Nasholds, M.W.M., Howard, K.A. U.S. Geological Survey 2025 1.0 vector digital data https://doi.org/10.5066/P14LPYPV This geologic database is a digitized version of the original 1:48,000-scale analog geologic map titled "Geologic map of the Mohave Mountains area, Mohave County, western Arizona", published by the U.S. Geological Survey (USGS) in 1999. The Mohave Mountains area surrounds Lake Havasu City, Arizona, in the Basin and Range physiographic province. The Mohave Mountains and the Aubrey Hills form two northwest-trending ranges adjacent to Lake Havasu (elevation 132 m; 448 ft) on the Colorado River. The low Buck Mountains lie northeast of the Mohave Mountains in the alluviated valley of Dutch Flat. Lowlands at Standard Wash separate the Mohave Mountains from the Bill Williams Mountains to the southeast. The highest point in the area is Crossman Peak in the Mohave Mountains, at an elevation of 1519 m (5148 ft). Arizona Highway 95 is now rerouted in the northwestern part of the map area from its position portrayed on the base map; it now also passes through the southern edge of the map area. Geologic mapping was begun in 1980 as part of a program to assess the mineral resource potential of Federal lands under the jurisdiction of the U.S. Bureau of Land Management (Light and others, 1983). Mapping responsibilities were as follows: Proterozoic and Mesozoic rocks, K.A. Howard; dikes, J.K. Nakata; Miocene section, J.E. Nielson; and surficial deposits, H.G. Wilshire. Earlier geologic mapping includes reconnaissance mapping by Wilson and Moore (1959). The present series of investigations has resulted in reports on the crystalline rocks and structure (Howard and others, 1982a), dikes (Nakata, 1982), Tertiary stratigraphy (Pike and Hansen, 1982; Nielson, 1986; Nielson and Beratan, 1990), surficial deposits (Wilshire and Reneau, 1992), tectonics (Howard and John, 1987; Beratan and others, 1990), geophysics (Simpson and others, 1986), mineralization (Light and McDonnell, 1983; Light and others, 1983), field guides (Nielson, 1986; Howard and others, 1987), and geochronology (Nakata and others, 1990; Foster and others, 1990). This product was made to digitally document the published large-scale geologic mapping of the area surrounding Lake Havasu City, the Audrey Hills, and the Mohave Mountains. The database is a product of the USGS National Cooperative Geologic Mapping Program (NCGMP), which aims to seamlessly map the geology of the United States at an intermediate scale (~1:100,000). The database can be queried or plotted and will be used for further compilation efforts focusing on geologic mapping in the Lower Colorado River region of the southwestern United States. AZ_2025_MohaveMountains_1-0-database.gdb is a composite geodataset that conforms to GeMS (Geologic Map Schema)--a standard format for the digital publication of geologic maps", available at http://ngmdb.usgs.gov/Info/standards/GeMS/. Metadata records associated with each element within the geodataset contain more detailed descriptions of their purposes, constituent entities, and attributes.). These metadata were prepared with the aid of script GeMS_FGDCMetadata.py, version of 2/27/24. 2025 publication date Complete None planned -114.3875 -113.9873 34.7587 34.3664 ISO 19115 Topic Category geoscientificInformation None GeMS (Geologic Map Schema) NCGMP (National Cooperative Geologic Mapping Program) GMEGSC (Geology, Minerals, Energy, and Geophysics Science Center) NGMDB (National Geologic Map Database) LOCOS (Geologic Mapping of the Lower Colorado River System) NGGDPP (National Geological and Geophysical Data Preservation Program) ReSciColl (Registry of Scientific Collections) Lithologic classification of geologic map units Mafic volcanic rock Gneiss Alluvium Sedimentary rock Sedimentary breccia Limestone Metamorphic rock Tuff Basalt Fanglomerate USGS Thesaurus plutonic rocks geologic maps digitization bedrock geologic units faulting (geologic) geologic history geologic contacts sedimentary rocks volcanic rocks metamorphic rocks igneous rocks USGS Metadata Identifier USGS:701145a9-638e-4dad-9691-7ddbeef83ad6 Common geographic areas Mohave Mountains Lake Havasu City Arizona Colorado River Aubrey Hills Havasu Wilderness None. Vector data not for use at scales larger (more detailed) than 1:48,000. Nonspatial tables and symbology files included in this release are not for use with other geologic map databases. Any derivative products utilizing these datasets shall clearly indicate their source. If data are modified in any way the user is obligated to describe the types of modifications that have been made. User specifically agrees not to misrepresent these datasets, nor to imply that changes that were made were approved by the USGS. Even though the dataset includes information about positional accuracy, it is NOT a survey document, and should not be utilized as such. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. When using this digital database, please also cite the original map. Suggested citation is Howard, K.A., Nielson, J.E., Wilshire, H.G., Nakata, J.K., Goodge, J.W., Reneau, S.L., John, B.E., and Hansen, V.L., 1999, Geologic map of the Mohave Mountains area, Mohave County, western Arizona: U.S. Geological Survey Miscellaneous Investigations Series I–2308, 2 sheets, scale 1:48,000, [Also available at https://doi.org/10.3133/i2308.] Morgan Nasholds U.S. Geological Survey Physical Scientist mailing and physical

2255 N Gemini Dr

Flagstaff AZ 86001 United States 928-556-7216 mnasholds@usgs.gov This digitized database was prepared by Morgan W.M. Nasholds, with additions by Keith A. Howard. The GeMS toolbox (https://github.com/usgs/gems-tools-pro) was used in digitizing the database into the GeMS schema, and creating metadata. Metadata was prepared using the USGS Metadata Wizard (https://www.usgs.gov/software/metadatawizard) and guidance provided by Ralph Haugerud (USGS; https://github.com/usgs/gems-tools-arcmap/wiki/CompleteMetadata#what-you-should-do). Digital and metadata review was provided by Joel Robinson (jrobins@usgs.gov). Funding for the compilation was provided by the USGS National Cooperative Geologic Mapping Program’s (NCGMP) and the National Geological and Geophysical Data Preservation Program's (NGGDPP) data preservation proposal to contribute to Registry of Scientific Collections (ReSciColl) to the USGS Geology, Minerals, Energy, and Geophysics Science Center (GMEGSC). Environment of Metadata Creation: Windows 11 Enterprise, Version 23H2, 64-bit operating system, x64-based processor; ESRI ArcPro 3.3.2. MetadataWizard version 2.1.0. Environment of Geodatabase Creation: Windows 11 Enterprise, Version 23H2, 64-bit operating system, x64-based processor; ESRI ArcPro 3.3.2. Howard, K.A. Nielson, J.E. Wilshire, H.G. Nakata, J.K. Goodge, J.W. Reneau S.L. John, B.E. Hansen, V.L. 1999 publication n/a U.S. Geological Survey https://doi.org/10.3133/i2308 The feature datasets, feature attribute tables, and nonspatial tables in this geodatabase have been structured and populated according to the guidelines specified in the GeMS documentation. Some line, point, and polygon feature classes in the database include confidence attribute IdentityConfidence that describes on a per-feature basis how confident the author or compiler is that a geologic feature is correctly identified. Some line feature classes also include attribute ExistenceConfidence that describes on a per-feature basis how confident the author or compiler is that the geologic feature exists. The values assigned to IdentityConfidence and ExistenceConfidence for a given feature apply to the accuracy of the original mapping, and not the accuracy of the compiler(s) translation of the mapping. The accuracy of the original mapping was not specifically evaluated; however, errors that were found during compilation/digitization are noted in the Notes field of the relevant feature class. No formal tests were performed to assess the accuracy of the original mapping. Attribute integrity was evaluated using scripted and visual workflows. The GeMS Validate Database tool was used to identify errors related to the schema and content of geodatabase, including attribution errors or inconsistencies. The GeMS Topology Check tool was used to identify potential attribution and geometry errors, and logical inconsistencies such as adjacency issues in feature classes ContactsAndFaults and MapUnitPolys. These tools were used iteratively during the compilation process until all errors were identified and fixed. In some cases, the mapping depicted by the original author(s) on the source map creates situations that are erroneously identified as errors by these tools. Refer to the tool help and GeMS documentation for more information. Attribute accuracy was also assessed during compilation by symbolizing the data based on attributes (following the specifications in the FGDC Digital Cartographic Standard for Geologic Map Symbolization) and visually comparing the depiction to the source mapping for discrepancies. As part of the USGS data review process, the attribute accuracy of the final database was further evaluated by a reviewer who was not involved in the compilation process. All errors or inconsistencies identified by the data reviewer were subsequently reconciled by the compiler(s). This geodatabase is a composite geodataset that encapsulates the spatial and nonspatial data needed to depict and describe the geology of the map area. It conforms to the GeMS standard, except for deviations noted in the Data Quality section of the metadata record associated with each data element. The geodatabase was digitized to replicate the source map as closely as possible, and therefore includes specific apparent geological and topological errors. Topological errors inherent to the original mapping are preserved as exceptions and, if notable, additionally clarified in both the Notes attribute field and metadata of their respective feature classes. GeMS Validation issues are additionally clarified in the metadata of their respective feature classes. Topology rules required by GeMS, plus two additional rules required by the Geologic Mapping of the Lower Colorado River System project (LOCOS), were applied to feature classes ContactsAndFaults and MapUnitPolys. In addition to the rules that are specific to each feature class, ContactsAndFaults and MapUnitPolys are also topologically related to each other. The GeMS rules for ContactsAndFaults are Must Not Overlap, Must Not Self-Overlap, Must Not Self-Intersect, Must Be Single Part, and Must Not Have Dangles, with the LOCOS team additionally including the topology rules Must Not Intersect Or Touch Interior and Must Not Have Pseudo-Nodes. The GeMS rules for MapUnitPolys are Must Not Overlap, Must Not Have Gaps, and Boundary Must Be Covered By (ContactsAndFaults). Topology rules are applied via the GeologicMap_Topology layer included in the geodatabase. Some topology errors are acceptable and are flagged as exceptions in the GeologicMap_Topology layer. More information about types of exceptions specific to each feature class can be found in the Data Quality section of the metadata records for ContactsAndFaults and MapUnitPolys. Topology validation and editing were conducted interactively during the compilation process using the topology validation and error inspector tools in ArcGIS Pro, and using the GeMS Topology Check tool. These tools were used iteratively by the compilers until all identified errors were fixed or attributed as exceptions. The GeMS Validate Database tool was used to identify errors related to the schema and content of the geodatabase. Additional logical consistency tests were conducted manually to evaluate and search for invalid attributes or attribute combinations. These tests included interactive sorting of attribute table values, SQL queries, and generation of frequency tables. These tests were performed iteratively by the compilers until identified errors were fixed or noted as exceptions. As part of the USGS data review process, the logical consistency of the final database was further evaluated by a data reviewer who was not involved in the compilation process. This included reviewing the data, reviewing the metadata record(s), and cross checking the metadata content against the associated data. All errors or inconsistencies identified by the data reviewer were subsequently reconciled by the compiler(s). This geodatabase contains all the geologic features depicted on the published source map. Furthermore, it includes all the schema and attribute elements required by the GeMS standard, unless otherwise noted in the Data Quality section of the metadata record associated with each data element. A formal assessment of the horizontal positional accuracy of the features in the database has not been conducted. Feature attribute LocationConfidenceMeters is included in most feature classes in a GeMS database and is used to store the estimated positional accuracy of spatial features on a per-feature basis. For this dataset, however, a value of -9999 was assigned for that attribute for all features in the database except the map neatline. This is because meaningful values could not be assigned with certainty. In this database the locational accuracy of the features is a function of the accuracy of the original mapping, the accuracy of the georeferenced scan of the source map, and how closely the features were digitized to match the source map. The U.S. National Map Accuracy Standard for the 1:48,000-scale topographic base of the source map is about 24.4 meters (80.1 feet). Features that are perfectly located relative to the topography on the source map would also adhere to that standard - meaning that the geologic feature on the source map would be within about +/- 40 feet of that location on the ground. However, the actual locational error may be much greater than that due to the complexities inherent in mapping geologic features, compiling them on topographic maps prior to the existence of GPS and GIS, and then digitizing them from scanned and georeferenced hardcopy maps. A formal accuracy assessment of the vertical positional information in the dataset has either not been conducted or is not applicable. U.S. Geological Survey 2020 publication Techniques and Methods 11-B10 https://doi.org/10.3133/tm11B10 Digital and/or Hardcopy 2020 publication date GeMS Digital geologic map publication standards. Ralph Haugerud, Evan Thoms, and others 2023 application/service https://github.com/DOI-USGS/gems-tools-pro https://github.com/doi-usgs/gems-tools-arcmap Digital 2023 publication date GeMS toolbox Tools used to create and manipulate the dataset. Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey] 2006 publication Federal Geographic Data Committee Document FGDC-STD-013-2006 https://ngmdb.usgs.gov/fgdc_gds/geolsymstd.php Digital and/or Hardcopy 2006 publication date FGDC-STD-013-2006 Cartographic standards and some term definitions in dataset glossary nonspatial table. K.K.E. Neuendorf, J.P. Mehl Jr., J.A. Jackson 2011 5th edition, revised, and some recent updates from 2022–2023 online version publication Accessed multiple times 2022–2023; subscription required. https://www.americangeosciences.org/pubs/glossary#online Digital and/or Hardcopy 2011 publication date AGI Glossary of Geology Definitions for the dataset glossary nonspatial table. C. B. Talbert, D.A. Ignizio, and K. D. Enns. 2017 application/service https://www.sciencebase.gov U.S. Geological Survey https://doi.org/10.5066/f7v9870d Digital 2017 publication date Metadata Wizard Tool used to create and manipulate the metadata. Howard, K.A. Nielson, J.E. Wilshire, H.G. Nakata, J.K. Goodge, J.W. Reneau, S.L. John, B.E. Hansen, V.L. 1999 publication n/a US Geological Survey https://doi.org/10.3133/i2308 Digital and/or Hardcopy 1999 publication date MohaveMtnsArea48k_USGS_I-2308 Original publication upon which the digital database is based. Digitization of the map was accomplished by heads-up digitizing features of interest from several georeferenced scans of the source map that was downloaded from the National Geologic Map Database (NGMDB). The original scan had distortion issues with the basemap, and it was determined that instead georeferencing 9 portions of the map to their respective topographic quadrangles (e.g. the portion of the map covering the Franconia 7.5' topographic quadrangle was georeferenced and clipped to the Franconia quadrangle original topographic map) to increase accuracy of digitization efforts. Slight offsets remained due to the original basemap issues, however, these offsets are small enough to be acceptable within the U.S. National Map Accuracy Standard for a 1:48,000-scale map (24.4 meters or 80.1 feet). Features were compiled into feature classes ContactsAndFaults, MapUnitPoints (later renamed to MapUnitLabelPoints, as the GeMS schema uses MapUnitPoints to denote exposures of map units too small to show as a polygon), OrientationPoints, OverlayPolys, and CartographicLines. Map unit polygons were built as needed using the ArcToolbox Feature To Polygon tool and specifying ContactsAndFaults and MapUnitLabelPoints (not included in the published database) as input layers to define polygon boundaries and attributes. For efficiency, only a subset of the fields in each attribute table were populated during compilation, and attribute domains were attached to those fields to streamline data entry and ensure attribute consistency. Topology rules were connected to ContactsAndFaults via a topology layer to ensure topologic integrity. For line and point feature classes, the Type field was populated with the symbol from the FGDC Cartographic Standard for Geologic Map Symbology for the feature (e.g., 01.01.01 for “contact”, and 06.02 for “inclined bedding”). The map unit designation for each polygon was entered in the MapUnitLabelPoints feature class. Errors or uncertainties that were encountered in the original mapping were preserved and noted in the Notes field of the corresponding feature class, or attributed as exceptions in the topology layer. During Phase 1, all geologic features from the source map was digitized. The digitization of the southern third of this map was initially digitized as part of the compilation efforts toward another publication: the Bedrock geologic map of the Parker 30 by 60-minute quadrangle, California and Arizona. The digitization of the remainder of the map took place after compilation processes for the Parker map were completed. FGDC-STD-013-2006 20250227 Morgan Nasholds U.S. Geological Survey Physical Scientist mailing and physical

2255 N Gemini Dr

Flagstaff AZ 86001 United States 928-556-7216 mnasholds@usgs.gov This step included finalizing the vector data and fully populating the nonspatial tables. The GeMS Validate Database and Topology Check tools were run iteratively until the database achieved Level 2 compliance. Level 3 compliance could not be fully achieved because some fault attitudes in OrientationPoints were populated with two map units (e.g., Tys/Xgp), reflecting the instances where the map units on either side of the fault at the location of the attitude were different. This deviation from the GeMS standard caused the Validate Database script to fail on criteria 3.8 (No map units without entries in DescriptionOfMapUnits). The unit combinations causing this are Xap/Xgl, Tys/Xgp, Xgb/Xgp, Tfl/Xgp, Xgb/Tvu, Xgb/Tfla, Xgb/Tfl, Xgb/Xgl, Kbg/Xgp, Xgb/QTs1, Xgl/Xgs, and Tvu/Xgl. The database passes all other Level 3 criteria. 20250501 The database and metadata were reviewed by a GIS specialist not involved in the compilation process. These reviews are part of the USGS review and approval process required by USGS for information products that will be publicly released. 20250618 The lead compiler addressed the comments from the data and metadata reviews. Database and metadata standards that were developed by the LOCOS project were also incorporated during this phase. After all changes were made the GeMS Validate Database and Topology Check tools were run iteratively until the database again achieved the highest level of GeMS compliance possible. After the database and metadata were finalized, the data package was prepared for approval and submittal to the NGMDB. 20250702 Universal Transverse Mercator 11 0.9996 -117.0 0.0 500000.0 0.0 coordinate pair 0.6096 0.6096 meters North_American_Datum_1983 GRS 1980 6378137.0 298.257222101 Database AZ_2025_MohaveMountains_1-0-database.gdb contains the following elements: nonspatial table DataSources (7 rows); nonspatial table DescriptionOfMapUnits (72 rows); nonspatial table Glossary (43 rows); nonspatial table GeoMaterialDict (101 rows); RepurposedSymbols (3 rows); feature dataset GeologicMap which contains feature class OrientationPoints (811 features), feature class GeochronPoints (45 features), feature class ContactsAndFaults (9543 features), feature class CartographicLines (3 features), feature class OverlayPolys (14 features), feature class MapUnitOverlayPolys (7 features), feature class GeologicLines (28 features), feature class MapUnitLines (3471 features), and feature class MapUnitPolys (3737 features). Nasholds, M.W.M., and Howard, K.A., 2025, Digital database for the Geologic map of the Mohave Mountains area, Mohave County, western Arizona: U.S. Geological Survey Data Release, https://doi.org/10.5066/P14LPYPV U.S. Geological Survey USGS Information Services mailing

Box 25286

Denver CO 80225 United States 303-202-4700 Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P14LPYPV None. 20250812 Morgan Nasholds U.S. Geological Survey Physical Scientist mailing and physical

2255 N Gemini Dr

Flagstaff AZ 86001 United States 928-556-7216 mnasholds@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998