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Structure of the Santo Domingo Basin and La Bajada Constriction Area, New Mexico

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Structure of the Santo Domingo Basin and La Bajada Constriction Area, New Mexico Structure of the Santo Domingo Basin and La Bajada Constriction Area, New Mexico By Scott A. Minor, Mark R. Hudson, V.J.S. Grauch, and David A. Sawyer Chapter E of The Cerrillos Uplift, the La Bajada Constriction, and Hydrogeologic Framework of the Santo Domingo Basin, Rio Grande Rift, New Mexico Edited by Scott A. Minor Professional Paper 1720–E U.S. Department of the Interior U.S. Geological Survey Contents Abstract .........................................................................................................................................................91 Introduction...................................................................................................................................................91 Santo Domingo Basin Structural Framework .........................................................................................92 Regional Tectonic Setting ..................................................................................................................92 Structural Geometry ...........................................................................................................................92 Faults and Faulting ..............................................................................................................................95 Kinematics...................................................................................................................................95 Structure of Tetilla and La Bajada Fault Zones .....................................................................96 Deformational Style of the Tetilla Fault Zone ........................................................................99 Basinward Shift of Rift Border Faulting ...............................................................................103 Structural Development of Santo Domingo Basin ......................................................................105 Structural Geology of La Bajada Constriction ......................................................................................106 Structural Symmetry.........................................................................................................................106 Sanchez and Northern La Bajada Fault Zones ............................................................................108 Hydrogeologic Character of Santo Domingo Basin Faults .................................................................108 Fault Zone Structure and Hydrogeology .......................................................................................108 Fault Zone Cement Patterns ............................................................................................................111 Hydrogeologic Summary .................................................................................................................113 References Cited........................................................................................................................................113 Figures E1. Map of the northern Albuquerque and Santo Domingo Basins showing major intrabasin and basin-bounding faults ......................................................................................93 E2. Rose diagrams showing frequency of orientation and slip geometry of faults in the Santo Domingo and northern Albuquerque Basins ...................................................95 E3. Map of major faults in Santo Domingo Basin region highlighting fault-plane exposures with lower angle slickenline rakes or overprinted slickenlines (or both) .....97 E4. Geologic map of the southwestern part of Tetilla Peak quadrangle showing structural geometry of the Tetilla fault zone where it is truncated by the younger La Bajada fault zone .............................................................98 E5. Rose diagrams showing orientation and kinematic attributes of fault-slip data collected within the La Bajada and Tetilla fault zones .............................100 E6. Sketch maps showing two structural interpretations of the La Bajada and branching Tetilla fault zones based on structural and paleomagnetic data ..................101 E7. Equal-area projections of rock magnetic data from samples of Eocene Galisteo Formation ....................................................................................................................102 E8–10. Maps of: E8. Northern Albuquerque, Santo Domingo, and Española Basins, showing migration patterns and timing of active rift-border faulting ...................................104 E9. La Bajada constriction area showing structural configuration of intrabasin area and basin borders ................................................................................................107 E10. Northernmost La Bajada fault zone showing inward hooking and scalloped traces where it overlaps with opposite-displacement Sanchez fault .................109 E11. Diagram of generalized fault zone showing various architectural components and damage zone fracture types observed in faults exposed in studied basins ...........110 E12. Map of Santo Domingo Basin region showing asymmetrically distributed carbonate and silica fault zone cements ..............................................................................112 Table E1. Rock magnetic data from Eocene Galisteo Formation, New Mexico ..............................103 Structure of the Santo Domingo Basin and La Bajada Constriction Area, New Mexico By Scott A. Minor, Mark R. Hudson, V.J.S. Grauch, and David A. Sawyer these faults do not provide complete structural closure of the Abstract northeast end of the basin, they may locally redirect and retard southerly, down-gradient flow of ground water through the The Santo Domingo Basin, located within the Rio Grande constriction area. A series of segmented, right-stepping, faulted rift in northern New Mexico, is topographically subdued and antiforms and grabens within the La Bajada constriction track structurally distinct compared with the adjacent Española and the northeastward migration of the local rift axis. northern Albuquerque rift basins, yet it contains structural Fault zones in the Santo Domingo Basin area are charac- elements in common with both neighboring basins. A northeast terized by outer damage zones, which typically contain strike- elongation of the Santo Domingo Basin is expressed along parallel minor fractures that may either enhance or impede its northwestern and southeastern margins by partly buried, groundwater flow along the faults, and by centrally located, relatively large displacement, northeast-striking faults and fault low permeability, clay-rich fault cores that likely impede cross- segments that merge with large north-striking fault zones bor- fault flow. Host-rock lithologies strongly influence the width of dering the adjacent basins. Internally, the Santo Domingo Basin fault-zone components and control variations in fracturing and exhibits a symmetric, semiconcentric, inward-dipping fault pat- other brittle-strain features. An abundance of asymmetrically tern that is centered on the deepest part of the basin as defined distributed fault-zone cements indicates that fault-parallel and by a gravity low. Geologic age relations on the margins of the fault-compartmentalized groundwater flow was, and may con- Española, Santo Domingo, and northern Albuquerque Basins tinue to be, common in the basin aquifers. The Santo Domingo suggest that active border faulting progressively migrated Basin contains many faults of varied geometry, internal struc- basinward during the Neogene. This relation is clearly demon- ture, and cement distribution that impart significant heterogene- strated on the east shoulder of the Santo Domingo Basin by the ity of permeability within the basin aquifer. Tetilla fault zone, an early rift-border and extensional-transfer structure that was abandoned sometime before about 2.5 Ma as basin-margin subsidence was taken up on the La Bajada fault zone farther west. Owing to basinward migration of faulting in Introduction the Santo Domingo Basin, intrabasin faults may have longer Studies by the U.S. Geological Survey were begun in growth-fault histories and larger dip-slip displacements in the 1996 to improve understanding of the geologic framework of subsurface compared with the border faults, an interpretation the Albuquerque composite basin and adjoining areas, in order supported by the presence of pronounced gravity gradients well that more accurate hydrogeologic parameters could be applied basinward of the outer border faults. Fault slickenline observa- to new hydrologic models. The ultimate goal of this multidis- tions indicate that most basinal faults formed with nearly pure ciplinary effort has been to provide better quantify estimates of normal slip and that many of these faults were reactivated with future water supplies for northern New Mexico’s growing urban greater components of strike-slip motion. Oblique- and strike- centers, which largely subsist on aquifers in the Rio Grande rift slip reactivated normal faults, concentrated near the north- basin (Bartolino and Cole, 2002). From preexisting hydrologic western and southeastern basin margins, may be related to the models it became evident that hydrogeologic uncertainties were lateral transfer of extensional strain to adjoining basins. Paleo- large in the Santo Domingo Basin area, immediately upgradient magnetic results from the Tetilla fault zone suggest that such from the greater Albuquerque metropolitan area, and particu- strain
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