Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 47251 - 47280 of 59547

Full-Text Articles in Entire DC Network

Ancient Dna Analyses Exclude Humans As The Driving Force Behind Late Pleistocene Musk Ox (Ovibos Moschatus) Population Dynamics, Paula F. Campos, Eske Willerslev, Andrei Sher, Ludovic Orlando, Erik Axelsson, Alexei Tikhonov, Kim Aaris-Sorensen, Alex D. Greenwood, Ralf-Dietrich Kahlke, Pavel Kosintsev Jan 2010

Ancient Dna Analyses Exclude Humans As The Driving Force Behind Late Pleistocene Musk Ox (Ovibos Moschatus) Population Dynamics, Paula F. Campos, Eske Willerslev, Andrei Sher, Ludovic Orlando, Erik Axelsson, Alexei Tikhonov, Kim Aaris-Sorensen, Alex D. Greenwood, Ralf-Dietrich Kahlke, Pavel Kosintsev

Biological Sciences Faculty Publications

The causes of the late Pleistocene megafaunal extinctions are poorly understood. Different lines of evidence point to climate change, the arrival of humans, or a combination of these events as the trigger. Although many species went extinct, others, such as caribou and bison, survived to the present. The musk ox has an intermediate story: relatively abundant during the Pleistocene, it is now restricted to Greenland and the Arctic Archipelago. In this study, we use ancient DNA sequences, temporally unbiased summary statistics, and Bayesian analytical techniques to infer musk ox population dynamics throughout the late Pleistocene and Holocene. Our results reveal …

Go to article

Simulating Dioxane Transport In A Heterogeneous Glacial Aquifer System (Washtenaw County, Michigan) Using Publicly Available Models And Data, Rungroj Benjakul Jan 2010

Simulating Dioxane Transport In A Heterogeneous Glacial Aquifer System (Washtenaw County, Michigan) Using Publicly Available Models And Data, Rungroj Benjakul

Dissertations, Master's Theses and Master's Reports - Open

The primary challenge in groundwater and contaminant transport modeling is obtaining the data needed for constructing, calibrating and testing the models. Large amounts of data are necessary for describing the hydrostratigraphy in areas with complex geology. Increasingly states are making spatial data available that can be used for input to groundwater flow models. The appropriateness of this data for large-scale flow systems has not been tested. This study focuses on modeling a plume of 1,4-dioxane in a heterogeneous aquifer system in Scio Township, Washtenaw County, Michigan. The analysis consisted of: (1) characterization of hydrogeology of the area and construction of …

Go to article

Differential Gps As A Monitoring Tool On Volcano Santa Ana (Illamatepec) And The Coatepeque Caldera, El Salvador, Hans N. Lechner Jan 2010

Differential Gps As A Monitoring Tool On Volcano Santa Ana (Illamatepec) And The Coatepeque Caldera, El Salvador, Hans N. Lechner

Dissertations, Master's Theses and Master's Reports - Open

We used differential GPS measurements from a 13 station GPS network spanning the Santa Ana Volcano and Coatepeque Caldera to characterize the inter-eruptive activity and tectonic movements near these two active and potentially hazardous features. Caldera-forming events occurred from 70-40 ka and at Santa Ana/Izalco volcanoes eruptive activity occurred as recently as 2005. Twelve differential stations were surveyed for 1 to 2 hours on a monthly basis from February through September 2009 and tied to a centrally located continuous GPS station, which serves as the reference site for this volcanic network. Repeatabilities of the averages from 20-minute sessions taken over …

Go to article

La Yeguada Volcanic Complex, Western Panama : An Assessment Of The Geologic Hazards Using New 40Ar/39Ar Ages, Karinne L. Knutsen Jan 2010

La Yeguada Volcanic Complex, Western Panama : An Assessment Of The Geologic Hazards Using New 40Ar/39Ar Ages, Karinne L. Knutsen

Dissertations, Master's Theses and Master's Reports - Open

La Yeguada volcanic complex is one of three Quaternary volcanic centers in Panama, and is located on the southern slope of the Cordillera Central mountain range in western Panama, province of Veraguas. To assess potential geologic hazards, this study focused on the main dome complex near the village of La Laguna and also examined a cinder cone 10 km to the northwest next to the village of Media Luna. Based on newly obtained 40Ar/39Ar ages, the most recent eruption occurred approximately 32 000 years ago at the Media Luna cinder cone, while the youngest dated eruption at …

Go to article

Measurements And Predictions Of Subsidence Induced By Soil Consolidation Using Persistent Scatterer Insar And A Hyperbolic Model, Sang-Wan Kim, Shimon Wdowinski, Timothy H. Dixon, Falk Amelung, Jeong W. Kim, Joong-Sun Won Jan 2010

Measurements And Predictions Of Subsidence Induced By Soil Consolidation Using Persistent Scatterer Insar And A Hyperbolic Model, Sang-Wan Kim, Shimon Wdowinski, Timothy H. Dixon, Falk Amelung, Jeong W. Kim, Joong-Sun Won

School of Geosciences Faculty and Staff Publications

A space-borne SAR interferometric technique is presented for measuring and predicting ground subsidence associated with soil consolidation. Instead of a conventional constant velocity model, a hyperbolic model is introduced for persistent scatterer SAR interferometry (PSI) processing. Twenty three JERS-1 SAR acquired between 1992 and 1998 were used to measure land subsidence in Mokpo city, Korea which had been primarily built on land reclaimed from the sea. Two subsidence field maps were derived and compared: a constant velocity model and a hyperbolic model. Non-linear components depending on the stage of soil consolidation are well represented by the hyperbolic model. The maximum …

Go to article

Seismic Interpretation And Reservoir Characterization Of The Middle Frio Formation In The Stratton Field Gulf Coast Basin Of South Texas Using Three-Dimensional Seismic And Well Log Data, Uchenna H. Aboaja Jan 2010

Seismic Interpretation And Reservoir Characterization Of The Middle Frio Formation In The Stratton Field Gulf Coast Basin Of South Texas Using Three-Dimensional Seismic And Well Log Data, Uchenna H. Aboaja

Masters Theses

"The Stratton field is a large mature gas field located between Nueces County and Kleberg County in the northwest Gulf Coast Basin of south Texas. The Oligocene middle Frio Formation is one of the major progradational units within the Stratton field. It is characterized by rapid deposition and high subsidence rates that create complex internal facies architecture. The reservoir facies architecture of the middle Frio Formation is described as channel-fill deposits, crevasses-splay deposits, and floodplain mudstones. Previous two-dimensional seismic studies indicate some level of compartmentalization. Three-dimensional seismic and well log data provided by the Bureau of Economic Geology at the …

Go to article

Cretaceous/Paleogene Boundary Biostratigraphy And Palynofacies Of The Alo-1 Well, Southeastern Nigeria, Janet Diane Raymer Jan 2010

Cretaceous/Paleogene Boundary Biostratigraphy And Palynofacies Of The Alo-1 Well, Southeastern Nigeria, Janet Diane Raymer

Masters Theses

"The Cretaceous/Paleogene boundary (K/Pg) has been studied in great detail because of the fascination most people have with the extinction of the dinosaurs. The response of the vegetation to this extinction event has been studied in detail in mid to high latitudes, but little is known about what happened in the tropics. Sixty-seven samples from the Nsukka and Imo formations in the Alo-1 well in the Anambra Basin, southeastern Nigeria have been studied for their palynological contents. The aims of the study was to use spores, pollen and dispersed organic matter components to interpret biostratigraphy, and evaluate depositional conditions across …

Go to article

Calcium Carbonate Precipitation Mechanisms And Geochemical Analysis Of Particulate Material Found Within The Waters Of Maramec Spring, St. James, Missouri, Kyle Steven Rybacki Jan 2010

Calcium Carbonate Precipitation Mechanisms And Geochemical Analysis Of Particulate Material Found Within The Waters Of Maramec Spring, St. James, Missouri, Kyle Steven Rybacki

Masters Theses

"The purpose of the present study is to determine whether a mineral phase is precipitating from solution in the natural Maramec Spring system giving the spring water a milky blue color, to identify the mineral phase, and to investigate potential mechanisms for inducing precipitation. Maramec Spring is a first-order magnitude spring located 11 km southeast of St. James, Missouri. The water that expels from Maramec Spring varies between being near saturation, but undersaturated in calcium, with respect to calcite (saturation index of 0.994 mg/L). Moving downstream, away from the conduit, the spring waters increase in pH and temperature. Eh is …

Go to article

Bagc.M: Three Dimensional Gravity Modeling Software With An Application In Death Valley, Ca, Brian Eugene Eslick Jan 2010

Bagc.M: Three Dimensional Gravity Modeling Software With An Application In Death Valley, Ca, Brian Eugene Eslick

Open Access Theses & Dissertations

Basin Anomaly Gravity Calculator (BAGC.m) is a 3D interactive gravity modeling package designed to create, edit, and calculate the gravitational attraction of basin models entirely within the MATLABTM environment. Gravity anomalies are calculated using the Rectangular Prism Method (Bott, 1960; Kane, 1962; and Plouff, 1966) which subdivides earth models into regularly spaced rectangular prisms. This approach requires large 3D matrices to store most realistic earth models. The process of model editing is simplified by storing basins as 2D gridded files which define the depth to the boundary between basement rock and sedimentary fill for each model cell. In order to …

Go to article

Studies Of Earthquakes Stress Drops, Seismic Scattering, And Dynamic Triggering In North America, Christian Rene Escudero Ayala Jan 2010

Studies Of Earthquakes Stress Drops, Seismic Scattering, And Dynamic Triggering In North America, Christian Rene Escudero Ayala

Open Access Theses & Dissertations

I use the Relative Source Time Function (RSTF) method to determine the source properties of earthquakes within southeastern Alaska-northwestern Canada in a first part of the project, and earthquakes within the Denali fault in a second part. I deconvolve a small event P-arrival signal from a larger event by the following method: select arrivals with a tapered cosine window, fast fourier transform to obtain the spectrum, apply water level deconvolution technique, and bandpass filter before inverse transforming the result to obtain the RSTF. I compare the source processes of earthquakes within the area to determine stress drop differences to determine …

Go to article

Investigations Of Grade Control, Macarthur Mine, Yerington, Nevada: An Oxidized Porphyry Copper System, Joseph Daniel Louis Lori Jan 2010

Investigations Of Grade Control, Macarthur Mine, Yerington, Nevada: An Oxidized Porphyry Copper System, Joseph Daniel Louis Lori

Open Access Theses & Dissertations

Supergene enriched, low-grade oxidized porphyry copper deposits are of great economic value. Oxidized porphyry sections are economic targets because even low-grade prospects have the potential to produce low-cost copper in an environmentally friendly fashion due to easy leachability and high recovery rates of the oxide mineralization. The MacArthur Mine, in the historic Yerington mining district of Nevada, is the focus of this study. The MacArthur is a tilted oxidized porphyry deposit, partially mined by open pit methods, hosted in the Jurassic Bear Quartz Monzonite of the Yerington batholith. The objective of the study is to define controls of copper oxide …

Go to article

Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete Jan 2010

Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete

Open Access Theses & Dissertations

Copper isotopes may prove to be a useful tool for investigating bacteria-metal interactions recorded in natural waters, soils, and rocks. However, experimental data that constrain Cu isotope fractionation in biologic systems are limited and unclear. In this study we utilized Cu isotopes (65Cu) as a tool to investigate Cu-bacteria interactions, including surface adsorption and intracellular incorporation. Experiments were conducted with individual Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial species as well as with bacterial consortia from several natural environments. Adsorption experiments were conducted with live or dead cells over the pH range 2.5 to 6. Surface adsorption of Cu …

Go to article

Seismic Investigation Of The Southern Rio Grande Rift, Lennox Emmanuel Thompson Jan 2010

Seismic Investigation Of The Southern Rio Grande Rift, Lennox Emmanuel Thompson

Open Access Theses & Dissertations

Competing models exist to explain what caused the Earth's crust to spread apart 29 million years ago to create a region known today as the Rio Grande Rift (RGR). The RGR extends from central Colorado through New Mexico to northern Mexico, near El Paso. The RGR has different geologic features that distinguish it from most other valleys (e.g., the RGR was not cut by a river nor does a river branch upstream). A growing body of evidence shows that geologic activity still occurs in the RGR, with a continuation of faulting, seismicity and widening at a small rate of about …

Go to article

Preliminary Archaeological Investigations At The Sierra Diablo Cave Site: Paleoindian And Archaic Occupations In Hudspeth County, Texas, Jose Javier Vasquez Jan 2010

Preliminary Archaeological Investigations At The Sierra Diablo Cave Site: Paleoindian And Archaic Occupations In Hudspeth County, Texas, Jose Javier Vasquez

Open Access Theses & Dissertations

It is generally rare to find archaeological sites in the Southwest that retain the type of contextual integrity that the Sierra Diablo Cave exhibits. Often times, cave sites such as the one currently studied offer excellent preservation of cultural materials due to the general lack of moisture and isolation from wind and water erosion. The research aimed to determine when the site was occupied as well as the types of activities that were occurring during those occupations. It exhibits an extensive stratigraphic sequence that contains a well pronounced Late Archaic Period assemblage (Strata A and B) and a Late Pleistocene/Early …

Go to article

Sonolytic Degradation Of Parathion And The Formation Of Byproducts, Juan Juan Yao, Nai Yun Gao, Yang Deng, Yan Ma, Hai Jun Li, Bin Xu, Lei Li Jan 2010

Sonolytic Degradation Of Parathion And The Formation Of Byproducts, Juan Juan Yao, Nai Yun Gao, Yang Deng, Yan Ma, Hai Jun Li, Bin Xu, Lei Li

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Ultrasonic degradation of parathion has been investigated in this study. At a neutral condition, 99.7% of 2.9 μM parathion could be decomposed within 30 min under 600 kHz ultrasonic irradiation at ultrasonic intensity of 0.69 W/cm2. The degradation rate increased proportionally with the increasing ultrasonic intensity from 0.10 to 0.69 W/cm2. The parathion degradation was enhanced in the presence of dissolved oxygen due to formation of more {radical dot}OH, but was inhibited in the presence of nitrogen gas owning to the free radical scavenging effect in vapor phase within the cavitational bubbles. CO32 -, HCO3-, and Cl- exhibited the inhibiting …

Go to article

Gadolinium Concentration Analysis In Brain Phantom By X-Ray Fluorescence, Musaed Almalki, Samir Abdul Majid, Philip H. Butler, Lou Reinisch Jan 2010

Gadolinium Concentration Analysis In Brain Phantom By X-Ray Fluorescence, Musaed Almalki, Samir Abdul Majid, Philip H. Butler, Lou Reinisch

Research, Publications & Creative Work

We have measured the X-ray fluorescence from gadolinium as a function of concentration and position in tumors of different sizes and shapes in a head phantom. The gadolinium fluorescence was excited with a 36 GBq Am-241 source. The fluorescence signal was detected with a CdTe detector and a multi-channel analyzer. The fluorescence peak was clearly separated from the scattered X-rays. Concentrations of 5.62–78.63 mg/ml of Gd ion were used in 1, 2, and 3 cm diameter spherical tumors and a 2 9 4 cm oblate spheroid tumor. The data show trends approaching saturation for the highest concentrations, probably due to …

Go to article

Diatom Stratigraphy Defining Ice Sheet Grounding Chronology, Ross Sea, Antarctica, Juan Manuel Chow Jan 2010

Diatom Stratigraphy Defining Ice Sheet Grounding Chronology, Ross Sea, Antarctica, Juan Manuel Chow

LSU Doctoral Dissertations

Evidence of Antarctic ice sheet behavior and paleoenvironment is often approached from proxy records because there is a dearth of direct records from Antarctica itself. The studies presented here seek to augment our knowledge of translations of the West Antarctic Ice Sheet’s (WAIS) marine termination based on direct biostratigraphic evidence. Diatom analyses were conducted from two areas of Ross Sea, Antarctica. In the first study, diatoms were used to constrain the age of diamictons from five seismic units in the Eastern Basin and thus expand our knowledge of WAIS behavior during the Southern Hemisphere Last Glacial Maximum (LGM). All five …

Go to article

Oxidation Of Reduced Sulfur Compounds: A Triple-Oxygen-Isotope Perspective, Issaku E. Kohl Jan 2010

Oxidation Of Reduced Sulfur Compounds: A Triple-Oxygen-Isotope Perspective, Issaku E. Kohl

LSU Doctoral Dissertations

The Earth’s geochemical evolution is recorded in the rocks that compose its lithosphere. Specifically, sulfate minerals have been identified as being repositories of information concerning the past hydrosphere, atmosphere and biosphere. This is due to the non-labile nature of SO42- and its ability to store a record of the oxidative reactions and oxygen sources involved in its formation. Microbial dissimilatory sulfate reduction (MDSR) and sulfide oxidation cause oxygen from H2O and O2 to be trapped to varying degrees in ambient, dissolved SO42-. In order to better interpret the H2O and O2 signals in SO42-, we must deepen our understanding of …

Go to article

Provenance Of The Neoproterozoic Ocoee Supergroup, Eastern Great Smoky Mountains, Suvankar Chakraborty Jan 2010

Provenance Of The Neoproterozoic Ocoee Supergroup, Eastern Great Smoky Mountains, Suvankar Chakraborty

University of Kentucky Doctoral Dissertations

The Ocoee Supergroup is a sequence of Neoproterozoic, immature, continental rift facies clastic sediments. Potential source rocks were tested by analyzing modes of detrital framework minerals, detrital mineral chemistry, whole rock geochemistry and detrital zircon U/Pb geochronology by LA-ICP-MS for Ocoee siltstone-sandstone dominated formations. Ocoee units are arkosic to subarkosic siltstones/sandstones, and ternary tectonic discrimination diagrams confirm a continental basement uplift source. Alkali feldspar predominates over plagioclase feldspar. Detrital feldspar compositions of Ocoee sediments as a group are similar to feldspar in local basement granitic rocks except for high-Ca plagioclase grains present locally in basement granitic rocks. The high alkali …

Go to article

High Geologic Slip Rates Since Early Pleistocene Initiation Of The San Jacinto And San Felipe Fault Zones In The San Andreas Fault System, Southern California, Usa, Susanne U. Janecke, R. J. Dorsey, D. Forand, A. N. Steely, S. M. Kirby, A. T. Lutz, B. A. Housen, B. Belgarde, V. E. Langenheim, T. M. Rittenour Jan 2010

High Geologic Slip Rates Since Early Pleistocene Initiation Of The San Jacinto And San Felipe Fault Zones In The San Andreas Fault System, Southern California, Usa, Susanne U. Janecke, R. J. Dorsey, D. Forand, A. N. Steely, S. M. Kirby, A. T. Lutz, B. A. Housen, B. Belgarde, V. E. Langenheim, T. M. Rittenour

Geosciences Faculty Publications

The San Jacinto right-lateral strike-slip fault zone is crucial for understanding plate-boundary dynamics, regional slip partitioning, and seismic hazards within the San Andreas fault system of southern California, yet its age of initiation and long-term average slip rate are controversial. This synthesis of prior and new detailed studies in the western Salton Trough documents initiation of structural segments of the San Jacinto fault zone at or slightly before the 1.07-Ma base of the Jaramillo subchron. The dextral faults changed again after ca. 0.5–0.6 Ma with creation of new fault segments and folds. There were major and widespread basinal changes in …

Go to article

Mixing By Shear Instability At High Reynolds Number, W. R. Geyer, A. C. Lavery, M. E. Scully, J. H. Trowbridge Jan 2010

Mixing By Shear Instability At High Reynolds Number, W. R. Geyer, A. C. Lavery, M. E. Scully, J. H. Trowbridge

CCPO Publications

Shear instability is the dominant mechanism for converting fluid motion to mixing in the stratified ocean and atmosphere. The transition to turbulence has been well characterized in laboratory settings and numerical simulations at moderate Reynolds number-it involves "rolling up", i.e., overturning of the density structure within the cores of the instabilities. In contrast, measurements in an energetic estuarine shear zone reveal that the mixing induced by shear instability at high Reynolds number does not primarily occur by overturning in the cores; rather it results from secondary shear instabilities within the zones of intensified shear separating the cores. This regime is …

Go to article

Citizen Professionals: The Effective Practices Of Experts Helping Community Organizations, Sarah Hippensteel Hall Jan 2010

Citizen Professionals: The Effective Practices Of Experts Helping Community Organizations, Sarah Hippensteel Hall

Antioch University Dissertations & Theses

Although numerous local, state, and federal laws and policies address water pollution, many problems remain. To address these problems thousands of groups of citizens, who are concerned with their water resources - rivers, streams, lakes, ponds, and groundwater - organized around the U.S. over the past several decades. To succeed, these community organizations need the resources and capacity to reach their goals. To gain capacity, some community organizations turn to people outside the organization for assistance. Citizen professionals are helpers who work jointly with an organization to help develop an organization's adaptive capacity to deal with challenges and achieve goals. …

Go to article

Investigating The Source Of Thermal Anomalies In The Northern United Arab Emirates (Uae) Desert Using Geophysical Methods, Khalid Ahmad Jan 2010

Investigating The Source Of Thermal Anomalies In The Northern United Arab Emirates (Uae) Desert Using Geophysical Methods, Khalid Ahmad

Doctoral Dissertations

"We conducted geophysical surveys to investigate the source of thermal anomalies and to delineate any potential water transport pathways from the recharge zones in the Oman Mountains to the location of the temporal thermal anomalies within the desert plain of the United Arab Emirates (UAE). In the visible region of the spectrum of both ASTER and MODIS satellite images, the desert plain of the UAE appears as a bare sandy surface. However, detailed examination of these images in the thermal bands reveal cooler thermal anomalies within the desert plain following major rainfall events. This anomaly has a cooler surface of …

Go to article

The Widespread Occurrence Of Coupled Carbonate Dissolution/Reprecipitation In Surface Sediments On The Bahamas Bank, David J. Burdige, Xinping Hu, Richard C. Zimmerman Jan 2010

The Widespread Occurrence Of Coupled Carbonate Dissolution/Reprecipitation In Surface Sediments On The Bahamas Bank, David J. Burdige, Xinping Hu, Richard C. Zimmerman

OES Faculty Publications

Using two complimentary approaches (pore water advection/diffusion/reaction modeling and stable isotope mass balance calculations) we show that carbonate dissolution/reprecipitation occurs on early diagenetic time scales across a broad range of sediments on the Great Bahamas Bank. The input of oxygen into the sediments, which strongly controls sediment carbonate dissolution, has two major sources belowground input by seagrasses (that is, seagrass O2 pumping), and permeability-driven advective pore water exchange. The relative importance of these O2 delivery mechanisms depends on both seagrass density, and on how bottom water flow interacts with the seagrass canopy and leads to this advective exchange. …

Go to article

Causes Of Tropical Atlantic Paleo-Salinity Variation During Periods Of Reduced Amoc, Xiuquan Wan, Ping Chang, Matthew W. Schmidt Jan 2010

Causes Of Tropical Atlantic Paleo-Salinity Variation During Periods Of Reduced Amoc, Xiuquan Wan, Ping Chang, Matthew W. Schmidt

OES Faculty Publications

During periods of reduced Atlantic meridional overturning circulation (AMOC) associated with a freshening of northern North Atlantic surface water, paleo proxy records indicate a corresponding surface salinity increase over the entire tropical Atlantic. Although latitudinal-shifts in the mean position of the Atlantic Intertropical Convergence Zone (ITCZ) can explain certain features of the paleo salinity reconstructions, this mechanism does not offer an explanation for the reconstructed basin-wide paleo-salinity response to AMOC change. Here, we present new results from general circulation model simulations that suggest the sea surface salinity (SSS) increase in the tropical north Atlantic during periods of weakened AMOC is …

Go to article

Candoluminescence Of Cave Gypsum, John R. Sweet, John W. Hess, William B. White Jan 2010

Candoluminescence Of Cave Gypsum, John R. Sweet, John W. Hess, William B. White

International Journal of Speleology

A selection of gypsum specimens from a variety of caves as well as CaSO4 synthesized in the laboratory emit both a green and yellow candoluminescence when excited by a hydrogen diffusion flame. The green emission is attributed to dehydration of gypsum to bassanite and the yellow emission appears upon further dehydration to anhydrite. The source of the luminescence is ascribed to minor concentrations of Mn2+ in the gypsum.

Go to article

Urban Speleology Applied To Groundwater And Geo-Engineering Studies: Underground Topographic Surveying Of The Ancient Arca D’Água Galleries Catchworks (Porto, Nw Portugal), H. I. Chaminé, M. J. Afonso, P. M. Robalo, P. Rodrigues, C. Cortez, F. A. Monteiro Santos, J. P. Plancha, P. E. Fonseca, A. Gomes, N. F. Devy-Vareta, J. M. Marques, M. E. Lopes, G. Fontes, A. Pires, F. Rocha Jan 2010

Urban Speleology Applied To Groundwater And Geo-Engineering Studies: Underground Topographic Surveying Of The Ancient Arca D’Água Galleries Catchworks (Porto, Nw Portugal), H. I. Chaminé, M. J. Afonso, P. M. Robalo, P. Rodrigues, C. Cortez, F. A. Monteiro Santos, J. P. Plancha, P. E. Fonseca, A. Gomes, N. F. Devy-Vareta, J. M. Marques, M. E. Lopes, G. Fontes, A. Pires, F. Rocha

International Journal of Speleology

The Porto settlement (Northwest Portugal, Iberian Peninsula) was originally built in the twelfth century and has been developed on granitic hill slopes of the Douro riverside, being one of the oldest cities in Europe. In the urban area of Porto, the second most important city of the Portuguese mainland, there is a population of about 216,000 inhabitants. This study highlights the importance of urban speleological mapping applied to groundwater and geo-engineering studies. All the water that flows from the so-called Paranhos or Arca D’Água springs is captured by catchwork galleries and their utilization date back around 1120 AD. Paranhos spring …

Go to article

Palaeomagnetic Research On Karst Sediments In Slovenia, Nadja Zupan Hajna, Andrej Mihevc, Petr Pruner, Pavel Bosàk Jan 2010

Palaeomagnetic Research On Karst Sediments In Slovenia, Nadja Zupan Hajna, Andrej Mihevc, Petr Pruner, Pavel Bosàk

International Journal of Speleology

We have conducted palaeomagnetic and magnetostratigraphic research on karst sediments in Slovenia since 1997. More than 2,000 samples were taken and analysed in 36 different profiles at 21 locations in caves and on the surface. Standard palaeomagnetic analyses were used (thermal and alternating field demagnetisation, magnetic susceptibility measurements, etc.). There is no evidence of younger marine deposition than Eocene in the SW part of Slovenia. Younger sediments occur only in caves and very rarely on the karst surface (different soils and a few remains of terrigeneous sediments). Marine and terrestrial Tertiary to Plio–Quaternary deposition occurs in the SE and E …

Go to article

A Re-Appraisal Of The Stratigraphy, Palaeontology And Dating Of Cow Cave, Chudleigh, Devon, England, Jim W. Simons Jan 2010

A Re-Appraisal Of The Stratigraphy, Palaeontology And Dating Of Cow Cave, Chudleigh, Devon, England, Jim W. Simons

International Journal of Speleology

Cow Cave is an important Quaternary paleontological site in Chudleigh Gorge, Devon, UK., now known to have a sequence of cave-earths and stalagmite floors that range in age from Upper Middle Pleistocene (~MIS 7 interglacial) through to the Holocene (Flandrian) and the present day. Excavations in 1927-1934, and again in 1962-3, have provided a rich fauna, with some artefacts. Here, the stratigraphy of the deposits is now more fully described and the faunal remains are considered in their stratigraphical contexts. Data supporting the existence of former cave entrances are presented along with an analysis of the processes of sedimentation and …

Go to article

Geology Of Central Eleuthera, Bahamas: A Field Trip Guide, Pascal Kindler, John E. Mylroie, H. Allen Curran, James L. Carew, Douglas W. Gamble, Thomas A. Rothfus Jan 2010

Geology Of Central Eleuthera, Bahamas: A Field Trip Guide, Pascal Kindler, John E. Mylroie, H. Allen Curran, James L. Carew, Douglas W. Gamble, Thomas A. Rothfus

Geosciences: Faculty Publications

See other Smith authored Field Trip Guides of Gerace Research Centre.

Go to article

First Prev Next Last