eng utf8 dataset dataset Ivan Santiago PR Office of Management and Budget GIS Specialist processor 2018-12-04 ISO 19139 Geographic Information - Metadata - Implementation Specification 2007 geometryOnly composite 26644 0 2018-05-22 revision mapDigital Geologic units digitized from USGS Geologic maps of Puerto Rico at a scale of 1:20,000.LAST REVISION: November, 2018: Adding aggregate percent slope calculations on various columns: mean, median, stdev, min, and max. Percent slopes derived from CRIM Basemap (1998) Digital Elevation Model (30m pixel to avoid unnecesary detail). Sept 28, 2018. Error corrections: spurious areas (less than 10sq meters) . Some unit_codes were changed to avoid inconsistencies: Ql to Qlc (lagoon deposits; clay) at Central Aguirre Quadrangle, Qaf to Qafl (artificial fill) at Humacao and Naguabo Quadrangles to distinguish from Alluvial fan deposits. Register (vectorize) geologic units portrayed in scanned geologic 1:20K quadrangle maps. Some quadrangles do not have geologic studies-publications at a scale of 1:20,000. These are Guánica, Sabana Grande, Rincón, Vieques and Culebra quadrangles. There are some maps and reports published covering some or parts of these areas but not at a scale of 1:20,000. For Guánica quadrangle map, we used a thesis published by Martínez A.L, 2001 Department of Geology, UPR-Mayaguez Campus For Desecheo Island: USGS Professional Paper 739: Geology of Isla Desecheo...(VM Seiders, RP Briggs, L Glover III), 1972. Isla de Mona: Isla de Mona Geologic Quadrangle USGS Report I-718 (RP Briggs, VM Seiders) 1972 Vieques Island: Ginny R Grove, Laboratory of Geology, Dept of Public Works, Area of Natural Resources, Nov. 1972 Culebra Island: Thomas H Banks, Geological Map of Culebra and Adjacent Islands, Masters Thesis, Rice University, 1960 Original scanned maps: US Geological Survey. Vectorization: PR Office of Management and Budget Downloadable Data Geology Puerto Rico geología geologic units Not for navigational purposes. Note that the original scale is 1:20,000: 1mm in original map represents 20 meters on the ground. vector eng utf8 geoscientificInformation Version 6.2 (Build 9200) ; Esri ArcGIS 10.6.1.9270 true -67.954456 -65.21959 17.875309 18.517236 File Geodatabase Feature Class 10.3 Ivan Santiago PR Office of Management and Budget GIS Specialist processor Esri file geodatabase, spatialite, geopackage 10.6 dataset Known issues: 1. Some official USGS Geologic Quadrangles were missing. (Rincón, Guánica, Culebra, Desecheo, Vieques, Sabana Grande). Most of these areas were completed using alternate sources, published theses, or USGS reports with the exception of Sabana Grande Quadrangle area. A map of at a scale of 1:100k was used to fill the void area of Sabana Grande Quad. 2. Accuracy depends on geologist's judgement on drawing boundaries of geologic units and formations on printed maps. Other accuracy issues are related to scanned map geo-referencing. Most of eastern part of Puerto Rico quadrangles were georeferenced with less control points (at least four) and using first order polynomial method. Westernmost quadrangles were more "adjusted" having substantialy more control points to alineate with existent features (using "Adjust" method). The third accuracy issue is related to adjacent quadrangles edgematching. Each geologic map is a different publication. Most of adjacent geologic units do not necesarily match with their counterparts at the adjacent quadrangle. 3. Atributes: This vectorization task includes a complete description of geologic units. The size of the unit description field has a length of 4,000 character spaces. Please be aware that some of GIS formats do not support this very-long text field type and sometimes truncate to a length of 255 spaces (eg shapefiles). There are some inconsistencies with the ages of adjacent geologic units, especially at Monte Guilarte Quadrangle. These are not errors, they are the interpretation of the geologist. 4. Some geologic formation names in old geologic quadrangles have been renamed by the USGS, particularly Formations A, B, C, D, J, K, L, at Barranquitas, Central Aguirre, Caguas, Comerío, Cayey, Guayama, and Patillas quadrangles. Scanning. This process was done by other sources, posibly US Geological Survey. Process dates: from Jan, 2014 to July, 2018 Most of Geologic quadrangle maps at a scale of 1:20K, were available for download a USGS web site Georeferencing: Process dates: from Jan, 2014 to July, 2018 Georeferencing scanned maps was done at PR Office of Management and Budget. Scanned maps were georeferenced against an USGS quadrangle index geodataset. The first half of geologic quadrangles were georeferenced using few control points and first order polynomial method. Some combined quadrangles were more difficult for georeferencing, especially Punta Tuna and Fajardo. That's why the second half of scanned maps were georeferenced using the "Adjust" method available using Georeferencing tool on ArcGIS 10.3. Vectorization Process dates: from Jan, 2014 to July, 2018 Manual tracing of geologic unit boundaries of geologic quadrangles and available geologic maps and reports Attribute completion: Process dates: from Jan, 2014 to July, 2018 Adding descriptions of geologic units and geologic formations, code, unit names, period, epoch, geologic unit descriptions, including all descriptive narrative. A composite identifier was included to help others exporting long geologic unit descriptions. notPlanned