Geology of the Malaspina District, Gulf of Alaska Tertiary Province, Alaska

Miller, D.J.1961Geology of the Malaspina District, Gulf of Alaska Tertiary Province, AlaskageodatabaseOpen-File ReportOF 61-101United StatesU.S. Geological Survey2 sheets, scale 1:96,000https://dggs.alaska.gov/pubs/id/10668Geology of the Malaspina District, Gulf of Alaska Tertiary Province, Alaska, Open-File Report 61-101, presents the geology of the Malaspina district within the Gulf of Alaska Tertiary province, one of five maps compiled at a common scale to document an arcuate belt more than 300 miles long and 2 to 40 miles wide in which sedimentary rocks of Tertiary age were exposed or inferred beneath Quaternary deposits and glacial cover. Field studies in this province were conducted intermittently from 1944 to 1960 as part of the U.S. Geological Survey program of petroleum investigations in southern Alaska. The geology shown on two previously published maps of the Malaspina district was combined, revised, and plotted on an updated base, with a geologically complex area in the Samovar Hills also shown on a larger scale insert. Previously published descriptions of bedrock geology and surficial deposits apply to this compilation except where modified by new stratigraphic and structural interpretations. Rocks formerly assigned to a crystalline complex in part of the Samovar Hills were reinterpreted as a volcanic unit of probable Mesozoic age, consistent with correlations in adjoining districts. The crystalline complex north of the Chugach St. Elias fault was considered to include more metamorphosed equivalents of this volcanic unit and possibly older Paleozoic rocks. Newly collected fossils supported a Late Cretaceous age for the Yakutat Group, and rocks previously mapped as an early Tertiary siltstone sequence were reassigned to an undifferentiated sedimentary unit of Paleocene and Eocene age. Surficial deposits previously divided into fourteen units were simplified into four broader map units on the present compilation. The dataset provides geologic, structural, stratigraphic, and geochronologic information organized according to the GeMS and AK GeMS mapping schemas. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: https://dggs.alaska.gov/pubs/id/10668.The purpose of this report was to document the geologic mapping and stratigraphic interpretations of the Malaspina district within the Gulf of Alaska Tertiary province, based on field studies carried out between 1944 and 1960. The report preserved the geologic framework developed during early U.S. Geological Survey petroleum investigations and provided a consolidated record of mapping, unit correlations, and revisions made at that time. By integrating earlier maps, updating unit assignments using information then available, and simplifying surficial categories, the report served as a historical reference for regional geologic research, stratigraphic studies, and the development of geologic mapping practices in southern Alaska.This geodatabase is organized according to the AK GeMS mapping schema Hendricks, M.D., Macpherson, A.E., Athey, J.E., Wyatt, W.C., Montayne, Simone, Buchanan, Wes, Rivera, P.G., and Steinleitner, A.M., 2024, AK GeMS data dictionary: A description of the Alaska geologic mapping schema: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 170 v. 2, 13 p. https://doi.org/10.14509/31172. The distribution package includes ESRI fonts and style files, along with usage instructions. Further documentation of the symbology is provided by Ekberg, P.G., Hendricks, M.D., and Athey, J.E., 2021, AK GeMS symbology: A description of the AK GeMS style file: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 169, 7 p. https://doi.org/10.14509/3058419442026ground conditionCompleteNone planned-141.516243-139.43999060.40039359.638655ISO 19115 Topic CategorygeoscientificInformationAlaska Division of Geological & Geophysical SurveysArgilliteBedrockConglomerateEstuaryGeneralizedGeologicGeologic MapGeologyGlacialGlacial DepositsGravelGraywackeIceIgneousIntrusiveMarineMarine DepositsMetamorphicMudstoneNonmarineRocksSandSandstoneSedimentarySiltstoneSlateSurficialTillTilliteUnconsolidated DepositsVolcanicAlaska Division of Geological & Geophysical SurveysAgassiz GlacierAgassiz LakesAka LakeAlder StreamAtrevida GlacierAugusta GlacierBancas PointBlack GlacierBlizhni PointBlossom GlacierBlossom IslandCaetani RiverCape SitkagiChaix HillsCoal GlacierCrater BasinCrater LakeDaisy GlacierDisenchantment BayDome PassEsker StreamFloral HillsFloral PassForney StreamFountain StreamGaliano GlacierGrand Wash RiverGull IslandHaenke GlacierHaenke IslandHayden GlacierHaydon PeakHitchcock GlacierHitchcock HillsHoof HillIcy BayKageet PointKame StreamKarr HillsKichyatt PointKwik DeltaKwik StreamLake CaetaniLibbey GlacierLucia GlacierLucia NunatakLucia StreamMalaspina GlacierMalaspina LakeManby StreamMarvine GlacierMiller GlacierMoore NunatakMoraine IslandMount AugustaMount CookMount HuxleyMount OwenNazina Mining DistrictNew ReefOily LakeOsar StreamPinnacle GlacierPinnacle PassPinnacle Pass HillsPoint GloriousPoint ManbyPoint RiouRiou BaySacred LakeSamovar HillsSchooner BeachSeward GlacierSitkagi BluffsStrawberry IslandSudden StreamTaan FiordTerrace PointThe HumpTsimpshian PointTurner GlacierTyndall GlacierYahtse RiverYakataga Mining DistrictYakutat BayYakutat Mining DistrictYana StreamAlaska Division of Geological & Geophysical SurveysYakataga FormationWalker, J.D., Geissman, J.W., Bowring, S.A, and Babcock, L.E., comp., 2012, Geologic Time Scale v. 4.0: Geological Society of AmericaCretaceousMesozoicQuaternaryTertiaryThis report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.Alaska Division of Geological & Geophysical SurveysMetadata Managermailing and physical

3354 College Road

FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysPlease view our website (https://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.Kinney Engineering, LLC staff used scanned and georeferenced paper maps to digitize geologic features into an AK GeMS database. Chris Wyatt conducted quality control of this digitizing work and completed the creation of the AK GeMS database. Ally M. Steinleitner implemented final database quality control and packaging. This geologic map (or report or conversion or product, etc.) was funded by the USGS National Cooperative Geologic Mapping Program under STATEMAP award number G24AC00521, 2024, and the State of Alaska General Fund. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government.Combellick, R.A.1993Geologic hazards in and near proposed state of Alaska oil and gas lease sale 79 (Cape Yakataga)Public Data FilePDF 93-81Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys11 phttps://doi.org/10.14509/1620Combellick, R.A.1994Geologic hazards in the Yakataga planning area, southeastern Alaska: an overviewReport of InvestigationRI 94-29Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys9 phttps://doi.org/10.14509/2512Combellick, R.A.Long, W.E.1983Geologic hazards in southeastern Alaska: an overviewReport of InvestigationRI 83-17Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys17 phttps://doi.org/10.14509/2356Emond, A.M.Graham, G.R.C.Eden, KarstenPrecision GeoServices Inc.2021Icy Cape airborne magnetic geophysical survey, southeast AlaskaGeophysical ReportGPR 2021-1Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys10 phttps://doi.org/10.14509/29742Hansen, R.A.Combellick, R.A.1998Planning scenario earthquakes for southeast AlaskaMiscellaneous PublicationMP 34Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys5 phttps://doi.org/10.14509/743Lyle, W.M.Palmer, I.F., Jr.1976Stratigraphic study of the Gulf of Alaska tertiary province, northern Gulf of Alaska areaAlaska Open-File ReportAOF 93Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys173 p., 23 sheetshttps://doi.org/10.14509/189McGee, D.L.1973Gulf of Alaska petroleum seepsAlaska Open-File ReportAOF 32Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys9 phttps://doi.org/10.14509/131Motyka, R.J.Moorman, M.A.1987Geothermal resources of southeast AlaskaProfessional ReportPR 93Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys1 sheet, scale 1:1,000,000https://doi.org/10.14509/2274Attribute fields within each feature class are populated using the map symbology and corresponding applicable values from the GeMS and AK GeMS specifications. When known, certainty in attribute interpretation is indicated in the relevant fields. Attribute accuracy varies throughout the map and is scale-dependent.All polygon features were topologically validated according to the AK GeMS geologic mapping schema specifications.This publication is a U.S. Geological Survey Open-File Report (OF), which provide rapid public release of scientific information. The series includes interpretive reports, maps, supporting data, preliminary findings, interim computer programs, user guides, and bibliographies.Certainty in feature boundaries or location varies throughout the map. Data fields within each feature class and the accompanying orientation and location confidence lookup tables record the authors' degree of confidence in the location of applicable features.Ekberg, P.G.Hendricks, M.D.Athey, J.E.2021AK GeMS symbology: A description of the AK GeMS style fileMiscellaneous PublicationMP 169Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys7 phttps://doi.org/10.14509/30584paper2021publication dateEkberg, P.G. and others, 2021GIS analysis and digital cartographyHendricks, M.D.Ekberg, P.G.Athey, J.E.Wyatt, W.C.Willingham, A.L.Naibert, T.J.2021AK GeMS data dictionary: A description of the Alaska geologic mapping schemaMiscellaneous PublicationMP 170Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys10 phttps://doi.org/10.14509/30669paper2021publication dateHendricks, M.D. and others, 2021GIS analysis and digital cartographyU.S. Geological Survey National Cooperative Geologic Mapping Program2020GeMS (Geologic Map Schema) - A standard format for the digital publication of geologic mapsTechniques and MethodsTM 11-B10United StatesU.S. Geological Survey1 phttps://dggs.alaska.gov/pubs/id/30585paper2020publication dateU.S. Geological Survey National Cooperative Geologic Mapping Program, 2020GIS analysis and digital cartographyGeologic mapping - Geologic mapping for this compilation was based on field studies completed between 1944 and 1960 as part of U.S. Geological Survey petroleum investigations in southern Alaska. Two previously published maps of the Malaspina district were combined, revised, and transferred to an updated base, with the complex Samovar Hills area shown on a larger scale insert. Published descriptions of bedrock and surficial units were incorporated except where modified by new stratigraphic and structural interpretations. Fossil data were used to refine ages of key units, several rock units were reassigned based on revised correlations, and surficial deposits were simplified from fourteen units to four broader map categories.1960Data packaging - DGGS organized and attributed the geologic and geographic features according to the AK GeMS schema, then programmatically transformed the data into four distribution formats: (1) an AK GeMS data package containing the full database and supporting files, (2) a GeMS data package converted to the USGS base standard, (3) a SQLite database file, and (4) a simplified shapefile package with shapefile representations of the data.2026vectorUniversal Transverse Mercator70.999600-1410500000.0000000coordinate pair.00000001.00000001MetersNAD27Clarke 18666378206.4294.9786982malaspina_ak_gems_dbGeodatabase, layer files, style files, and fontsDGGS and USGSmalaspina_ak_gems_dbmalaspina_gems_dbGeodatabase, layer files, style files, and fontsDGGS and USGSmalaspina_gems_dbmalaspina_gems_geopackageSQLite Database fileDGGS and USGSmalaspina_gems_geopackagemalaspina_gems_shapefileShapefiles and open data filesDGGS and USGSmalaspina_gems_shapefileAlaska Division of Geological & Geophysical SurveysMetadata Managermailing and physical

3354 College Road

FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysFGDC Content Standard for Digital Geospatial MetadataFGDC-STD-001-1998If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys.https://dggs.alaska.gov/metadata/dggs.extdggs metadata extensions