DOCSLIB.ORG

Geological Society of America Bulletin

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geological Society of America Bulletin Downloaded from gsabulletin.gsapubs.org on January 11, 2012 Geological Society of America Bulletin Structural framework of the Edwards Aquifer recharge zone in south-central Texas David A. Ferrill, Darrell W. Sims, Deborah J. Waiting, Alan P. Morris, Nathan M. Franklin and Alvin L. Schultz Geological Society of America Bulletin 2004;116, no. 3-4;407-418 doi: 10.1130/B25174.1 Email alerting services click www.gsapubs.org/cgi/alerts to receive free e-mail alerts when new articles cite this article Subscribe click www.gsapubs.org/subscriptions/ to subscribe to Geological Society of America Bulletin Permission request click http://www.geosociety.org/pubs/copyrt.htm#gsa to contact GSA Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. Notes Geological Society of America Downloaded from gsabulletin.gsapubs.org on January 11, 2012 Structural framework of the Edwards Aquifer recharge zone in south-central Texas David A. Ferrill² Darrell W. Sims Deborah J. Waiting CNWRA, Southwest Research Institutet, San Antonio, Texas, 78238-5166, USA Alan P. Morris Department of Earth and Environmental Science, University of Texas, San Antonio, Texas 78249, USA Nathan M. Franklin CNWRA, Southwest Research Institutet, San Antonio, Texas, 78238-5166, USA Alvin L. Schultz 1241 Milam Building, 115 East Travis Street, San Antonio, Texas 78205, USA ABSTRACT parallel to fault-bedding intersections. At water recharge (Clark, 2000). The high- all scales, aquifer permeability is either un- volume, high ¯ow-rate subsurface ¯ow is also The Edwards Aquifer, the major source changed or enhanced parallel to faults and likely dominated by faults, fractures, and so- of water for many communities in central in many cases decreased perpendicular to lution cavities (Hovorka et al., 1998). Bal- Texas, is threatened by population growth faults. cones system faults also provide natural dis- and development over its recharge zone. charge sites near New Braunfels and San The location of the recharge and con®ned Keywords: Edwards Aquifer, Edwards Marcos and during periods of high rainfall zones and the ¯ow paths of the aquifer are Group, Balcones fault zone, faults and within San Antonio itself (San Pedro and San controlled by the structure of and defor- faulting, normal faults. Antonio Springs; see Fig. 1). mation processes within the Balcones fault In faulted strata, geologic structures (faults system, a major system of predominantly INTRODUCTION and fractures) exert three controls on aquifer down-to-the-southeast normal faults. We permeability and ¯ow: (1) Faults thin or offset investigate the geologic structure of the Ed- The Edwards Aquifer of south-central Tex- aquifer strata and alter the overall geometry of wards Aquifer to assess the large-scale as is composed of Cretaceous limestones of and communication between fault blocks (Al- aquifer architecture, analyze fault offset the Edwards Group, consisting of a lower (the lan, 1989; Maclay, 1989). (2) Fault zones pro- and stratigraphic juxtaposition relation- Kainer Formation) and upper part (the Person vide barriers to, or pathways for, ¯uid ¯ow or ships, evaluate fault-zone deformation and Formation), and the overlying Georgetown may form both barriers and pathways (Ma- dissolution and fault-system architecture, Formation (Figs. 1 and 2) (Maclay and Small, clay, 1995; Caine et al., 1996). This fault and and investigate fault-block deformation and 1983; Barker et al., 1994; Maclay, 1995). The fracture conductivity may be in¯uenced by the scaling of small-scale (intrablock) normal Edwards Aquifer is con®ned beneath younger current stress ®eld and fault activity (Finkbei- faults. Characterization of fault displace- sedimentary rocks and serves as the primary ner et al., 1997; Ferrill et al., 1999b). (3) ment shows a pattern of aquifer thinning water source for many communities, including Fault-block deformation by formation of small that is likely to in¯uence fault-block com- the city of San Antonio (Sharp and Banner, faults and fractures leads to permeability an- munication and ¯ow paths. Flow-path con- 1997; Hovorka et al., 1998). Aquifer recharge isotropy (Mayer and Sharp, 1998; Ferrill et al., striction may be exacerbated by increased occurs primarily by stream¯ow loss and in®l- 2000). fault-segment connectivity associated with tration into porous parts of the Edwards Aqui- In addition to the three general controls de- large fault displacements. Also, increased fer, where they are exposed within the Bal- tailed above, carbonate rock layers like those fault-zone deformation associated with cones fault system, and responds to rainfall in of the Edwards Aquifer are subject to local- larger-displacement faults is likely to fur- the recharge zone and upslope catchment area. ized groundwater ¯ow and associated lime- ther in¯uence hydrologic properties. Over- Water in the aquifer locally follows tortuous stone dissolution (Deike, 1990). Such disso- all, faulting is expected to produce strong ¯ow paths controlled by the Balcones fault lution may enhance the permeability of fault permeability anisotropy such that maxi- system. Most recharge of the aquifer occurs and fracture systems, including solution en- mum permeability is subhorizontal and along the Balcones fault system where faults, largement at scales from individual fractures fractures, and dissolution features such as sink to cave networks consisting of ®ssures, an- ²E-mail: [email protected]. holes and caves are major sites for ground- gular passages, and fracture-controlled net- GSA Bulletin; March/April 2004; v. 116; no. 3/4; p. 407±418; doi: 10.1130/B25174.1; 8 ®gures; 1 table. For permission to copy, contact [email protected] q 2004 Geological Society of America 407 Downloaded from gsabulletin.gsapubs.org on January 11, 2012 FERRILL et al. Figure 1. Location map of a part of the Balcones fault system and Edwards Aquifer recharge zone in northwest San Antonio and Texas Hill Country. Geologic map of Barnes (1983) is draped over the hill-shaded digital elevation model. White box shows the location of the Castle Hills 7.59 quadrangle (area of Fig. 3). Fault traces (black lines) are from Collins and Hovorka (1997). Yellow dots are locations of well-bore data used in construction of geologic framework model. Cretaceous geologic units: KauÐAustin Group; KedÐEdwards Group; KgrÐGlen Rose Group. Map coordinates shown are UTM, zone 14 (black numbers) and Geographic Coordinate System (red numbers). 408 Geological Society of America Bulletin, March/April 2004 Downloaded from gsabulletin.gsapubs.org on January 11, 2012 STRUCTURAL FRAMEWORK OF THE EDWARDS AQUIFER RECHARGE ZONE tem near San Antonio, Texas, as well as sup- porting examples of well-exposed and struc- turally similar examples from analogous faulted limestones in west Texas. These in- vestigations span the range of structural scales: (1) three-dimensional geologic frame- work modeling to constrain large-scale aquifer architecture in the study area, (2) analysis of fault offset and stratigraphic juxtaposition, (3) analysis of fault-zone deformation and disso- lution and fault-system architecture, and (4) examination of fault-block deformation and small-scale (intrablock) normal faults. The re- sult is a systematic overview of fault-system characteristics and deformation mechanisms that are likely to in¯uence recharge into and ¯ow within the Edwards Aquifer. CHARACTERIZATION OF AQUIFER ARCHITECTURE The Balcones fault system is a broad en echelon system of mostly southeast-dipping normal faults that formed during the middle to late Tertiary (Foley, 1926; Murray, 1961; Young, 1972). The arcuate zone trends east- northeast and spans much of central Texas. The 25±30-km-wide Balcones fault system has a maximum displacement of 366 m (Weeks, 1945) and de®nes the transition from structurally stable ¯at-lying rocks of the Texas craton to gently coastward-dipping sedimen- tary deposits of the subsiding Gulf of Mexico. At the margin of the Texas Hill Country northwest of San Antonio, exposures in Cre- taceous platform carbonates include the Ed- wards Group, a succession of carbonate strata deposited along the margin between the Cen- tral Texas platform and the ancestral Gulf of Mexico (Fig. 1) (Rose, 1972). Offset of car- bonate strata across the Balcones fault system resulted in a broad, weathered escarpment of vegetated limestone hills rising from the pre- dominantly clastic coastal plains to the up- lands of the Texas craton. Within the fault sys- tem, the dip of bedding varies from gentle Figure 2. Stratigraphic column showing relationship between lithologic stratigraphy and coastward dips to nearly horizontal; a few model stratigraphy. Stratigraphic column is after Collins (2000). Note that prominent hanging-wall beds locally dip northward into shale units (Eagle Ford Formation, Del Rio Formation) separate the limestones of the some faults. Growth faulting is not apparent Austin Group, Buda Formation, and Edwards Aquifer strata. The Glen Rose Formation in outcrop along the fault zone. Faulting has is considered to be the lower con®ning unit. Argillaceous (clay-rich) layers in the Glen been interpreted as being rooted in the deeply Rose are not as thick or as clay rich as those of the Eagle Ford or Del Rio Formations.
Load more

Recommended publications
  • Geophysical Mapping of Mount Bonnell Fault of Balcones Fault Zone
    Geophysical mapping of Mount Bonnell fault of Balcones fault zone and its implications on Trinity-Edwards Aquifer interconnection, central Texas, USA Mustafa Saribudak1 Abstract There are up to 1200 ft (365 m) of total displacement across the Geophysical surveys (resistivity, natural potential [self-po- BFZ. Faults generally dip steeply (45–85°), varying primarily tential], conductivity, magnetic, and ground penetrating radar) due to specific rock properties and local stress fields (Ferrill and were conducted at three locations across the Mount Bonnell fault Morris, 2008). in the Balcones fault zone of central Texas. The normal fault has The BFZ includes the Edwards and Trinity aquifers, which hundreds of meters of throw and is the primary boundary between are primary sources of water for south-central Texas communities, two major aquifers in Texas, the Trinity and Edwards aquifers. including the city of San Antonio. The Trinity Aquifer underlies In the near surface, the fault juxtaposes the Upper Glen Rose the Edwards Aquifer through the Balcones fault zone. Formation on the Edwards Plateau, consisting of interbedded The BFZ’s most prominent fault is the Mount Bonnell, with limestone and marly limestone, against the Edwards Group, which a vertical throw of up to 600 ft (183 m) (Figure 1). The fault is mostly limestone, on the eastern down-thrown side (coastal hydrogeologically juxtaposes these Cretaceous carbonate aquifers plain). The Upper Glen Rose member is considered to be the during the Miocene tectonic deformation associated with the Upper Trinity Aquifer and also a confining zone underlying the Balcones fault zone, where the younger Edwards Group limestone Edwards Aquifer.
    [Show full text]
  • LOCAL SPOTLIGHT Edwards Aquifer, San Antonio, Texas, United States—Protecting Groundwater
    LOCAL SPOTLIGHT Edwards Aquifer, San Antonio, Texas, United States—Protecting groundwater Photo: © Blake Gordon Photo: © Blake Gordon North America Left. Officials release a benign "tracer dye" into Edwards Aquifer drainage systems to chart flows and track the underground water pathways. Right. Hydrogeologist descends into a sinkhole to check on the Edwards Aquifer. The challenge As one of the largest, most prolific artesian aquifers in the world, the Edwards Aquifer serves as the primary source of drinking water for nearly 2 million central Texans, including every resident of San Antonio—the second largest city in Texas—and much of the surrounding Hill Country. Its waters feed springs, rivers and lakes and sustain diverse plant and animal life, including rare and endangered species. The aquifer supports agricultural, industrial and recreational activities that not only sustain the Texas economy, but also contribute immeasurably to the culture and heritage of the Lone Star State. AUSTIN The aquifer stretches beneath 12 Texas counties, and the land above it includes several important hydrological areas. Two areas in particular— the drainage area and the recharge zone—replenish the aquifer by “catching” rainwater, which then seeps through fissures, cracks and sinkholes into the porous limestone that dominates the region. While this natural filtration system helps refill the aquifer with high-quality water, the growing city of San Antonio is expanding into territories of the very sensitive recharge zone, increasing the risk of contamination. In Edwards Aquifer SAN ANTONIO addition to a rising population, the state’s water supplies have been impacted by multi-year droughts. By 2060, Texas is projected to be home to approximately 50 million people while the annual available water resources are estimated to decrease by nearly 10 percent.
    [Show full text]
  • Stewardship of the Edwards Aquifer
    STEWARDSHIP OF THE EDWARDS AQUIFER What is the Edwards Aquifer? “The Edwards Aquifer is one of the most valuable resources in the central How does this affect me? Aquifer: an underground area that holds enough water Texas area. In most places, it takes time for stormwater to travel to provide a usable supply. over land and filter through soil to reach the rivers and This aquifer provides water for lakes that supply drinking water to residents. In the municipal, industrial, and agricultural Edwards Aquifer region, recharge features provide a direct link between groundwater and our underground uses as well as sustaining a number of water supply. This means that stormwater pollution rare and endangered species. directly affects the quality of our drinking water. To preserve these beneficial uses, As a result, TCEQ has implemented extra water quality San Antonio ReportSan Texans must protect water quality in requirements to protect the aquifer. Examples include Source: this aquifer from degradation water quality treatments like rain gardens and water resulting from human activities.” quality ponds, as well as erosion and sedimentation While other aquifers in Texas are made up of sand and controls at construction sites. gravel, the Edwards Aquifer is a karst aquifer, composed - Texas Commission on Environmental of porous limestone formations that serve as conduits Quality (TCEQ), RG-348 for water as it travels underground. (Edwards Aquifer Authority) As shown in the graphic to the right, the Edwards Aquifer region encompasses much of South Central Texas. Portions of the City Antonio ReportSan of West Lake Hills lie within the Edwards Aquifer Contributing and Recharge Zones.
    [Show full text]
  • April 2014 Midden
    The Midden League City Rain Garden by Chris LaChance Galveston Bay Area Chapter - Texas Master Naturalists April 2014 Table of Contents President’s Corner by Maureen Nolan-Wilde, President 2014 Prairie Ponderings 2 Wetland Wanderings 2 In mid-January, current and former board members took part in a planning day at Julie Receives Award 4 Galveston Island State Park. The purpose of the day was to build on the Chapter’s accomplishments, identify opportunities and help plan for the future. 2014 Plant of the Yr. 4 Early People of Texas 6 We developed a “roadmap” that can be used to set goals and focus our efforts for 2014 and beyond. We identified the following areas where we can make immediate Heritage Book Study - 6 improvements: Review Membership 7 Succession planning for key roles (learning exactly what board members and Outreach Survey committee chairs do so that, in the future, this knowledge isn’t lost), Coastal Mammals AT 7 Pelican AT 8 Leveraging current technologies (for example, making better use of the website, social media and tools for sending messages to our members), Diurnal Raptors AT 9 GBA Clan 10 Growing our outreach efforts (such as stewardship and education in schools). WaterSmart Award 12 Since that meeting, we have launched an image database that contains over 1,000 GBAC 1st Camp Out 12 pictures and has been viewed more than 10,200 times. This database, which is easily 2014 Class Fun 14 accessible and can be viewed 24/7, is a great example of using technology to make us more efficient and effective.
    [Show full text]
  • Groundwater Availability of the Barton Springs Segment of the Edwards Aquifer, Texas: Numerical Simulations Through 2050
    GROUNDWATER AVAILABILITY OF THE BARTON SPRINGS SEGMENT OF THE EDWARDS AQUIFER, TEXAS: NUMERICAL SIMULATIONS THROUGH 2050 by Bridget R. Scanlon, Robert E. Mace*, Brian Smith**, Susan Hovorka, Alan R. Dutton, and Robert Reedy prepared for Lower Colorado River Authority under contract number UTA99-0 Bureau of Economic Geology Scott W. Tinker, Director The University of Texas at Austin *Texas Water Development Board, Austin **Barton Springs Edwards Aquifer Conservation District, Austin October 2001 GROUNDWATER AVAILABILITY OF THE BARTON SPRINGS SEGMENT OF THE EDWARDS AQUIFER, TEXAS: NUMERICAL SIMULATIONS THROUGH 2050 by Bridget R. Scanlon, Robert E. Mace*1, Brian Smith**, Susan Hovorka, Alan R. Dutton, and Robert Reedy prepared for Lower Colorado River Authority under contract number UTA99-0 Bureau of Economic Geology Scott W. Tinker, Director The University of Texas at Austin *Texas Water Development Board, Austin **Barton Springs Edwards Aquifer Conservation District, Austin October 2001 1 This study was initiated while Dr. Mace was an employee at the Bureau of Economic Geology and his involvement primarily included initial model development and calibration. CONTENTS ABSTRACT .......................................................................................................................................1 INTRODUCTION..............................................................................................................................1 STUDY AREA...................................................................................................................................3
    [Show full text]
  • Geology of the Balcones Fault Zone Along the Growth Corridor of San Antonio, Boerne, Wimberley, and New Braunfels, South-Central Texas
    Geology of the Balcones Fault Zone along the Growth Corridor of San Antonio, Boerne, Wimberley, and New Braunfels, South-Central Texas Edward W. Collins Bureau of Economic Geology, The University of Texas at Austin, University Station, Box X, Austin, TX 78713-7508 Extended Abstract The south-central Texas region that encompasses San Antonio, Boerne, Wimberley, and New Braunfels and adjacent areas west of San Antonio and northeast of New Braunfels is undergoing rapid urban growth. It lies within part of the recharge zone of the Edwards aquifer and includes a complex part of the Balcones Fault Zone (Fig. 1). The geology of this region is important to geologists and other professionals involved in planning land use, designing construction projects, and studying the Edwards aquifer. Recharge of the aquifer may be locally enhanced at karst features, faults, and joints. Faulted aquifer strata partly influence regional ground-water flow, and faults locally juxtapose strata having different physical properties, creating potential construction/foundation problems. Geologic maps are some of the most basic and useful sources of information for this geologically critical area of Central Texas. In this study, maps (scale 1:24,000) were prepared for a >1,250 mi2 region; additional mapping west of San Antonio and Boerne is ongoing. Maps have been interpreted using standard field mapping techniques and studying aerial photographs. Compilation and field verification of existing geologic maps of various scales aided map interpretation. This study benefited greatly from the many previous stratigraphic, structural, and mapping studies of the region. The Balcones Fault Zone, one of the main structural features of Central Texas, extends from near Del Rio east-northeastward to San Antonio, where the zone bends northward through New Braunfels, Austin, Georgetown, and Waco and continues toward Dallas.
    [Show full text]
  • Edwards Aquifer Region 1615 N
    EDWARDS AQUIFER REGION 1615 N. St Mary’s Street • San Antonio, Texas 78215 • 210.222.2204 • 1.800.292.1047 • www.edwardsaquifer.org Drainage basins in the drainage area collect surface water runoff and funnel it into streams that cross the recharge zone. In the artesian zone, the water fl ows generally from west to east. Water movement through the Edwards Limestone Drainage County Lines is generally slower south and east of the fresh Area EAA Jurisdictional Boundary water zone. This water remains in contact with Recharge San Antonio City Limits the limestone and gypsum longer, allowing NORTH Zone dissolved mineral concentrations to increase Major Rivers to over 1,000 milligrams/liter. Artesian Minor Rivers WEST EAST Zone Intermittent Streams SOUTH How Does The Aquifer Work? Th is generalized diagram of a north-south cross section of the Edwards Aquifer streams that fl ow downhill to the recharge zone. In the recharge zone, where region highlights the key components of the aquifer and how they inter-relate the Edwards Limestone is exposed at the land surface, the water actually enters About 85% of precipitation falling and function to form a natural underground system for storing water. the aquifer through cracks, crevices, caves, and sinkholes, and then percolates on the area is lost back to the further underground into the artesian zone. Here, a complex network of atmosphere by evaporation or Th e Edwards Aquifer is a karst aquifer, which means it consists of porous, interconnected spaces, varying in size from microscopic pores to open caverns, by transpiration of water vapor honeycombed formations of Edwards Limestone and other associated limestones from vegetation.
    [Show full text]
  • The Edwards Aquifer (Part A)
    E-PARCC COLLABORATIVE GOVERNANCE INITIATIVE Program for the Advancement of SYRACUSE UNIVERSITY Maxwell School Research on Conflict and Collaboration THE EDWARDS AQUIFER (PART A) Amidst of one of the worst Texas droughts in recent memory, attorney Robert Gulley wondered why he had left his position at an established law practice to take on the position of program director for the Edwards Aquifer Recovery Implementation Program (EARIP). As the program director, Robert now worked for 26 different organizations and his job was to assist them, using a consensus-based stakeholder process, through one of the most contentious and intractable national disputes involving scarce groundwater resources at the Edwards Aquifer, one of the most valuable water resources in the Central Texas area. This dispute had already spanned decades and, to make this task even more daunting, the competing interests on both sides had made numerous unsuccessful attempts over the years to resolve this conflict. Hot weather, droughts, and the resulting conflicts between stakeholders are frequent occurrences in Texas. Robert, who had returned to his home state specifically for this position, knew that this drought would only intensify the tensions amongst the stakeholders involved. The Edwards Aquifer (“Aquifer”) provides approximately 90 percent of the water for over two million people living and working in the South-Central Texas area. The Aquifer supplies the water that services the city of San Antonio and other municipalities; a multi-million agricultural and ranching industry in the western part of the region that views water as a coveted property right; as well as the recreational activities that provide the backbone of the economies of rapidly-growing, nearby cities of San Marcos and New Braunfels (Figure 1).
    [Show full text]
  • Barton Springs Segment of the Edwards (Balcones Fault Zone) Aquifer, Central Texas
    OLD G The Geological Society of America Memoir 215 OPEN ACCESS Barton Springs segment of the Edwards (Balcones Fault Zone) Aquifer, central Texas Brian B. Hunt Brian A. Smith Barton Springs/Edwards Aquifer Conservation District, Austin, Texas 78748, USA Nico M. Hauwert Balcones Canyonland Preserve, City of Austin, Austin Water, Wildland Conservation Division, Austin, Texas 78738, USA ABSTRACT The Barton Springs segment of the Edwards (Balcones Fault Zone) Aquifer is a prolifi c karst aquifer system containing the fourth largest spring in Texas, Barton Springs. The Barton Springs segment of the Edwards Aquifer supplies drinking water for ~60,000 people, provides habitat for federally listed endangered salamanders, and sustains the iconic recreational Barton Springs pool. The aquifer is composed of Lower Cretaceous carbonate strata with porosity and permeability controlled by dep- ositional facies, diagenesis, structure, and karstifi cation creating a triple permeability system (matrix, fractures, and conduits). Groundwater fl ow is rapid within an inte- grated network of conduits discharging at the springs. Upgradient watersheds pro- vide runoff to the recharge zone, and the majority of recharge occurs in the streams crossing the recharge zone. The remainder is direct recharge from precipitation and other minor sources (infl ows from Trinity Group aquifers, the San Antonio segment, the bad-water zone, and anthropogenic sources). The long-term estimated mean water budget is 68 ft3/s (1.93 m3/s). The Barton Springs/Edwards Aquifer Conserva- tion District developed rules to preserve groundwater supplies and maximize spring fl ow rates by preserving at least 6.5 ft3/s (0.18 m3/s) of spring fl ow during extreme drought.
    [Show full text]
  • Geologic Summary
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE G 4032 provided by UT Digital Repository T3 cs 2005 C6 GEOL MAPS Miscellaneous Map No. 43 eologic Map of the West Half of the Taylor, Texas, 30 x 60 Minute Quadrangle: Central Texas Urban Corridor, Encompassing Round Rock, Georgetown, Salado, Briggs, Liberty Hill, and Leander Edward W. Collins ;;;;;;;;;;;;;;; -!!!!!!!!!!!!!!! Ill - Q. < - :::E ;;;;;;;;;;;;;;; CJ .J - 0 rn w ;;;;;;;;;;;;;;; er c(J -;;;;;;;;;;;;;;; " c(J U) c(J 0 = c() Ill ;;;;;;;;;;;;;;; ::r 0 ~ ...-'! 0 - ru N Ill 0 ;;;;;;;;;;;;;;; M - I- N = M 0 - 'It' -!!!!!!!!!!!!!!! - " Bureau of Economic Geology Scott W. Tinker, Director John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin Austin, Texas 78713-8924 2005 Miscellaneous Map No. 43 Geologic Map of the West Half of the Taylor, Texas, 30 x 60 Minute Quadrangle: Central Texas Urban Corridor, Encompassing Round Rock, Georgetown, Salado, Briggs, Liberty Hill, and Leander Edward W. Collins Bureau of Economic Geology Scott W. Tinker, Director John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin Austin, Texas 78713-8924 2005 ( CONTENTS ABSTRACT ....................................................................................................................... l INTRODUCTION ............................................................................................................ 1 Methods .....................................................................................................................
    [Show full text]
  • Aquifers of Texas
    Texas Water Development Board Report 345 Aquifers of Texas bY John B. Ashworth, Geologist and Janie Hopkins, Geologist November 1995 Aquifers of‘Texas November1935 Texas Water Development Board Craig D. Pedersen, Executive Administrator Texas Water Development Board William B. Madden, Chairman No6 Fernandez, Vice Chairman Charles W. Jenness, Member Elaine M. Barron, M.D., Member Lynwood Sanders, Member Charles L. Geren, Member Authorization for use or reproduction of any original material contained in this publication, i.e., not obtained from other sources, is freely granted. The Board would appreciate acknowledgement. Published and Distributed by the Texas Water Development Board P.O. Box 13231 Austin, Texas787 1 l-323 1 iii Aquifers of Texas November 1995 Table of Contents Page INTRODUCTION.. ................. 1 GENERAL GROUND-WATER PRINCIPLES.. 7 MAJOR AQUIFERS Ogallala. .......................... 10 Gulf Coast. ..................... 12 Edwards (Balcones Fault Zone). ..... 14 Carrizo-Wilcox. ................ 16 Trinity. ............................ 18 Edwards-Trinity (Plateau). ......... 20 Seymour. ......................... 22 Hueco-Mesilla Bolson. ..... 24 Cenozoic Pecos Alluvium. ....... 26 MINOR AQUIFERS Bone Spring-Victorio Peak. ...... 30 Dockum. ......................... 32 Brazos River Alluvium. ... 34 Hickoryv. ........................ 36 West Texas Bolsons. .......... 38 Queen City. ................. 40 Woodbine. .................. 42 Edwards-Trinity (High Plains). ... 44 Blaine. ........................ 46 Sparta. ........................ 48 Nacatoch. ...................... 50 52 lgneous. ......................... 54 Rita Blanca. .................... 56 Ellenburger-San Saba. ...... 58 Blossom. ....................... 60 Marble Falls. ................... 62 Rustler. ............................. 64 Capitan Reef Complex. ..
    [Show full text]
  • HCA Issue: Edwards Aquifer Authority V. Day What the Supreme Court Did (And Did Not) Say About Groundwater in Texas Photo By: Chase Fountain
    HCA Issue: Edwards Aquifer Authority v. Day What the Supreme Court Did (and Did Not) Say about Groundwater in Texas Photo by: Chase Fountain HCA is a passionate community caring for the unique features, spring-fed streams, heritage ranch lands, spectacular beauty and vibrant culture of the Texas Hill Country for the benefit of future generations. In Texas, groundwater in place is owned by the overlying landowner, but it is subject to reasonable regulation by the state (for example, through groundwater districts). Regulation of groundwater can result in a compensable taking. Another case, Bragg v. Edwards Aquifer Authority, is likely to shed some additional light on questions left unanswered in Day about when regulation of groundwater results in a compensable taking. What the Court Did Say: • The Court did hold that groundwater is owned in place by the overlying • emanating from the Conservation Amendment of the Texas Constitution, landowner. “In our state the landowner is regarded as having absolute Article XVI, Section 59, and implemented through Water Code Chapter 36. title… to the oil and gas in place beneath his land. .Each owner of land owns separately, distinctly and exclusively all the oil and gas under • The Court did state that state regulation to limit groundwater use based his land and is accorded the usual remedies against trespassers who solely on historical use such as that applied in the Edwards Aquifer can appropriate the minerals or destroy their market value…We now hold cause a taking of private property. (i.e. Districts cannot limit groundwater that this correctly states the common law regarding the ownership of pumping permits to only those who can demonstrate prior beneficial use groundwater in place.” during some specific time period).
    [Show full text]