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Main Ranges (main + range)
Selected AbstractsDEVONIAN CARBONATES OF THE NIGEL PEAK AREA, ROCKY MOUNTAINS, CANADA: A FOSSIL PETROLEUM SYSTEM?JOURNAL OF PETROLEUM GEOLOGY, Issue 3 2008J. Köster In this study we report on Devonian (Frasnian , Famennian) limestones and dolostones exposed near Nigel Peak in the Main Ranges of the Canadian Rocky Mountains. These carbonates are a proximal facies of the Southesk-Cairn Carbonate Complex. The investigated strata are stratigraphically equivalent to the oil- and gas bearing Nisku Formation in the subsurface of the Western Canada Sedimentary Basin, about 300 km to the east. The rocks were investigated by polarisation and cathodoluminescence microscopy, total organic carbon analysis, Rock-Eval pyrolysis, solid bitumen reflectance measurements, gas chromatography and fluid inclusion analysis. Thin section analyses showed that silt-grade quartz and saddle dolomite increase upward from the base of the stratigraphic section, and that porosities are generally low. This is due to reduction of pore space due to early cementation and extensive dolomitization. Cathodoluminescence identified up to four generations of calcite cements. TOC values ranged from 0.2 to 2.4 %. Rock-Eval pyrolysis of carbonate samples resulted in measurable S1 peaks but not S2 peaks, indicating that there was no residual petroleum generation potential. Organic petrographic analyses identified dispersed kerogen and migrabitumen, and calculated vitrinite reflectance values were around 4 % on average which implies peak temperatures of 234,262 °C (due to deep burial) or 309,352 °C (due to short term hydrothermal heating). Fluid inclusion data indicates at least one pulse of hot fluids with elevated homogenization temperatures of > 300 °C, and this may explain the high thermal maturity of the studied rocks. [source] Description, biology and conservation of a new species of Australian tree frog (Amphibia: Anura: Hylidae: Litoria) and an assessment of the remaining populations of Litoria genimaculata Horst, 1883: systematic and conservation implications of an unusual speciation eventBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2007CONRAD J. HOSKIN The Australian populations of the green-eyed tree frog Litoria genimaculata consist of a northern and southern genetic lineage that meet in a mosaic contact zone comprising two independent areas of contact: one where the main ranges of the lineages overlap, and the second where a population of the southern lineage is isolated within the range of the northern lineage. A recent study failed to find significant reproductive isolation between the main ranges of the two lineages, despite deep genetic divergence, partial postzygotic isolation, and call differences. The study did, however, demonstrate rapid phenotypic divergence and speciation of the isolated population of the southern lineage from both the parapatric northern lineage and from the allopatric, but genetically similar, main range of the southern lineage. Herein, the isolated population of the southern lineage is described as a distinct species, Litoria myola sp. nov., whereas the remainder of the southern lineage and the northern lineage are retained as a single, paraphyletic species, Litoria genimaculata. Resolving this unusual systematic situation demonstrates the value of using multiple lines of evidence in delimiting species. Litoria myola sp. nov. has a very small distribution and population size and warrants a Critically Endangered listing (B1, 2) under IUCN criteria. Threats and management recommendations are outlined, and the conservation of hybrid zones as areas of evolutionary novelty is discussed. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 91, 549,563. [source] Glechoma hederacea (Lamiaceae) in North America: invasion history and current distribution,FEDDES REPERTORIUM, Issue 1-2 2004M. Scholler Glechoma hederacea L. (Ground-ivy, Lamiaceae), a perennial mat-forming herb, is native to the temperate regions of Eurasia and was introduced elsewhere (South East Asia, New Zealand and North America). Based on data obtained from herbaria, literature, online and other data bases and field studies, we documented the invasion history and current distribution of this plant in North America. At present, the plant is recorded from all but two continental states of the USA and all southern provinces of Canada. There are two main ranges: the larger one covers mainly the eastern part of the U.S.A. and a smaller one stretches along the West Coast. While published records of Glechoma hederacea date from 1814, the oldest specimen is from 1829. During the 19th century the species spread westwards at a rate of approximately 30 km/year. The spread and present range of G. hederacea can only be explained by climatic factors (degree of oceanicity) and considering human activity. Especially long distance propagation of vegetative parts of the plants and the change of the environment that accompanies human settlements may have had a major influence on these processes. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Glechoma hederacea L. (Lamiaceae) in Nordamerika: Invasionsgeschichte und derzeitige Verbreitung Glechoma hederacea (Gewöhnlicher Gundermann; Lamiaceae), eine im temperaten Eurasien beheimatete ausdauernde krautige Pflanze konnte sich als Neophyt in Südostasien, Neuseeland und Nordamerika etablieren. Basierend auf Daten aus der Literatur und Datenbanken, Belegdaten aus Herbarien und Felduntersuchungen werden die Ausbreitungsgeschichte der Art in Nordamerika und ihr gegenwärtiges Areal dokumentiert. Gegenwärtig ist die Art aus allen kanadischen Provinzen und mit Ausnahme von zwei Bundesstaaten auch von allen kontinentalen Bundesstaaten der USA dokumentiert. Es gibt zwei Hauptareale: ein großes, welches einen Großteil der östlichen USA einnimmt und ein kleineres an der Westküste. Der älteste Nachweis von 1814 von Glechoma hederacea stammt aus der Literatur, der älteste Beleg von 1829. Im Laufe des 19. Jahrhunderts breitete sich die Art mit einer Geschwindigkeit von etwa 30 km/Jahr nach Westen aus. Ausbreitungsgeschwindigkeit und das gegenwärtige Areal können nur mit Hilfe klimatischer (Ozeanität) und anthropogener Faktoren erklärt werden. Der Mensch trägt vor allem zur Verbreitung vegetativer Pflanzenteile bei und schafft in Siedlungen günstige Wachstumsbedingungen. [source] Regionalisation of chemical variability in European mountain lakesFRESHWATER BIOLOGY, Issue 12 2009LLUÍS CAMARERO Summary 1. We carried out a coordinated survey of mountain lakes covering the main ranges across Europe (including Greenland), sampling 379 lakes above the local tree line in 2000. The objectives were to identify the main sources of chemical variability in mountain lakes, define a chemical classification of lakes, and develop tools to extrapolate our results to regional lake populations through an empirical regionalisation or upscaling of chemical properties. 2. We investigated the main causes of chemical variability using factor analysis (FA) and empirical relationships between chemistry and several environmental variables. Weathering, sea salt inputs, atmospheric deposition of N and S, and biological activity in soils of the catchment were identified as the major drivers of lake chemistry. 3. We tested discriminant analysis (DA) to predict the lake chemistry. It was possible to use the lithology of the catchments to predict the range of Ca2+ and SO42, into which a lake of unknown chemistry will decrease. Lakes with lower SO42, concentrations have little geologically derived S, and better reflect the variations in atmospheric S loading. The influence of marine aerosols on lakewater chemistry could also be predicted from the minimum distance to the sea and altitude of the lakes. 4. The most remarkable result of FA was to reveal a factor correlated to DOC (positively) and NO3, (negatively). This inverse relationship might be the result either of independent processes active in the catchment soils and acting in an opposite sense, or a direct interaction, e.g. limitation of denitrification by DOC availability. Such a relationship has been reported in the recent literature in many sites and at all scales, appearing to be a global pattern that could reflect the link between the C and N cycles. 5. The concentration of NO3, is determined by both atmospheric N deposition and the processing capacity of the catchments (i.e. N uptake by plants and soil microbes). The fraction of the variability in NO3, because of atmospheric deposition is captured by an independent factor in the FA. This is the only factor showing a clear pattern when mapped over Europe, indicating lower N deposition in the northernmost areas. 6. A classification has been derived which takes into account all the major chemical features of the mountain lakes in Europe. FA provided the criteria to establish the most important factors influencing lake water chemistry, define classes within them, and classify the surveyed lakes into each class. DA can be used as a tool to scale up the classification to unsurveyed lakes, regarding sensitivity to acidification, marine influence and sources of S. [source] Description, biology and conservation of a new species of Australian tree frog (Amphibia: Anura: Hylidae: Litoria) and an assessment of the remaining populations of Litoria genimaculata Horst, 1883: systematic and conservation implications of an unusual speciation eventBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2007CONRAD J. HOSKIN The Australian populations of the green-eyed tree frog Litoria genimaculata consist of a northern and southern genetic lineage that meet in a mosaic contact zone comprising two independent areas of contact: one where the main ranges of the lineages overlap, and the second where a population of the southern lineage is isolated within the range of the northern lineage. A recent study failed to find significant reproductive isolation between the main ranges of the two lineages, despite deep genetic divergence, partial postzygotic isolation, and call differences. The study did, however, demonstrate rapid phenotypic divergence and speciation of the isolated population of the southern lineage from both the parapatric northern lineage and from the allopatric, but genetically similar, main range of the southern lineage. Herein, the isolated population of the southern lineage is described as a distinct species, Litoria myola sp. nov., whereas the remainder of the southern lineage and the northern lineage are retained as a single, paraphyletic species, Litoria genimaculata. Resolving this unusual systematic situation demonstrates the value of using multiple lines of evidence in delimiting species. Litoria myola sp. nov. has a very small distribution and population size and warrants a Critically Endangered listing (B1, 2) under IUCN criteria. Threats and management recommendations are outlined, and the conservation of hybrid zones as areas of evolutionary novelty is discussed. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 91, 549,563. [source] | ||||||||||