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"Pit Craters", Lava Tubes, And Open Vertical Volcanic Conduits In Hawaii: A Problem In Terminology, William R. Halliday

International Journal of Speleology

Almost from the 1849 publication of the term pit crater, volcanologists have disagreed about the parameters differentiating these features from other vertical volcanic structures. Kaluaiki is a jameo giving entry to Thurston Lava Tube in Hawaii Volcanoes National Park. Long-standing misidentification of it as a pit crater is an example of misunderstandings arising from the lack of a clear definition of pit crater. In general, pit craters are unrelated to lava tube caves genetically, but two special cases are discussed. One probably is genetically related to a rift tube deep below the surface; the other is a complex of a …

Lava Tube Remelt By Radiant Heat And Burning Gasses, Kevin Allred

International Journal of Speleology

Some volcanologists assume that interior surfaces of hot lava tubes can commonly be remelted by burning gases and radiant heat. Pending further data, this appears to be unlikely.

The Origin Of Tubular Lava Stalactites And Other Related Forms, Kevin Allred, Carlene Allred

International Journal of Speleology

Tubular lava stalactites are often found in lava tubes. Field observations, sample analysis, and comparative studies indicate that these are segregations extruded during cooling from partially crystallized lava al about 1,070 - 1,000 °C. Retrograde boiling (gas pressure) within the lava provides a mechanism to expel the interstitial liquid. In addition to tubular lava stalactites, a variety of other lava features can also result, such as lava helictites, lava coralloids, barnacle-like stretched lava, runners, runner channels, and some lava blisters and squeeze-ups.

The 1981 Eruptive Fissure On Mt. Etna: Considerations On Its Exploration And Genesis, Angelo Leotta, Marco Liuzzo

International Journal of Speleology

This paper is targeted to an analysis of features common to various fissure caves on Mt. Etna, Sicily. The Authors report the preliminary results of the exploration carried out in the 1981 eruptive fissure, the technical problems met during the exploration, the flow trends and the different courses of the molten material inside the fissure, the particular morphologies. A genetic model is proposed, different from those characterising the lava tube cave genesis, and links are suggested between the various fissures and the main tectonic stress systems operating on Mt. Etna, as well as the morpho-structural conditions of the volcanic edifice …

Madison County Test Hole Logs, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Earthquakes In Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Oil And Gas Fields In Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Continuous Lake-Sediment Records Of Glaciation In The Sierra Nevada Between 52,600 And 12,500 14c Yr B.P., Larry Benson, Howard M. May, Ronald C. Antweiler, Terry I. Brinton, Michaele Kashgarian, Joseph P. Smoot, Steve P. Lund

United States Geological Survey: Staff Publications

The chemistry of the carbonate-free clay-size fraction of Owens Lake sediments supports the use of total organic carbon and magnetic susceptibility as indicators of stadial-interstadial oscillations, Owens Lake records of total organic carbon, magnetic susceptibility, and chemical composition of the carbonate-free, clay-size fraction indicate that Tioga glaciation began ~24,500 and ended by ~13,600 ¹⁴C yr B.P. Many of the components of glacial rock flour (e.g., TiO₂ , MnO, BaO) found in Owens Lake sediments achieved maximum values during the Tioga glaciation when valley glaciers reached their greatest extent. Total organic carbon and Si02 (amorphous) concentrations reached minimum values …

Early Life History Stages Of Gulf Sturgeon In The Suwannee River, Florida, Kenneth J. Sulak, James P. Clugston

United States Geological Survey: Staff Publications

Egg sampling confirmed that Suwannee River Gulf sturgeon Acipenser ozyrinchus desotoi, a subspecies of Atlantic sturgeon A. o. oxyrinchus use the same spawning site at river kilometer (rkm) 215 from the mouth of the river each year. Forty-nine eggs were recorded in 1995, and 368 were recorded in 1996. Spawning began 4-7 d after the March new moon in both years and lasted 10-11 d; in 1996, a second 10-d spawning round began on the April new moon. Developmental synchrony among eggs recovered suggested serval discrete spawning events in both years. Total eggs deposited for three 1996 sampling days …

Optical Digital Fragmentation Measuring Systems -- Inherent Sources Of Error, Norbert H. Maerz, Wei Zhou

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Automated optical imaging systems of measuring fragmentation are increasingly being used in the mining, comminution, and materials handling industries. These methods have been well received in many of the industries involved. Considering that in many of these applications there are no alternative ways of sizing material, having even a rudimentary measurement of size distributions allows evaluations of explosive, blast design, detonator performance, crusher and milling performance, and material degradation due to transport.

Optical methods have inherent limitations, which reflect on accuracy, precision, and reproducibility of measurement results. This stems from the fact that there are myriads of variables, which affect …

Paleosols As Holocene Proxy Climate Indicators, Mclean County, North Dakota, Deborah L. Beck

Theses and Dissertations

An exposure with 15 buried A-horizons near Douglas Creek, Lake Sakakawea, central North Dakota, has provided an excellent opportunity for paleoclimate reconstruction. Analyses included texture, stable carbon, radiocarbon, pollen, and phytoliths. The variations in these properties between individual soil horizons served to reconstruct the former environments of each soil horizon.

The paleosols were developed in a sequence of deposits in a mile-long tributary to the Missouri River. The soils are in a shallow valley fill exposed by wave action along the north shore of Lake Sakakawea. The 1996 exposure was up to 4m high and 51.5m wide. There were up …

A Methodology For Studying Denitrification By Recently Formed Sulfides, Bethany A. Bolles

Theses and Dissertations

Nitrate (N03) contamination due to anthropogenic sources is a serious and widespread health problem. In many groundwater systems, N03-can be reduced to a harmless gas, N2, through the bacterially mediated process of denitrification. During this process, bacteria gain energy by transferring electrons from an "electron donor" to nitrate, the "electron acceptor". It is typically believed that organic carbon is the most important electron donor in the denitrification process; however, increasing amounts of research suggest the importance of inorganic electron donors. The most extensive studies involving the reduction ofN03- by inorganic species have focused on pyrite (FeS2) and Fe(II). Few studies …

Comparison Of Median Indicator Kriging With Full Indicator Kriging In The Analysis Of Spatial Data, Donna Hill

Theses : Honours

In the earth sciences, and particularly in the mining of precious metals, data distributions are often strongly positively skewed. When making decisions on the potential profitability of a gold mine, for example, the high values of the distribution are of particular importance. Indicator kriging provides estimates of cumulative distribution functions from which grade tonnage curves may be calculated. Multiple or full indicator kriging requires a semivariogram to be modelled and a kriging system of equations to be solved for each cut off. This can be time consuming and modelling indicator semivariograms at high cut-offs may be difficult because of the …

Lava Caves Of The Republic Of Mauritius, Indian Ocean, Gregory J. Middleton

International Journal of Speleology

In their Underground Atlas, MIDDLETON & WALTHAM (1986) dismissed Mauritius as: “very old volcanic islands with no speleological interest”. Recent investigations indicate this judgement is inaccurate; there are over 50 significant caves, including lava tube caves up to 687 m long (one 665 m long was surveyed as early as 1769) and 35 m wide. Plaine des Roches contains the most extensive system of lava tube caves with underground drainage rising at the seashore. Notable fauna includes an insectivorous bat and a cave swiftlet (Collocalia francica), the nests of which are unfortunately prized for ‘soup”. The caves …

Bahamian Coral Reefs Yield Evidence Of A Brief Sea-Level Lowstand During The Last Interglacial, Brian White, H. Allen Curran, Mark A. Wilson

Geosciences: Faculty Publications

The growth of large, bank-barrier coral reefs on the Bahamian islands of Great Inagua and San Salvador during the last interglacial was interrupted by at least one major cycle of sea regression and transgression. The fall of sea level resulted in the development of a wave-cut platform that abraded early Sangamon corals in parts of the Devil's Point reef on Great Inagua, and produced erosional breaks in the reefal sequences elsewhere in the Devil's Point reef and in theCockburnTown reef on SanSalvador. Minor red caliche and plant trace fossils formed on earlier interglacial reefal rocks during the low stand. The …

Comparison Of Recent Coral Life And Death Assemblages To Pleistocene Reef Communities: Implications For Rapid Faunal Replacement On Recent Reefs, Benjamin J. Greenstein, Lora A. Harris, H. Allen Curran

Geosciences: Faculty Publications

Marine ecologists and paleoecologists are increasingly recognizing that the Pleistocene and Holocene fossil record of coral reefs is the exclusive database from which an assessment of the long-term responses of reef communities to environmental perturbations may be obtained. The apparent persistence of coral communities in the face of intense fluctuations in sea level and sea surface temperature during glacial and interglacial stages of Pleistocene time is in marked contrast to dramatic fluctuations in reef community structure documented by short-term monitoring studies. We compared the taxonomic structure of live and dead coral communities on a modem patch reef currently undergoing a …

Ophiomorpha Nodosa In Estuarine Sands Of The Lower Miocene Calvert Formation At The Pollack Farm Site, Delaware, Molly F. Miller, H. Allen Curran, Ronald L. Martino

Geosciences: Faculty Publications

No abstract provided.

Estimation Of Suspended Sediment Concentration In Water Using Integrated Surface Reflectance, Mahtab A. Lodhi, Donald C. Rundquist, Luoheng Han, Mark S. Kuzila

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Resource News-Winter 1997-98

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Resource News-Spring 1998

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Mineral Facts For Nebraska, Excluding Oil And Gas, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Oil And Gas Facts For Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Twin Platte Natural Resources District Groundwater Quality Study, D. C. Gosselin, L. Howard, J. Goeke

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Colfax County Test Hole Logs, Frank A. Smith, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Dodge County Test Hole Logs, Frank A. Smith, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Harlan County Test Hole Logs, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Washington County Test Hole Logs, Raymond R. Burchett, Frank A. Smith

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Platte County Test Hole Logs, Raymond R. Burchett, Scott E. Summerside

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Isotope Geochemistry Of Proterozoic Talc Occurrences In Archean Marbles Of The Ruby Mountains, Southwest Montana, U.S.A, John B. Brady, John T. Cheney, Amy Larson Rhodes, Angela Vasquez, Chris Green, Mathieu Duvall, Ari Kogut, Lewis Kaufman, Dana Kovaric

Geosciences: Faculty Publications

Talc occurs as massive, economic deposits in upper amphibolite facies marbles of Archean age in southwestern Montana. Previous workers have demonstrated that the talc is a replacement of the marble that resulted from interaction with a large volume of fluid. δ18O (SMOW) values for dolomite and calcite range from 20-25‰ for the unaltered Archean marbles to as little as 8-10‰ in the talc deposits, suggesting that the metasomatic fluids had low δ18O values. In contrast, δ13C values for calcite and dolomite are similar for all samples (-2 to +2‰ PDB). Therefore, it is likely that the metasomatic fluids were oxygen-rich …

Determining Capture Zones For Three-Dimensional, Heterogeneous, Anisotropic Aquifers By Monte Carlo Analysis, Jon Paul Jones

Theses and Dissertations

Most methods of delineating capture zones for pump-and-treat remedial design and wellhead protection assume a two-dimensional, homogeneous aquifer. Aquifers, however, are three-dimensional and heterogeneous, thereby introducing uncertainty in capture zone analysis. This study used a Monte Carlo analysis of three sets of statistical parameters defining aquifer heterogeneity. Each set had a different variance for the mean natural log hydraulic conductivity, which varied among the sets by a factor of four. The ensemble means of the capture zones for each set were estimated from 10 randomly generated fields with 12 layers each which were superimposed on each other for a total …