Expedition scientists on the JOIDES Resolution (JR) during the Ocean Drilling Program (ODP), Integrated Ocean Drilling Program, and International Ocean Discovery Program (IODP) carried out visual descriptions of hundreds of kilometers of cores to characterize the sequences drilled for subsequent subsampling and analysis. The methods and tools for this collaborative process, conducted under demanding workflow conditions, evolved over the decades along with evolving technologies, user expectations, and collective experience gained. The review presented here recognizes five phases of database and user application development from 1985 to 2024, culminating in the GEODESC (GEOlogical DESCription) toolset built in 2019–2023 and deployed during the last 2 years of JR operations. GEODESC was designed around spreadsheet-based data capture, continuing the approach users had independently applied and explicitly requested. Likewise, the final products are well-structured spreadsheets suitable for analysis and visualization. A relational database supports collaborative work, data security, and quality control. State-of-the-art web applications provide user-friendly interfaces that can be run on all major web browsers without the need to install software, making collaborations among globally distributed team members easy. GEODESC supports geological core description of all types of Earth materials at microscopic, macroscopic, and summary scales and supports micropaleontological data capture as well. GEODESC catalogs provide ready-to-use templates and template components based on programmatic experience for efficient project template creation and an application to customize templates to meet project needs. An observable definition syntax promotes quality and consistency among hundreds of observables. GEODESC web applications require an administrator to initiate projects and create user accounts with appropriate credentials and roles. The JOIDES Resolution Science Operator (JRSO) originally hosted the service, and it is now maintained by the Gulf Coast Repository (GCR) and used at the GCR and beyond. If not used directly at additional organizations, the modular, feature-rich, and highly configurable GEODESC tool set and its history may serve as a reference for current and future organizations developing software for geological descriptions.
The 500 m deep DAPGEO-02 multifunctional research borehole and monitoring station was drilled in Delft in spring 2022. Dinoflagellate biostratigraphy reveals that the borehole goes through the Neogene Upper North Sea Group, including the Waalre, Maassluis, Oosterhout, Diessen, and Groot Heide formations. Below, a stratigraphic gap exists between the late Miocene Diessen and the middle Miocene Groote Heide formations, followed by a much larger gap between the Groote Heide and the lower Eocene Dongen formations. The Dongen is preceded by the Landen Formation, and the borehole ends in marl of the Danian to possibly Upper Cretaceous Ommelanden Formation. The drilling had an extensive coring programme using the Smet coring system sampling in PVC core liners and Shelby tubes with a total of around 75 m of recovered core. Core shoe samples were taken where possible, and cuttings were taken every metre. The downhole logging programme included short and normal resistivities, spontaneous potential, induced polarisation, single-point resistance, electromagnetic induction, deviation, total and spectral gamma ray, full waveform sonic, P- and S-wave suspension, acoustic borehole imaging, and nuclear magnetic resonance. The borehole makes up the central location of a seismic-monitoring station with the lower 70 m uncased and equipped with geophones. These three-component geophones at 440 and 490 m depth are accompanied by an immediately adjacent 200 m deep borehole with geophones every 50 m depth and two orthogonally oriented 100 m laterally offset boreholes, each with a single geophone at 50 m depth. Optical fibres laterally connect the boreholes and are also placed in the 50 and 200 m boreholes. DAPGEO-02 has several scientific aims, including the detection and characterisation of any seismicity from nearby geothermal projects, as well as an investigation of the subsurface properties and the changes therein, providing material to allow an investigation of the impact of heterogeneity on high-temperature storage and an investigation into the hydro-chemo-mechanical properties of the Neogene and Paleogene clays. The data from this borehole are publicly available at the 4TU data repository, and physical sample requests can be made.
Studying life in the deep, rocky subseafloor involves many layers of technological and methodological challenges, and each drilling project or expedition must make a series of choices to address these challenges. We report on the workflow for sampling hard rock cores for microbiological and biogeochemical research that was developed and optimized during International Ocean Discovery Program (IODP) Expedition 399. All steps of the workflow, including selection of the sample and its shipboard homogenization and subsampling for specific analyses, were designed to maximize the potential for interdisciplinary collaborations and syntheses of results. Furthermore, multiple strategies to minimize and detect potential microbial and organic chemical contamination of the core samples were employed, including the shipboard detection of a fluorescent chemical tracer pumped into the drill fluid. Contamination tracer levels were detectable on the exterior surfaces of the core but absent in the homogenized interiors of most core samples. Based on the experiences and preliminary results of this expedition, recommendations for processing samples on future expeditions are presented.
The Trans-Amazon Drilling Project (TADP) is reconstructing the late Cenozoic history of Amazonian geology, climate, rivers, and forests. Drilling in the Acre Basin of western Brazil in 2023 recovered an 860 m drill core characterized by sediments that were deposited in a large paleo-river system. The overall sequence includes sandstones, siltstones, and mudstones that underwent varied degrees of weathering and pedogenesis. Here, we describe the ongoing geochronologic, geochemical, mineralogical, geophysical, and biotic analyses of the sedimentary record and present some preliminary inferences of the environmental history based on these initial results. Except for the uppermost ∼ 12 m, sediments from the drill core represent a single lithostratigraphic unit, assigned to the Solimões Formation, which is dominated by feldspar-rich sands of Andean origin. The pollen assemblage is quite different from Early to Middle Miocene floras that have been analyzed from a few sites elsewhere in the western Amazon. The novel pollen assemblage and new geochronological results suggest that the sequence may span the latest Miocene and all of the Pliocene Epoch, an interval that currently is not well represented in existing regional records and that is crucial for understanding the evolution of Amazonian biodiversity, as well as landscape transformations driven by Andean uplift and global climate change.
X-ray computed tomography (XCT) scans are one of the first measurements performed after the recovery of cores during expeditions using the drilling vessel (D/V) Chikyu. Despite their completeness and availability, XCT scan data have not been effectively utilized for routine visual core description and shipboard sampling. We designed a Python-based visualization workflow that is compatible with the systems on D/V Chikyu and implemented it in the onboard core workflow.
