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Geology

1996

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Full-Text Articles in Physical Sciences and Mathematics

The Geology And Structures In The Northern Hiko Range, Lincoln County, Nevada, Douglas D. Switzer Dec 1996

The Geology And Structures In The Northern Hiko Range, Lincoln County, Nevada, Douglas D. Switzer

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the northern Hiko Range, extension occurred in four temporally distinct episodes during the Cenozoic. The extensional events are (1) prevolcanic (> 27.31 ± 0. 03 Ma), (2) syn-volcanic (between 22.78 ± 0,03 and 18.5 ± 0.4 Ma), (3) Tertiary(?) post-volcanic ( < 14.7 ± 0.4 Ma), and ( 4) Pliocene(?) - Quaternary. Four fault sets are delineated based on orientation and cross-cutting relationships: (I) northeast- to northwest-striking moderately dipping prevolcanic faults, (2) east-west striking, steeply-dipping syn-volcanic faults, (3) east-west- and east-northeast-striking, steeply dipping Tertiary(?) post-volcanic faults, and (4) generally north-striking steeply dipping Pliocene (?) - Quaternary faults.

Prevolcanic faults in the northern Hiko Range are interpreted to be footwall faults to an Oligocene age extensional system. These faults increase the area affected by Oligocene extension and support existing evidence that suggests this event is widespread.

A tectonomagmatic rift model has been proposed to explain synvolcanic extension during the Tertiary in the northern Basin and Range …


Geology Newsletter- 1996, Department Of Geology Dec 1996

Geology Newsletter- 1996, Department Of Geology

Geological and Environmental Sciences News

Vol. 1, No. 21

  • Faculty News
  • Alumni/ Friends/ Former Faculty Notes
  • Geology Development
  • Donations
  • Scholarship Donations


A Depositional Analysis Of The Wymer Site, Berrien County, Michigan And Its Relationship To Post-Glacial Lake Levels In The Lake Michigan Basin, Kevin A. Kincare Dec 1996

A Depositional Analysis Of The Wymer Site, Berrien County, Michigan And Its Relationship To Post-Glacial Lake Levels In The Lake Michigan Basin, Kevin A. Kincare

Masters Theses

The Wymer site is an archeological site on the St. Joseph River floodplain 1.5 miles north of Berrien Springs, Michigan. Early and Middle Archaic cultural phases were found at the site. These sites are unusual in that their occurrence corresponds to low lake levels associated with Lake Chippewa and were assumed to occupy the now submerged shoreline areas.

A site evaluation was undertaken to examine the types of sediments and depositional structures. Trenches, grainsize analysis, 14C samples and valley topography were used to determine that the site was a point bar situated on a terrace above the modern floodplain. …


Morphological Features, Ages And Neotectonic Significance Of Pamukkale Travertines, Erhan Altunel Nov 1996

Morphological Features, Ages And Neotectonic Significance Of Pamukkale Travertines, Erhan Altunel

Bulletin of the Mineral Research and Exploration

No abstract provided.


Cycle Symmetry And Its Causes, Cisco Group (Virgilian And Wolfcampian), Texas, Wan Yang Nov 1996

Cycle Symmetry And Its Causes, Cisco Group (Virgilian And Wolfcampian), Texas, Wan Yang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

181 transgressive-regressive cycles composed of nonmarine and marine carbonate and siliciclastic rocks of the Cisco Group on the Eastern Shelf, Texas, display complex characteristics at both hemicycle and full-cycle scales. They are delineated on the basis of successive changes of depositional environments, stratal boundary relations, and stratigraphic position. Transgressive and regressive stratigraphic environment gradients are defined as the magnitude of environmental shift divided by thickness for each hemicycle. They indicate the rates of lateral environmental shifts during transgression and regression. Cycle symmetry index is defined as the ratio between transgressive and regressive stratigraphic environment gradients. It provides a measure of …


Yellow Sea & East China Sea Bibliography, Nicole D. Scott, Patricia T. Carrier, John D. Milliman Nov 1996

Yellow Sea & East China Sea Bibliography, Nicole D. Scott, Patricia T. Carrier, John D. Milliman

Reports

No abstract provided.


Depositional Environment And Sequence Stratigraphic Interpretation Of Miocene St. Marys Formation, Calvert County, Maryland, John J. Blandin Oct 1996

Depositional Environment And Sequence Stratigraphic Interpretation Of Miocene St. Marys Formation, Calvert County, Maryland, John J. Blandin

OES Theses and Dissertations

The Miocene St. Marys Formation at Calvert Cliffs, Maryland is divided into four depositional packages made up of marine fades representing shallow shelf through intertidal conditions. These depositional packages are separated by five laterally persistent surfaces and were defined based on detailed depositional fades analysis of 24 measured sections, averaging 17 meters thick. These four packages make up two marine sequences, stratigraphic units bound above and below by surfaces of sea level fall. The lower sequence is composed of a single depositional package, while the upper sequence is composed of three upward-shallowing depositional packages (i.e. para-sequences). A fifth depositional package …


Naticid Gastropod Prey Selectivity Through Time And The Hypothesis Of Escalation, Patricia H. Kelley, Thor A. Hansen Oct 1996

Naticid Gastropod Prey Selectivity Through Time And The Hypothesis Of Escalation, Patricia H. Kelley, Thor A. Hansen

Geology Faculty Publications

The hypothesis of escalation posits that biologic hazards such as predation have increased during the Phanerozoic. Previously, a survey of drilling frequencies in the Cretaceous and Paleogene of the North American Coastal Plain suggested an episodic pattern of escalation within the naticid gastropod predator-prey system. This study examines escalation from the perspective of naticid prey selectivity. If escalation occurred within the system, less selectivity of prey may be apparent in the Paleogene compared to younger assemblages. We test this hypothesis for four Eocene Coastal Plain assemblages. Contrary to predictions, intraspecific prey size selectivity was well developed for nine of eleven …


Timing Of Latest Eocene Molluscan Extinction Patterns In Mississippi, David M. Hassl, Thor A. Hansen Oct 1996

Timing Of Latest Eocene Molluscan Extinction Patterns In Mississippi, David M. Hassl, Thor A. Hansen

Geology Faculty Publications

Molluscs removed from 12 bulk samples of the Yazoo Formation (upper Eocene), exposed in a quarry at Cynthia, Mississippi, are similar in com- position and diversity to those found in the underlying upper Eocene Moodys Branch Formation, when dif- ferences in outcrop area are considered (74% of the Yazoo species are also found in the Moodys Branch). This suggests there was no significant extinction during the late Eocene (at the P15/P16 biozone boundary) as has been reported for planktic foraminifera. Only 11.4% of the species from the Yazoo extend into the Oligocene Red Bluff Formation, suggesting a large molluscan extinction …


Low Temperature Magnetic Properties Of Siderite And Magnetite In Marine Sediments, Bernard A. Housen, S. K. Banerjee, B. M. Moskowitz Oct 1996

Low Temperature Magnetic Properties Of Siderite And Magnetite In Marine Sediments, Bernard A. Housen, S. K. Banerjee, B. M. Moskowitz

Geology Faculty Publications

Low temperature magnetic techniques provide useful tools to detect the presence of magnetite and pyrrhotite in sediments through identification of their low temperature transitions, to determine the amount of ultrafine-grained (superparamagnetic) material in sediments, and can potentially detect the presence of certain types of magnetotactic bacteria. Application of these types of experiments to nannofossil chalks from beneath the Barbados accretionary prism led to some unusual results, which are attributed to the presence of siderite. Thermal demagnetization of low-temperature remanence after cooling in zero field and in a 2.5 T field both displayed large remanence losses from 20 K to 40 …


Theoretical Analysis Of Cross Joint Geometries And Their Classification, Taixu Bai Sep 1996

Theoretical Analysis Of Cross Joint Geometries And Their Classification, Taixu Bai

FIU Electronic Theses and Dissertations

Joints as opening-mode fractures play important roles as indicators of tectonic stress fields and as pathways for underground fluid flow. This thesis analytically investigates the relationships among cross joint geometry, orientations and ratios of remote principal stresses, and fluid pressure. Results show that main trends of cross joints are perpendicular to the least far field stresses during cross joint formation, and cross joint paths can be used to determine relative magnitudes of remote principal stresses. Based on the theoretical derivation, cross joint geometries are grouped into five main categories: curving-parallel, curving-perpendicular, quasi-curving-parallel, quasi-curving-perpendicular and non-curving geometries. By introducing the concepts …


Localized Amplification Of Seismic Waves And Correlation With Damage Due To The Northridge Earthquake: Evidence For Focusing In Santa Monica, Stephen S. Gao, Kelly H. Liu, Paul M. Davis, Leon Knopoff Sep 1996

Localized Amplification Of Seismic Waves And Correlation With Damage Due To The Northridge Earthquake: Evidence For Focusing In Santa Monica, Stephen S. Gao, Kelly H. Liu, Paul M. Davis, Leon Knopoff

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The analysis of seismograms from 32 aftershocks recorded by 98 seismic stations installed after the Northridge earthquake in the San Fernando Valley, the Santa Monica Mountains, and Santa Monica, California, indicates that the enhanced damage in Santa Monica is explained in the main by focusing due to a lens structure at a depth of several kilometers beneath the surface and having a finite lateral extent. The diagnosis was made from the observation of late-arriving S phases with large amplitudes, localized in the zones of large damage. The azimuths and angles of incidence of the seismic rays that give rise to …


The Effects Of The Kalamazoo Station No. 4 On The Nearby Kleinstuck Nature Preserve, Robert J. Buechler Aug 1996

The Effects Of The Kalamazoo Station No. 4 On The Nearby Kleinstuck Nature Preserve, Robert J. Buechler

Masters Theses

This was a 15 month study that studied the effects of Kalamazoos' Municipal Pumping Station No. 4 on the Kleinstuck Nature Preserve. The preserve is about a quarter of a mile in the up gradient direction of Station No. 4. This study demonstrates that there is a direct correlation between the pumping and the water levels at the preserve. Pumping records show that there is no correlation between precipitation and the water levels at the preserve.

There are other factors which exaggerate this effect. It has been found that the drain field at the Y.M.C.A. parking lot, the breaching of …


Spatial And Temporal Variability In The Distribution Of Nitrate In An Agriculturally-Impacted Aquifer, Cass County, Michigan, Caroline Lo Vetere Aug 1996

Spatial And Temporal Variability In The Distribution Of Nitrate In An Agriculturally-Impacted Aquifer, Cass County, Michigan, Caroline Lo Vetere

Masters Theses

Ground-water sampling in a shallow unconfined aquifer within a predominantly agricultural area in southwestern Michigan indicated spatial and temporal variability in the distribution of nitrate. The unconfined aquifer, which is about 40 feet thick, consists of glacially-deposited sand and gravel with interbedded clay lenses and is separated from a lower semi-confined aquifer by a 3-to 26-feet-thick till layer.

The site of the study was a 47-acre agricultural field, characterized by corn and alfalfa hay production, to which hog manure and commercial fertilizers were frequently applied. The shallow water table and relatively permeable glacial sands in the vadose zone combined to …


Hydrostratigraphy And Allostratigraphy Of The Cenozoic Alluvium In The Northwestern Part Of Las Vegas Valley, Clark County, Nevada, David J. Donovan Aug 1996

Hydrostratigraphy And Allostratigraphy Of The Cenozoic Alluvium In The Northwestern Part Of Las Vegas Valley, Clark County, Nevada, David J. Donovan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This investigation was conducted to determine the location, nature, and boundaries of the most permeable unit within the alluvial aquifer material in Las Vegas Valley. It was prompted by declines in specific capacity of about 90% at the Las Vegas Valley Water District's West Central Well Field. It was hypothesized that the decline in specific capacity resulted from dewatering of the most permeable interval of the alluvium. Lithologic descriptions from wells and aquifer test information were analyzed for geologic and hydrogeologic variability. New information, in the form of detailed unpublished lithologic and hydrologic information, was available from twenty water wells …


The Petrogenesis Of Andesites Produced During Regional Extension: Examples From The Northern Mccullough Range, Nv And Xitle Volcano, Mexico, Kelly Ann Boland Aug 1996

The Petrogenesis Of Andesites Produced During Regional Extension: Examples From The Northern Mccullough Range, Nv And Xitle Volcano, Mexico, Kelly Ann Boland

UNLV Theses, Dissertations, Professional Papers, and Capstones

Andesite dominated volcanic systems produced during regional crustal extension remain a relatively unexplored aspect of andesite petrogenesis. In the southern Basin and Range province, thick sections of andesite and basaltic andesite have been documented in areas including the Piute Range, California, the Eldorado Range, Nevada, and the McCullough Range, Nevada. The northern McCullough Range, located 20 miles south-southeast of Las Vegas, is an ideal place to study the petrogenesis of an andesite dominated system. This area contains a mid-Miocene stratocone composed mainly of a 1200 m thick section of andesite flows that formed synchronous with regional extension.

The northern McCullough …


Quantification Of Extraterrestrial Lava Flow Effusion Rates Through Laboratory Simulations, Tracy K.P. Gregg, Jonathan H. Fink Jul 1996

Quantification Of Extraterrestrial Lava Flow Effusion Rates Through Laboratory Simulations, Tracy K.P. Gregg, Jonathan H. Fink

Geology Faculty Publications and Presentations

We have used carefully controlled laboratory simulations to develop a model which relates lava flow morphology to effusion rate and rheology. Through comparisons with measured and estimated eruption rates on Earth, this approach allows us to constrain eruptive styles and compositions of extraterrestrial lava flows. By applying this model to lava flows on the Moon, Mars and Venus, we have determined that all the common flow morphologies (domes, folds and levees) on these planets could have been produced by basalt-like or andesite-like lavas through either continuous or episodic emplacement. The presence of more evolved magma compositions on other planets is …


Investigation Of Spatial Patterns Of Ground-Water Exchange With Lakes, Using A Three-Dimensional Numerical Model, Indranil Bandopadhyay Jul 1996

Investigation Of Spatial Patterns Of Ground-Water Exchange With Lakes, Using A Three-Dimensional Numerical Model, Indranil Bandopadhyay

FIU Electronic Theses and Dissertations

Hydrogeologic variables controlling groundwater exchange with inflow and flow-through lakes were simulated using a three-dimensional numerical model (MODFLOW) to investigate and quantify spatial patterns of lake bed seepage and hydraulic head distributions in the porous medium surrounding the lakes. Also, the total annual inflow and outflow were calculated as a percentage of lake volume for flow-through lake simulations. The general exponential decline of seepage rates with distance offshore was best demonstrated at lower anisotropy ratio (i.e., Kh/Kv = 1, 10), with increasing deviation from the exponential pattern as anisotropy was increased to 100 and 1000. 2-D vertical section models constructed …


Correlation Of The Upper Ellensburg Formation With The Old Scab Mountain Eruptive Center, East-Central Cascade Range, Washington, Christopher Charles Humphrey Jul 1996

Correlation Of The Upper Ellensburg Formation With The Old Scab Mountain Eruptive Center, East-Central Cascade Range, Washington, Christopher Charles Humphrey

Dissertations and Theses

The Ellensburg Formation, preserved in the Nile basin 50 km northwest of Yakima, Washington, consists of a series of middle to late Miocene epiclastic and pyroclastic rock assemblages rich in porphyritic hornblende-biotite dacite. Geochemical, petrographic, and stratigraphic correlations indicate that Old Scab Mountain, a dacite porphyry intrusion, located at the western margin of the basin (lat. 46°53'30", long. 121°13'00"), is the probable source for much of the upper Ellensburg volcaniclastic material in the basin. The dacite intrusion exposed at Old Scab Mountain was emplaced at depths of 1 to 3 km and underlaid a now eroded volcanic edifice. This volcanic …


Swath Mapping On The Continental Shelf And Slope: The Eel River Basin, Northern California, John A. Goff, Larry A. Mayer, John E. Hughes Clarke, Lincoln F. Pratson Jul 1996

Swath Mapping On The Continental Shelf And Slope: The Eel River Basin, Northern California, John A. Goff, Larry A. Mayer, John E. Hughes Clarke, Lincoln F. Pratson

Affiliate Scholarship

First Paragraph

The STRATAFORM program sponsored by the Office of Naval Research (Nittrouer and Kravitz, 1996, this issue) seeks to understand how sedimentary processes lead to the formation of the stratigraphic sequences on continental margins. A central challenge facing this effort is to understand the transport of sediments in shore-parallel as well as shore-perpendicular directions• Multidimensionality is necessary to describe, for example, the accumulation of sediments from river inputs, the distribution of gullies and canyons on the slope, the meandering of channels, and the structure of slumps and slides.


Marine Pore-Water Sulfate Profiles Indicate In Situ Methane Flux From Underlying Gas Hydrate, Walter S. Borowski, Charles K. Paull, William Ussler Iii Jul 1996

Marine Pore-Water Sulfate Profiles Indicate In Situ Methane Flux From Underlying Gas Hydrate, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Marine pore-water sulfate profiles measured in piston cores are used to estimate methane flux toward the sea floor and to detect anomalous methane gradients within sediments overlying a major gas hydrate deposit at the Carolina Rise and Blake Ridge (U.S. Atlantic continental margin). Here, sulfate gradients are linear, implying that sulfate depletion is driven by methane flux from below, rather than by the flux of sedimentary organic matter from above. Thus, these linear sulfate gradients can be used to quantify and assess in situ methane flux, which is a function of the methane inventory below.


Ua66/8/3 Annual Report, Wku Geography & Geology Jul 1996

Ua66/8/3 Annual Report, Wku Geography & Geology

WKU Archives Records

Annual report created by and about WKU Geography & Geology.


Comprehensive Conjunctive-Use Management Of Connected Surface Water Groundwater Systems Using Stochastic Inputs And Uncertainties, Seshadri Suryanarayana Jul 1996

Comprehensive Conjunctive-Use Management Of Connected Surface Water Groundwater Systems Using Stochastic Inputs And Uncertainties, Seshadri Suryanarayana

Civil & Environmental Engineering Theses & Dissertations

A comprehensive conjunctive-use management model is developed. The dynamics of flow and solute transport processes in connected surface water groundwater systems are integrated by a dual programming management model. The governing aquifer flow parameters and streamflows are treated as stochastic random processes. Multiple realizations of the random field are generated and are explicitly incorporated in a non-linear optimization model along with other system, environmental, and management constraints. To facilitate management of large aquifer systems, a linked simulation-optimization approach is used. The simulation program generates the response matrices for flow and transport processes. The management model then determines optimal well discharges …


Beach Response To Subsidence Following A Cascadia Subduction Zone Earthquake Along The Washington-Oregon Coast, Debra Lee Doyle Jun 1996

Beach Response To Subsidence Following A Cascadia Subduction Zone Earthquake Along The Washington-Oregon Coast, Debra Lee Doyle

Dissertations and Theses

Beach shoreline retreat induced by coseismic subsidence in the Cascadia subduction zone is an important post-earthquake hazard. Sand on a beach acts as a buffer to wave attack, protecting dunes, bluffs and terraces. The loss of sand from a beach could promote critical erosion of the shoreline. This study was initiated in order to estimate the potential amount of post subsidence shoreline retreat on a regional scale in the Central Cascadia Margin. The study area is a 331 km stretch of coastline from Copalis, Washington to Florence, Oregon. Several erosion models were evaluated, and the Bruun model was selected as …


Modeling Transport Of Colloid-Bound Herbicides And Heavy Metals To Groundwater, Anastasios D. Karathanasis, R. E. Phillips, A. K. Seta Jun 1996

Modeling Transport Of Colloid-Bound Herbicides And Heavy Metals To Groundwater, Anastasios D. Karathanasis, R. E. Phillips, A. K. Seta

KWRRI Research Reports

Recent studies have suggested that contaminant transport to groundwater may be enhanced by association with colloidal particles. This study evaluated the role of water dispersible colloids with diverse mineralogical composition in co-transporting selected herbicides and heavy metals through intact soil columns. Colloid recovery in the eluents ranged from 45-90% for the herbicides and 10-60% for the heavy metals. The presence of colloids enhanced the transport of atrazine by 2-18%, and metolachlor by 8-30%. The corresponding increase for Cu and Zn was 2-150 and 5-30 times, respectively. For Pb, there was essentially no elution in the absence of colloids, suggesting nearly …


Mapped Karst Ground-Water Basins In The Lexington 30 X 60 Minute Quadrangle, James C. Currens, Joseph A. Ray Jun 1996

Mapped Karst Ground-Water Basins In The Lexington 30 X 60 Minute Quadrangle, James C. Currens, Joseph A. Ray

Map and Chart--KGS

No abstract provided.


Wear Due To The Physical And Petrographic Properties Of Rocks And Their Dynamic Interactions With Mining Equipment, Christian Poppeliers May 1996

Wear Due To The Physical And Petrographic Properties Of Rocks And Their Dynamic Interactions With Mining Equipment, Christian Poppeliers

Dissertations and Theses

Wear to mining equipment reduces operational efficiency. If wear rates can be predicted, appropriate matching of alloys to the mine' s geologic conditions can aid in improving the operational efficiency. This study addresses rock characteristics which lead to wear. Macroscopic rock tools which lead to wear include sharp edges and comers on rocks. During a rock/equipment interaction, these rock tools cause high point pressures on the surface of the equipment which leads to ductile cutting and gouging of the surface and subsequent removal of metal. Hard mineral grains, or grain tools, produce abrasion as the grains move across equipment surfaces. …


Prolonged History Of Silicic Peralkaline Volcanism In The Eastern Pacific Ocean, Wendy A. Bohrson, Mary R. Reid, Anita L. Grunder, Matthew Heizler, T. Mark Harrison, Jeffrey Lee May 1996

Prolonged History Of Silicic Peralkaline Volcanism In The Eastern Pacific Ocean, Wendy A. Bohrson, Mary R. Reid, Anita L. Grunder, Matthew Heizler, T. Mark Harrison, Jeffrey Lee

All Faculty Scholarship for the College of the Sciences

Socorro Island, Mexico, is an alkaline and peralkaline volcanic island located in the eastern Pacific Ocean on a mid-ocean ridge spreading center that was abandoned at ∼3.5 Ma. Silicic peralkaline rocks comprise up to 80% of the surface of the island, rendering Socorro virtually unique in the Pacific Ocean. Precise, replicate 40Ar/39Ar ages of 21 peralkaline trachytes and rhyolites reveal a history of episodic volcanic activity from ∼540 to 370 ka that may have culminated with caldera formation; repose periods between these episodes may have had maximum duration of ∼30 kyr. After up to 200 kyr of …


Remote Sensing Of Volcanic Ash Clouds Using Special Sensor Microwave Imager Data, David J. Delene, William I. Rose, Norman C. Grody May 1996

Remote Sensing Of Volcanic Ash Clouds Using Special Sensor Microwave Imager Data, David J. Delene, William I. Rose, Norman C. Grody

Department of Geological and Mining Engineering and Sciences Publications

Measurements from the satellite-based special sensor microwave imager (SSM/I) were used to collect passive microwave radiation (19–85 GHz) for the August 19, 1992 (UT date), Crater Peak/Spurr volcanic cloud. This eruption was also imaged by a ground-based C-band radar system at Kenai, Alaska, 80 km away, and by the thermal infrared channels of the polar-orbiting advanced very high resolution radiometer (AVHRR). The SSM/I sensor detects scattering of Earth-emitted radiation by millimeter size volcanic ash particles. The size of ash particles in a volcanic ash cloud can be estimated by comparing the scattering at different microwave frequencies. The mass of particles …


Aminostratigraphy Of Thatcher Basin, Se Idaho: Reassessment Of Pleistocene Lakes, Amy Hochberg May 1996

Aminostratigraphy Of Thatcher Basin, Se Idaho: Reassessment Of Pleistocene Lakes, Amy Hochberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Quaternary geologic history of Lake Thatcher, southeastern Idaho, is pivotal in determining when the Bear River carved its through-flowing channel into the Bonneville Basin. Bright's reconstruction of the history of Lake Thatcher was based on 14C dates that are now known to be inaccurate. Lava Creek B ash found interbedded with lacustrine sediment suggests that Thatcher Basin contained a lake well before Bright's original estimate of 34 ka.

D/L ratios, which measure the extent of racemization in fossil gastropods, in conjunction with paleosols and tephra, were used to correlate between four localities across Thatcher Basin to reassess lake-level …