TY - JOUR AB - The objective of International Ocean Discovery Program (IODP) Expedition 384 was to carry out engineering tests with the goal of improving the chances of success in deep (>1 km) drilling and coring in igneous ocean crust. A wide range of tools and technologies for potential testing were proposed by the Deep Crustal Drilling Engineering Working Group in 2017 based on reports from recent crustal drilling expeditions. The JOIDES Resolution Facility Board further prioritized the testing opportunities in 2018. The top priority of all recommendations was an evaluation of drilling and coring bits because rate of penetration and bit wear and tear are the prevalent issue in deep crustal drilling attempts, and bit failures often require an excessive amount of fishing and hole cleaning time. The plan included drilling in basalt with three different types of drill bits: a tungsten carbide insert (TCI) tricone bit, a polycrystalline diamond compact (PDC) bit, and a more novel TCI/PDC hybrid bit. In addition, a TCI bit was to be paired with an underreamer with expanding cutter blocks instead of extending arms. Finally, a type of rotary core barrel (RCB) PDC coring bit that was acquired for the R/V JOIDES Resolution several years ago but never deployed would also be given a test run. A second objective was added when additional operating time became available for Expedition 384 as a result of the latest schedule changes. This objective included the assessment and potential improvement of current procedures for advanced piston corer (APC) core orientation. Expedition 384 began in Kristiansand, Norway, on 20 July 2020. The location for tests was based on various factors, including the JOIDES Resolution's location at the time, our inability to obtain territorial clearance in a short period of time, and a suitable combination of sediment and igneous rock for the drilling and coring operations. IODP Expedition 395, which was postponed due to the COVID-19 pandemic, had proposed sites that were suitable for our testing and offered the opportunity to carry out some serendipitous sampling, logging, and casing work for science. We first spent 3 days triple coring the top 70 m of sediment at Site U1554 (Proposed Site REYK-6A) to obtain cores for evaluating potential problems with the magnetic core orientation tools and for assessing other potential sources of errors that might explain prior anomalous core orientation results. Comparison of the observed core orientation from magnetic orientation tools to the expected orientation based on the paleomagnetic directions recorded in the cores revealed an 180° misalignment in the assembly of one of the tools. This misalignment appears to have persisted over several years and could explain most of the problems previously noted. The assembly part was fixed, and this problem was eliminated for future expeditions. We subsequently spent 20 days at Site U1555 (Proposed Site REYK-13A) to test the three types of drill bits, an underreamer, and a coring bit in six holes. The TCI bits were the best performers, the TCI/PDC hybrid bit did not stand up to the harsh formation, and the PDC bit did not get sufficient run time because of a mud motor failure. The cutter block underreamer is not considered able to perform major hole opening in basalt but could be useful for knocking out ledges. The PDC coring bit cut good quality basalt cores at an unacceptably low rate. In the seventh and final hole (U1555G), we used a regular RCB coring bit to recover the entire 130 m basalt section specified in the Expedition 395 Scientific Prospectus and provided the project team with shipboard data and samples. The basalt section was successfully wireline logged before the logging winch motor failed, which precluded further operations for safety reasons. Additional operations plans in support of Expedition 395, including coring, logging, and casing at Site U1554, had to be canceled, and Expedition 384 ended prematurely on 24 August in Kristiansand. AU - Blum, P. AU - Rhinehart, B. AU - Acton, G.D. PY - 2020 ST - International Ocean Discovery Program Expedition 384 Preliminary Report T2 - International Ocean Discovery Program TI - International Ocean Discovery Program Expedition 384 Preliminary Report UR - https://doi.org/10.14379/iodp.pr.384.2020 ID - 7098 ER - TY - CHAP A2 - Jansen, E., Raymo, M.E., Blum, P., et al. AU - Jansen, Eystein AU - Raymo, Maureen E. CY - College Station, TX J2 - Affiliation (analytic): University of Bergen, Department of Geology, Bergen Affiliation (monographic): University of Bergen, Department of Geology, Bergen, Norway Coordinates: N650000 N750000 W0010000 W0200000 illus., incl. geol. sketch maps, block diag. Contains 69 references Research Program: ODP Ocean Drilling Program Document Type: Journal Article Bibliographic Level: Analytic Source Note: Proceedings of the Ocean Drilling Program; initial reports; North Atlantic-Arctic gateways II; covering Leg 162 of the cruises of the drilling vessel JOIDES Resolution, Edinburgh, United Kingdom, to Málaga, Spain, Sites 980-987, 7 July-2 September 1995, Eystein Jansen, Maureen E. Raymo, Peter Blum, Espen S. Andersen, William E. N. Austin, Karl-Heinz Baumann, Viviane Bout-Roumazeilles, Susan J. Carter, James E. T. Channell, James L. Cullen, Benjamin Flower, Sean Higgins, David A. Hodell, Julie A. Hood, Sang Min Hyun, Minoru Ikehara, Teresa King, Robert Larter, Benoît Lehman, Sigurd Locker, Katherine McIntyre, Jerry McManus, Lisa B. Meng, Suzanne O'Connell, Joseph D. Ortiz, Frank R. Rack, Anders Solheim, Wuchang Wei and Lona Dearmont. Proceedings of the Ocean Drilling Program, Part A: Initial Reports, Vol.162, p.5-20. Publisher: Texas A&M University, Ocean Drilling Program, College Station, TX, United States. ISSN: 0884-5883 Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. GeoRef ID: 2006059936 DOI: 10.2973/odp.proc.ir.162.101.1996 KW - Arctic Ocean Arctic region Atlantic Ocean Body waves Bottom currents Cenozoic Currents Drilling Elastic waves Glacial geology High-resolution methods Ice Ice sheets Leg 162 Lithofacies Milankovitch theory North Atlantic Norwegian Sea Ocean Drilling Program P-waves Paleo-oceanography Paleobathymetry Paleoclimatology Paleocurrents Quaternary Sea ice Sediment transport Sedimentation rates Seismic waves 12 Stratigraphy, Historical Geology and Paleoecology LA - English PB - Ocean Drilling Program PY - 1996 SN - 0884-5883 SP - 5–20 ST - Leg 162: new frontiers on past climates T2 - Proceedings of the Ocean Drilling Program, Initial Reports TI - Leg 162: new frontiers on past climates UR - https://doi.org/10.2973/odp.proc.ir.162.101.1996 VL - 162 ID - 18983 ER - TY - JOUR AB - The Eirik Drift lies on the continental slope south of Greenland, where it has been formed under the influence of Northern Component Water (NCW). NCW flow is an essential part of the global Thermohaline Circulation (THC), which is closely connected to the world's climate. Changes in pathways and intensity of NCW flow bear information about modifications of the North Atlantic THC in a changing climate. There is some disagreement about when deep-current controlled sedimentation at the Eirik Drift started. While the onset of drift building was previously dated as early Pliocene or late Miocene in age we suggest that the effect of large-scale current deposition had been initiated by at least 19-17 Ma based on the seismostratigraphic analysis of sedimentary structures identified in a set of high-resolution seismic reflection data. This assumption of an early Miocene onset of NCW flow is supported by regional evidence regarding the breaching of the Greenland-Scotland Ridge, which is documented in several erosional unconformities within the North Atlantic. After the onset of deep-current controlled sedimentation at the Eirik Drift, two major changes in the deep-current system are revealed during the Miocene: At the mid- to late Miocene boundary (12-10 Ma) and at 7.5 Ma. Abstract Copyright (2013) Elsevier, B.V. AU - Müller-Michaelis, Antje AU - Uenzelmann-Neben, Gabriele AU - Stein, Rüdiger J2 - Affiliation (analytic): Alfred-Wegner-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhavem Affiliation (monographic): Alfred-Wegner-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhavem, Germany Coordinates: N581236 N581236 W0482206 W0482206; N572800 N572900 W0483200 W0483200; N581400 N581400 W0453800 W0453900; N583000 N583000 W0462400 W0462400 illus., incl. sects., 2 tables, sketch map Contains 52 references Research Program: IODP Integrated Ocean Drilling Program; ODP Ocean Drilling Program Document Type: Journal Article Bibliographic Level: Analytic Source Note: Marine Geology, Vol.340, p.1-15. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0025-3227 Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands GeoRef ID: 2013059091 DOI: 10.1016/j.margeo.2013.04.012 KW - Arctic region Atlantic Ocean Cenozoic Continental slope Cores Depositional environment Eirik Drift Expedition 303 Expeditions 303/306 Geophysical methods Geophysical profiles Geophysical surveys Greenland IODP Site U1305 IODP Site U1306 IODP Site U1307 Integrated Ocean Drilling Program Labrador Sea Leg 105 Lithofacies Lower Miocene Marine environment Miocene Neogene North Atlantic Northwest Atlantic ODP Site 646 Ocean Drilling Program Paleocurrents Reflection methods Seismic methods Seismic profiles Seismic stratigraphy South Greenland Surveys Tertiary Vertical seismic profiles 12 Stratigraphy, Historical Geology and Paleoecology 20 Geophysics, Applied LA - English PY - 2013 SN - 0025-3227 SP - 1–15 ST - A revised early Miocene age for the instigation of the Eirik Drift, offshore southern Greenland: evidence from high-resolution seismic reflection data T2 - Marine Geology TI - A revised early Miocene age for the instigation of the Eirik Drift, offshore southern Greenland: evidence from high-resolution seismic reflection data UR - https://doi.org/10.1016/j.margeo.2013.04.012 VL - 340 ID - 3407 ER - TY - JOUR AU - Parnell-Turner, R., Briais, A., and LeVay, L.J. PY - 2022 ST - Expedition 395C Preliminary Report: Reykjanes Mantle Convection and Climate: Crustal Objectives T2 - International Ocean Discovery Program TI - Expedition 395C Preliminary Report: Reykjanes Mantle Convection and Climate: Crustal Objectives UR - https://doi.org/10.14379/iodp.pr.395C.2022 ID - 21316 ER - TY - JOUR AB - The intersection between the Mid-Atlantic Ridge and Iceland hotspot provides a natural laboratory where the composition and dynamics of Earth's upper mantle can be observed. Plume-ridge interaction drives variations in the melting regime, which result in a range of crustal types, including a series of V-shaped ridges (VSRs) and V-shaped troughs (VSTs) south of Iceland. Time-dependent mantle upwelling beneath Iceland dynamically supports regional bathymetry and leads to changes in the height of oceanic gateways, which in turn control the flow of deep water on geologic timescales. Expedition 395 has three objectives: (1) to test contrasting hypotheses for the formation of VSRs, (2) to understand temporal changes in ocean circulation and explore connections with plume activity, and (3) to reconstruct the evolving chemistry of hydrothermal fluids with increasing crustal age and varying sediment thickness and crustal architecture. This expedition will recover basaltic samples from crust that is blanketed by thick sediments and is thus inaccessible when using dredging. Major, trace, and isotope geochemistry of basalts will allow us to observe spatial and temporal variations in mantle melting processes. We will test the hypothesis that the Iceland plume thermally pulses on two timescales (5-10 and ∼30 Ma), leading to fundamental changes in crustal architecture. This idea will be tested against alternative hypotheses involving propagating rifts and buoyant mantle upwelling. Millennial-scale paleoclimate records are contained in rapidly accumulated sediments of contourite drifts in this region. The accumulation rate of these sediments is a proxy for current strength, which is moderated by dynamic support of oceanic gateways such as the Greenland-Scotland Ridge. These sediments also provide constraints for climatic events including Pliocene warmth, the onset of Northern Hemisphere glaciation, and abrupt Late Pleistocene climate change. Our combined approach will explore relationships between deep Earth processes, ocean circulation, and climate. Our objectives will be addressed by recovering sedimentary and basaltic cores, and we plan to penetrate ∼130 m into igneous basement at five sites east of Reykjanes Ridge. Four sites intersect VSR/VST pairs, one of which coincides with Björn drift. A fifth site is located over 32.4 My old oceanic crust that is devoid of V-shaped features. This site was chosen because it intersects Oligocene-Miocene sediments of Gardar drift. Recovered sediments and basalts will provide a major advance in our understanding of mantle dynamics and the linked nature of Earth's interior, oceans, and climate. AU - Parnell-Turner, Ross AU - Briais, Anne AU - LeVay, Leah J2 - Affiliation (analytic): Scripps Institution of Oceanography, San Diego, CA Coordinates: N600000 N610000 W0220000 W0290000 Contains 45 references Research Program: IODP2 International Ocean Discovery Program Document Type: Monograph Bibliographic Level: Monograph Source Note: Scientific Prospectus (International Ocean Discovery Program), Vol.395, 33p. Publisher: International Ocean Discovery Program, College Station, TX, United States. ISSN: 2332-1385 Copyright Information: GeoRef, Copyright 2020 American Geosciences Institute. GeoRef ID: 2020056619 URL access: Open access DOI: 10.14379/iodp.sp.395.2020 KW - Atlantic Ocean Basalts Basement Cenozoic Chemical composition Convection Crust Drilling Expedition 395 Geophysical methods Geophysical profiles Geophysical surveys Hydrothermal alteration Igneous rocks International Ocean Discovery Program Mantle Marine sediments Metasomatism Neogene North Atlantic Oceanic crust Paleo-oceanography Paleoclimatology Pleistocene Pliocene Quaternary Reykjanes Ridge Sediments Seismic methods Seismic profiles Surveys Tertiary Volcanic rocks Well-logging 18 Geophysics, Solid-Earth 20 Geophysics, Applied LA - English PY - 2020 SN - 2332-1385 ; ST - Expedition 395 Scientific Prospectus: Reykjanes Mantle Convection and Climate T2 - International Ocean Discovery Program TI - Expedition 395 Scientific Prospectus: Reykjanes Mantle Convection and Climate UR - https://doi.org/10.14379/iodp.sp.395.2020 ID - 5531 ER - TY - JOUR AB - Abstract Overflow of Northern Component Water, the precursor of North Atlantic Deep Water, appears to have varied during Neogene times. It has been suggested that this variation is moderated by transient behavior of the Icelandic mantle plume, which has influenced North Atlantic bathymetry through time. Thus pathways and intensities of bottom currents that control deposition of contourite drifts could be affected by mantle processes. Here, we present regional seismic reflection profiles that cross sedimentary accumulations (Björn, Gardar, Eirik, and Hatton Drifts). Prominent reflections were mapped and calibrated using a combination of boreholes and legacy seismic profiles. Interpreted seismic profiles were used to reconstruct solid sedimentation rates. Björn Drift began to accumulate in late Miocene times. Its average sedimentation rate decreased at ∼2.5 Ma and increased again at ∼0.75 Ma. In contrast, Eirik Drift started to accumulate in early Miocene times. Its average sedimentation rate increased at ∼5.5 Ma and decreased at ∼2.2 Ma. In both cases, there is a good correlation between sedimentation rates, inferred Northern Component Water overflow, and the variation of Icelandic plume temperature independently obtained from the geometry of diachronous V-shaped ridges. Between 5.5 and 2.5 Ma, the plume cooled, which probably caused subsidence of the Greenland-Iceland-Scotland Ridge, allowing drift accumulation to increase. When the plume became hotter at 2.5 Ma, drift accumulation rate fell. We infer that deep-water current strength is modulated by fluctuating dynamic support of the Greenland-Scotland Ridge. Our results highlight the potential link between mantle convective processes and ocean circulation. AU - Parnell-Turner, Ross AU - White, Nicholas J. AU - McCave, I. Nick AU - Henstock, Timothy J. AU - Murton, Bramley AU - Jones, Stephen M. DO - https://doi.org/10.1002/2015GC005947 IS - 10 N1 - https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015GC005947 PY - 2015 SN - 1525-2027 SP - 3414–3435 ST - Architecture of North Atlantic contourite drifts modified by transient circulation of the Icelandic mantle plume T2 - Geochemistry, Geophysics, Geosystems TI - Architecture of North Atlantic contourite drifts modified by transient circulation of the Icelandic mantle plume UR - https://doi.org/10.1002/2015GC005947 VL - 16 ID - 19419 ER - TY - JOUR AB - Coherent bathymetric features along the Reykjanes Ridge indicate that there were significant changes in the flux of buoyant material within the Icelandic Hot Spot during the Neogene. The radial extent of the topographic swell associated with this hot spot is of the order of 1000 to 2000 km, and therefore these changes affected the Greenland-Scotland Ridge (GSR). At present, sill depths along the GSR are generally less than 500 m with the deepest passage being less than 1000 m, making the overflow water sensitive to even small changes in the ridge depths. Reconstructions of Neogene mantle plume activity correlate with the deepwater circulation patterns in the North Atlantic. Times of high mantle plume activity caused Northern Component Water (NCW) production to cease. NCW fluxes resumed once this phase of high mantle plume activity slowed. The long-term climate change during the Neogene must be controlled by factors other than NCW production. However, climatic optima during the late early Miocene and early Pliocene appear to have been augmented by high NCW fluxes, while subsequent middle Miocene and “middle” Pliocene coolings correlate with uplifts on the GSR and reduced NCW flux. We suggest that reductions in NCW may have contributed to both of these cooling events. AU - Wright, James D. AU - Miller, Kenneth G. DO - https://doi.org/10.1029/95PA03696 IS - 2 N1 - https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/95PA03696 PY - 1996 SN - 0883-8305 SP - 157–170 ST - Control of North Atlantic Deep Water circulation by the Greenland-Scotland Ridge T2 - Paleoceanography and Paleoclimatology TI - Control of North Atlantic Deep Water circulation by the Greenland-Scotland Ridge UR - https://doi.org/10.1029/95PA03696 VL - 11 ID - 13595 ER -