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

Physical Sciences and Mathematics Commons

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

Articles 1 - 12 of 12

Full-Text Articles in Physical Sciences and Mathematics

Exceptionally Preserved Jellyfishes From The Middle Cambrian, Paulyn Cartwright, Susan L. Halgedahl, Jonathan R. Hendricks, Richard D. Jarrard, Antonio C. Marques, Allen G. Collins, Bruce S. Lieberman Oct 2007

Exceptionally Preserved Jellyfishes From The Middle Cambrian, Paulyn Cartwright, Susan L. Halgedahl, Jonathan R. Hendricks, Richard D. Jarrard, Antonio C. Marques, Allen G. Collins, Bruce S. Lieberman

Jonathan R. Hendricks

Cnidarians represent an early diverging animal group and thus insight into their origin and diversification is key to understanding metazoan evolution. Further, cnidarian jellyfish comprise an important component of modern marine planktonic ecosystems. Here we report on exceptionally preserved cnidarian jellyfish fossils from the Middle Cambrian (~505 million years old) Marjum Formation of Utah. These are the first described Cambrian jellyfish fossils to display exquisite preservation of soft part anatomy including detailed features of structures interpreted as trailing tentacles and subumbrellar and exumbrellar surfaces. If the interpretation of these preserved characters is correct, their presence is diagnostic of modern jellyfish …


Plio-Quaternary Exhumation History Of The Central Nepalese Himalaya: 2. Thermo-Kinematic Model Of Thermochronometer Age Prediction Model, David Whipp Jr, Todd Ehlers, Ann Blythe, Katharine Huntington, Kip Hodges, Douglas Burbank May 2007

Plio-Quaternary Exhumation History Of The Central Nepalese Himalaya: 2. Thermo-Kinematic Model Of Thermochronometer Age Prediction Model, David Whipp Jr, Todd Ehlers, Ann Blythe, Katharine Huntington, Kip Hodges, Douglas Burbank

Ann Blythe

[1] In the Himalaya and other active convergent orogens, linear relationships between thermochronometer sample age and elevation are often used to estimate long-term exhumation rates. In these regions, high-relief topography and nonvertical exhumation pathways may invalidate such one-dimensional (1-D) interpretations and lead to significant errors. To quantify these errors, we integrate apatite fission track (AFT) ages from the central Himalaya with a 3-D coupled thermokinematic model, from which sample cooling ages are predicted using a cooling-rate-dependent algorithm. By changing the slip partitioning between faults near the Main Central thrust and the Main Frontal thrust system at the Himalayan range front, …


Plio-Quaternary Exhumation History Of The Central Nepalese Himalaya: 1. Apatite And Zircon Fission Track And Apatite [U-Th]/He Analyses, Ann Blythe, D Burbank, A Carter, K Schmidt, J Putkonen May 2007

Plio-Quaternary Exhumation History Of The Central Nepalese Himalaya: 1. Apatite And Zircon Fission Track And Apatite [U-Th]/He Analyses, Ann Blythe, D Burbank, A Carter, K Schmidt, J Putkonen

Ann Blythe

No abstract provided.


International, Cooperative Research In The Apuseni Mountains Of Western Romania, Lee J. Florea, Bogdan P. Onac Jan 2007

International, Cooperative Research In The Apuseni Mountains Of Western Romania, Lee J. Florea, Bogdan P. Onac

Lee J Florea, PhD, P.G.

In May of 2006, nine American scientists and cavers from the Karst Research Group at the University of South Florida traveled to western Romania to attend and present at an international conference on records of climate change in caves in the historic Roman town of Baile Hurculane. The conference, co-sponsored by the “Emil Racoviţă” Speleological Institute of Romania and the Karst Waters Institute, drew more than 100 experts in the field of climate change and karst, and was a wonderful time spent alongside the thermal springs and Austro-Hungarian bathhouses nestled within the massive limestone canyon of the Cerna River. Following …


I Sinkholes Nella Letteratura Scientifica Internazionale: Una Breve Rassegna, Con Particulare Riferimento Agli Stati Uniti D'America, Lee J. Florea, Mario Parise Jan 2007

I Sinkholes Nella Letteratura Scientifica Internazionale: Una Breve Rassegna, Con Particulare Riferimento Agli Stati Uniti D'America, Lee J. Florea, Mario Parise

Lee J Florea, PhD, P.G.

Fenomeni di sinkholes sono diffusi in moltissimi paesi del mondo, in ambiti geologici e morfologici alquanto differenziati, e coinvolgono svariate litologie, sia nelle successioni di copertura che in quelle direttamente affioranti alla superficie. Il presente contributo intende fornire una breve rassegna, certamente non esaustiva, sullo stato dell’arte delle ricerche relative ai sinkholes in ambito internazionale. Esso consiste in una descrizione della più aggiornata e diffusa classificazione dei sinkholes e, a seguire, in descrizioni delle più tipiche casistiche di sinkholes nei vari paesi. Tra questi, viene dato particolare risalto agli Stati Uniti d’America (e, più in particolare, alla Florida), dove le …


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. …


Fractal Characterization Of Fracture Networks: An Improved Box-Counting Technique, Ankur Roy, Edmund Perfect, William M. Dunne, Larry Mckay Jan 2007

Fractal Characterization Of Fracture Networks: An Improved Box-Counting Technique, Ankur Roy, Edmund Perfect, William M. Dunne, Larry Mckay

Larry McKay

Box counting is widely used for characterizing fracture networks as fractals and estimating their fractal dimensions (D). If this analysis yields a power law distribution given by N $\propto$ r−D, where N is the number of boxes containing one or more fractures and r is the box size, then the network is considered to be fractal. However, researchers are divided in their opinion about which is the best box‐counting algorithm to use, or whether fracture networks are indeed fractals. A synthetic fractal fracture network with a known D value was used to develop a new algorithm for the box‐counting method …


The Impact Of Grey Literature In Advancing Global Karst Research: An Information Needs Assessment For A Globally Distributed Interdisciplinary Community, Todd A. Chavez, Anna H. Perrault, Pete Reehling, Courtney Crummett Jan 2007

The Impact Of Grey Literature In Advancing Global Karst Research: An Information Needs Assessment For A Globally Distributed Interdisciplinary Community, Todd A. Chavez, Anna H. Perrault, Pete Reehling, Courtney Crummett

Anna H. Perrault

A survey of the global karst community was conducted in 2006. The survey was distributed via the World Wide Web to known karst researchers. The instrument was designed to generate an initial inventory of core grey information types, to assess levels of usage of grey information by the respondents, and to gauge the karst community’s willingness to participate in building and expanding both this collection and the associated controlled vocabularies.


The Impact Of Grey Literature In Advancing Global Karst Research: An Information Needs Assessment For A Globally Distributed Interdisciplinary Community, Todd A. Chavez, Anna H. Perrault, Pete Reehling, Courtney Crummett Jan 2007

The Impact Of Grey Literature In Advancing Global Karst Research: An Information Needs Assessment For A Globally Distributed Interdisciplinary Community, Todd A. Chavez, Anna H. Perrault, Pete Reehling, Courtney Crummett

Todd A. Chavez

A survey of the global karst community was conducted in 2006. The survey was distributed via the World Wide Web to known karst researchers. The instrument was designed to generate an initial inventory of core grey information types, to assess levels of usage of grey information by the respondents, and to gauge the karst community’s willingness to participate in building and expanding both this collection and the associated controlled vocabularies.


The Diachroneity Of Alluvial-Fan Lithostratigraphy?: A Test Case From Southeastern Ebro Basin Magnetostratigraphy, Nicholas Swanson-Hysell, David Barbeau Dec 2006

The Diachroneity Of Alluvial-Fan Lithostratigraphy?: A Test Case From Southeastern Ebro Basin Magnetostratigraphy, Nicholas Swanson-Hysell, David Barbeau

David L Barbeau Jr

Alluvial-fan strata contain valuable proxy data for kinematic, climatic and sediment-flux phenomena associated with high-relief source regions. Proper application of this data is dependent upon acquisition of accurate high-resolution chronostratigraphic data, best achieved through magnetostratigraphy. Collection of magnetostratigraphic and other proxy data from composite alluvial-fan sections assumes the chronostratigraphic significance of lithostratigraphy. We present the first test of this assumption with new magnetostratigraphy collected from Paleogene rocks of the southeastern Ebro basin. We report five new magnetostratigraphic sections that collectively sample 850 m of alluvial-fan and associated fluvial strata. One-hundred meters of lithostratigraphic overlap between these sections reveals equivalent magnetic …


Evidence Of Four Generations Of Monazite Growth In Proterozoic Migmatites Of The Santa Fe Range, North-Central New Mexico, Dan Heuer Dec 2006

Evidence Of Four Generations Of Monazite Growth In Proterozoic Migmatites Of The Santa Fe Range, North-Central New Mexico, Dan Heuer

Dan Heuer

No abstract provided.


In The Heat Of The Law, It's Not Just Steam: Geothermal Resources And The Impact On Thermophile Biodiversity, Donald J. Kochan, Tiffany Grant Dec 2006

In The Heat Of The Law, It's Not Just Steam: Geothermal Resources And The Impact On Thermophile Biodiversity, Donald J. Kochan, Tiffany Grant

Donald J. Kochan

Significant research has been conducted into the utilization of geothermal resources as a ‘green’ energy source. However, minimal research has been conducted into geothermal resource utilization and depletion impacts on thermophile biodiversity. Thermophiles are organisms which have adapted over millions of year to extreme temperature and chemical compositions and exist in hot springs and other geothermal resources. Their ability to withstand high temperatures makes them invaluable to scientific and medical research. Current federal and California case law classify geothermal resources as a mineral, not a water resource. Acquisition of rights to develop a geothermal resource owned or reserved by the …