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Response To Request For Evaluation Of The Feasibility Of Erecting A Regional Wind Energy System Within The East Bay Of R.I., Non-Price Proposal, Boreal Renewable Energy Development Aug 2009

Response To Request For Evaluation Of The Feasibility Of Erecting A Regional Wind Energy System Within The East Bay Of R.I., Non-Price Proposal, Boreal Renewable Energy Development

East Bay Energy Consortium Documents

No abstract provided.


Strain Rate Patterns From Dense Gps Networks, Matthias Hackl, Rocco Malservisi, Shimon Wdowinski Jul 2009

Strain Rate Patterns From Dense Gps Networks, Matthias Hackl, Rocco Malservisi, Shimon Wdowinski

School of Geosciences Faculty and Staff Publications

The knowledge of the crustal strain rate tensor provides a description of geodynamic processes such as fault strain accumulation, which is an important parameter for seismic hazard assessment, as well as anthropogenic deformation. In the past two decades, the number of observations and the accuracy of satellite based geodetic measurements like GPS greatly increased, providing measured values of displacements and velocities of points. Here we present a method to obtain the full continuous strain rate tensor from dense GPS networks. The tensorial analysis provides different aspects of deformation, such as the maximum shear strain rate, including its direction, and the …


Archaeometric Comparison Between The Neolithic Pottery Of Different Cultures At The Archaeological Site Of Alba Iulia (Transylvania, Romania), Bruno Fabbri, Mihai Gligor, Sabrina Gualtieri, Simona Varvara Jun 2009

Archaeometric Comparison Between The Neolithic Pottery Of Different Cultures At The Archaeological Site Of Alba Iulia (Transylvania, Romania), Bruno Fabbri, Mihai Gligor, Sabrina Gualtieri, Simona Varvara

Studia UBB Geologia

A large quantity of pottery has been discovered at the Lumea Nouă Neolithic and Eneolithic settlement in Alba Iulia City (Romania). It belongs to different cultures, and in this paper a comparison among three of them is made: Vinča, Lumea Nouă and Foeni. An analogous number of samples has been selected for each of the three cultures, together with some clay samples collected in the Alba Iulia settlement area. The samples have been analysed by means of XRF, XRPD, and in thin section. Significant differences among the three cultures are only related to the alkalis contents. The Lumea Nouă pottery …


Fore-Arc Motion And Cocos Ridge Collision In Central America, Peter Lafemina, Timothy Dixon, Rob Govers, Edmundo Norabuena, Henry Turner, Armando Saballos, Glen Mattioli, Marino Protti, Wilfried Strauch May 2009

Fore-Arc Motion And Cocos Ridge Collision In Central America, Peter Lafemina, Timothy Dixon, Rob Govers, Edmundo Norabuena, Henry Turner, Armando Saballos, Glen Mattioli, Marino Protti, Wilfried Strauch

School of Geosciences Faculty and Staff Publications

We present the first regional surface velocity field for Central America, showing crustal response to interaction of the Cocos and Caribbean plates. Elastic half-space models for interseismic strain accumulation on the dipping subduction plate boundary fit the GPS data well and show strain accumulation offshore and beneath the Nicoya and Osa peninsulas in Costa Rica but not in Nicaragua. Since large subduction zone earthquakes occur in Nicaragua, we suggest that interseismic locking in Nicaragua and some other parts of Central America occurs but is mainly shallow, depth, too far offshore to be detected by our on-land GPS measurements. Our data …


Water Current, Volume 41, No. 2, Spring 2009 Apr 2009

Water Current, Volume 41, No. 2, Spring 2009

Water Current Newsletter

Fall Symposium: Platte River Basin Science and Resource Management – October 14 and 15 in Kearney
WRAP Exploring Critical Issues
Meet the Faculty: Jesse Korus, Mehmet Can Vuran
UNL to Announce Formation of the Global Water Institute Engineering
Emerging Contaminants in Natural Waterways: Where is the Smoking Gun?
Featured Partner: NACEE: Nebraska Alliance for Conservation and Environmental Education
Protect State’s Legacy of Living Rivers
Zellmer Authors Book Chapter
Sixth Annual University of Nebraska–LincolnWater Law, Policy and Science
Conference:“Blue Gold: When Water Meets Money”April 29, 30Embassy Suites Hotel, Lincoln
Rain Gardens and Urban Stormwater Management Education in Nebraska
UNL Presenters at …


The Biscayne Aquifer Of Southeastern Florida, Kevin J. Cunningham, Lee J. Florea Jan 2009

The Biscayne Aquifer Of Southeastern Florida, Kevin J. Cunningham, Lee J. Florea

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.


My Trig Book, Bruce Kessler Jan 2009

My Trig Book, Bruce Kessler

Mathematics Faculty Publications

This is the MATH 117 Trigonometry text developed by Dr. Bruce Kessler for the Gatton Academy of Math and Science at Western Kentucky University for the Academy sections of the course. The text has also been used in two online course offerings.


My Trig Book, Bruce Kessler Jan 2009

My Trig Book, Bruce Kessler

Mathematics Faculty Publications

This is the MATH 117 Trigonometry text developed by Dr. Bruce Kessler for the Gatton Academy of Math and Science at Western Kentucky University for the Math and Science sections of the course. The text has also been used in two online course offerings.


The Pecos River Hypogene Speleogenetic Province: A Basin-Scale Karst Paradigm For Eastern New Mexico And West Texas, Usa, Kevin W. Stafford, Alexander Klimchouk, Lewis Land, Marcus O. Gary Jan 2009

The Pecos River Hypogene Speleogenetic Province: A Basin-Scale Karst Paradigm For Eastern New Mexico And West Texas, Usa, Kevin W. Stafford, Alexander Klimchouk, Lewis Land, Marcus O. Gary

Faculty Publications

Since the mid-Tertiary, lateral migration and entrenchment of the Pecos River Valley in eastern New Mexico and west Texas, USA, has significantly influenced regional groundwater flow paths, providing a focus for ascending flow in multi-storey artesian systems and a powerful potentiometric driving force for hypogene speleogenesis. Individual occurrences of hypogene karst phenomena associated with the central Pecos River Valley are widespread throughout the greater Delaware Basin region, including development in a wide range of Permian carbonate and evaporate fades. Hypogene occurrences are well-documented as far north as Santa Rosa, New Mexico and as far south as Lake Amistad, Texas. Throughout …


Resistivity And Conductivity Studies Of The Rattlesnake Springs, New Mexico Watershed, Claudia Santiago Jan 2009

Resistivity And Conductivity Studies Of The Rattlesnake Springs, New Mexico Watershed, Claudia Santiago

Open Access Theses & Dissertations

Rattlesnake Springs are a high-discharge artesian springs situated in the upper Black River Valley in southwestern Eddy Country, New Mexico. The aquifer that supplies the Rat- tlesnake Springs has been the main water source for domestic use by visitors of Carlsbad Caverns National Park and residents of neighboring ranches since the 1930s. Several ge- ological studies relying on surface geology and limited water wells had previously been conducted in the area to examine the trend of ground water flow. In this study I used con- ductivity and resistivity geophysical techniques to identify possible locations of fractures in the subsurface of …


Using Gis To Quantify Patterns Of Glacial Erosion On Northwest Iceland: Implications For Independent Ice Sheets, Sarah M. Principato, Jeremiah S. Johnson Jan 2009

Using Gis To Quantify Patterns Of Glacial Erosion On Northwest Iceland: Implications For Independent Ice Sheets, Sarah M. Principato, Jeremiah S. Johnson

Environmental Studies Faculty Publications

Glacial erosion patterns on northwest Iccliind are quantified using a Geographic Information System (GIS) in order to interpret subglacial characteristics of part of northwest Iceland affected by ice sheet glaciation. Ice scour lake density is used as a proxy for glacial erosion. Erosion classes are interpreted from variations in the density of lake basins. Lake density was calculated using two dilTerent methods: the first is sensitive to the total number of lakes in a specific area, and the second is sensitive to total lake area in a specific area. Both of these methods result in a value for lake density, …


Geochemistry Of The Middle Miocene Collision-Related Yamadaği ( Eastern Anatolia) Calc-Alkaline Volcanics, Turkey, Taner Eki̇ci̇, Musa Alpaslan, Osman Parlak, Ali̇ Uçurum Jan 2009

Geochemistry Of The Middle Miocene Collision-Related Yamadaği ( Eastern Anatolia) Calc-Alkaline Volcanics, Turkey, Taner Eki̇ci̇, Musa Alpaslan, Osman Parlak, Ali̇ Uçurum

Turkish Journal of Earth Sciences

Major, trace element and K-Ar age determinations are reported for a suite from the Yamadağı volcanics in the Eastern Anatolia. The exposed rocks mainly consist of medium-potassium calc-alkaline basaltic andesites, andesites and dacites. Petrographical data exhibit disequilibrium mineral textures, such as resorption of the ferromagnesian phases, clinopyroxene-mantled orthopyroxene, and sieve-textured plagioclases. The Yamadağı volcanics have a calk-alkaline character, and trace element characteristics exhibit that the volcanics resemble subduction zone volcanics and/or volcanics assimilated by continental crust. K/Ar age determinations show that the Yamadağı volcanics were formed during the 12 ± 0.5 - 15 ± 0.5 Ma time interval. Geochemical characteristics …


Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California: Implications For The Structure And Tectonics Of The San Andreas Fault Zone, S. D. Springer, James P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke Jan 2009

Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California: Implications For The Structure And Tectonics Of The San Andreas Fault Zone, S. D. Springer, James P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke

Geosciences Faculty Publications

The San Andreas Fault Observatory at Depth (SAFOD) drill hole encountered indurated, high-seismic-velocity arkosic sedimentary rocks west of the active trace of the San Andreas fault in central California. The arkosic rocks are juxtaposed against granitic rocks of the Salinian block to the southwest and against fine-grained Great Valley Group and Jurassic Franciscan rocks to the northeast. We identify three distinct lithologic units using cuttings, core petrography, electrical resistivity image logs, zircon fission-track analyses, and borehole-based geophysical logs. The upper arkose occurs from 1920 to 2530 m measured depth (mmd) in the borehole and is composed of five structural blocks …


Temporal And Geochemical Insights Related To Volcanic And Plutonic Activity Within Big Bend National Park, Texas, Daniel Paul Miggins Jan 2009

Temporal And Geochemical Insights Related To Volcanic And Plutonic Activity Within Big Bend National Park, Texas, Daniel Paul Miggins

Open Access Theses & Dissertations

Big Bend National Park located in the southeastern part of the Trans-Pecos Magmatic Province in west Texas contains a diverse suite of volcanic and intrusive rocks. Ongoing geologic mapping, geochronology, and geochemical studies have focused on the timing and geological relationships associated with these volcanic and intrusive rocks. Igneous activity within Big Bend National Park occurred from 46.5 to 22.0 Ma. Precise 40Ar/39Ar and U-Pb zircon geochronology has resolved the timing of this activity into five discrete episodes: 1) eruption and emplacement of both intrusive and volcanic mafic rocks at 46.5 Ma followed by ~42.0 Ma mafic volcanic pulse; 2) …


Investigating The Margins Of Pleistocene Lake Deposits With High-Resolution Seismic Reflection In Pilot Valley, Utah, John V. South Nov 2008

Investigating The Margins Of Pleistocene Lake Deposits With High-Resolution Seismic Reflection In Pilot Valley, Utah, John V. South

Theses and Dissertations

A vast area of the northeastern Great Basin of the western USA was inundated by a succession of Plio-Pleistocene lakes, including Lake Bonneville (28 ka to 12 ka). The Pilot Valley playa, located just east of the Utah-Nevada border near Wendover, Utah, within the eastern Basin and Range Province, represents an 8 to 16 km wide and ~50 km long remnant of these lakes. The playa corresponds to the upper surface of a closed basin that is delimited by two mountain ranges, which are mantled by recent alluvial fans over which the playa sediments have prograded. In order to investigate …


In Memoriam Sep 2008

In Memoriam

Studia UBB Geologia

No abstract provided.


Gsi: Geo Scene Investigation! On-Site Programming (Grade 7), Discover Mojave: Forever Earth Sep 2008

Gsi: Geo Scene Investigation! On-Site Programming (Grade 7), Discover Mojave: Forever Earth

Curriculum materials (FE)

GSI: Geo Scene Investigation! introduces students to the differences between observations and interpretations and to some of the fundamental principles of geology. Students identify specific geologic processes and landforms in the landscape surrounding them at Lake Mead National Recreation Area (NRA) by solving mysteries with a set of geology-related clues.


The Mayan Ice Cap: Glacial Geology And Paleoclimate Of The Northern Guatemalan Highlands, Alex Joseph Roy Aug 2008

The Mayan Ice Cap: Glacial Geology And Paleoclimate Of The Northern Guatemalan Highlands, Alex Joseph Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Sierra de los Cuchumatanes region of the northern Guatemalan highlands supported a large plateau ice cap with an area of -40 km2 along with a group of 5 cirque glaciers -1 to 2 km2 during the local last glacial maximum (LLGM). A comprehensive mapping reconstruction of the northern Guatemalan highlands is presented here, including glacial geology and an estimate of maximum ice limits from physical evidence and computer modeling. The glacial geologic map was produced via field mapping with global positioning system (GPS) surveying combined with aerial stereo photographic and topographic map analysis. This new field work on moraine …


Gsi: Geo Scene Investigation! On-Site Programming, Support Materials (Grade 7), Discover Mojave: Forever Earth Jul 2008

Gsi: Geo Scene Investigation! On-Site Programming, Support Materials (Grade 7), Discover Mojave: Forever Earth

Curriculum materials (FE)

What happened geologically to produce the landscape we see today? What was the stage like that ultimately produced the Colorado River? What are the processes that are still at work today?

To begin exploring and discovering the answers to these questions, we can look at what’s happened in the past and also examine the clues that are evident on today’s landscape. Lake Mead’s geologic past can be organized like acts in a play. These geologic “acts” represent the area’s significant geologic events. The acts are not equal in terms of time (millions of years), nor is all geologic time accounted …


Finding Concealed Active Faults: Extending The Southern Whidbey Island Fault Across The Puget Lowland, Washington, Brian L. Sherrod, Richard J. Blakely, Craig S. Weaver, Harvey M. Kelsey, Elizabeth Barnett, Lee Liberty, Karen L. Meagher, Kristin Pape May 2008

Finding Concealed Active Faults: Extending The Southern Whidbey Island Fault Across The Puget Lowland, Washington, Brian L. Sherrod, Richard J. Blakely, Craig S. Weaver, Harvey M. Kelsey, Elizabeth Barnett, Lee Liberty, Karen L. Meagher, Kristin Pape

CGISS Publications and Presentations

The southern Whidbey Island fault zone (SWIF), as previously mapped using borehole data, potential field anomalies, and marine seismic reflection surveys, consists of three subparallel, northwest trending strands extending ~100 km from near Vancouver Island to the northern Puget Lowland. East of Puget Sound, the SWIF makes landfall between the cities of Seattle and Everett but is concealed beneath a thick mantle of young glacial deposits and vegetation. A ~20-km-wide, northwest trending swath of subparallel, low-amplitude aeromagnetic anomalies crosses this region of the Puget Lowland and is on strike with the SWIF. The most prominent aeromagnetic anomaly, the Cottage Lake …


Geology Of The Southern Reveille Range, Nye County, Nevada, Matthew Alan Mckelvey May 2008

Geology Of The Southern Reveille Range, Nye County, Nevada, Matthew Alan Mckelvey

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Reveille Range in central Nevada provides a unique window into the mid-Miocene geology and volcanology of the central Great Basin during the "ignimbrite flare up." Although faulted along its margins, the interior of the range is relatively undeformed thus preserving volcanic centers. The Reveille Range contains three mid-Miocene caldera complexes. Previous studies have identified the Goblin Knobs caldera (25.6 Ma) in the central Reveille Range and the caldera of northern Reveille Range (25.3 Ma) to the north. These calderas are completely filled with intracaldera tuffs. This study has identified a younger third caldera located in the southern part of …


Provenance Analysis Of The Cretaceous Pythian Cave Conglomerate, Northern California, Gregory Alan Augsburger Apr 2008

Provenance Analysis Of The Cretaceous Pythian Cave Conglomerate, Northern California, Gregory Alan Augsburger

Earth and Environmental Geosciences Student Honors Theses

Reconstructions of the Mesozoic paleogeography of the North American Cordillera depend on data that can link displaced terranes to each other and/or to the North American craton. The Pythian Cave Conglomerate (PCC) sits unconformably on the eastern terranes of the Klamath Mountains south of Yreka, California and has the potential to yield valuable information about the tectonic history of the region. The PCC is approximately 60 m thick, with the lower 40 m dominated by cobble conglomerate with thin sandstone lenses, and the upper 20 m containing thicker and more laterally continuous interbedded sandstone layers. Originally interpreted as Tertiary conglomerate …


An Ordovician Global Reference Section Recently Selected In Oklahoma, Daniel Goldman, Stephen A. Leslie, Stig M. Bergström, Jaak Nõlvak, Seth A. Young, Stanley C. Finney Apr 2008

An Ordovician Global Reference Section Recently Selected In Oklahoma, Daniel Goldman, Stephen A. Leslie, Stig M. Bergström, Jaak Nõlvak, Seth A. Young, Stanley C. Finney

Department of Earth, Environment and Sustainability Faculty Publications

Ordovician fossil faunas are characterized by a marked biogeographic differentiation that results in a minimal similarity between most North American faunas and those of major Ordovician areas elsewhere in the world. This provincial distribution of most fossils has led to establishment of different schemes of fossil-based regional stages in, for instance, North America, Baltoscandia, China, and the British Isles.

Because these chrono-stratigraphic units have been largely based on shelly fossils with distributions restricted to a particular region, it has been impossible in most cases to establish a precise international correlation of these regional stages. Furthermore, some general terms, such as …


Backstripping The Chesapeake Bay Impact Structure: Differentiating Regional Tectonics From Impact Effects, Travis Gary Hayden Apr 2008

Backstripping The Chesapeake Bay Impact Structure: Differentiating Regional Tectonics From Impact Effects, Travis Gary Hayden

Masters Theses

The Chesapeake Bay impact structure is a ca. 35.4 Ma old crater located on the coastal plain of Virginia along the eastern seaboard of North America. The impact generated a crater between 85 and 90 km in diameter, and over 2000 meters deep. Deposition returned to normal shortly after impact, resulting in a unique record of both the impact related and subsequent passive margin sedimentation. We use backstripping to show that the impact strongly affected sedimentation for 7 m.y. through a combination of impact derived crustal scale tectonics, dominated by the introduction and subsequent removal of a negative thermal anomaly, …


Pamphlet To Accompany Geologic Map Gmc-34: Geologic Map Of The O’Neill 1º X 2º Quadrangle, Nebraska, With Configuration Maps Of Surfaces Of Formations, Robert F. Diffendal Jr., Michael R. Voorhies, E. Jane Voorhies, H. E. Lagarry, C. L. Timperley, M. E. Perkins Jan 2008

Pamphlet To Accompany Geologic Map Gmc-34: Geologic Map Of The O’Neill 1º X 2º Quadrangle, Nebraska, With Configuration Maps Of Surfaces Of Formations, Robert F. Diffendal Jr., Michael R. Voorhies, E. Jane Voorhies, H. E. Lagarry, C. L. Timperley, M. E. Perkins

Robert F. Diffendal, Jr., Publications

This map is necessarily generalized. It is based primarily on data from 7.5’ surficial geologic quadrangle maps of the map area prepared by the authors principally from 1991 to 2000, from Voorhies (unpublished data, 1974), as well as data from test-hole drilling done across the quadrangle by the Conservation and Survey Division, University of Nebraska, and its cooperators over many years since the 1930s. For more detailed information, consult the geologic data files of the Conservation and Survey Division, School of Natural Resources, University of Nebraska-Lincoln. The quadrangle is mostly covered by vegetation and Holocene sediments. Limited good exposures of …


Metcrax 2006 - Meteorological Experiments In Arizona's Meteor Crater, C. David Whiteman, Sebastian Hoch, Maura Hahnenberger, Andreas Muschinski, Vincent Hohreiter, Mario Behn, Yonghum Cheon, Sharon Zhong, Wenqing Yao, David Fritts, Craig Clements, Thomas Horst, William Brown, Steven Oncley Jan 2008

Metcrax 2006 - Meteorological Experiments In Arizona's Meteor Crater, C. David Whiteman, Sebastian Hoch, Maura Hahnenberger, Andreas Muschinski, Vincent Hohreiter, Mario Behn, Yonghum Cheon, Sharon Zhong, Wenqing Yao, David Fritts, Craig Clements, Thomas Horst, William Brown, Steven Oncley

Faculty Publications, Meteorology and Climate Science

The Meteor Crater Experiment (METCRAX 2006) was conducted in October 2006 at Arizona's Meteor Crater to investigate stable boundary layer evolution in a topographically uncomplicated basin surrounded by the nearly homogeneous plain of the Colorado Plateau. The two goals of the experiment were 1) to investigate the microscale and mesoscale structure and evolution of the stable boundary layer in the crater and its surroundings and 2) to determine whether atmospheric seiches or standing waves are produced inside the crater. This article provides an overview of the scientific goals of the experiment; summarizes the research measurements, the crater topography, and the …


Geological Mapping Of Orhon, Tariat, And Egiin Dawaa, Central Mongolia, Through The Interpretation Of Remote Sensing Data, Tara Alexandra Stolz Jan 2008

Geological Mapping Of Orhon, Tariat, And Egiin Dawaa, Central Mongolia, Through The Interpretation Of Remote Sensing Data, Tara Alexandra Stolz

Browse all Theses and Dissertations

Multi-spectral satellite data from the Advanced Spaceborn Thermal Emission and Reflection Radiometer (ASTER) and Landsat Thematic Mapper (TM) were used to make interpretations regarding the surface lithology and structure of the Tariat, Egiin Dawaa, and Orhon regions in Central Mongolia. These areas experienced widespread Cenozoic volcanism. This study mapped the locations and extents of the volcanic flows, located cinder cones and faults evident in the areas, and identified a possible exposure of the Mongolian granitic batholith in the Orhon area. ER Mapper, a geospatial imaging software, was used to generate and run algorithms. Image transforms and supervised classifications were used …


In Memoriam Jean Philippe Marcoux, A.M. Celal Şengör Jan 2008

In Memoriam Jean Philippe Marcoux, A.M. Celal Şengör

Turkish Journal of Earth Sciences

No abstract provided.


Composition, Microstructures, And Petrophysics Of The Mozumi Fault, Japan: In Situ Analyses Of Fault Zone Properties And Structure In Sedimentary Rocks From Shallow Crustal Levels, Angela J. Isaacs, James P. Evans, Peter T. Kolesar, Tsuyoshi Nohara Jan 2008

Composition, Microstructures, And Petrophysics Of The Mozumi Fault, Japan: In Situ Analyses Of Fault Zone Properties And Structure In Sedimentary Rocks From Shallow Crustal Levels, Angela J. Isaacs, James P. Evans, Peter T. Kolesar, Tsuyoshi Nohara

Geosciences Faculty Publications

[1] We characterize the chemical, microstructural, and geophysical properties of fault-related rock samples from the 80–100 m wide Mozumi fault zone, north central Honshu, Japan. The fault is exposed in a research tunnel 300–400 m below the ground, and we combine geological data with borehole geophysical logs to determine the elastic and seismic properties of the fault zone. Detailed mapping within the tunnel reveals that the fault zone consists of two zones of breccia to foliated cataclasites 20 and 50 m thick. Two narrow (tens of centimeters wide) principal slip zones on which most of the slip occurred bound the …


Modern Strain Localization In The Central Walker Lane, Western United States: Implications For The Evolution Of Intraplate Deformation In Transtensional Settings, Benjamin E. Surpless Jan 2008

Modern Strain Localization In The Central Walker Lane, Western United States: Implications For The Evolution Of Intraplate Deformation In Transtensional Settings, Benjamin E. Surpless

Earth and Environmental Geosciences Faculty Research

Approximately 25% of the differential motion between the Pacific and North American plates occurs in the Walker Lane, a zone of dextral motion within the western margin of the Basin and Range province. At the latitude of Lake Tahoe, the central Walker Lane has been considered a zone of transtension, with strain accommodated by dip-slip, strike-slip, and oblique-slip faults. Geologic data indicate that extension and strike-slip motion are partitioned across the central Walker Lane, with dip-slip motion resulting in E–W to ESE–WNW extension along the present-day western margin of the central Walker Lane since approximately 15 Ma, and dextral strike-slip …