IODP Expedition 397
Iberian Margin Paleoclimate
Daily Science Report for 31 October 2022
Location: Hole U1586D (37°37.2835′N, 10°42.6289′W; water depth 4693.6 mbsl; proposed Site SHACK-11B)
Science Update: After displacing the hole with high-viscosity mud, the drill string was raised, and the end of the pipe was set at 84.6 mbsf for logging. The triple combo tool string was rigged up by 0445 h and deployed, but only reached 255 mbsf (~100 m off bottom). We conducted an upward pass collecting magnetic susceptibility, resistivity, density (with caliper), neutron porosity, temperature, and natural gamma radiation (NGR) data through the open hole. However, we were unable to pull the tool string into the drill pipe. After several attempts, and with the tools stuck 20 m into the BHA, we deployed a Kinley wireline cutter and crimper to sever the wireline. The wireline was cut and recovered by 1745 h, and with the triple combo hanging partly inside the BHA by the Kinley crimper, the drilled crew spent the rest of the day recovering and racking the drill pipe back on board.
Cores U1586D-35X through 38X were split and described. Core U1586D-35X contains heavily bioturbated nannofossil ooze with clay. Cores U1586D-36X through 38X yielded interbedded brownish and greenish silty clay and whitish-brown calcareous sand. The sand beds are thin- to medium-bedded and some contain laminations. Core drilling disturbance ranges from light to strong (biscuiting).
The scientific party held the first all-hands meeting in the conference room and the Co-Chief Scientists presented the scientific and operational objectives for Site U1587 (proposed Site SHACK-14A). Laboratory teams continued working on Site U1586 reports and presentations.
Daily Science Report for 30 October 2022
Location: Hole U1586D (37°37.2835′N, 10°42.6289′W; water depth 4693.6 mbsl; proposed Site SHACK-11B)
Science Update: We completed coring in Hole U1586D at 2315 h with Cores U1586D-25X to 38X reaching 350 mbsf. The total core recovered from Hole U1586D was 337.78 m (97%), and the total core recovered at the site was 1346.84 m (96%). We then proceeded to clean the hole by pumping 30 barrels of high-viscosity mud in preparation for downhole logging.
Cores U1586D-20X through 34X were split and described. They predominantly consist of slightly to heavily bioturbated nannofossil ooze with varying proportions of clay, silt, and planktonic foraminifers. Trace fossils such as Chondrites, Planolites, and Zoophycos are commonly observed. The core shows mostly light to moderate biscuiting drilling disturbance.
Scientists are conducting laboratory measurements and working on the Site U1586 reports.
Daily Science Report for 29 October 2022
Location: Hole U1586D (37°37.2835′N, 10°42.6289′W; water depth 4693.6 mbsl; proposed Site SHACK-11B)
Science Update: Increasing heave overnight resulted in some APC cores firing unintentionally during orientation (Cores U1586D-5H and 6H), causing incomplete strokes and heavy drilling disturbance in the cores. At 0100 h, in an attempt to improve the quality of the cores, we decided to pause coring operations until heave conditions subsided. At 0700 h, with the heave around 2 m and continuing to decrease, we changed to the XCB rotary system and resumed coring. Cores U1586D-13X through 25X were retrieved from 111.3 to 234.8 mbsf and recovered 120.3 m, with recovery ranging from 72% to 102% (average 97%).
Cores U1586D-11H through 19X were measured, split, and described. As observed in the same stratigraphic interval in the previous holes, the lithology in these cores consists of sparse to moderately bioturbated nannofossil ooze with varying amounts of clay, silt, and planktonic foraminifers. Trace fossils are moderate to abundant. The change of coring system in Core U1586D-13X resulted in significant improvement in the integrity of all subsequent cores.
As per COPE protocol, the COVID-19 mitigation period ended today. Testing and wearing masks will no longer be mandatory.
Daily Science Report for 28 October 2022
Location:
- Hole U1586C (37°37.2911′N, 10°42.6216′W; water depth 4692.4 mbsl; proposed Site SHACK-11B)
- Hole U1586D (37°37.2835′N, 10°42.6289′W; water depth 4693.6 mbsl; proposed Site SHACK-11B)
Science Update: We completed coring Hole U1586C to a total depth of 349.1 mbsf with Core U1586C-38X. Total recovery for Hole U1586C is 331.76 m (98%). Then we proceeded to raise the drill pipe above the seafloor and move the ship 20 m to the southwest to start Hole U1586D. At 0715 h, after picking up the top drive, installing the sinker bars, and placing the end of the pipe at 4702 mbrf, we spudded Hole U1586D at 4693.6 mbsl. APC coring continued through Core U1586D-12H, extending the hole from the seafloor to 111.3 mbsf, under increasing heave as the day came to an end.
Cores U1586C-29X through 38X and U1586D-1H through 10H were split and described. Cores U1586C-29X through 36X consist of nannofossil ooze with varying amounts of clay, silt, and planktonic foraminifers. Trace fossils are abundant. Core U1586C-35X shows several centimeter-thick sandy layers. Interbedded sand beds increase in number and thickness in Cores U1586C-37X and 38X. Lithology boundaries are characterized by changes in color and range from sharp to gradational. As in Holes U1586A through U1586C, Cores U1586D-1H through 10H consist of sparse to moderately bioturbated nannofossil ooze with varying amounts of clay, silt, and planktonic foraminifers. Increased heave resulted in Cores U1586D-3H, and 5H through 9H being moderately to severely impacted by drilling disturbance.
COVID-19 mitigation measures continued to be followed with mask wearing and social distancing.
Daily Science Report for 27 October 2022
Location: Hole U1586C (37°37.2911′N, 10°42.6216′W; water depth 4692.4 mbsl; proposed Site SHACK-11B)
Science Update: Cores U1586C-25X through 37X were retrieved from 213.3 to 339.4 mbsf. They recovered 114.25 m, with recovery ranging from 73% to 101%, an average of 91%.
Cores U1586C-16X through 28X were split and described. Cores U1586C-16X through 27X consist of sparse to moderately bioturbated nannofossil ooze with varying amounts of clay, silt, and planktonic foraminifers. Core U1586C-28X consists of silty clay with carbonate and authigenic grains. Alternating light and dark beds are observed throughout the core, with the dark silty clay presenting a reddish-brown color. Lithology boundaries are characterized by changes in color and range from sharp to gradational.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 26 October 2022
Location: Hole U1586C (37°37.2911′N, 10°42.6216′W; water depth 4692.4 mbsl; proposed Site SHACK-11B)
Science Update: Cores U1586C-6H through 24X were retrieved from 42 to 213.3 mbsf and recovered 174.1 m, with recovery ranging from 87% to 107% (overall 102%). Core U1586C-13H registered a partial stroke and overpull during retrieval. At that point, we changed to the XCB coring system and continued deepening the hole. At 1300 h, two expedition participants disembarked onto the Portuguese tug Spartacus for repatriation.
Cores U1586C-1H through 15X were split and described. They consist of sparse to moderately bioturbated nannofossil ooze with varying amounts of clay, silt, and planktonic foraminifers. Contacts between lithologies are mostly color boundaries, irregular and gradational. Scientists are analyzing their data and working on the site reports.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 25 October 2022
Location:
Hole U1586B (37°37.2478′N, 10°42.5506′W; water depth 4690.5 mbsl; proposed Site SHACK-11B)
Hole U1586C (37°37.2911′N, 10°42.6216′W; water depth 4692.4 mbsl; proposed Site SHACK-11B)
Science Update: Coring of Hole U1586B was completed at noon after retrieving Cores U1586B-36X through 40X, from 308.4 to 350 mbsf. The total core recovered in Hole U1586B was 335.13 m (96%). The drill string was raised, and the bit was positioned above the seafloor at 4657 mbrf. The ship was moved 150 m to the southwest and over the coordinates of Hole U1586C. At 1615 h, after servicing the rig, the drill bit was set at 4698 mbrf and coring in Hole U1586C began. Cores U1586C-1H through 5H advanced the hole from the seafloor to 42 mbsf, recovering 43.4 m (103%). A seafloor depth of 4692.4 mbsl was established based on the recovery (3.93 m) in Core U1586C-1H.
Cores U1586B-31X through 40X were split and described. Cores U1586B-31X through 37X consist of bioturbated nannofossil ooze with varying amounts of clay, silt, and planktonic foraminifers. Sand content increases in Core 37X and the lithology changes to interbedded calcareous silty sand, sand, and coarse sand in Cores U1586B-38X through 40X. Bioturbation is moderate to heavy.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 24 October 2022
Location: Hole U1586B (37°37.2478′N, 10°42.5506′W; water depth 4690.5 mbsl; proposed Site SHACK-11B)
Science Update: The swell dropped sufficiently by 0645 h and we returned to drilling operations. We washed down to the bottom of the hole, installed the sinker bars, and deployed an XCB core barrel. Core U1586B-25X penetrated from 209.4 to 219.1 mbsf, recovering 2.16 m (22%). Coring continued to Core 35X, deepening the hole to 308.4 mbsf by midnight, and retrieving another 86.4 m. Overall core recovery was 88.6 m or 89.5%. Core 30X was advanced only 2 m to reestablish a good core offset with Hole U1586A. Coring operations and laboratory activities were suspended at ~2130 h due to smoke and fumes from the overheating of the superconducting rock magnetometer’s (SRM) degaussing coils. The system was isolated, and the situation was addressed by the JRSO technical staff and Siem Offshore personnel. Coring resumed and the scientists returned to work in the Core Laboratory before crossover.
Cores U1586B-25X through 30X were split and described. They consist of bioturbated nannofossil ooze with varying amounts of clay and planktonic foraminifers. Bioturbation is moderate to heavy. Trace fossils such as Chondrites, Planolites, and Zoophycos are commonly observed. The stratigraphic correlators successfully tied the records from Holes U1586A and U1586B down to ~150 mbsf using strong signals in magnetic susceptibility, color reflectance, and natural gamma in the cored sediments.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 23 October 2022
Location: Hole U1586B (37°37.2478′N, 10°42.5506′W; water depth 4690.5 mbsl; proposed Site SHACK-11B)
Science Update: Only Cores U1586B-23X and 24X (190–209.4 mbsf) were retrieved today before high seas forced us to pause coring operations at 0500 h. These cores retrieved 16.75 m of material (86%). The drill bit was raised to 146.2 mbsf and we remained on hold for the rest of the day. The plan is to continue deepening the hole once sea conditions improve and the ship’s heave drops consistently below 3.5 m.
Cores U1586B-20X through 24X were split and described. They consist of bioturbated nannofossil ooze with varying amounts of clay and planktonic foraminifers. Bioturbation varies from light to intense. Pyritized burrows are observed throughout the sequence. Slight to moderate drilling disturbance is present in some cores. Taking advantage of the pause in coring operations, laboratory teams started working on the site reports and continued data analyses.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 22 October 2022
Location: Hole U1586B (37°37.2478′N, 10°42.5506′W; water depth 4690.5 mbsl; proposed Site SHACK-11B)
Science Update: Cores U1586B-10H through 22X were retrieved from 75 to 190 mbsf and recovered 115.1 m, with recovery ranging from 62% to 163% (average 100%). Cores 15H and 16H registered partial strokes and the latter experienced overpull upon retrieval. We changed to the XCB coring system after Core U1586B-16H to improve the recovery of the same interval cored with the half-length advanced piston coring (HLAPC) system in Hole U1586A.
Prior to recovering Core U1586B-17X, debris from the pipe stabber fell into the pipe, blocking the GS fishing tool from latching onto the core barrel. On the second attempt to recover the core, the drill crew mounted a custom-made fishing tool to the bottom of a rotary core barrel (RCB) and deployed it. This tool latched around the outside of the core barrel, allowing us to successfully retrieve the XCB barrel and the core. Coring continued uneventfully for the rest of the day.
Cores U1586B-1H through 19X were split and described. They consist of slightly to heavily bioturbated nannofossil ooze with varying amounts of clay and planktonic foraminifers. Pyrite nodules filling burrows are observed throughout the sequence. Slight to moderate drilling disturbance is present in some cores.
The switch to XCB coring at a shallower depth than for Hole U1586A brought up material in excellent condition. However, because of coring-induced disturbance through the HLAPC cored section of Hole U1586A, stratigraphic correlation is problematic in this part of the sequence. Using magnetic susceptibility and natural gamma signals, the scientists successfully constructed a continuous and complete sequence from marine isotope stage (MIS) 1 through 23.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 21 October 2022
Location: Hole U1586B (37°37.2478′N, 10°42.5506′W; water depth 4690.5 mbsl; proposed Site SHACK-11B)
Science Update: By 1000 h, sea conditions had improved sufficiently to continue coring. We picked up the top drive, spaced out the bit, and spudded Hole U1586B at 1145 h. Cores 1H through 9H advanced the hole from the seafloor to 75 mbsf and recovered 79.5 m. Recovery ranged from 101% to 127% (average 108%). A seafloor depth of 4690.5 mbsl was established based on the recovery (1.24 m) in Core U1586B-1H.
Cores U1586A-40X through 42X were split and described. They consist of interbedded calcareous silty clay, fine sand, and coarse sand. The core color alternates between light and whitish-green to reddish-brown, with moderate to intense bioturbation and abundant ichnofossils. XCB coring disturbance (biscuiting) is light to moderate. Scientists continue to analyze samples from Hole U1586A for geochemical, petrophysical, and micropaleontological properties.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 20 October 2022
Location: Site U1586 (37°37.3492′N, 10°42.5501′W; proposed Site SHACK-11B)
Science Update: We completed coring in Hole U1586A at 0715 h with Cores 40X to 42X reaching the Environmental Protection and Safety Panel (EPSP) approved penetration depth of 350 mbsf. The total core recovery for Hole U1586A was 339.5 m (97%). We then proceeded to raise the drill string, clearing the seafloor at 0930 h, and ending Hole U1586A. With the drill bit raised to 4657 mbrf and sea conditions deteriorating, we moved the ship 100 m to the northeast to the position of Hole U1586B and began waiting on sea conditions to improve.
Cores U1586A-29X through 39X were split and described. Cores U1586A-29X through 36X consist of slightly to intensely bioturbated nannofossil ooze with varying amounts of clay, silt, and planktonic foraminifers. Contacts between lithologies are mostly gradational although sharp erosional boundaries also are observed. Cores U1586A-37X through 39X consist of alternating clay, silt clay, clayey silt, and nannofossil ooze. Cores are intensely bioturbated and ichnofossils are abundant throughout. The base of Core 39X is estimated to be ~13.9 Ma.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 19 October 2022
Location: Hole U1586A (37°37.3108′N, 10°42.5987′W; water depth 4691.1 mbsl; proposed Site SHACK-11B)
Science Update: After reaching refusal with the half-length APC coring system on Core U1586A-26F, we switched to the XCB rotary system and continued coring. Cores U1586A-27X through 38X were retrieved from 205.8 to 315.1 mbsf and recovered 106.7 m, with recovery ranging from 70% to 132% (average 97%).
Cores U1586A-17H through 28F were split and described. They consist of slightly to heavily bioturbated nannofossil ooze with varying amounts of clay and planktonic foraminifers. Contacts between lithologies range from gradational to sharp erosional boundaries. Some piston cores show strong coring disturbance (i.e., basal flow-in and uparching). Core recovery and quality and the preservation of bioturbation structures are excellent in the XCB cores. The Stratigraphic Correlation Team calculated an average sedimentation rate of 5 cm/ky for Cores U1586-1H to 16H, based on a preliminary tuning between Site U1586 and Expedition 339 Site U1385. The base of Core 33X is estimated to be of late Miocene age (~11 Ma).
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 18 October 2022
Location: Hole U1586A (37°37.3108′N, 10°42.5987′W; water depth 4691.1 mbsl; proposed Site SHACK-11B)
Science Update: Cores U1586A-9H through 19H were retrieved from 72.9 to 177.4 mbsf and recovered 103.3 m, with recovery ranging from 90% to 106% (average 99%). Partial strokes were experienced on Cores U1586A-16H through 19H, indicating we were reaching APC refusal. Therefore, we switched to the half-length APC coring system and continued coring. Cores U1586A-20F through 26F were retrieved from 177.4 to 205.8 mbsf and recovered 28.1 m, with recovery ranging from 59% to 110% (average 101%). Partial strokes were experienced on Cores U1586A-24F through 26F. Formation temperature measurements were taken on Cores 10H (91.9 mbsf, 5.74°C) and 13H (120.4 mbsf, 5.77°C).
Cores U1586A-4H through 16H were split and described. They consist of bioturbated nannofossil ooze with varying amounts of clay and planktonic foraminifers. Nodules filling burrows are observed through the sequence. Slight to moderate drilling disturbance is apparent in the top section of most cores. The base of Core U1586A-22F is estimated to be of late Miocene age (~5.98 Ma).
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 17 October 2022
Location: Hole U1586A (37°37.3108′N, 10°42.5987′W; water depth 4691.1 mbsl; proposed Site SHACK-11B)
Science Update: The day started while lowering the drill string to the seafloor. At 0900 h, we installed the sinker bars and the Icefield MI-5 core orientation tool and positioned the drill bit at 4692.4 mbrf in preparation for taking the first core of the expedition, but the first attempt did not recover any sediment. We lowered the bit to 4699 mbrf and the second attempt to spud the hole was successful. Coring in Hole U1586A started at 1205 h with Core U1586A-1H recovering 6.4 m (100%) and establishing a seafloor depth of 4691.1 mbsl (meters below sea level). APC coring continued with Cores U1586A-1H through 8H penetrating from the seafloor to 72.9 mbsf (meters below seafloor), with core recovery ranging from 80% to 107% (average 101%). Only Core 3H experienced a partial stroke. Formation temperature measurements were taken on Cores 4H and 7H.
Cores U1586A-1H through 3H were split and described. They consist of bioturbated clayey nannofossil ooze with dark patches in more heavily bioturbated intervals. The base of Core 7H is estimated to be of mid-Pleistocene age (~0.97–1.17 Ma).
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 16 October 2022
Location: Hole U1586A (37°37.3110′N, 10°42.5982′W; water depth 4686 mbsl; proposed Site SHACK-11B)
Science Update: With the harbor pilot aboard at 0800 h, the ship left the dock after the last line was released at 0830 h. The pilot departed at 0902 h, and the ship was underway to proposed Site SHACK-11B (Site U1586) in the Iberian Margin. We completed the 99 nmi voyage to Site U1586 at 1814 h. The thrusters were deployed, and the drill string was made up with a 5 inch drill pipe and an advanced piston corer/extended core barrel (APC/XCB) bottom-hole assembly (BHA) and lowered to 1281 mbrf (meters below rig floor) by midnight. Wind and sea conditions remained calm throughout the day.
The scientists continued training on IODP core flow procedures and setting up the laboratories.
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel.
Daily Science Report for 15 October 2022
Location: Rocha Pier, Lisbon, Portugal
Science Update: Bunkering and all port call activities were completed. The scientists received hands-on training on IODP sampling procedures, core imaging, core description, and laboratory instrumentation.
The Co-Chief Scientists and JRSO and Siem Offshore key personnel attended the prespud meeting to review planned operations at proposed Site SHACK-11B (Site U1586).
COVID-19 mitigation measures continued to be followed with mask wearing, social distancing, and daily antigen testing of all personnel. The ship is scheduled to depart from Lisbon on 16 October at 0800 h.
Daily Science Report for 14 October 2022
Location: Rocha Pier, Lisbon, Portugal
Science Update: Port call activities continued for Expedition 397. The fresh and frozen food shipment and other catering supplies arrived and were loaded on board and stored. The ship loaded 700 mt of fuel. JRSO staff and scientists continued laboratory setup and training; scientists received laboratory safety orientations and core flow tours. Shipboard COVID-19 safety protocols and testing are being followed and the ship is scheduled to depart Lisbon on 16 October.
Daily Science Report for 13 October 2022
Location: Rocha Pier, Lisbon, Portugal
Science Update: The Expedition 397 scientists, JRSO staff, and ship’s crew cleared immigration formalities, boarded the vessel in the morning, and settled into their cabins. After lunch, the day-shift scientists and new technicians received a general presentation on ship safety. Scientists started to set up their computers to access the ship’s network and to learn their laboratories. Other port call activities included distribution of oncoming freight. Shipboard COVID-19 safety protocols are being followed and the ship is scheduled to depart Lisbon on 16 October.
Daily Science Report for 12 October 2022
Location: Rocha Pier, Lisbon, Portugal
Science Update: Port call activities continued with the loading and offloading of freight. The Expedition 397 scientists, JRSO staff, and ship’s crew continued to isolate in their hotel rooms in Lisbon, Portugal, following JRSO and Siem Offshore quarantine and COVID-19 testing procedures prior to boarding the vessel on 13 October.
Virtual orientation and preparation meetings continued. Scientists received introductions on core curation and sampling, life on board the JOIDES Resolution (including our JRSO Code of Conduct), and boarding instructions. The Co-Chief Scientists presented the scientific and operational objectives for the expedition and for the first proposed site, SHACK-11B (Site U1586). The sedimentology team conducted a crossover and Q&A session with JRSO staff aboard the JOIDES Resolution on GEODESC, the new core description application. Laboratory teams continued to work on their Methods chapters and discuss their sampling and measuring plans for the expedition. The ship is scheduled to depart Lisbon on 16 October.
Daily Science Report for 11 October 2022
Location: Rocha Pier, Lisbon, Portugal
Science Update: IODP Expedition 397, Iberian Margin Paleoclimate, officially began in Lisbon, Portugal, at 1045 h on 11 October 2022 upon arrival of the JOIDES Resolution at the end of Expedition 397T. Port call activities began with the arrival of oncoming shipments and offloading freight.
All oncoming Expedition 397 personnel, including JRSO staff and scientists, arrived two to three days earlier in Lisbon to follow a four-day hotel quarantine. The quarantine includes PCR and antigen tests, according to the COVID-19 mitigation protocol. Taking advantage of the quarantine in the hotel, the Expedition 397 scientists and JRSO staff began virtual expedition preparations and preboarding orientations. These meetings included an introduction to the expedition, IODP coring and logging tools and procedures, imaging resources, and publications services. Laboratory teams began meeting to discuss methods and shipboard sampling strategies and to continue drafting their Methods chapters. All expedition participants plan to board the JOIDES Resolution on 13 October and the ship is scheduled to depart Lisbon on Sunday 16 October.