Physical Sciences and Mathematics Commons^™

Experimental Studies Of Fe-Mg Carbonates And Their Role In Petrogenesis

Andrea M. Koziol

Morphogenesis By Symbiogenesis, Michael J. Chapman, Lynn Margulis

Lynn Margulis (1938 - 2011)

Here we review cases where initiation of morphogenesis, including the differentiation of specialized cells and tissues, has clearly evolved due to cyclical symbiont integration. For reasons of space, our examples are drawn chiefly from the plant, fungal and bacterial kingdoms. Partners live in symbioses and show unique morphological specializations that result when they directly and cyclically interact. We include here brief citations to relevant literature where plant, bacterial or fungal partners alternate independent with entirely integrated living. The independent, or at least physically unassociated stages, are correlated with the appearance of distinctive morphologies that can be traced to the simultaneous …

Sediment Control At Water Intakes Along Sand Bed Rivers, Fred L. Ogden

Fred L. Ogden

Results from five physical hydraulic model studies of riverside water intakes situated along the Missouri River reach between Sioux City, Iowa, and St. Louis, Missouri, are presented. Movable-bed, undistorted Froude-scale models are used to determine the effectiveness of structural modifications in the vicinity of the intake to limit the influx of bed-load sediments. Solutions developed in each case include a series of submerged flow-turning vanes located on the riverward side of the intake. A sediment-barrier wall between the vanes and intake ...

Atmospheric Circulation Anomalies Associated With 1996/1997 Summer Precipitatipn Events On Sajama Ice Cap, Bolivia, Mathias Vuille, Douglas R. Hardy, Carsten Braun, Frank Keimig, Raymond S. Bradley

Raymond S Bradley

The analysis of atmospheric circulation anomalies related to snowfall eVents on Sajama volcano (Bolivian Andes) provides important information for the calibration of an ice core, recently recovered from the summjt. Seventeen precipitation episodes were recorded on Sajama volcano during the 1996/1997 summer season (November 1996 to Marcb 1997) by snow depth sensors and additional measurements of an automatic weather station located on the summit. The analysis of atmospheric circulation patterns during these events is pased on zonal and meridional wind, air temperature, relative humiqity, geopotential height and horizontal divergence at three pressure levels (400, 500, and 700 hPa levels), atmosphenc …

Annual And Daily Meteorological Cycles At High Altitude On A Tropical Mountain, Douglas R. Hardy, Mathias Vuille, Carsten Braun, Frank Keimig, Raymond S. Bradley

Raymond S Bradley

An automated weather station was installed in October 1996 at the summit of Nevado Sajama, located in the western Andean Cordillera of Bolivia (6542 m, 18°06¢S, 68°53¢W). Meteorological conditions on the mountain are being observed to improve the calibration of geochemical variations within tropical ice cores. This article documents the design and operation of the station and presents a discussion of measurements made through the first annual cycle. Variables analyzed include pressure, incoming solar radiation, air temperature, humidity, wind, and snow accumulation. Large diurnal fluctuations were recorded in most variables, which is not unexpected given the location at 18°S; the …

Cosmopolitan Distribution Of The Large Composite Microbial Mat Spirochete, Spirosymplokos Deltaeiberi, Lynn Margulis, Antoni Navarrete, Mónica Solé

Lynn Margulis (1938 - 2011)

Inocula from organic-rich black muds immediately underlying intertidal laminated microbial mats dominated by Microcoleus chthonoplastes yielded large, variable diameter spirochetes. These unusual spirochetes, previously reported only from the Alfacs Peninsula at the delta of the Ebro river in northeast Spain, contain striking arrays of cytoplasmic granules packed into their protoplasmic cylinders. On several occasions, both in summer and winter, the huge spirochetes were recognized in samples from mats growing in the Sippewissett salt marsh at Woods Hole Massachusetts. They were also seen in similar samples from microbial mats at North Pond, Laguna Figueroa, Baja California Norte, Mexico. The identity of …

Sustainable Development As A Framework For National Governance, John C. Dernbach

John C. Dernbach

No abstract provided.

Reflections On Comparative Law, Environmental Law, And Sustainability, John C. Dernbach

John C. Dernbach

No abstract provided.

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

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 …

Deep Water Formation And Poleward Ocean Heat Transport In The Warm Climate Extreme Of The Cretaceous (80 Ma), Esther C. Brady, Robert M. Deconto, Starley L. Thompson

Robert M DeConto

An ocean simulation of the “greenhouse” climate of the Late Cretaceous, about 80 million years ago (Ma), demonstrates that warm salty deep water, consistent with proxy climate data, can be formed by cooling in the high latitude Southern Hemisphere. This is contrary to the long standing hypothesis of deep water formation due to evaporation over low latitude marginal seas. A reduced equator to pole temperature gradient is maintained with a poleward ocean heat transport that is not larger than today's.

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 …

Geometry,Mechanisms, And Significance Of Extensional Folds From Examples In The Rockymountain Basin And Range Province, Susanne U. Janecke, C. J. Vandenburg, J. J. Blankenau

Susanne U. Janecke

No abstract provided.

Active Tectonics And Ultrahigh-Pressure Rocks, Ann Blythe

Ann Blythe

This chapter compares modern exhumation and surface uplift rates with the rates needed for the preservation of ultrahigh pressure (UHP) metamorphic rocks. The highest recorded exhumation rates of ~ 5–10 mm/a are inferred from isotopic and fission-track analyses in the Himalaya, Southern Alps of New Zealand, and D’Entrecasteaux Islands. Similar rates (~7 mm/a) of surface uplift are measured from leveling surveys in Nepal and correlations of marine terraces in the Southern Alps. In Nepal, however, this surface uplift rate is occurring despite erosion, and the true rate of surface uplift is probably considerably higher. In restraining bends along the San …

Longitudinal Study Of Dental Development In Chimpanzees Of Known Chronological Age: Implications For Understanding The Age At Death Of Plio-Pleistocene Hominids, Robert Anemone, Mark Mooney

Robert L. Anemone

Reconstruction of life history variables of fossil hominids on the basis of dental development requires understanding of and comparison with the pattern and timing of dental development among both living humans and pongids. Whether dental development among living apes or humans provides a better model for comparison with that of Plio-Pleistocene hominids of the genus Australopithecus remains a contentious point. This paper presents new data on chimpanzees documenting developmental differences in the dentitions of modern humans and apes and discusses their significance in light of recent controversies over the human or pongid nature of australopithecine dental development. Longitudinal analysis of …

Biogeography Of The Late Paleocene Benthic Foraminiferal Extinction, Ellen Thomas

Ellen Thomas

During the Late Paleocene Thermal Maximum (LPTM) benthic foraminifera at middle bathyal and greater depths suffered extinction of 30-50% of species during a few thousand years. Extinction was less severe at neritic to upper bathyal depths, where temporary changes in faunal composition prevailed. Pre-extinction deep-sea faunas were cosmopolitan and diverse, and contained heavily calcified species. Immediate post-extinction faunas were more variable geographically, exhibited low diversity, and were dominated by thin-walled calcareous or agglutinated taxa, possibly because CaCO3 dissolution increased globally from neritic to abyssal depths just before the extinction. These assemblages were dominated either by long-lived taxa such as Nuttallides …

Strategies Of Representation, Relationship, And Resistance: British Women Travelers And Mormon Plural Wives, C. 1870-1890, Karen M. Morin, J.K. Guelke

Karen M. Morin

During the 1870s and 1880s, several British women writers traveled by transcontinental railroad across the American West via Salt Lake City, Utah, the capital of the Church of Jesus Christ of Latter-day Saints, or Mormons. These women subsequently wrote books about their travels for a home audience with a taste for adventures in the American West, and particularly for accounts of Mormon plural marriage, which was sanctioned by the Church before 1890. "The plight of the Mormon woman," a prominent social reform and literary theme of the period, situated Mormon women at the center of popular representations of Utah during …