 Ma). Routine catwalk samples for interstitial water chemistry and sediment bulk geochemistry are being measured in the Chemistry laboratory. Expedition scientists presented their results from Site U1343 at the science meeting and are working on site reports.


Daily Science Report for 14 August 2009

LOCATION: At Site U1344 (GAT-3C), 59°3.0'N, 179°12.2'W (3220 mbsl)

SCIENCE UPDATE: We arrived at Site U1344 at 01:54 hr. Hole U1344A was spudded at 09:40 hr establishing a seafloor depth of 3183.4 m. By midnight, we recovered Cores U1344A-1H through 15H. Wholeround core sections from the first 11 cores have been measured with the track systems and down to Core U1344A-4H have been split, the working halves measured for Formation Factor, sampled in low resolution for postcruise research and routine shipboard physical properties; and the archive halves imaged, measured for color reflectance and described. The sediment in these cores is predominantly dark greenish gray diatom-rich silty clay to clayey silt with occasional sandy layers, and sponge spicule aggregates. The sediment is moderately bioturbated. Routine catwalk samples for interstitial water chemistry and sediment bulk geochemistry are being measured in the Chemistry laboratory. Biostratigraphic markers (diatoms and radiolarians) provide an estimated age between 250 and 430 ka at the base of Core U1344A-13H. Expedition scientists are working on site reports and preparing presentations for the science meeting.


Daily Science Report for 13 August 2009

LOCATION: In transit to Site U1344 (GAT-3C)

SCIENCE UPDATE: We departed Site U1343 at 12:30 hrs after successfully completing coring (Holes U1343A through U1343E) and logging (Hole U1343E) operations at this site. All whole-round core sections from Hole U1343E were measured with the track systems and down to Core U1343E-80X have been split, the working halves sampled in low resolution for postcruise research, and the archive halves imaged, measured for color reflectance and described. Cores from the bottom-most section of the hole contain authigenic carbonate layers, intervals with centimeter-long shell fragments, and occasional ash layers. Expedition scientists continue to analyze and describe core samples, and at the same time are preparing presentations for the science meeting and working on the site reports. The estimated time of arrival at Site U1344 is 0200 hrs on August 14th.


Daily Science Report for 12 August 2009

LOCATION: At Site U1343 (GAT-4C) 57°33.4'N, 175°49.0'W (1975 mbsl)

SCIENCE UPDATE: We successfully completed XCB coring and downhole wireline logging of Hole U1343E to the maximum depth of 745 m DSF. The amount of sediment recovered is 700.27 m (or 94%). Downhole logging was performed using the triple combo and the FMS sonic tools. All wholeround core sections were measured with the fast multisensor logger (fast track) and down to Core U1343E-74X in the WRMSL and NGR. All cores down to U1343E-57X have been split, the working halves sampled in low resolution for postcruise research, and the archive halves imaged, measured for color reflectance and described. The lithology remains the same as in the previous cores. Biostratigraphic markers provide an estimated age between 1.7 and 1.9 Ma (radiolarian datum) at the base of Core U1343E-70X and 2.1 Ma (diatom datum) at the base of Core U1343E-77X. We continue processing and analyzing catwalk samples for interstitial water chemistry and bulk sediment geochemistry, as well as working on the site reports.


Daily Science Report for 11 August 2009

LOCATION: At Site U1343 (GAT-4C) 57°33.4'N, 175°49.0'W (1975 mbsl)

SCIENCE UPDATE: We continue XCB coring of Hole U1343E. The current depth stands at 667 m DSF (Core U1343E-75X) with 667.19 m of sediment recovered. Whole-round core sections are flowing smoothly and relentlessly through the multisensor loggers. Down to Core U1343E-37X have been split, the working halves sampled in low resolution for postcruise research, and the archive halves imaged, measured for color reflectance and described. The lithology in the hole remains pretty much the same as in the previous cores at this site. That is, alternating diatom rich clayey silt and diatom rich silty clay in varying shades of dark green to greenish gray. The sediment is slight to moderately bioturbated, with occasional sandy mottles and laminae, gravel size clasts, sponge spicules aggregates, and an 8 cm cobble found in Core U1343-34X. Gas expansion cracks continue to affect most cores. Biostratigraphic markers (radiolarians and diatoms) provide an estimated age between 1.7 and 1.9 Ma at the base of Cores U1343E-60X and -62X. The top of the Jaramillo subchron was identified in Section U1343E-28H-5 (~232 m CSF-A) and the bottom in Section U1343E-32H-4 (~266 m CSF-A). We continue processing and analyzing Catwalk samples for interstitial water chemistry and bulk sediment geochemistry, as well as working on the site reports.


Daily Science Report for 10 August 2009

LOCATION: At Site U1343 (GAT-4C) 57°33.4'N, 175°49.0'W (1975 mbsl)

SCIENCE UPDATE: We continue APC/XCB coring of Hole U1343E. The current depth stands at 465.7 m DSF (Core U1343E-54X) with 463.49 m of sediment recovered. Whole-round core sections continue to flow incessantly through the multisensor loggers. Down to Core U1343E-19H have been split, sampled in low resolution for postcruise research, imaged, measured for color reflectance and described. Sediment in Hole U1343E consists of alternating diatom bearing silty clay, diatom sand and diatom silt in varying shades of dark greenish gray. The sediment is slight to moderately bioturbated, with sandy mottles and laminae throughout, and occasional gravel size clasts, and sponge spicules aggregates. Gas expansion cracks continue to affect most cores. Biostratigraphic markers (radiolarians) provide an estimated age between 0.9 and 1.9 Ma at the base of Core U1343E-42X. The Brunhes/Matuyama boundary was identified in Core 21H in Holes U1343A and U1343B. We continue processing and analyzing catwalk samples for interstitial water chemistry and bulk sediment geochemistry. Scientists continue working on their site reports.


Daily Science Report for 9 August 2009

LOCATION: At Site U1343 (GAT-4C) 57°33.4'N, 175°49.0'W (1975 mbsl)

SCIENCE UPDATE: We continue APC coring of Hole U1343E (only one mudline core was recovered from Hole U1343D and the hole was terminated after the first core failed to recover the desired length). The current depth in Hole U1343E stands at 216.5 m DSF (Core U1343E-26H) with a recovery of 217.14 m of sediment. All core sections from Hole U1343C have been measured for physical properties on the laboratory track systems. Sediment in Hole U1343C is predominantly gray diatom-rich silty clay with green foraminifer-bearing diatom ooze, occasional ash layers, laminated intervals, gravel size clasts, pyrite mottles, and semilithified authigenic carbonate layers. Gas expansion cracks continue to affect most cores. Biostratigraphic markers (silicoflagellates) provide an estimated age of 0.7 Ma at the base of Core U1343E-25H. We continue processing and analyzing catwalk samples for interstitial water chemistry and bulk sediment geochemistry, as well as high resolution sampling of the microbiology dedicated cores. Scientists continue working on their site reports.


Daily Science Report for 8 August 2009

LOCATION: At Site U1343 (GAT-4C) 57°33.4'N, 175°49.0'W (1975 mbsl)

SCIENCE UPDATE: We completed APC coring of Hole U1343C to a total depth of 234.2 m DSF recovering 231.04 m of sediment (99% recovery). All core sections from Hole U1343C were measured for physical properties on the fast track logger, and down to Core U1343C-4H on the wholeround multisensor track. These track systems are used for determining variations in lithology, porosity and density. Fast track measurements continue to be used successfully to guide the amount of core penetration and therefore cover any existing coring gaps between holes at a site. Cores U1343A-10H through 22H and U1343C-1H through 7H have been split, imaged, measured for color reflectance and described. The sediments at Site U1343 are predominantly gray diatom-rich silty clay with green foraminifer-bearing diatom ooze, occasional ash layers, gravel size clasts, and pyrite mottles. Gas expansion cracks continue to affect most cores. Biostratigraphic markers (radiolarians, silicoflagellates, diatoms) provide an estimated age between 0.74 and 0.9 Ma at the base of Core U1343C-20H. We continue processing and analyzing catwalk samples for interstitial water chemistry and bulk sediment geochemistry, as well as high resolution sampling of the microbiology dedicated cores. The science meeting for Site U1342 was held in the afternoon to present and discuss our results. Scientists continue working on their site reports.


Daily Science Report for 7 August 2009

LOCATION: At Site U1343 (GAT-4C) 57°33.4'N, 175°49.0'W (1975 mbsl)

SCIENCE UPDATE: We completed APC coring of Holes U1343A and U1343B to total depths of 201 and 34.56 m DSF, respectively. Sediment recovery was 204.03 m CSF-A (101%) in Hole U1343A, and 34.56 m CSF-A (97%) in Hole U1343B. Hole U1343B is a microbiology dedicated hole. All core sections from Hole U1343A have been measured for physical properties and down to Core U1343A-9H have been split, imaged, measured for color reflectance and described. The sediments are predominantly gray diatom-rich silty clay with green foraminifer-bearing diatom ooze, occasional ash layers, gravel size clasts, and pyrite mottles. Abundant gas expansion cracks occur throughout the sedimentary section. Biostratigraphic markers provide an estimated age of 0.3 Ma for the base of Core U1343A-11H (diatoms) and 0.46 Ma for the base of Core 12H (radiolarians). The recovered section spans the Brunhes Chron. In the chemistry lab, geochemists and microbiologists have been measuring routine catwalk samples for interstitial water chemistry and bulk sediment geochemistry, and some of them have spent the last twelve hours in the Cold Room carrying out extensive high resolution sampling of the microbiology dedicated cores. The scientific party also continues writing the site reports and preparing presentations for the Site U1342 science meeting.


Daily Science Report for 6 August 2009

LOCATION: At Site U1343 (GAT-4C) 57°33.4'N, 175°49.0'W (1975 mbsl)

SCIENCE UPDATE: We continue to describe the hard rock cores recovered from Hole U1342D on the Bowers Ridge. Cores U1342D-7X through 13X consist of alternating gray, green, and red volcanoclastic sandstones, siltstones, and polymict and monomict breccias covered by a basaltic layer on the uppermost part of the section. Some of the layers are well sorted; sandstones exhibit layering, dewatering structures, and pebbles. Some pebbles show alteration rims. Catwalk samples are being measured for chemical properties. We held the Site U1341 science meeting to discuss and compare results and scientists are also working on their site reports.


Daily Science Report for 5 August 2009

LOCATION: In transit to Site U1343 (GAT-4C)

SCIENCE UPDATE: We completed XCB coring of Hole U1342D (Cores U1342-7X through 19X) to a total depth of 127.7 m CSF recovering 80.69 m of sediments, basalt, and volcanic breccia (overall recovery 74%). All APC cores from Site U1342 were measured for physical properties and described. Inorganic and organic chemical analyses of core sediment and pore waters are being carried out. XCB Cores U1342-7X through 10X have been split into working and archive halves and the sections are ready for initial description after the pre-site meeting for Site GAT-4C tomorrow morning. Expedition scientists are working on their data and site reports.


Daily Science Report for 4 August 2009

LOCATION: At Site U1342 (BOW-15A), 54°49.7'N, 176°55.0'E (848 mbsl)

SCIENCE UPDATE: We completed APC coring of Holes U1342B, U1342C and U1342D to a depth of 43 (recovery 44.83 m), 45.4 (recovery 46.73 m) and 44.0 m CSF-A (recovery 44.18 m) respectively. Hole U1342D was advanced without coring 18.6 m through hard basatic rock until a drill break indicated that it was possible to continue the hole with the XCB system. Hole U1342D was then XCB cored to a depth of 87.9 m recovering Cores U1342D-7X through 11X. We obtained 12.3 m of basaltic rocks with occasional thin sandy layers (recovery 48.5%). The sedimentary section at Site U1342 contains alternating units of laminated diatom ooze, olive green foraminifer-bearing diatom ooze, gray foraminifer-diatom bearing clayey silts; occasional ash layers and pebbles. Bioturbation is moderate throughout. The age at the bottom of sedimentary section is estimated at 1.8 Ma according to radiolarian biostratigraphy and paleomagnetostratigraphy. The Brunhes/Matuyama boundary was identified in Section U1342A-4H-3; the base of the Jaramillo subchron in Section U1342A-5H-2. Sedimentation rate at the site is estimated at 3 cm/ky. Expedition scientists discussed the results from Site U1341 at the science meeting and continue working on their data and the site reports.


Daily Science Report for 3 August 2009

LOCATION: At Site U1342 (BOW-15A), 54°49.7'N, 176°55.0'E (848 mbsl)

SCIENCE UPDATE: We completed coring Hole U1342A before midnight recovering Cores U1342A-1H through 7H and 9X. The hole was terminated earlier than expected after reaching vesicular basalt (andesite) at 53.3 m CSF-A. The sediments recovered in Hole U1342A consist of alternating units of beautifully laminated diatom ooze and silty clays in Cores U1342A-1H through 4H; occasional pennate diatom mats, planktonic foraminifer-rich laminae and intervals with large benthic foraminifers, nannofossils. Core U1342A-6H contained mostly sand with abundant sponge spicules, multicolored volcanic glass and crystals, and large radiolarians. The age at the bottom of Core U1342A-7H is estimated at 2.4 Ma according to radiolarian biostratigraphy. Expedition scientists are comparing and discussing their data, preparing presentations for the science meeting and working on the site reports.


Daily Science Report for 2 August 2009

LOCATION: In transit to Site U1342 (BOW-15A)

SCIENCE UPDATE: We successfully completed coring Hole U1341C recovering Cores U1341C-1H through 27H to a total depth of 230 m CSF-A. Total recovery for this hole was 240.39 m of sediment (105%). All cores were measured for physical properties using the laboratory track systems. Cores U1341C-1H through 22H have been split, imaged and described. The Bruhnes/Matuyama boundary (0.781 Ma) was identified in Section U1341C-10H-3; the top of the Jaramillo subchron in Section U1341C-12H-7. Expedition scientists are comparing and discussing their data, preparing presentations for the science meeting and working on the site reports.


Daily Science Report for 1 August 2009

LOCATION: At Site U1341 (BOW-14B), 54°2.0'N, 179°0.5'E (2139.5 mbsl)

SCIENCE UPDATE: We successfully completed downhole logging of Hole U1341B with two passes of the logging tools (triple combo and FMSsonic) to maximum depth (600 m CSF-A). After rigging down the logging tools and pulling the drill string out of the hole the vessel was offset 20 m east and Hole U1341C was spudded at 1810 hr. Cores U1341C-1H through 7H were recovered by midnight and routine whole-round measurements are underway on the laboratory track systems. Cores U1341C-1H and 2H have been split, imaged, measured for color reflectance and described. Core Catcher Sample U1341C-6H-CC is estimated to be ~0.3 Ma according to radiolarian biostratigraphy. Expedition scientists are comparing and discussing their data and working on the site reports.




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Modified on Tuesday, 01-Sep-2009 18:34:28 CDT.