
James P. EvansUtah State University | USU · Department of Geology
James P. Evans
PhD
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203
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Introduction
Skills and Expertise
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January 1987 - present
December 1986 - present
Publications
Publications (203)
Analysis of PRISM and SNOTEL station data paired with USGS streamflow gage data in the western United States shows that, in snow‐dominated mountainous watersheds, streamflow regimes differ between watersheds with karst geology and their non‐karst neighbours. These carbonate aquifers exhibit a spectrum of flow paths encompassing karst conduits, incl...
Play Fairway Analysis (PFA) methodology was adapted for geothermal exploration at Camas Prairie, Idaho. Geophysical data, structural and geologic mapping, volcanic rock ages and vent locations, and the distribution of thermal springs and wells all indicated a relatively high geothermal potential along the southern margin of the Prairie. An explorat...
Coseismic temperature rise activates fault dynamic weakening that promotes earthquake rupture propagation. The spatial scales over which peak temperatures vary on slip surfaces are challenging to identify in the rock record. We present microstructural observations and electron backscatter diffraction data from three small‐displacement hematite‐coat...
Understanding carbon dioxide (CO2) reservoir to surface migration is crucial to successful carbon capture and sequestration approaches; especially fault/reservoir interactions under injection pressure. Through seismic imaging, we explore regolith and shallow stratigraphy across the Little Grand Wash fault. The presence of natural CO2 seeps, travert...
This study integrates the results of numerical modeling analyses based on outcrop studies and structural kinematic restorations to evaluate the mechanics of thrust fault initiation and development in mechanically layered sedimentary rocks. A field-based reconstruction of a mesoscopic thrust fault at Ketobe Knob in central Utah provides evidence of...
Zircon (U–Th)/He (zircon He) thermochronometry and visual radiation damage relationships reveal the timing and patterns of Orocopia Schist and North American basement exhumation in the Mecca Hills, CA. Zircon crystals from these units were selected to maximize the spectrum in visual metamictization and effective U (eU) concentrations, and thus He r...
High‐spatial resolution textural and geochemical data from thin slip surfaces in exhumed fault zones archive thermal and rheological signatures of past fault slip. A network of minor, glossy, iridescent silica fault mirrors (FMs) cut Paleoproterozoic gneiss in the Wasatch fault zone (WFZ), Utah. We report field to nanoscale observations from scanni...
Recent exploration for geothermal resources in the Snake River Plain (SRP) used a Play Fairway Analysis (PFA) approach. PFA integrates geophysical, geological, and geochemical data into a statistical framework to locate regions with high geothermal potential. The three parameters indicating geothermal potential reviewed in this assessment were heat...
The occurrence of induced earthquakes in crystalline rocks kilometers from deep wastewater injection wells poses questions about the influence nonconformity contacts have on the downward and lateral transmission of pore-fluid pressure and poroelastic stresses. We hypothesize that structural and mineralogical heterogeneities at the sedimentary–cryst...
Abstract. The occurrence of induced earthquakes in crystalline rocks kilometres from deep wastewater injection wells poses questions about the influence nonconformity contacts have on the downward and lateral transmission of pore fluid pressure and poroelastic stresses. We hypothesize that structural and mineralogical heterogeneities at the sedimen...
Abstract A geothermal exploration corehole was drilled to a total depth of 1821.5 m on the Mountain Home Air Force Base near Mountain Home, Idaho. The corehole was used to collect an unusually large amount of data, including uniaxial compressive stress (UCS) experiments on core samples, to evaluate the geothermal potential of the western Snake Rive...
We used hydrogeologic models to assess how fault‐zone properties promote or inhibit the downward propagation of fluid overpressures from a basal reservoir injection well (150 m from fault zone, Q = 5000 m³/day) into the underlying crystalline basement rocks. We varied the permeability of the fault‐zone architectural components and a crystalline bas...
Historically, aseismic fault creep has been measured primarily at <40 m apertures with creep meters, at km’s distances with GPS methods, and with inSAR. In this project, we difference high resolution point clouds recently generated using structure from motion photogrammetry (SfM) against older LiDAR data, to ascertain the three dimensional deformat...
We integrated new geologic data with published geophysical data to document that the southernmost San Andreas fault zone, onshore of the Salton Sea, southern California, is a transpressional, 1-4-km-wide ladder-like structure. This newly identified Durmid ladder structure is a voluminous right-reverse fault zone that broadens across Durmid Hill aro...
Camas Prairie, Idaho, is an EW-trending structural graben that lies north of the Snake River Plain hotspot track. It is bounded on the north by the Idaho Batholith, and on the south by the Mount Bennett Hills. This region was investigated by the SRP Geothermal Play Fairway Analysis team, which included focused geologic, geochemical, and geophysical...
A 1912-m exploration corehole was drilled along the axis of the eastern Snake River Plain, Idaho. Two temperature logs run on the corehole display an obvious inflection point at about 960 m. Such behavior is indicative of downward fluid flow in the wellbore. The geothermal gradient above 935 m is 4.5 °C/km, while the gradient is 72–75 °C/km from 98...
Storage of anthropogenic CO2 in geological formations relies on a caprock as the primary seal preventing buoyant super-critical CO2 escaping. Although natural CO2 reservoirs demonstrate that CO2 may be stored safely for millions of years, uncertainty remains in predicting how caprocks will react with CO2-bearing brines. This uncertainty poses a sig...
Play Fairway Analysis (PFA) is a methodology adapted from the petroleum industry that
integrates data at the regional or basin scale to define favorable plays for exploration in a
systematic fashion. Phase 2 of our Play Fairway Analysis of the Western Snake River Plain
(WSRP) province in southern Idaho had three primary goals: first, to fill data g...
We examined 109.3 m of core in deformed crystalline rocks, acquired at 50 spots over 3013 vertical meters in the Cajon Pass deep drill hole, along with samples from nearby outcrops in southern California, to determine the nature of deformation and alteration near faults of the San Andreas fault system. The upper 3-3.5 km section of the crustal colu...
Exhumed faults record the temperatures produced by earthquakes. We show that transient elevated fault surface temperatures preserved in the rock record are quantifiable through microtextural analysis, fault-rock thermochronometry, and thermomechanical modeling. We apply this approach to a network of mirrored, minor, hematite-coated fault surfaces i...
Project HOTSPOT, the Snake River Scientific Drilling Project (International Continental Scientific Drilling Program), tested for deep geothermal resources and examined the petrology of volcanic rocks with three drillholes in the central and western Snake River Plain (western USA). The MH-2 drillhole targeted fractured crystalline and hydrothermally...
In the brittle crust, the distribution of natural rock fractures and their failure modes are a function of rock strength and its interactions between overburden pressure, pore-fluid pressure, and tectonic loading. The characterization of variability in rock strength and the associated changes in subsurface strain distribution is especially importan...
We used hydrologic models to explore the potential linkages between oil-field brine reinjection and increases in earthquake frequency (up to Md 3.26) in southeastern New Mexico and to assess different injection management scenarios aimed at reducing the risk of triggered seismicity. Our analysis focuses on saline water reinjection into the basal El...
Inexpensive remotely-piloted aerial vehicles and Structure from Motion (SfM) software enable rapid creation of high resolution digital surface models (DSMs) and orthophotos that are a powerful data set in many types of studies, including evaluation of geologic hazards. We used photographs taken from a DJI Phantom II quadcopter outfitted with a GoPr...
Storage of anthropogenic CO2 in geological formations relies on a caprock as the primary seal preventing buoyant super-critical CO2 escaping. Although natural CO2 reservoirs demonstrate that CO2 may be stored safely for millions of years, uncertainty remains in predicting how caprocks will react with CO2-bearing brines. This uncertainty poses a sig...
Supplementary Figures 1-6, Supplementary Tables 1-4 and Supplementary References
We examined the potential impact on CO2 transport of zones of deformation bands in reservoir rock that transition to opening-mode fractures within overlying caprock. Sedimentological and petrophysical measurements were collected along an approximately 5 m × 5 m outcrop of the Slick Rock and Earthy Members of the Entrada Sandstone on the eastern fla...
The San Andreas Fault Observatory at Depth (SAFOD), near Parkfield, California, is a borehole drilled through two active deforming zones of the San Andreas fault, the Southwest Deforming Zone (SDZ) and the Central Deforming Zone (CDZ). These zones accommodate displacement by seismic slip and aseismic creep. Elevated fluid pressures and fluid–rock i...
The Snake River Plain is a zone of high heat flow but little geothermal energy exploration has occurred. Project Hotspot, the Snake River Scientific Drilling Project, tested for deep geothermal resources and drilled the MH-2 on the Mountain Home Air Force Base by drilling into fractured crystalline and hydrothermally altered basalt to a total depth...
At Green River CO2 and CO2- SO4- charged fluids leak to surface up the Little Grand Wash fault, migrating into overlying aquifers. Drill-core collected in a 2012 drilling campaign, 90 m away from the fault trace, documents bleaching related to these migrating fluids. The mineralogy and Sr, S, O and C-isotope compositions of two 6-9 cm thick bleache...
Faults zones are complex structural features composed of three dimensional strain volumes that vary in scale. Fault zone architecture and the distribution of fault facies is important in understanding the affect these rocks have on permeability and fluid migration within and across the fault zone. We examine along -strike variations in a well-expos...
Black mudstones and shales within the Permian Phosphoria Formation are prolific source rocks for oil that has travelled 100’s km in carrier beds of central Wyoming. Phosphatic and vanadium-rich beds of the Meade Peak Member Historical mining exploration occurred locally throughout the Idaho-Utah-Wyoming fold-and-thrust belt since the 1900’s. The Pa...
Techniques directly dating fault slip are few, limiting the ability to interpret the rock record of seismicity. Hematite is commonly found in fault zones, amenable to (U-Th)/He dating, and slip surface hematite may be reset by shear heating events and/or recrystallization. Glossy hematite-coated fault surfaces in the Wasatch fault footwall damage z...
We present evidence for ancient seismicity in the form of tectonic pseudotachylyte and coeval, cyclic hydrothermal alteration, and cataclasis along fault zones exhumed from 2.4 to 6.0 km in the central Sierra Nevada, CA. The Glacier Lakes fault (GLF) and Granite Pass fault (GPF) are exhumed left-lateral to left-lateral oblique, strike-slip faults w...
Coordinated drilling efforts are an important method to investigate active
tectonics and magmatic processes related to faults and volcanoes. The US
National Science Foundation (NSF) recently sponsored a series of workshops
to define the nature of future continental drilling efforts. As part of this
series, we convened a workshop to explore how cont...
The sedimentologic and tectonic histories of clastic cap rocks and their inherent mechanical properties control the nature of permeable fractures within them. The migration of fluid through mm- to cm-scale fracture networks can result in focused fluid flow allowing hydrocarbon production from unconventional reservoirs or compromising the seal integ...
Deep injection of large volumes of disposal fluids and CO2 injection schemes focuses on a suite of rocks that have been overlooked, and place attention on the integration of hydrogeology, geomechanics, and subsurface structural geology as never before. Uncertainty regarding the strength and mode of failure of reservoirs and the potential for seismi...
ScienceDirect 1876-6102 © 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of the Organizing Committee of GHGT-12 Abstract Understanding the long-term response of CO 2 injected into porous reservoirs is one...
We document new geological indicators of ancient seismicity in the form of highly reflective, iridescent, hematite-coated fault surfaces. Small faults that cut the Paleoproterozoic Farmington Canyon Complex in the footwall damage zone of the Brigham City segment of the Wasatch fault (Utah, USA) are smooth to striated surfaces, tens of square centim...