Identification_Information: Citation: Citation_Information: Originator: Michael P. Pantea Originator: James C. Cole Publication_Date: 2004 Title: Three-Dimensional Geologic Framework Modeling of Faulted Hydrostratigraphic Units within the Edwards Aquifer, Northern Bexar County, Texas Edition: Version 1.0 Geospatial_Data_Presentation_Form: model Series_Information: Series_Name: USGS SIR Issue_Identification: 2004-5226 Publication_Information: Publication_Place: Denver Colorado Publisher: US Geological Survey Online_Linkage: http://pubs.usgs.gov/sir/2004/5226 Description: Abstract: This report describes a digital, three-dimensional faulted stratigraphic model we have constructed to represent the geologic framework of the Edwards Aquifer system in the area of San Antonio, northern Bexar County, Texas. The model is based on mapped geologic relationships that reflect the complex structures of the Balcones fault zone, detailed lithologic descriptions and interpretations of about 40 principal wells (and qualified data from numerous other wells), and a conceptual model of the gross geometry of the Edwards Group units derived from prior interpretations of depositional environments and paleogeography. The digital model depicts the complicated intersections of numerous major and minor faults in the subsurface, as well as their individual and collective impacts on the continuity of the aquifer-forming units of the Edwards Group and the Georgetown Formation. The model allows for detailed examination of the extent of fault dislocation from place to place, and thus the extent to which the effective cross-sectional area of the aquifer is reduced by faulting. The model also depicts the internal hydrostratigraphic subdivisions of the Edwards aquifer, consisting of three major and eight subsidiary hydrogeologic units. This geologic framework model is useful for visualizing the geologic structures within the Balcones fault zone and the interactions of en-echelon fault strands and flexed connecting relay ramps. The model also aids in visualizing the lateral connections between hydrostratigraphic units of relatively high and low permeability across the fault strands. Purpose: This report describes a digital, three-dimensional faulted stratigraphic model we have constructed to represent the geologic framework of the Edwards Aquifer system in the area of San Antonio, northern Bexar County, Texas. This paper describes the data and processes we used to construct a digital 3-dimensional (3-D) model of the Edwards aquifer for an area of northern Bexar County. Our primary goal was to use sophisticated geologic modeling software (Earth Vision; Dynamic Graphics Corp., Alameda CA) to accurately represent the faulted lithologic units that make up the hydrogeologic framework in this area. This model allows us to view and evaluate the overall shape and form of the aquifer in this region, and to assess the amount of dislocation of the aquifer across the many strands of the Balcones fault zone. A secondary purpose of this report is to examine the functionality and feasibility of an interactive 3-D model viewer that allows each user considerable graphic capability to manipulate and explore the 3-D model on his own choice of computer platform. This report package includes the fully-functional 3-D viewer capabilities, the data files used to generate the hydrostratigraphic model, a tutorial help file to explain the 3-D viewer functions, and ancillary materials for the modeling project. Supplemental_Information: Includes data sets used to create the model. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2004 Currentness_Reference: Publication date Status: Progress: complete Maintenance_and_Update_Frequency: none planned Spatial_Domain: Bounding_Coordinates: East_Bounding_Coordinate:-98.341944 West_Bounding_Coordinate:-98.805666 North_Bounding_Coordinate:29.722583 South_Bounding_Coordinate:29.525777 Keywords: Theme: Theme_Keyword_Thesaurus: American Geological Institute Glossary of Geology Theme_Keyword: Three Dimensional model Theme_Keyword: earth Vision Theme_Keyword: 3-D Theme_Keyword: Hydrostratigraphic Units Theme_Keyword: Edwards Aquifer Theme_Keyword: Edwards Group Theme_Keyword: Balcones Fault Theme_Keyword: Balcones Fault Escarpment Theme_Keyword: Kainer Formation Theme_Keyword: Person Formation Theme_Keyword: Basal Nodular member Theme_Keyword: Dolomitic member Theme_Keyword: Kirschberg Evaporite member Theme_Keyword: Grainstone member Theme_Keyword: Regional Dense member Theme_Keyword: Leached and Collapsed member Theme_Keyword: Cyclic and Marine member Theme_Keyword: Georgetown Formation Theme_Keyword: Upper Glen Rose Theme_Keyword: Glen Rose Formation Theme_Keyword: Lower Cretaceous Place: Place_Keyword_Thesaurus: Board on Geographic Names Place_Keyword: Texas Place_Keyword: Bexar County Access_Constraints: none Use_Constraints: None Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Michael P. Pantea Contact_Organization: US Geological Survey Contact_Address: Address_Type: Mailing Address Address: PO Box 25046, MS 980, Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Contact_Voice_Telephone: 303-236-5554 Contact_Electronic_Mail_Address: mpantea@usgs.gov Data_Set_Credit: San Antonio, Texas, office of the US Geological Survey provided source data Data_Quality_Information: Logical_Consistency_Report: Data is logically consistent Completeness_Report: Data set was used to create the model, and is complete Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Well locations based on GPS and / or State of Texas location information Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Well locations based on GPS and / or State of Texas location information Lineage: Process_Step: Process_Description: Model created 2004 using Earth Vision software, version 7.5 Process_Date: 2004 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 14 Transverse_Mercator: Scale_Factor_at_Central_Meridian: .9996 Longitude_of_Central_Meridian: -99.0 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: Coordinate pair Coordinate_Representation: Abscissa_Resolution: 20 Ordinate_Resolution: 20 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: NAD 27 Ellipsoid_Name: Clark 1866 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.98 Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: US Geological Survey Contact_Address: Address_Type: Mailing Address Address: USGS Information Services, PO 25286, Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 888 ASK USGS Resource_Description: SIR 2004_5226 Distribution_Liability: Neither the United States Government nor any agency thereof nor any of their employees makes any warranty, expressed or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed at this web site or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Although these data have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and (or) the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data, software, or related materials Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: Executable and data files Digital_Transfer_Option: Offline_Option: Offline_Media: CD-ROM Recording_Format: ISSO Fees: see http://mapping.usgs.gov/esic/prices/ Metadata_Reference_Information: Metadata_Date: 2004 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Michael P. Pantea Contact_Organization: US Geological Survey Contact_Address: Address_Type: Mailing Address Address: PO 25046, MS 980, Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303-236-5554 Contact_Electronic_Mail_Address: mpantea@usgs.gov Metadata_Standard_Name: FGDC content standard for digital geospatial metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Access_Constraints: none Metadata_Use_Constraints: none