A search for distant radio galaxies from SUMSS and NVSS – III. Radio spectral energy distributions and the z–α correlation     

Ilana J. Klamer  Ron D. Ekers  Julia J. Bryant  Richard W. Hunstead  Elaine M. Sadler  Carlos De Breuck 《Monthly notices of the Royal Astronomical Society》2006,371(2):852-866

  相似文献   

New interpretation of the Franciscan mélange at San Simeon coast,California: tectonic intrusion into an accretionary prism     

Yujiro Ogawa  Ryota Mori  Toshiaki Tsunogae  Yildirim Dilek  Ron Harris 《International Geology Review》2015,57(5-8):824-842

Many concepts and interpretations on the formation of the Franciscan mélange have been proposed on the basis of exposures at San Simeon, California. In this paper, we show the distribution of chaotic rocks, their internal structures and textures, and the interrelationship between the chaotic rocks and the surrounding sandstones (turbidites). Mélange components, particularly blueschists, oceanic rocks, including greenstone, pillow lava, bedded chert, limestone, sandstone, and conglomerate, have all been brecciated by retrograde deformation. The Cambria Slab, long interpreted as a trench slope basin, is also strongly deformed by fluidization, brecciation, isoclinal folding, and thrusting, leading us to a new interpretation that turbiditic rocks (including the Cambria Slab) represent trench deposits rather than slope basin sediments. These rocks form an accretionary prism above mélanges that were diapirically emplaced into these rocks first along sinistral-thrust faults, and then along dextral-normal faults. Riedel shear systems are observed in several orders of scale in both stages. Although the exhumation of the blueschist blocks is still controversial, the common extensional fractures and brecciation in most of the blocks in the mélanges and further mixture of various lithologies into one block with mélange muddy matrix indicate that once deeply buried blocks were exhumed from considerable depths to the accretionary prism body, before being diapirically intruded with their host mélange along thrust and normal faults, during which retrograde deformation occurred together with retrograde metamorphism. Recent similar examples of high-pressure rock exhumation have been documented along the Sofugan Tectonic Line in the Izu forearc areas, in the Mineoka belt in the Boso Peninsula, and as part of accretionary prism development in the Nankai and Sagami troughs of Japan. These modern analogues provide actively forming examples of the lithological and deformational features that characterize the Franciscan mélange processes.  相似文献   

High velocities and seismic anisotropy in Pleistocene turbidites off Western Canada     

Earl E. Davis  Ron M. Clowes 《Geophysical Journal International》1986,84(2):381-399

  相似文献   

Resolving mechanisms of toxicity while pursuing ecotoxicological relevance?     

Hinton DE  Kullman SW  Hardman RC  Volz DC  Chen PJ  Carney M  Bencic DC 《Marine pollution bulletin》2005,51(8-12):635-648

In this age of modern biology, aquatic toxicological research has pursued mechanisms of action of toxicants. This has provided potential tools for ecotoxicologic investigations. However, problems of biocomplexity and issues at higher levels of biological organization remain a challenge. In the 1980s and 1990s and continuing to a lesser extent today, organisms residing in highly contaminated field sites or exposed in the laboratory to calibrated concentrations of individual compounds were carefully analyzed for their responses to priority pollutants. Correlation of biochemical and structural analyses in cultured cells and tissues, as well as the in vivo exposures led to the production and application of biomarkers of exposure and effect and to our awareness of genotoxicity and its chronic manifestations, such as neoplasms, in wild fishes. To gain acceptance of these findings in the greater environmental toxicology community, “validation of the model” versus other, better-established often rodent models, was necessary and became a major focus. Resultant biomarkers were applied to heavily contaminated and reference field sites as part of effects assessment and with investigations following large-scale disasters such as oil spills or industrial accidents.

Over the past 15 years, in the laboratory, small aquarium fish models such as medaka (Oryzias latipes), zebrafish (Danio rerio), platyfish (Xiphophorus species), fathead minnow (Pimephales promelas), and sheepshead minnow (Cyprinodon variegatus) were increasingly used establishing mechanisms of toxicants. Today, the same organisms provide reliable information at higher levels of biological organization relevant to ecotoxicology. We review studies resolving mechanisms of toxicity and discuss ways to address biocomplexity, mixtures of contaminants, and the need to relate individual level responses to populations and communities.  相似文献   

Rhinocerotid tooth enamel 18O/16O variability between 23 and 12 Ma in southwestern France     

Ilhem Bentaleb  Cyril Langlois  Céline Martin  Paula Iacumin  Matthieu Carré  Pierre-Olivier Antoine  Francis Duranthon  Issam Moussa  Jean-Jacques Jaeger  Nicholas Barrett  Ron Kandorp 《Comptes Rendus Geoscience》2006,338(3):172-179

The relationship between the oxygen isotope ratio of mammal tooth enamel and that of drinking water was used to reconstruct changes in the Miocene oxygen isotope ratio of rainfall (meteoric water ${\delta }^{18}$O_MW). These, in turn, are related to climatic parameters (temperature, precipitation and evaporation rate). ${\delta }^{18}$O values of rhinocerotid teeth from the Aquitaine Basin (southwestern France) suggest a significant climatic change between 17 and 12 Ma, characterized by cooling together with precipitation increase, in agreement with other terrestrial and oceanic records. To cite this article: I. Bentaleb et al., C. R. Geoscience 338 (2006).  相似文献   

Geographical Thought: An Introduction to Ideas in Human Geography by Anoop Nayak and Alex Jeffrey. Pearson Education,Harlow, 2011, xv + 337 pages (ISBN 978‐0‐13‐222824‐4) (pbk).     

Ron Johnston 《Singapore journal of tropical geography》2012,33(3):414-416

  相似文献   

Palaeoleptus burmanicus n. gen., n. sp., an Early Cretaceous shore bug (Hemiptera: Palaeoleptidae n. fam.) in Burmese amber     

George Poinar Jr.  Ron Buckley 《Cretaceous Research》2009,30(4):1000-1004

Palaeoleptus burmanicus gen. et sp. nov. (Hemiptera: Leptopodomorpha: Palaeoleptidae fam. nov.) is described from Early Cretaceous Burmese amber. The fossil is characterized by nearly completely coreaceous wings with only a small membranous area at the distal tip, and a unique wing venation consisting of eight closed cells, including four obliquely orientated toward the embolar wing margin and two large vertically-positioned cells extending nearly to the apical wing margin. Additional characters are large, compound eyes, three pairs of cephalic trichobothria, four antennal segments all similar in texture, spines on the profemur, ocelli positioned on a tubercle and a rostrum extending to the mesocoxae, with the second segment bearing four pairs of spines. The female fossil contains an asymmetrical subgenital plate orientated toward the left side of the body, indicating a side-by-side mating behavior as occurs in extant Leptopodomorpha.  相似文献   

A Student's Introduction to Geographical Thought: Theories,Philosophies, Methodologies          下载免费PDF全文

Ron Johnston 《Geographical review》2018,108(2):315-318

  相似文献   

Long-term optical variability properties of the Palomar–Green quasars     

Uriel Giveon †  Dan Maoz  Shai Kaspi  Hagai Netzer  Paul S. Smith 《Monthly notices of the Royal Astronomical Society》1999,306(3):637-654

  相似文献   

Learning and regional development     

Ron Boschma 《GeoJournal》1999,49(4):339-343

  相似文献