The data are mean daily discharge data at United States Geological Survey gages. Once column provides the date (mm/dd/yyyy) and the other column provides the mean daily discharge in cubic feet per second. This dataset is associated with the following publication: Costigan, K., K. Jaeger, C. Goss, K. Fritz , and P. Goebel. Understanding controls on flow permanence in intermittent rivers to aid ecological research: integrating meteorology, geology and land cover. ECOHYDROLOGY. Wiley Interscience, Malden, MA, USA, online, (2016).

This Data Release contains 1:24,000-scale geospatially-enabled geological data to accompany the Geology of the Mineral and Lake Anna West quadrangles, Virginia. The map product is a cooperator series publication and, as such, does not have a specific abstract. Geologic mapping for this map product was completed between 2014 and 2017, with most of the field work occurring between January 2016 and May 2017. Numerous foot traverses were completed along creeks and roads throughout the field area; the shore of Lake Anna was accessed by kayak to provide additional data. Distributions of soil units were considered when assigning bedrock type in areas where outcrop was lacking and helped to distinguish fluvial terrace deposits. Hill-shade raster images created from LiDAR datasets and geophysical data sets proved useful in the field to trace bedrock and surficial units. GPS location control and field data were collected and recorded in digital databases using a variety of geologic mapping applications for an iPad 3rd Gen Model A1403 and Motion C5v tablet using Fieldmove 2013.1. Structural measurements were also plotted on field maps. Data collected included lithology and the orientation of foliations, folds, lineations, joints, and faults. Representative rock samples of significant formations were thin-sectioned for petrographic analysis; a few samples from these and surrounding quadrangles were analyzed for zircon U-Pb geochronology and geochemistry.

The British Geological Survey has collected over 50,000 offshore samples using grabs, dredges and shallow coring devices (to a maximum depth of 6m below the sea bed). The collection also includes additional third party data and has assisted in the creation of BGS marine geology maps. The distribution is variable, but in general there are sample stations spaced approximately every 5 - 10 km across the entire UK Continental Shelf (UKCS), and in some localised areas the sampling density is much higher. The data held include digital data and analogue records (sample data sheets), plus associated physical sample material. Sample data sheets, which have been scanned, contain index information and geological descriptions. They become more detailed from 1983 onwards. Coded geological descriptions were entered on sheets which were subsequently digitized, and this information is available for about 10,000 samples. The data also includes results of analyses such as micropalaeontological examination or age dating. All sample material is managed as part of the BGS materials collection and are available for examination and subsampling. The data are stored within the National Geoscience Data Centre (NGDC) and Marine Environmental Data and Information Network (MEDIN) Data Archive Centre (DAC) for Geology and Geophysics. These geological data are delivered via the BGS GeoIndex. Separate layers are provided for different types of sample: borehole-type samples, grab samples and other equipment types. These layers contain the geological data, and metadata about the samples themselves, as well as links to scanned datasheets and core logs, are provided in separate metadata layers. For some of these samples, particle size analysis (PSA), geochemical and geotechnical data are also available, and these data are provided in separate layers. The data are applicable to a wide range of uses including environmental, geotechnical and geological studies. Reference: Fannin, NGT. (1989) Offshore Investigations 1966-87. British Geological Survey Technical Report WB/89/2, British Geological Survey.

Reconnaissance geologic maps and sample data, Teller A-1, A-2, A-3, B-1, B-2, B-3, C-1, and Bendeleben A-6, B-6, C-6, D-5, D-6 quadrangles, Seward Peninsula, Alaska, Open-File Report 69-236, provides 1:63,360 geologic mapping of parts of the Seward Penninsula, in western Alaska. This map was published by the USGS and has been scanned, digitized, and attributed by DGGS staff. The dataset contains geologic, structural, stratigraphic, and geochronologic data organized according to the GeMS and AK GeMS mapping schemas. The geodatabase and ESRI fonts and style files are available from the DGGS website: https://dggs.alaska.gov/pubs/id/10827.

The Geologic Map Index of Alaska (Map Index) is a GIS web feature service paired with an interactive web map application that provides access to an actively growing geographic index of geology-related maps of Alaska and adjacent areas. This online research tool provides the locations and outlines of most DGGS and U.S. Geological Survey (USGS) geologic maps of Alaska in a single, interactive web application. It allows searches of the map database by geographic area of interest, keywords, publishing agency, dates, and other criteria. The search results link DGGS's comprehensive, multi-agency publications database, where users can view and download publications for free. Map Index provides access to traditional geologic maps and sample location, geologic hazards, and geologic resources maps. In addition, DGGS plans to add outlines and data to the application for new and remaining geologic maps published by DGGS, USGS, U.S. Bureau of Mines, and U.S. Bureau of Land Management. Reports without maps can be accessed through DGGS's comprehensive publications database, .

Historic Marine Geologic data reports available are from academia, government, and non-U.S. sources. These reports were originally in paper or film form and were scanned to Portable Document Format (PDF) to enable online browse/download and archive in digital form. The following are examples of the types of analyses of sediment or rock from the ocean floor or lakebeds worldwide which may be included in individual data reports: descriptions of composition and/or lithology, grain size and other physical properties, mineralogy, geochemistry, paleontology, petrology, paleomagnetism and acoustics of sediment. They may also contain low-resolution photographs of cores or dredges, or the ocean floor. Reports are searchable via the Marine Geology Digital Inventory and may also be linked to/discoverable via the Index to Marine and Lacustrine Geological Samples (IMLGS). Scanned images of most paper data reports are available to view online, however, some Copyrighted reports contributed through the World Data Center System are available for on-site inspection only. For these reports, the geologic inventory provides links to the contributing institution for ordering.

Marine Geologic data compilations and reports in the NCEI archive are from academic and government sources around the world. Over ten terabytes of analyses, descriptions, and images of sediment and rock from the ocean floor and lakebeds are available. Examples of data available include sediment/rock composition, physical properties, petrology/mineralogy, geochemistry, paleontology, paleomagnetism, x-rays, photographs, and other imagery. All reports and data, regardless of format, are accessible via the Marine Geology Digital Inventory and/or linked to the Index to Marine and Lacustrine Geological Samples (IMLGS). Searches offer free, immediate download of digital data, many images, and .PDF reports, and information on how to obtain full-resolution images from the archive, and order CD-ROMs, microfilm, or oversize charts. Some larger data sets, including the IMLGS, have their own web interfaces. The IMLGS provides searches of sea floor and lakebed cores, grabs, dredges, and drill samples available from sample repositories at partner institutions, with links to browse and download related information from NCEI and other sources.

This layer provides geological descriptions associated with offshore sampling activities. It contains a variety of geoscientific observations; these include rock/sediment classification, grain size, sorting, sphericity, roundness, hardness, plasticity, presence of flora or fauna, colour, chronostratigraphy and lithostratigraphy. Note that this layer contains data at depth. Related data in Offshore Sample Data - Activity & Scan collection.

In 1986 and 1987, the U.S. Geological Survey (USGS), the Dirección General de Geología, Minas e Hidrocarburos, and the Universidad de Costa Rica conducted a mineral-resource assessment of the Republic of Costa Rica. The results were published as a large 80- by 50-cm color folio (U.S. Geological Survey and others, 1987). The 75-page document consists of maps as well as descriptive and interpretive text in English and Spanish covering physiographic, geologic, geochemical, geophysical, and mineral site themes as well as a mineral-resource assessment. The following maps are present in the original folio: 1) Physiographic base map at a scale of 1:500,000 with hypsography, place names, and drainage. 2) Geologic map at a scale of 1:500,000. 3) Regional geophysical maps, including gravity, aeromagnetic, and seismicity maps at various scales. 4) Mineral sites map at a scale of 1:500,000 showing mines, prospects, and occurrences. 5) Volcanological framework of the Tilarán region important for epithermal gold deposits at a scale of 1:100,000. 6) Rock sample locations, mining areas, and vein locations for several parts of the country. 7) Permissive areas delineated for selected mineral deposit types. 8) Digital elevation model. This CD-ROM contains most of the above maps; it lacks items 1 and 8 and the seismicity and aeromagnetic maps of item 3.

Bedrock is the solid rock at or below the land surface. Over much of Ireland, the bedrock is covered by materials such as soil and gravel. The Bedrock maps show what the land surface of Ireland would be made up of if these materials were removed. As the bedrock is commonly covered, bedrock maps are an interpretation of the available data. Geologists map and record information on the composition and structure of rock outcrops (rock which can be seen on the land surface) and boreholes (a deep narrow round hole drilled in the ground). Areas are drawn on a map to show the distribution of rocks. The Geological Lines show the details of the structural geology; faults, folds and unconformities. Faults and folds are the result of great pressure being applied to rock across a whole continent or more. These rocks will either break under the pressure, forming faults, or they will bend to form folds. Faults are recorded in the Geological Lines layer as lines where the break in the rock meets the surface. Folds are shown only using the lines of their axes, synclinal (where the rock folds downwards) and anticlinal (where the rock folds upwards). Unconformities are where there is a gap in the rock record, typically where rock has been eroded away in the past and a new rock deposited on top.Geologists map and record information on the structural geology. Lines are drawn on a map to show the location and extent of these structures. The structural symbols layer is used to describe the geology of an area through dip and strike information. Dip and strike describe the behaviour of the rock bedding plane. To describe a geometric plane two values are required; the angle from horizontal that it is dipping and the direction that it is dipping. Geologists describe the dip direction by the strike value; this is the azimuth perpendicular to the steepest dip of the plane.The measurements that this layer contains give information about the geometry of the rock units under the ground. These measurements are the only way to see if the rocks are folded and faulted and how. With this information we can also start to see why the rocks have the shapes that they do.In terms of time scale in geology, Quaternary is the present-day time and it began 2.6 million years ago. A lot of this time period relates to the Ice Age.Quaternary sediments are the soft material that has been deposited during this time. In Ireland much of this is related to the movement of glaciers and ice sheets. The main types of sediments shown on the map are tills (boulder clays), gravels, sands and peat. Over most parts of Ireland, these sediments cover the bedrock (solid rock at or below the land surface).Geologists map and record information from the shallow sediments which can be seen at or near the surface. This information along with boreholes (a deep narrow round hole drilled in the ground), geophysical data (information on the physical properties of the Earth's surface and subsurface e.g. magnetics, gravity and electromagnetics) and geochemical data (chemical properties) is used to create the map. Areas are drawn on a map to show where sediments are found.Quaternary geomorphology is the record of landscape features that were created in the last 2.6 million years. In Ireland, movement of glaciers and ice sheets created many of these features. The main features included are; erratic dispersion; landforms created under ice; landforms created at the ice margin and landforms created by mountain ice.An erratic is a rock which has been moved by ice and deposited in another location. Erratics are identified as the erractic rock type is different to the usual rocks found in that location. Geologists study the composition of erratics and can determine where the rock came from (the source). Once the source is known, the direction of ice flow can be determined (Inferred Erratic Path). The end of these erratic flow paths are termed erratic limits.Subglacial landforms are created beneath the ice. They were created during ice expansion. An example of these are drumlins. Drumlins are smooth, oval-shaped hills, shaped like a half-buried egg. They are made up of glacial till. As the glaciers retreated, they left these deposits behind. The exact process of drumlin formation is unknown. Mega-scale glacial lineations, like drumlins, are typically smooth hills of subglacially-deposited material, but are much longer. They are produced beneath zones of fast-flowing ice. Striae (Glacial striations) are scratches or gashes cut into bedrock by glacial movement, usually by particles embedded in glacier ice. They provide a reliable record of ice flow direction.Deglacial landforms are created at the ice margin. They were created during ice retreat. A moraine is material left behind by a moving glacier. Kame terraces, deltas and fans are all ice marginal landforms deposited by water issuing from a glacier.Landforms created by mountain ice include corries and trimlines. A corrie (cirque) is a half open, steep-sided round hollow made in the side of a mountain by the action of a glacier. A trimline is a clear line on the side of a valley formed by a glacier. The line marks the most recent highest extent of the glacier. The line may be visible due to changes in color to the rock or to changes in vegetation on either side of the line.Geologists map and record evidence during field visits, from air photographs and from Digital Elevation Models (DEMs). This data along with boreholes (a deep narrow round hole drilled in the ground) and geophysics help to create the map. Areas are drawn on a map to show where features are found, lines are drawn to show the direction of other features and some features are shown as points.These are vector datasets. Vector data portray the world using points, lines, and polygons (areas).

This dataset consists of cartographic data in digital line graph (DLG) form for the northeastern states (Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island and Vermont). Information is presented on two planimetric base categories, political boundaries and administrative boundaries, each available in two formats: the topologically structured format and a simpler format optimized for graphic display. These DGL data can be used to plot base maps and for various kinds of spatial analysis. They may also be combined with other geographically referenced data to facilitate analysis, for example the Geographic Names Information System.

This data release includes 40Ar/39Ar data from the U.S. Geological Survey for samples from Old Mine Park Area, Trumbull, Connecticut. Mineral samples were collected by Robert Wintsch and Harold Moritz. Potassium-bearing mineral grains were separated from the bulk sample and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon Dating (BARD) Laboratory in Reston, Virginia. The data provide age constraints on units in the relevant geologic mapping area.

Field data including geological map with sample locations, sample description, thin section images, Electron Backscatter Diffraction (EBSD) and Energy Dispersive X-ray Spectrometry (EDS) data. Field work and targeted sampling took place, in May 2023, around the exceptional field exposure of an interpreted Slow Earthquake zone in Col d’Amoss, New Caledonia. This data has come into existence through research funded by the NERC Grant NE/X012778/1 Exploring the geological signature of Slow Earthquakes through legacy experiments and field analysis.

The U.S. Geological Survey assessed undiscovered petroleum resources in the downdip Paleogene formations of the U.S. Gulf Coast in 2018. During the assessment new data and information were collected to evaluate thermal maturity, source rock character, and unconventional reservoir rock prospectivity for the Cenozoic-aged section in south Louisiana. Samples were analyzed using multiple analytical approaches, including programmed pyrolysis (Rock-Eval), Leco TOC, organic petrographic analysis including vitrinite reflectance (Ro, %), and X-ray diffraction mineralogy.

This dataset consists of digital geologic data for the Dry Valley Hydrographic area, Nevada and California. It was compiled from individual 1:250,000-scale geologic data for Washoe County, Nevada, 1:62,500-scale geologic data for the Chilcoot and Doyle 15' quadrangles in California and the results of field mapping within the study area in 2004. A revised geologic map was needed in the study area because the available published maps have large discrepancies between the reported geologic units along the state line. The 2004 field mapping was confined to an area approximately 2000 feet east and west of the California/Nevada state line and about 1.5 miles north and south of Dry Valley Creek. No attempt was made to resolve discrepancies between the published maps in the area outside of the designated mapping area.

The discrepancies between geologic units in the previously published maps directly affect flow calculations used in the water budget for Dry Valley. The geologic unit involved in the greatest discrepancy is a non-welded rhyolitic tuff. Contacts between this unit and Quaternary basin-fill sediments were refined based on field mapping and sampling; and aerial photography. During mapping, low hills along the southern side of the valley floor 0.5 to 1.3 miles east of the state line mapped as Quaternary alluvium by previous efforts were recognized as non-welded rhyolitic tuff. In the locations described above, the non-welded tuff is distinguished by a lag deposit of yellow and red rhyolitic gravel at land surface. In the sub-surface, reached by digging, the tuff is weathered to a dense clay. Outcrops of the tuff with faint bedding planes were located in washes. Sample points, outcrops, and contacts between the tuff and unconsolidated sediments were located in the field using a handheld Garmin GPS unit (model GPS76).

The Alaska Geochemical Database Version 3.0 (AGDB3) contains new geochemical data compilations in which each geologic material sample has one best value determination for each analyzed species, greatly improving speed and efficiency of use. Like the Alaska Geochemical Database Version 2.0 before it, the AGDB3 was created and designed to compile and integrate geochemical data from Alaska to facilitate geologic mapping, petrologic studies, mineral resource assessments, definition of geochemical baseline values and statistics, element concentrations and associations, environmental impact assessments, and studies in public health associated with geology. This relational database, created from databases and published datasets of the U.S. Geological Survey (USGS), Atomic Energy Commission National Uranium Resource Evaluation (NURE), Alaska Division of Geological & Geophysical Surveys (DGGS), U.S. Bureau of Mines, and U.S. Bureau of Land Management serves as a data archive in support ...

This dataset accompanies geologic map publication " Geologic and geophysical maps of the onshore parts of the Santa Maria and Point Conception 30' x 60' quadrangles, California "; U.S. Geological Survey Scientific Investigations Map 3473. Data presented here include the digital geologic map database, paleontological sample locations and descriptions, and point data sets from magnetic and gravity data. The geologic database includes spatial feature classes and non-spatial tables that collectively contain the geologic information presented in the map plate. Fossil sample localities are included as a point feature class in the geologic map database and as two spreadsheet tables of fossil sample localities and fossil checklists. The location of gravity stations in the map area are compiled and augmented by new measurements of the Santa Maria and northern part of the Point Conception 30 x 60 quadrangle, California. This dataset represents an edited version of Langenheim (2013) U.S. Geological Survey Open-File Report 2013-1282 and includes data that were collected after that publication. Point data representing the isostatic gravity field, gridded at a 200-m spacing, are presented for two reduction densities: 2000 kg/m3 and 2670 kg/m3. Point data representing the magnetic field, gridded at a 200-m spacing, are presented for magnetic data that have been filtered to emphasize shallow-depth and medium-depth magnetic sources. Boundaries of density and magnetic sources were derived from application of the maximum horizontal gradient method for the Santa Maria and Point Conception 30 x 60 quadrangle, California. Point data representing the maximum horizontal gradient boundaries in the magnetic field are presented for the total magnetic field and for magnetic data that have been filtered to emphasize shallow-depth and medium-depth magnetic sources. Point data representing the maximum horizontal gradient boundaries in the gravity field are presented for two reduction densities: 2000 kg/m3 and 2670 kg/m3.

This submission contains a number of maps and shapefiles related to the Utah FORGE site. Examples include geologic maps (several variations) and GIS data for the Utah FORGE site outline.

All data are georeferenced to UTM, zone 12N, NAD 83, NAVD 88.

Multiple subaerial landslides adjacent to Prince William Sound, Alaska (for example, Dai and others, 2020; Higman and others, 2023; Schaefer and others, 2024) pose a threat to the public because of their potential to generate ocean waves (Dai and others, 2020; Barnhart and others, 2021; Barnhart and others, 2022) that could impact towns and marine activities. One bedrock landslide on the west side of Barry Arm fjord drew international attention in 2020 because of its large size (~500 M m3) and tsunamigenic potential (Dai and others, 2020). As part of the U.S. Geological Survey response to the detection of the potentially tsunamigenic landslide at Barry Arm, as well as a broader effort to evaluate bedrock landslide and tsunamigenic potential throughout Prince William Sound (for example, Schaefer and others, 2024), we assessed rock mass quality and collected structural geology data in a large part of northwest Prince William Sound (including Barry Arm) in June and July, 2021. The quality (strength) of a rock mass depends on the properties of intact rock and the characteristics of discontinuities (for example, bedding, fractures, cleavage) that cut the rock. Rock mass quality can be estimated in the field using a variety of classification schemes. In the summer of 2021, most of our fieldwork was boat-based and was therefore conducted at sites along the coastline. A small number of sites in and near Barry Arm were accessed by helicopter, and sites near the town of Whittier were accessed by driving and hiking. At each field site, we made our measurements at rock outcrops, which were typically found at the base of cliffs, along ridge lines, in flat areas in coastal zones, and in areas recently scoured and plucked by glaciers. In two dimensions, outcrops ranged in size from about 30 m2 to 100 m2. We visited a total of 73 sites in the field. Most sites were in metamorphosed Cretaceous flysch, but a few were in Tertiary granitic rocks (Nelson and others, 1985; Winkler, 1992; Wilson and others, 2015). Of the 73 sites, we collected rock mass quality data and structural data at 54 sites, and only strike and dip of bedding in flysch at 19 sites. At each of the 54 sites, we collected data that we later used to classify rock mass quality according to four commonly used classification schemes; Rock Mass Quality (Q, for example, Barton and others, 1974, Coe and others, 2005); Rock Mass Rating (RMR, for example, Bieniawski, 1989); Slope Mass Rating (SMR, for example, Romana, 1995, Moore and others, 2009) and Geologic Strength Index (GSI, for example, Marinos and Hoek, 2000, Marinos and others, 2005). We also determined Rock Quality Designation (RQD, for example, Deere and Deere, 1989, Palmström, 1982) and estimated intact rock strength using a Proceq Rock Schmidt Type N hammer (see RatingsReadMe.pdf for details). Schmidt hammer rebound values were converted to Uniaxial Compressive Strength (UCS) using equations developed for the same rock types that we observed in the field, but at different locations. For flysch, rebound values from the Type N Schmidt hammer were converted to UCS by first converting Type N rebound values to Type L rebound values, then using these Type L values in the equation shown in Table 3 and Figure 3 of Morales and others (2004). For granitic rocks, UCS values were calculated using Type N rebound values in equation 2 of Katz and others (2000). Additionally, we collected strikes and dips of any observed bedding, fractures, and cleavage. All four rock mass quality classification schemes use data from characteristics of discontinuities present in the rock. Discontinuity data that we collected in the field included: total number of discontinuities, roughness of the surface of the discontinuities, number of sets of discontinuities, type of filling or alteration on the surface of discontinuities, aperture or “openness” of discontinuities, and the amount of water present. A file of a blank field data collection sheet (FieldDataCollectionSheet) is included in this data release. Numerical ratings for each of these factors are assigned based on the correlation of field measurements and observations with descriptive rankings. The rankings used for Q, RMR, SMR, and GSI classification schemes are shown in Table 1, Table 2, Table 3, and Figures 1 and 2. Additional details regarding descriptive rankings and numerical ratings not shown in the tables and figures are provided in the RatingsReadMe.pdf. All field measurements, numerical ranking values, and calculated Q, RMR, SMR, GSI, and RQD values are included in the RMQMeasurements_Ratings_Values2021 file (.csv and .xlsx). Site names beginning with “JAC”, followed by numbers, are locations where both rock mass quality and structural data were collected. Site names beginning with “JACSD”, “srl”, and “fault” are locations where only the strike and dip of bedding was measured. Question marks in the data files indicate a lack of certainty in field observations. Abbreviations of rating parameters (for example, R4e, Jw, etc.) for the RMR, SMR, and Q classification systems used in column headings are defined in more detail in Tables 1 and 2. All structural measurements are provided in the StructuralData2021 file (.csv and .xlsx). The planar and toppling calculations used for determining SMR values are included in the SMRCalculationsWorksheet2021 file (.csv and .xlsx). Final Q, RMR, SMR, GSI, and RQD values for each site are presented in a separate file (FinalRockStength_QualityValues2021, .csv and .xlsx). All rock mass quality values are positively correlated with rock quality. That is, as Q, RMR, SMR, GSI, and RQD values increase, rock quality increases. Additional information in this release includes photos, field sketches, and geographic data. Photos from each site are included in a separate folder (2021PhotosbySiteName), organized by the individual site names and the names of the photographers. Field sketches for eight sites are in a SketchesinFieldNotesbySiteName zipped folder. A Google Earth 2021SiteLocations.kml file showing site locations, site names, and geographic coordinates is also included. Samples of rock were collected at some of the 2021 sites in the summer of 2022. These sample names are noted in a column in the RMQMeasurements_Rating_Values2021 file. Physcial samples are held by Lauren N. Schaefer with the U.S. Geological Survey, Geologic Hazards Science Center in Golden, Colorado. Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. References Barton, N., Lien, R., and Lunde, J., 1974, Engineering classification of rock masses for the design of tunnel support: Rock Mechanics, v. 6, p. 189-236. https://doi.org/10.1007/BF01239496 Barnhart, K.R., Jones, R.P., George, D.L., Coe, J.A., and Staley, D.M., 2021, Preliminary assessment of the wave generating potential from landslides at Barry Arm, Prince William Sound, Alaska: U.S. Geological Survey Open-File Report 2021–1071, 28 p., https://doi.org/10.3133/ofr20211071. Barnhart, K.R., Collins, A. L., Avdievitch, N. N., Jones, R.P., George, D.L., Coe, J.A., and Staley, D.M., 2022, Simulated inundation extent and depth in Harriman Fjord and Barry Arm, western Prince William Sound, Alaska resulting from the hypothetical rapid motion of landslides into Barry Arm Fjord, Prince William Sound, Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P9QGWH9Z Bieniawski, Z.T., 1989, Engineering rock mass classifications a complete manual for engineers and geologist in mining, civil, and petroleum engineering: John Wiley & Sons, New York, 251 p. Coe, J.A., Harp, E.L., Tarr, A.C., and Michael, J.A., 2005, Rock-fall hazard assessment of Little Mill campground, American Fork Canyon, Uinta National Forest, Utah: U.S. Geological Survey Open File Report 2005-1229, 48 p., two 1:3000-scale plates. http://pubs.usgs.gov/of/2005/1229/ Dai, C., Higman, B., Lynett, P. J., Jacquemart, M., Howat, I. M., Liljedahl, A. K., Dufresne, A., Freymueller, J.T., Geertsema, M., Ward Jones, M., and Haeussler, P.J., 2020, Detection and assessment of a large and potentially tsunamigenic periglacial landslide in Barry Arm, Alaska. Geophysical Research Letters, v. 47 (22), e2020GL089800. https://doi.org/10.1029/2020GL089800 Deere, D.U., and Deere, D.W., 1989, Rock Quality Designation (RQD) after twenty years: Contract Report GL-89-1, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss., 25 p. Higman, B., Lahusen, S.R., Belair, G.M., Staley, D.M., and Jacquemart, M., 2023, Inventory of Large Slope Instabilities, Prince William Sound, Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P9XGMHHP Katz, O., Reches, Z., and Roegiers, J.-C., 2000, Evaluation of mechanical rock properties using a Schmidt hammer: International Journal of Rock Mechanics and Mining Sciences, v. 37, p. 723-728. https://doi.org/10.1016/S1365-1609(00)00004-6 Marinos, P., and Hoek, E., 2000, GSI: a geologically friendly tool for rock mass strength estimation. In: Proceedings of the GeoEng2000 at the international conference on geotechnical and geological engineering, Melbourne, Technomic publishers, Lancaster, pp. 1422–1446. Marinos, V., Marinos, P., and Hoek, E., 2005, The geological strength index: applications and limitations: Bulletin of Engineering Geology and the Environment, v. 64, p. 55-65 https://doi.org/10.1007/s10064-004-0270-5 Moore, J.R., Sandrers, J.W., Dietrich, W.E., and Glaser S.D., 2009, Influence of rock mass strength on the erosion rate of alpine cliffs: Earth Surface Processes and Landforms, v. 34, p. 1339-1352. https://doi.org/10.1002/esp.1821 Morales, T., Uribe-Etxebarria, G., Uriarte, J.A., and Fernández de Valderrama, I., 2004, Geomechanical characterisation of rock masses in Alpine regions: the Basque Arc (Basque-Cantabrian basin, Northern Spain): Engineering Geology, v. 71, p. 343–362.

This data release contains Rock-Eval pyrolysis, organic petrographic (reflectance), and X-ray diffraction mineralogy data for subsurface Mesozoic rock samples from the eastern onshore Gulf Coast Basin (primarily Mississippi and Louisiana). Samples were analyzed in support of the U.S. Geological Survey (USGS) assessment of undiscovered petroleum resources in the Upper Cretaceous Tuscaloosa marine shale and evaluation of shale gas prospectivity in the Aptian section of the Mississippi Salt Basin.