IODP Expedition 317
Canterbury Basin Sea Level
Daily Science Report for 31 December 2009
LOCATION: Site U1354 (proposed site CB-02A), 44.847°S, 171.787°E
SCIENCE UPDATE: Coring resumed in the morning and Cores U1354C-2H through 14X (65-174 m DSF) were recovered with an average recovery rate of 82%. Cores U1354B-11H through 15H and U1354C-2H through 5X were described today and consist of sandy marl, calcareous sandy mud, silty sand, and mud with abundant shells and shell fragments. Subtle as well as distinct lithologic contacts were observed, including some likely to represent sequence boundaries. The age at the bottom of the hole is >2.78 Ma.
The ship's new bell was installed at the bow and as midnight approached the bell was struck 8 times for the old year followed by 8 strikes for the new year. This was followed by a rapid ringing of the bell as a signal for New Year's celebrations to begin (and to climax in a few days in Wellington).
Daily Science Report for 30 December 2009
LOCATION: Site U1354 (proposed site CB-02A), 44.847°S, 171.787°E
SCIENCE UPDATE: Cores U1354B-1H through 15H (0-77 m DSF)
were recovered with an average
recovery of 100%. At noon, operations in Hole U1354B were terminated
because of strong winds that made it impossible to keep position within
the safe range. Current status is waiting on weather. Cores U1354A-9H
through 19H and Cores U1354B-1H through 10H were described today and
consist of greenish gray mud with abundant shells and shell fragments,
green muddy sand, mud, shelly mud, shell hash, and well-sorted fine gray
sand with abundant shell fragments. Good correlations between lithologic
boundaries and seismic sequence boundaries exist for this late
Pleistocene (<0.44 Ma) interval.
Daily Science Report for 29 December 2009
LOCATION: Site U1354 (proposed site CB-02A), 44.847°S, 171.787°E
SCIENCE UPDATE: The vessel arrived at Site U1354 and began coring operations in the early morning. Cores U1354A-1H through 19H (0-85.4 m DSF) were recovered with
an average recovery of 96%, which concluded operations at Hole U1354A.
Cores U1354A-1H through 8H were described today and consist of gray and
green homogeneous mud, sandy mud with rare shell-rich layers, thick and
thin layers of well-sorted fine-grained sand, marl, and shell hash. The
age at the bottom of the hole is 1.26-1.56 Ma. A shallow subsurface
fresh water layer observed at the last, more landward site does not seem
to exist here.
Daily Science Report for 28 December 2009
LOCATION: Site U1353 (proposed site CB-01A), 44.769°S, 171.674°E
SCIENCE UPDATE: The triple combo logging tool string was rigged up in the early
morning, without nuclear sources (neutron porosity, gamma ray density)
to minimize the operational risk in a difficult formation. The tool was
successfully lowered to TD (~600 m DSF), and after a short repeat
section from TD to ~550 m WRF, the main pass from TD to the seafloor
was logged. Spectral gamma ray, caliper, and resistivity were recorded
over the entire interval. The FMS sonic tool string was subsequently
deployed with a downlog from the seafloor to ~340 m WRF where an
obstruction was encountered. Several attempts to pass failed, so a log
was recorded from that point up. A second attempt reached ~300 m WRF
before encountering an obstruction. While pulling out, numerous tight
pulls were observed, indicating hole collapse. Upon trying to enter the
pipe, the tool became embedded in the formation along with the drill
pipe. When efforts to enter the pipe failed, a "Reverse Cut And Thread"
operation was employed whereby the pipe is pulled up one stand at a time
and the cable is cut off in segments. The cable remained attached so the
tool's tension could be controlled to ensure it remained in the pipe as
far as possible. The pipe and tools reached surface in the early
evening. As suspected, both centralizers were found to have mechanical
damage caused by debris jamming the arms while they were being pulled
into pipe. In the evening, the vessel was secured for transit to the
next site in DP mode.
Daily Science Report for 27 December 2009
LOCATION: Site U1353 (proposed site CB-01A), 44.769°S, 171.674°E
SCIENCE UPDATE: Hole U1353C was drilled without coring to a depth of 500 m DSF. The hole is being displaced with mud in preparation for logging. Scientists are completing final version of Site U1352 reports and draft versions of Site U1353 reports.
Daily Science Report for 26 December 2009
LOCATION: Site U1353 (proposed site CB-01A), 44.769°S, 171.674°E
SCIENCE UPDATE: Cores U1353B-79X through 98X (423-614 m DSF) were recovered with an average nominal recovery of 4%. Cores U1353A-71X through 98X were described today and consist of homogeneous sandy mud. The age at the bottom of the hole, which targeted and is assumed to have penetrated seismic reflector U5, is early-mid Miocene. This concluded operations at Hole U1353B. A cement plug was deployed per protocol and drilling of a dedicated logging hole, Hole U1352C, began.
Daily Science Report for 25 December 2009
LOCATION: Site U1353 (proposed site CB-01A), 44.769°S, 171.674°E
SCIENCE UPDATE: Cores U1353B-55H through 78X (248-423 m DSF) were recovered
with an average nominal recovery of 13% (100% for Cores 55H-60H; 8% for Cores 61X through 78X). Cores U1353A-31X through 70X were described today and consist of homogeneous sandy mud similar to that recovered in lithologic Unit II at Site U1351. The age at the bottom of the hole is 3.7-4.3 Ma. Expedition participants enjoyed artistic, culinary, and social Christmas attractions offered by many crew and science party members over the past two days.
Daily Science Report for 24 December 2009
LOCATION: Site U1353 (proposed site CB-01A), 44.769°S, 171.674°E
SCIENCE UPDATE: Cores U1353B-34H through 54H (177-248 m DSF) were recovered with an average nominal recovery of 73%. Poor coring conditions persist, with short APC cores, XCB coring attempts with no recovery, and most recovered material having caved into the hole. Cave-in material is mostly comprised of shell hash washed out of sandy mud formation by the borehole circulation required to drill. We anticipate that coring conditions will improve with depth. Cores U1353A-9H through 30H were described today and the short intervals representing the formation consist of green calcareous sand and sandy mud with rare shells. At least one significant lithologic boundary was recovered that may be correlated to the other sites drilled during Expedition 317. The age at the bottom of the hole is >3.7 Ma.
Daily Science Report for 23 December 2009
LOCATION: Site U1353 (proposed site CB-01A), 44.769°S, 171.674°E
SCIENCE UPDATE: Cores U1353B-12H through 33H (73-177 m DSF) were recovered with an average nominal recovery of 53%. Coring has been deteriorating starting with U1353B-13H (80 m DSF). APC cores achieved half strokes at best, most much less. Moreover, almost all liners were severely shattered, leaving the recovered sediment highly disturbed. A significant portion, if not all, of many cores is considered to be material that has fallen into the bottom of the hole. Seven XCB cores were attempted but were not able to recover any significant amount of material. Cores U1353A-6H through 8H, and Cores U1353B-1H through 8H were described today and consist of green muddy very fine sand, greenish gray mud with rare shells, and a thick beds of very fine massive sand. The age at the bottom of Hole U1353B is 2.7-3.1 Ma.
Daily Science Report for 22 December 2009
LOCATION: Site U1353 (proposed site CB-01A), 44.769°S, 171.674°E
SCIENCE UPDATE: Operations at Site U1353 began in the early morning. Cores U1353A-1H through 8H (0-56 m DSF), and U1353B-1H though 11H (0-73.2 m DSF) were recovered with an average nominal recovery of 101% each. None of the APC coring attempts achieved full (9.5 m) stroke because of the sand and stiff clay layers in these mid-shelf sediments. Cores U1353A-1H thought 5H were described today and consist of dark greenish gray moderately bioturbated micaceous very fine to fine sandy marl with scattered shell fragments (including ~6-7 m Holocene) intercalated with 1-6 m thick massive gray well-sorted fine sand layer (beach sand). The age at the bottom of the hole is ~0.44 Ma based on calcareous nannofossils.
Daily Science Report for 21 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: At the time operations at Hole U1352C were concluded, the winds and swells were too high for operations at the next site in shallow (<200 m) water. In anticipation of a delay of ~24 h due to weather, we decided to core Hole U1352D until departure to the next site. Fourteen cores were retrieved from 0-127 m DSF with an average nominal recovery of 103%. At 1800 h the vessel was prepared for transit to the next Site U1353 (proposed site CB-01A), based on improved sea state, and left Site U1352 at sunset.
Daily Science Report for 20 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Pulling pipe from total depth (1928 m DSF) in Hole U1352C in preparation for logging operations proceeded without problems in the lower ~1000 m of the hole. 400 barrels of mud were pumped at 880 m DSF to help support upper hole stability. However, excessive drag required the use of the top drive to rotate the pipe and rotation experienced excessive torque, indicating that sediment was packing in on the pipe. The pipe was eventually raised to the logging depth of ~80 m DSF. The VIT camera was deployed to observe and document the cone of cuttings at the sea floor while logging. The triple combo tool string was rigged up without the radioactive source and lowered to ~550 m WRF where several attempts did not allow the tool to pass. Logging Hole U1352C had to be abandoned due to the upper hole apparently collapsing. Logging tools, VIT camera, and pipe were recovered.
Daily Science Report for 19 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-143R through -148R (1875-1928 m DSF) were recovered with an average recovery rate of 63%. This concluded coring in the deepest sediment hole ever drilled by three generations of scientific ocean drilling programs. The pipe is being pulled in preparation for logging operations. Cores U1352C-139R through 148R were described and consist of white limestone with ichnofossils and stylolites. The age at the bottom of the hole is Eocene.
Daily Science Report for 18 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-134R through 142R (1793-1875 m DSF) were recovered with an average recovery rate of 58%. The Marshall Paraconformity, the deep target at this site, was penetrated with Core 140R (1851-1861 m DSF) as seen from the recovery of white chalk through the core liner and confirmed with an Oligocene (~30 Ma) microfossil fauna in the subsequent core catcher samples. Cores U1352C-130R through 138R were described and consist of the same "zebra" or "bar code" rock recovered for the past few days. It is comprised of bioturbated sandy marlstone, now turning into silty limestone, with mm to cm-thick dark layers and seams that occur as bedding-parallel layers or variably deformed, inclined, and splayed surfaces following or cross-cutting ichnofabric. The dark "layers" are now thought to represent dikes and sills injected with glauconitic sand and mud presumed to exist below this formation.
Daily Science Report for 17 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-125R through 133R (1707-1793 m DSF) were recovered with an average recovery rate of 62%. Hole U1352C is now the deepest sediment hole ever drilled during a DSDP, ODP, or IODP expedition, and the deepest hole ever drilled during one expedition. Cores U1352C-120R through 129R were described and display a significant change in lithology. The interval above ~1700 m consists of bioturbated sandy marlstone with dark, wavy, dissolution seams that have thickened from sub-millimeter "laminae" a few hundred meters upcore to >1 cm thick layers spaced several cm or dm apart in the last few cores. Below that interval, glauconitic sand is dispersed in the marl and occurs as discrete, cm-scale, parallel and cross-laminated glauconitic sand layers that often scour the underlying sediment. The age at the bottom of the hole is middle early Miocene (18.0-18.7 Ma) based on robust calcareous nannofossil and planktonic foraminifer datums.
Daily Science Report for 16 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: After completing the wiper trip in the morning, Cores U1352C-119R through 124R (1662-1707 m DSF) were recovered with an average recovery rate of 60%. Cores U1352C-115R through 119R were described and consist of greenish gray marlstone with dark, wavy, discontinuous seams along the edges of burrows and bedding planes. The rocks are now hard enough to seriously jam in the core barrel and fractured pieces are capable of puncturing and deforming the core liner. The age at the bottom of the hole is late early Miocene (16-17 Ma) based on calcareous nannofossils and planktonic foraminifers.
Daily Science Report for 15 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-112R through 118R (1594-1662 m DSF) were recovered with an average recovery rate of 88%. A wiper trip is currently underway to maintain the hole for another ~200 m of coring. Cores U1352C-106R through 114R were described and consist of dark and lighter greenish gray marlstone with wavy lamination and cm-scale sandy intervals with planar and cross-lamination. Laminated intervals have a relatively high abundance (>2%?) of organic constituents. Magnetic susceptibility and natural gamma ray signals show a decreasing trend while reflectance L* increases, possibly reflecting increasing carbonate content. The age at the bottom of the hole is early middle Miocene (13.5-15.9 Ma) based on calcareous nannofossils and planktonic foraminifers.
Daily Science Report for 14 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-102R through 111R (1496-1594 m DSF) were recovered with an average recovery rate of 66%. Cores U1352C-101R through 105R were described and consist of dark greenish gray, bioturbated marlstone. Most intervals show mass flow structures, including slump deformation, fluidization structures, dm-scale sand layers with very coarse clasts, graded beds and lamination, and at least one complete turbidite sequence. White shell fragments, black carbonaceous components, and glauconitic clasts are included in the sand layers. The age at the bottom of the hole is middle Miocene (13.5-15.9 Ma). Gas data show a conspicuous and yet to be explained decrease in C1, C2, and C3 concentrations from 1250 to 1400 m CSF before returning to the large-scale downhole trend from 1400 to 1550 m CSF.
Daily Science Report for 13 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-93R through 101R (1419-1496 m DSF) were recovered with an average recovery rate of 26%. Six core barrels were retrieved empty except for small pieces in the core catcher; two barels were essentially full. A change in lithology was not indicated by the recovered material. Cores U1352C-89R through 100R were described and consist of dark greenish gray, bioturbated marlstone with wavy lamination intervals, a slumped interval, and a sand bed with erosional base and glauconitic clasts, indicating penetration of a mass transport unit. The age at the bottom of the hole is late Miocene.
Daily Science Report for 12 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-83R through 92R (1337-1419 m DSF) were recovered with an average recovery rate of 52%. This included three half-cores with 43% recovery and seven full-length cores with 62% recovery. Cores U1352C-71R through 88R were described and consist of dark greenish gray, well-sorted marlstone with heavy bioturbation. 2-5 cm thick layers of dark calcareous mudstone at approximately half-meter intervals exhibit a cyclic pattern. A few thin sand layers were also present. The sediment is of late Miocene age. A planktic foraminifer marker indicates an age of 5.3-5.6 Ma near the bottom of the hole.
Daily Science Report for 11 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: During the first half of the day, Cores U1352C-69R through
75R (1242-1304 m DSF) yielded a strongly bi-modal recovery of either
9-10 m (94-104%) or 0-0.6 m (0-7%). No drastic changes in lithology were
observed. This pattern indicated possible loss of cores after they were
cut, a plausible scenario given the long, cleanly cut, small-diameter,
continuous cores we were recovering. We decided to cut half cores to
increase recovery and Cores U1352C-72R through 82R (1304-1337 m DSF)
recovered cores ranging from 0.5 to 4.8 m in length. Average recovery
for seven long cores was 48%, the average for seven short cores was 60%.
The time penalty for cutting short cores was ~40 min per 9.6-m interval.
Cores U1352C-55R through 70R were described and consist of the familiar
greenish gray, bioturbated sandy marlstone of lower Pliocene age. An
interval with a sharp contact and an interval with laminated sand layers
were observed in Core U1352C-61R. The Pliocene/Miocene boundary was
identified in Core U1352C-73R (1275-1285 m DSF).
Daily Science Report for 10 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-47R through 62R (1151-1208 m DSF)
retrieved in the morning had an impressive recovery of 79%. At that
point, coring slowed down with a piece of hard core jamming the bit.
After the bit had been de-plugged, coring and recovery failed to pick
up. Cores U1352C-63R through 68R (1208-1242 m DSF) had a nominal
recovery rate of 4%. The age near the bottom of the hole is still early
Pliocene. Cores U1352C-42R through 54R were described and consist of the
familiar dark greenish gray, bioturbated sandy marlstone. Two thin
layers, one with laminated silty sand and the other with broken shells
and rip-up clasts, were also observed and are eagerly anticipated to
bring about a downhole change from the hundreds of meters of homogeneous
green marl described for several days.
Daily Science Report for 9 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-42R through 56R (1007-1147 m DSF) were recovered with a recovery rate of 53%. The age at the bottom of the hole is early Pliocene. Cores U1352C-31R through 41R were described and consist of dark greenish gray, bioturbated sandy marlstone.
Daily Science Report for 8 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352C-27R through 41R (660-863 m DSF) were recovered with a recovery rate of 51%. The age at the bottom of the hole is early Pliocene. Cores U1352C-14R through 30R were described and consist of greenish gray, bioturbated sandy marlstone.
Daily Science Report for 7 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Hole U1352C was drilled to 666 m DSF before cutting Cores U1352C-6R through 26R (660-863 m DSF; 22% recovery). Cores from the interval 575-671 m CSF in Hole U1352C were described and consist of greenish gray sandy marlstone and sandy calcareous mud. The marlstones recovered in 1-3 m intervals in this RCB hole are the same lithology found jamming the core catcher of the XCB bit at similar depths in Hole U1352B.
Daily Science Report for 6 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Hole U1352C was drilled to 575 m DSF before three spot cores (Cores U1352C-2R through 4R; 575-604 m DSF) were taken to cover a major recovery gap in Hole U1352B. Total recovery was 12.8 m (44%). Drilling then continued with the next target depth for coring at ~660 m DSF. The remaining cores from Hole U1352B (Cores U1352B-73X through 94X; 629-822 m CSF) were described and consist of homogeneous gray mud.
Daily Science Report for 5 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Hole U1352B was logged with the Triple Combo tool string from a depth of 487 m WSF, where a borehole obstruction prevented the tool from being lowered further. Two passes were successfully recorded. The caliper indicated excessive borehole size that would not permit an adequate clamp for the VSI tool needed to obtain reliable data and the Vertical Seismic Profiling (VSP) plan was canceled. The FMS/Sonic tool string was subsequently deployed and also encountered a borehole obstruction, now somewhat higher in the hole. FMS/Sonic logs were recorded from a depth of 442 m WSF. After rigging down the logging tools, drilling operations began in Hole U1352C to a current depth of ~150 m DSF (without coring). Cores U1352B-53X through 72X (447-629 m CSF) were described and consist of homogeneous gray mud with decreasing numbers of green sandy intervals compared to the overlying sequence.
Daily Science Report for 4 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352B-82X through -94X (711-831 m DSF) were retrieved with an average recovery rate of 15%. Given low recovery, slowing penetration, and very hot conditions at the bit, it was decided to terminate coring operations to avoid damage to equipment that would pose a risk to the hole. Preparations for logging began. The age near the bottom of the hole is late Pliocene. Preservation of nannofossils is variable in the lowermost ~200 m of the section. Cores U1352B-38H through 52X described today continue to consist of dm to m-scale successions of olive-green calcareous, medium to fine sand with erosional bases fining upward into light gray sandy mud and mud.
Daily Science Report for 3 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352B-63X through -81X (543-711 m DSF) were retrieved with an average recovery rate of 51%. The age near the bottom of the hole is late Pliocene. Preservation of nannofossils is variable in the lowermost ~100 m of the section. Cores U1352B-22H through 37X described today continue to consist of dm to m-scale successions of olive-green medium to fine sand with erosional bases fining upward into light gray sandy mud and mud. The sediment is turning more calcareous downhole.
Daily Science Report for 2 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352B-36H through -62X (295-543 m DSF) were retrieved with an average recovery rate of 83%. The age near the bottom of the hole is ~1.7 Ma based on nannofossil biostratigraphy. Cores U1352B-10H through 21H described today contain dm to m-scale successions of olive-green medium to fine sand with erosional bases fining upward into gray sandy mud and mud. Core logging data, particularly natural gamma ray data, can be correlated in great detail to ODP Site 1119 records, which were dated and interpreted in terms of MIS stratigraphy.
Daily Science Report for 1 December 2009
LOCATION: Site U1352 (proposed site CB-04B), 44.94°S, 172.02°E
SCIENCE UPDATE: Cores U1352B-12H through -35H (103-295 m DSF) were recovered with an average recovery rate of 99%. The age near the bottom of the hole is ~1 Ma based on nannofossil biostratigraphy. Cores U1352B-1H through 9H described today contain gray and greenish gray mud with interbedded dark-gray fine sand beds of 1-10 cm thickness and medium to coarse grained sandy mud beds with shell fragments. Soft-sediment deformation occurs in some intervals.