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Full-Text Articles in Physical Sciences and Mathematics

Biogeography And The Cambrian Radiation Of Arachnomorph Arthropods, Jonathan R. Hendricks, Bruce S. Lieberman Jan 2007

Biogeography And The Cambrian Radiation Of Arachnomorph Arthropods, Jonathan R. Hendricks, Bruce S. Lieberman

Jonathan R. Hendricks

Biogeographic patterns in primarily Cambrian arachnomorph taxa are investigated using a recently constructed phylogenetic hypothesis in order to explore the biogeographic context of the Cambrian radiation. A modified version of Brooks Parsimony Analysis is employed to elucidate patterns of vicariance and geodispersal in taxa from six regions (Laurentia, Baltica, Siberia, Australia, Africa and China). Well resolved vicariance and geodispersal trees are very similar and reconstruct Laurentia and China as sister areas. This close area relationship between Laurentia and China provides extensive evidence for congruent vicariance and range expansion in Cambrian arachnomorphs, while data from trilobites do not show this pattern. …


Architecture Of Air-Filled Caves Within The Karst Of The Brooksville Ridge, West-Central Florida, Lee J. Florea Aug 2006

Architecture Of Air-Filled Caves Within The Karst Of The Brooksville Ridge, West-Central Florida, Lee J. Florea

Lee J Florea, PhD, P.G.

Air-filled caves surveyed in the Brooksville Ridge of west-central Florida provide insight into the organization of karstic permeability within the unconfined portions of the Upper Floridan Aquifer. The morphology of the passages that compose these caves in geologically young, high-permeability limestones is strikingly different from caves found in ancient carbonates far from the influence of the coast. Cave passages in west-central Florida are laterally extensive and tiered. Principal horizons of cave development occur between +3 m and +5 m, +12 m and +15 m, and +20 m and +22 m above modern sea level. The primary guide of cave passage …


Morphologic Features Of Conduits And Aquifer Response In The Unconfined Floridan Aquifer System, West Central Florida, Lee J. Florea, H L. Vacher Jun 2006

Morphologic Features Of Conduits And Aquifer Response In The Unconfined Floridan Aquifer System, West Central Florida, Lee J. Florea, H L. Vacher

Lee J Florea, PhD, P.G.

Conduits within the unconfined Floridan Aquifer of west-central Florida include both horizontal and vertical components. In this paper, we investigate each and propose theories based upon cave survey data and a collection of over 300 Florida cave maps. First, we find that vertical portions of conduits visually correlate to fractures, and these fractures tend to be the dominant control of conduit directionality. Length-weighted rose diagrams of passage directions reveal a NW-SE and NE-SW pattern of conduit directions statistically similar to results found in remote sensing studies of photolinears. Secondly we note that horizontal elements of conduits occur at consistent horizons …


Le Voragini Catastrofiche Della Florida, Lee J. Florea, Robert Brooks, Tom Turner, Mario Parise Jan 2006

Le Voragini Catastrofiche Della Florida, Lee J. Florea, Robert Brooks, Tom Turner, Mario Parise

Lee J Florea, PhD, P.G.

The West-Central Florida landscape is worlds away from white-sand beaches and palm trees: gentle rolling hills, dense jungle-like forests, pine tree and palmetto scrub lands, impenetrable cypress swamps, and alligator-laden rivers. Numerous crystal-clear springs offer a glimpse of the hidden world below these wildly-diverse ecosystems. Internationally recognized in the cave diving community, Florida harbors some of the longest and most spectacular underwater cave systems. Lesser known are Florida’s “dry” caves, that rarely have large natural openings and, though often smaller than their aquatic counterparts, the beauty found within can rival the world’s best show-caves. Little was known about caves and …


Community Education In Karst At The Geological Alumni Society Geopark, University Of South Florida, Beth Fratesi, Lee J. Florea Jan 2006

Community Education In Karst At The Geological Alumni Society Geopark, University Of South Florida, Beth Fratesi, Lee J. Florea

Lee J Florea, PhD, P.G.

No abstract provided.


Cave Levels, Marine Terraces, Paleoshorelines, And The Water Table In Peninsular Florida, Lee J. Florea, H L. Vacher Jan 2006

Cave Levels, Marine Terraces, Paleoshorelines, And The Water Table In Peninsular Florida, Lee J. Florea, H L. Vacher

Lee J Florea, PhD, P.G.

Levels of passages are a common feature of many cave systems around the world. Likewise, coastal and marine terraces are common in coastal plain settings. This paper extends the discussion of cave levels from traditional research sites in the interior lowlands of the United States to the Atlantic Coastal Plains, namely peninsular Florida. Are there levels in Florida caves, and is there a link between the elevation of cave levels, marine terraces, paleoshorelines, and thus the water table, above and below present sea level in peninsular Florida?


Refine Slip Rates And Segmentation Of The Northern Sangre De Cristo Fault, Colorado’S Largest Active Fault, James P. Mccalpin Jan 2006

Refine Slip Rates And Segmentation Of The Northern Sangre De Cristo Fault, Colorado’S Largest Active Fault, James P. Mccalpin

James P. McCalpin

We excavated a 25 m-long trench on the northern part of the Crestone section of the Northern Sangre de Cristo fault zone, to see whether the Crestone section might be composed of more than one (independent) rupture segments. The Carr Gulch trench exposed evidence for 3 paleoearthquake displacements in the past 27.4 ka. The existence of 3 colluvial deposits (units 2, 3, 4) indicates that the ca. 4.5 m of surface offset was formed during 3 surface-faulting events with an average displacement of about 1.5 m each. The events occurred at about 8 ka, 20 ka, and between 22.5 and …


Using State-Wide Gis Data To Identify The Coincidence Betwen Sinkholes And Geologic Structure, Lee J. Florea Aug 2005

Using State-Wide Gis Data To Identify The Coincidence Betwen Sinkholes And Geologic Structure, Lee J. Florea

Lee J Florea, PhD, P.G.

The Kentucky GIS coverage of sinkholes, completed in 2003, consists of 101,176 polygons representing the uppermost closed contour of every karst sinkhole identified using USGS 1:24,000 scale topographic maps. This resource is a useful tool for delineating karst landscapes in Kentucky because karstified limestones underlie 55% of the areal surface of the state. For hydrologic studies, alignments of sinkholes commonly indicate preferential flowpaths for groundwater; and this information aids in large-scale planning and zoning. In this paper, I demonstrate the effectiveness of using this sinkhole coverage as a tool for delimiting structural features of Kentucky.


The 2004 Vaca Pateau Geoarcheology Expedition - Belize, Lee J. Florea, Beth Fratesi, Philip Reeder, Amber Yuellig Jul 2005

The 2004 Vaca Pateau Geoarcheology Expedition - Belize, Lee J. Florea, Beth Fratesi, Philip Reeder, Amber Yuellig

Lee J Florea, PhD, P.G.

No abstract provided.


Karst Of Western Cuba: Observations, Geomorphology, And Diagenesis, Larry D. Seale, Limaris R. Soto, Lee J. Florea, Beth Fratesi Jun 2004

Karst Of Western Cuba: Observations, Geomorphology, And Diagenesis, Larry D. Seale, Limaris R. Soto, Lee J. Florea, Beth Fratesi

Lee J Florea, PhD, P.G.

In Cuba, we observed many karst features in a variety of hydrogeologic settings. These hy-drogeologic settings occur in close proximity only because of the complex tectonic history of the is-land. We observed caves within rocks ranging from Pleistocene to Jurassic, and representing a range of diagenetic ages from eogenetic to teloge-netic. Our observations are from the western one-third of the island of Cuba; however, we believe they are representative of hydrogeologic settings found throughout the island.


Light & Dark: The Hidden Wonders Of Buck Creek, Lee J. Florea Jan 2004

Light & Dark: The Hidden Wonders Of Buck Creek, Lee J. Florea

Lee J Florea, PhD, P.G.

As early morning mists rise from the banks of its supple waters, beams of light penetrate the Buck Creek valley illuminating its beauty. While light illuminates most of the land, there are secret places, nestled within the forest where darkness reigns supreme. Places beyond the touch of the sun, beyond the influence of seasons. Here time is measured not in cycles of light but by the flow of water and fall of rock. These are the caves, conduits for water past and present. Nestled in the hills of south-central Kentucky the caves along Buck Creek provide the lifeblood for a …


Sedimentation And Porosity Enhancement In A Breached Flank Margin Cave, Lee J. Florea, John Mylroie, Adam Price Jan 2004

Sedimentation And Porosity Enhancement In A Breached Flank Margin Cave, Lee J. Florea, John Mylroie, Adam Price

Lee J Florea, PhD, P.G.

No abstract provided.


Karst Gis Advances In Kentucky, Lee J. Florea, Randall L. Paylor, Larry Simpson, Jason Gulley Apr 2002

Karst Gis Advances In Kentucky, Lee J. Florea, Randall L. Paylor, Larry Simpson, Jason Gulley

Lee J Florea, PhD, P.G.

Little statewide geospatial data was available for Kentucky caves and karst in the past. Recent trends in land development have prompted a distinct need for these data in order to help minimize impact to cave and karst resources. During the past two years, the I-66 Special Project of the National Speleological Society, The Kentucky Speleological Survey, and the Kentucky Geological Survey have gathered, archived, and developed karst data for the state. Current projects include publication of karst basin maps, archiving cave entrance locations, archiving and georeferencing cave maps, creating polygon coverages of cave conduits, and a statewide sinkhole digitization project. …


Detection Of Iapetan Rifting (Rome Trough Tectonism) By Quaternary Karstification: Pulaski County, Kentucky, Lee J. Florea Jan 2002

Detection Of Iapetan Rifting (Rome Trough Tectonism) By Quaternary Karstification: Pulaski County, Kentucky, Lee J. Florea

Lee J Florea, PhD, P.G.

No abstract provided.


Solute Transport Through Laboratory-Scale Karstic Aquifers, Lee J. Florea, Carol M. Wicks Apr 2001

Solute Transport Through Laboratory-Scale Karstic Aquifers, Lee J. Florea, Carol M. Wicks

Lee J Florea, PhD, P.G.

Laboratory-scale models of branchwork and of network karstic aquifers were constructed to provide data needed for calibration of numerical models. The distribution and connectedness of the conduits and sinkholes were scaled similarly to those found in nature; however, the porosity of models (2 and 3%) and the recharge rate (80 cm/hr) could not be scaled appropriately. Pulses of 1-M NaCl were injected sequentially at ten locations on both models to determine transport parameters using QTRACER. For all experiments, the Reynolds numbers were <150, the Peclet numbers were >6, and the Froude numbers were ~0. The flow regime was laminar and subcritical and advective processes dominated …


Long Recurrence Records From The Wasatch Fault Zone, Utah, James P. Mccalpin Jan 2001

Long Recurrence Records From The Wasatch Fault Zone, Utah, James P. Mccalpin

James P. McCalpin

The Wasatch fault "megatrench" was excavated in September 1999 across two fault scarps totaling 18 meters high on the Salt Lake City segment of the Wasatch fault zone (WFZ). The purpose of the megatrench was to date a long series of consecutive earthquakes (8-12 events?) on the WFZ and measure the variability of recurrence times between the events.This variability could then be used in calculating the future probability of large earthquakes on the WFZ. The trench was located 1 km north of the mouth of Little Cottonwood Canyon, at an elevation of 1525 m, between the Bonneville highstand (ca. 17.5 …


Paleoseismicity Of Quaternary Faults Near Albuquerque, New Mexico: The Zia Fault, James P. Mccalpin Jan 2001

Paleoseismicity Of Quaternary Faults Near Albuquerque, New Mexico: The Zia Fault, James P. Mccalpin

James P. McCalpin

This study continues USGS-funded efforts to assess the activity and earthquake hazard potential of Quaternary faults in the Albuquerque metropolitan region. Our target in 2000 was the Zia fault, a 37 km-long normal fault that trends N-S in northern Llano de Albuquerque (LdA). The Zia fault is one of three major east-dipping normal faults that define the western margin of the Rio Grande rift in the northern Albuquerque basin, the other faults being the Calabacillas fault (to the west of the Zia fault) and the County Dump fault (to the east of the Zia fault) (Machette et al., 1998). In …


Ridgetop Splitting, Spreading, And Shattering Related To Earthquakes In Southern California, James P. Mccalpin Jan 1998

Ridgetop Splitting, Spreading, And Shattering Related To Earthquakes In Southern California, James P. Mccalpin

James P. McCalpin

Our mapping documents that anomalous ridgetop landforms are numerous in the San Gabriel and Santa Susana Mountains, and that many sites (37% of the San Gabriel sites, 16% of the Santa Susana sites) are not associated with any visible signs of landsliding. These sites may represent deep-seated gravitational spreading due to earthquake shaking. However, our factor analysis indicates that the spatial distribution of these suspected spreading landforms, with respect to ridge relief and distance to Late Quaternary faults, is essentially identical to that of landslides. Thus, it seems that if these spreading landforms represent the results of earthquake shaking, than …


Statistics Of Paleoseismic Data, James P. Mccalpin Jan 1998

Statistics Of Paleoseismic Data, James P. Mccalpin

James P. McCalpin

Compiled data from numerous neotectonic-geomorphic and trench studies reveals patterns in the spatial and temporal variation of coseismic fault displacement. Recurrence intervals between successive large earthquakes on faults define a near-symmetrical probability distribution with a coefficient of variance of 0.36. Normal faults have the most regular recurrence, and subduction zones the most variable. Variability in recurrence times at a site is not dependent on the number of recurrence intervals dated at that site. During historic surface-rupturing earthquakes slip has varied widely along strike. Based on 56 ruptures where more than 15 displacement measurements were made, the generic pattern is for …


Evaluation Of Chloride And Pesticide Transport In A Fractured Clayey Till Using Large Undisturbed Columns And Numerical Modeling, Peter R. Jorgensen, Larry Mckay, Niels H. Spliid Jan 1998

Evaluation Of Chloride And Pesticide Transport In A Fractured Clayey Till Using Large Undisturbed Columns And Numerical Modeling, Peter R. Jorgensen, Larry Mckay, Niels H. Spliid

Larry McKay

Saturated groundwater flow and tracer experiments using fluorescent dye, chloride, and the herbicides mecoprop and simazine were carried out in the laboratory using three large-diameter (0.5 m) undisturbed columns of fractured clayey till. Hydraulic conductivity of the columns ranged from 10−5 m/s in the shallowest column (1 m dept)) to 10−7 m/s in the deepest column (4 m depth) and were similar to field-measured values for these deposits. Results of the tracer experiments are consistent with a conceptual model of advective transport along the fractures combined with diffusion into the fine-grained matrix between the fractures. Arrival of the chloride tracer …


Field Experiments In A Fractured Clay Till: 2. Solute And Colloid Transport, Larry Mckay, Robert W. Gillham, John A. Cherry Jan 1993

Field Experiments In A Fractured Clay Till: 2. Solute And Colloid Transport, Larry Mckay, Robert W. Gillham, John A. Cherry

Larry McKay

A field tracer experiment was conducted in a lateral flow field in the weathered and highly fractured upper 6 m of a 40-m-thick clay-rich till plain in southwestern Ontario. In the upper 3 m where fractures are closely spaced (<0.13 m) the advancing front (C/C0 = 0.01) of the nonreactive solute tracers, bromide and 18O, migrated at rates of 0.01 to 0.07 m/d, over distances of 4 and 6 m and under a lateral hydraulic gradient of 0.24. In this same zone, two strains of colloid-sized bacteriophage tracers migrated at rates of 2 to >5 m/d. Simulations with a discrete fracture/porous matrix flow and transport model, which used the cubic law for flow in fractures, showed that diffusion of the solutes, but not the much larger colloids, into the matrix pore water between fractures is sufficient to cause the observed difference in solute and colloid transport rates. Transport-derived and hydraulic conductivity-derived fracture aperture values …


Field Experiments In A Fractured Clay Till: 1. Hydraulic Conductivity And Fracture Aperture, Larry Mckay, John A. Cherry, Robert W. Gillham Jan 1993

Field Experiments In A Fractured Clay Till: 1. Hydraulic Conductivity And Fracture Aperture, Larry Mckay, John A. Cherry, Robert W. Gillham

Larry McKay

Field values of horizontal hydraulic conductivity measured in the upper 1.5–5.5 m of a weathered and fractured clay-rich till were strongly influenced by smearing around piezometer intakes, which occurs during augering, and by the physical scale of the measuring device. Values measured in conventional augered piezometers were typically 1–2 orders of magnitude lower than those measured in piezometers designed to reduce smearing. Measurements of hydraulic conductivity in small-scale seepage collectors or piezometers, which typically intersect fewer than 10 fractures, vary over a much greater range, 10−10 to 10−6 m/s, than large-scale values based on infiltration into 5.5-m-deep trenches which intersect …


Surficial Geologic Map Of The East Cache Fault Zone, Cache County, Utah, James P. Mccalpin Jan 1989

Surficial Geologic Map Of The East Cache Fault Zone, Cache County, Utah, James P. Mccalpin

James P. McCalpin

The 1:50,000-scale map shows surficial geologic deposits and the faults that displace them along the East Cache fault zone in northern Utah. The East Cache fault is a north-trending normal fault that extends about 77 km along the eastern side of Cache Valley (an east-tilted graben) at the base of the Bear River Range. The map includes a description of Quaternary deposits along the fault zone, a description of the fault segments, and estimates of the age, size, and distribution of fault scarps in the fault zone.


Spatial And Temporal Analysis Of 1200 Landslides In A 900km2 Area, Middle Rocky Mountains, Wyoming, U.S.A., James P. Mccalpin Jan 1987

Spatial And Temporal Analysis Of 1200 Landslides In A 900km2 Area, Middle Rocky Mountains, Wyoming, U.S.A., James P. Mccalpin

James P. McCalpin

An inventory of approximately 1200 landslides in a 900 km2 area in the Salt River Range, western Wyoming, U.S.A., reveals regional and temporal controls on the landsliding process. Sliding is strongly controlled by eight weak formations in the 21 stratigraphic units of Cambrian through Cretaceous age. Morphologic dating of slides suggests that rockslides, slump-flows, and debris flows have occurred rather uniformly in time within the Holocene. In contrast, earthflows seem to be triggered more by cool/wet climatic epicycles in the last 5,000 years.


Field Trip Roadlog For The Bear River Landslide Complex, James P. Mccalpin Jan 1987

Field Trip Roadlog For The Bear River Landslide Complex, James P. Mccalpin

James P. McCalpin

The Bear River Landslide Complex occurs where the unconsolidated sediments of the Bear River Delta have been incised to a depth of 350 to 490 feet (106-150 m) north of Preston, Idaho. The slides are the result of the high pore pressure in confined aquifers in the deltaic sediments. High but variable volumes of groundwater flow and the laterally discontinuous nature of the deltaic sediments result in the varied types of earth movements found within the Landslide Complex. Landslide activity occurs during years of above average precipitation, and has been exacerbated by increased recharge from reservoirs and irrigation canals constructed …


Recommended Setback Distances From Active Normal Faults, James P. Mccalpin Jan 1987

Recommended Setback Distances From Active Normal Faults, James P. Mccalpin

James P. McCalpin

The geometry of near-surface ground breakage was analyzed from 40 trenches across Quaternary normal faults to help define reasonable setback distances. From each of the trench logs (28 on the Wasatch Fault, 11 on other Great Basin faults) eight parameters characteristic of surface rupture style were measured. Parameters included: 1) position of the main fault in relation to scarp morphology. 2) dip of the main fault. 3) number of faults on the upthrown block, 4) width of the upthrown block fault zone. 5) number of faults in the downthrown block. 6) width of the downthrown deformation zone, 7) ratio of …


The Bear River Landslide Complex, Preston, Idaho: Geologic Considerations And Historical Perspectives, James P. Mccalpin Jan 1987

The Bear River Landslide Complex, Preston, Idaho: Geologic Considerations And Historical Perspectives, James P. Mccalpin

James P. McCalpin

The Bear River Landslide Complex is a series of earth movements in northern Cache Valley, north of Preston, Idaho. The landslides occur in unconsolidated sediments of the Pleistocene Bear River Delta which formed where the river entered Lakes Bonneville and Provo. The Lake Bonneville delta deposits are up to 490 feet (150 m) thick and consist of a lower alluvial coarse sand and gravel unit, a middle delta front fine sand and silt unit, and an upper pro-delta clay up to 50 feet (15 m) thick. The interbedded character of the fine sands, silts, and clays, together with abrupt lateral …


Thermoluminescence (Tl) Dating In Seismic Hazard Evaluations: An Example From The Bonneville Basin, Utah, James P. Mccalpin Jan 1986

Thermoluminescence (Tl) Dating In Seismic Hazard Evaluations: An Example From The Bonneville Basin, Utah, James P. Mccalpin

James P. McCalpin

Thermoluminescence (TL) of minerals is the release of light when grains are heated to 1500 -5000 C. As sediments are buried longer they progressively acquire more TL from accumulated radiation damage from alpha, beta, and gamma rays and cosmic radiation. If the total amount of radiation dose received can be calculated, and the current dose rate measured, then dividing the total dose by the yearly dose rate will yield a TL age. Total doses are calculated by heating the sample until all TL is released, then re-irradiating the sample in the lab with known doses until the natural TL is …


Preliminary Age Classification Of Landslides For Inventory Mapping, James P. Mccalpin Jan 1984

Preliminary Age Classification Of Landslides For Inventory Mapping, James P. Mccalpin

James P. McCalpin

A preliminary age classification for landslides is proposed for inventory mapping, based on morphologic criteria visible on aerial photographs. Because landslide scars and deposits are generally disequilibrium landforms, they progress through observable morphologic stages as they age. Four age classes are distinguished: 1) active; 2) inactive-young; 3) inactive-mature; 4) inactive-old. Each age class reflects the age of latest movement only. The morphologic "freshness" of each part of the landslide must be evaluated, including: the head scarp, lateral scarps, marginal drainage, internal scarps and blocks, internal drainage pattern, vegetation type and density, and toe morphology. Morphologic parameters defined from air photos …