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1. Data report: detailed lithologic columns for IODP Expedition 385 and DSDP Leg 64 sites in the Guaymas Basin, Gulf of California, Mexico

   https://doi.org/10.14379/iodp.proc.385.202.2023  

   Persad, L.D.; Marsaglia, K.M. (June 2023, Proceedings of the International Ocean Discovery Program Expedition reports)

   The Guaymas Basin, in the central Gulf of California, is a marginal ocean basin characterized by active seafloor spreading and high sedimentation rates. It has been the focus of two drilling expeditions, Deep Sea Drilling Project (DSDP) Leg 64 and International Ocean Discovery Program (IODP) Expedition 385. Expedition 385 recovered over 4 km of middle Pleistocene to Holocene core at eight drill sites, providing only simplistic stratigraphic columns that were broadly divided into as many as four lithostratigraphic subunits largely based on diagenetic modifications of sediments (authigenic carbonate and silica). For this study, shipboard sedimentologic descriptions of these subunits were used to create new, more detailed lithostratigraphic columns at an approximately decimeter (core) scale for correlation purposes and sedimentary interpretation. This was accomplished through examination of slabbed core images, visual core description sheets, and a shipboard lithologic database. The new columns provide more detailed downhole variability in lithology. The lithologic classification scheme for Expedition 385 was then integrated with that of sites previously drilled during Leg 64 to translate published visual core descriptions so as to uniformly generate comparable stratigraphic columns for both sets of drill holes. These newly compiled and tabulated data provide a more detailed picture of stratigraphic variation of lithology on a core by core basis across the basin. 

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2. Chicxulub: Drilling the K-Pg Impact Crater

   https://doi.org/10.14379/iodp.proc.364.2017  

   Morgan, J.; Gulick, S.; Mellett, C.L.; Green, S.L. (December 2017, Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   The Chicxulub impact crater, on the Yucatán Peninsula of México, is unique. It is the only known terrestrial impact structure that has been directly linked to a mass extinction event and the only terrestrial impact with a global ejecta layer. Of the three largest impact structures on Earth, Chicxulub is the best preserved. Chicxulub is also the only known terrestrial impact structure with an intact, unequivocal topographic peak ring. Chicxulub’s role in the Cretaceous/Paleogene (K-Pg) mass extinction and its exceptional state of preservation make it an important natural laboratory for the study of both large impact crater formation on Earth and other planets and the effects of large impacts on the Earth’s environment and ecology. Our understanding of the impact process is far from complete, and despite more than 30 years of intense debate, we are still striving to answer the question as to why this impact was so catastrophic. During International Ocean Discovery Program (IODP) and International Continental Scientific Drilling Program (ICDP) Expedition 364, Paleogene sedimentary rocks and lithologies that make up the Chicxulub peak ring were cored to investigate (1) the nature and formational mechanism of peak rings, (2) how rocks are weakened during large impacts, (3) the nature and extent of post-impact hydrothermal circulation, (4) the deep biosphere and habitability of the peak ring, and (5) the recovery of life in a sterile zone. Other key targets included sampling the transition through a rare midlatitude Paleogene sedimentary succession that might include Eocene and Paleocene hyperthermals and/or the Paleocene/Eocene Thermal Maximum (PETM); the composition and character of suevite, impact melt rock, and basement rocks in the peak ring; the sedimentology and stratigraphy of the Paleocene–Eocene Chicxulub impact basin infill; the geo- and thermochronology of the rocks forming the peak ring; and any observations from the core that may help constrain the volume of dust and climatically active gases released into the stratosphere by this impact. Petrophysical properties measurements on the core and wireline logs acquired during Expedition 364 will be used to calibrate geophysical models, including seismic reflection and potential field data, and the integration of all the data will calibrate models for impact crater formation and environmental effects. The drilling directly contributes to IODP Science Plan goals: Climate and Ocean Change: How does Earth’s climate system respond to elevated levels of atmospheric CO2? How resilient is the ocean to chemical perturbations? The Chicxulub impact represents an external forcing event that caused a 75% species level mass extinction. The impact basin may also record key hyperthermals within the Paleogene. Biosphere Frontiers: What are the origin, composition, and global significance of subseafloor communities? What are the limits of life in the subseafloor? How sensitive are ecosystems and biodiversity to environmental change? Impact craters can create habitats for subsurface life, and Chicxulub may provide information on potential habitats for life, including extremophiles, on the early Earth and other planetary bodies. Paleontological and geochemical studies at ground zero will document how large impacts affect ecosystems and biodiversity. Earth Connections/Earth in Motion: What mechanisms control the occurrence of destructive earthquakes, landslides, and tsunami? Drilling into the uplifted rocks that form the peak ring will be used to groundtruth numerical simulations and model impact-generated tsunami, and deposits on top of the peak ring and around the Gulf of México will inform us about earthquakes, landslides, and tsunami generated by Chicxulub. These data will collectively help us understand how impact processes are recorded in the geologic record and their potential hazards. IODP Expedition 364 was a Mission Specific Platform expedition designed to obtain subseabed samples and downhole logging measurements from the post-impact sedimentary succession and the peak ring of the Chicxulub impact crater. A single borehole (Hole M0077A) was drilled into the Chicxulub impact crater on the Yucatán continental shelf, recovering core from 505.70 to 1334.69 meters below seafloor (mbsf) with ~99% core recovery. Downhole logs were acquired for the entire depth of the borehole. 

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3. Community Recommendations on Belonging, Accessibility, Justice, Equity, Diversity, and Inclusion Initiatives in Ocean Sciences: A Town Hall Discussion

   https://doi.org/10.5670/oceanog.2025.306  

   Middleton, Julien; Clem, Sarah; Gallagher, Katherine; Meyer-Gutbrod, Erin; Sefah-Twerefour, Amadi; Serres, Margrethe; Behl, Mona; Pierson, James (January 2025, Oceanography)

   During the 2024 Ocean Sciences Meeting (OSM24), The Oceanography Society’s Justice, Equity, Diversity, and Inclusion Committee hosted a town hall on “Scientific Societies’ Roles in Building Inclusive Communities.” The town hall aimed to assess ongoing efforts to improve belonging, accessibility, justice, equity, diversity, and inclusion (BAJEDI) within ocean sciences, promote community building and discussions surrounding BAJEDI topics, and highlight the role of scientific societies in equity efforts. Here, we summarize the resultant communal discussions, which focused on effective models for increasing participation in ocean sciences, how to make ocean science careers more accessible, and strategies to build a more equitable community culture. Discussions highlighted several professional societies working to increase BAJEDI within the field and offered tangible action items to increase accessibility and equity at all career stages. An optional survey was distributed to OSM24 attendees to assess their lived experiences. Survey results highlighted that although knowledge of BAJEDI issues and training opportunities have increased, bullying and discrimination are still common. We recommend action items, including increased standardization and public accessibility of demographic data, to continue improving BAJEDI within ocean sciences. 

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4. Low drilling percentage in Norian benthic assemblages from the Southern Italian Alps and the role of specialized durophages during the Late Triassic

   https://doi.org/https://doi.org/10.1016/j.palaeo.2018.06.034  

   Tackett, LS (January 2019, Palaeogeography, palaeoclimatology, palaeoecology)

   Drillholes represent one of the clearest lines of evidence for predation of benthic invertebrates in the fossil record and are frequently used as a primary proxy for predation intensity in the fossil record. Drillholes are abundant in the late Cretaceous and Cenozoic, but their occurrence is patchy in older deposits of the Mesozoic. The inconsistent record of drillholes in pre-Cretaceous deposits of Mesozoic age are problematic for interpretations of predation-prey dynamics and adaptive radiations, and the role of taphonomy or diagenesis have not been resolved. Here we present drilling percentages for assemblages of well-preserved shelly benthic invertebrates (mainly comprised of bivalves and rare gastropods) from the upper Norian (Upper Triassic) in northern Italy in order to compare these values with reported drilling percentages from the Carnian San Cassiano Formation, a rare Triassic sedimentary unit that has yielded many drilled fossils. The Norian fossil deposits reported here are comparable to those of the San Cassiano in terms of depositional environment, preservation, and region, and can be reasonably compared to the drilling percentage of fossils from the San Cassiano. The sampled deposits are collected from marly limestone horizons in the Argillite di Riva di Solto in the Southern Italian Alps, deposited in the Lombardian Basin, and which are interbedded with shale units containing well-preserved fish and arthropod fossils, enabling a correlation between paleoecological structure of the shelly benthos and the demersal-pelagic predator diversity. Over four hundred bivalve fossils yielded a drilling percentage of 0.24% (1/406), which is typical for fossil assemblages of this age, but the single occurrence of a drillhole in this study is in marked contrast to the many drilled specimens reported from the San Cassiano Formation deposit in Italy. The drilled specimen (with complete drillhole) was an infaunal bivalve and no incomplete drillholes were observed in other specimens. Thus, drilling percentages for the Triassic are consistently low, but present, suggesting that drilling predation was an ecologically minimal influence to benthic communities and unlikely to have driven the significant ecological changes observed in benthic communities during the Late Triassic. Although drilling predation occurred during the Late Triassic, we present an updated database of specialized durophagous predators (including fishes, sharks, and reptiles) that are likely to have been more ecologically influential on benthic communities during the Norian Stage, fishes in particular. 

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5. Expedition 365 Scientific Prospectus: NanTroSEIZE Stage 3: shallow megasplay long-term borehole monitoring system (LTBMS)

   https://doi.org/10.14379/iodp.sp.365.2015  

   Kopf, A.; Saffer, D.; Toczko, S. (December 2015, Scientific prospectus)

   null (Ed.)

   The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) program is a coordinated, multiexpedition drilling project designed to investigate fault mechanics and seismogenesis along subduction megathrusts through direct sampling, in situ measurements, and long-term monitoring in conjunction with allied laboratory and numerical modeling studies. The fundamental scientific objectives of the NanTroSEIZE drilling project include characterizing the nature of fault slip and strain accumulation, fault and wall rock composition, fault architecture, and state variables throughout the active plate boundary system. International Ocean Discovery Program (IODP) Expedition 365 will recover temporary monitoring instruments (a “GeniusPlug”) from previously drilled and cased Integrated Ocean Drilling Program Site C0010 and deploy a permanent long-term borehole monitoring system (LTBMS) in the same hole after deepening it to ~656 meters below seafloor (mbsf). These operations will complete preparations begun during Integrated Ocean Drilling Program Expedition 319 and continued during Integrated Ocean Drilling Program Expedition 332. This expedition will cover a period of 33 days, beginning on 26 March and ending on 27 April 2016. Site C0010 is located 3.5 km north of Integrated Ocean Drilling Program Site C0004 and was first drilled during Expedition 319. Operations during that expedition included drilling through the megasplay fault zone and into its footwall using logging while drilling (LWD), setting casing with screens spanning the fault zone, and installation of a simple temporary observatory (a “SmartPlug”) to monitor fluid pressure and temperature in the screened interval. Major lithologic boundaries as well as the location of the megasplay fault at ~407 mbsf were identified in LWD data and were used to select a depth interval spanning the fault for placement of the two screened casing joints. Three distinct lithologic packages were observed at Site C0010: slope deposits (Unit I, 0–182.5 mbsf), thrust wedge (Unit II, 182.5–407 mbsf), and overridden slope deposits (Unit III, 407 mbsf to total depth). During Expedition 332, the SmartPlug was recovered and replaced with an upgraded version, the GeniusPlug, which includes a set of geochemical and biological experiments housed in a 30 cm extension. This GeniusPlug will be recovered and replaced with a permanent LTBMS, which will be later linked to the Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) submarine network. This Scientific Prospectus outlines the scientific rationale, objectives, and operational plans for Site C0010 and describes the contingency plan. 

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