Results 41 to 50 of about 2,811 (192)
Proterozoic basins of Canada: Early Proterozoic sequences in Labrador
, 1981 Early Proterozoic ( Aphebian) sedimentary and volcanic rocks in Labrador are described from two tectonic belts: the Churchill Province of western Labrador, and the Makkovik Subprovince of eastern Labrador. The Aphebian in the Churchill Province is represented mainly by the Labrador Trough ( Kaniapiskau Supergroup) but also in the Laporte Croup, Lake ...
R J Wardle, D G Bailey
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Two new endemic species of Portulaca (Portulacaceae) from the Brazilian Pampa grasslands
Nordic Journal of Botany, EarlyView.Portulaca L. is a monophyletic, cosmopolitan genus of succulent plants comprising ca 153 species, with particularly high diversity in xerophytic ecosystems in tropical and subtropical regions. Based on morphological evidence, we describe and illustrate two new species from the Brazilian Pampa, Portulaca guaritensis and Portulaca guenoa.
José Roberto Ferraz +3 more
wiley +1 more source
Geology of Elu Inlet and Melville Sound, Nunavut, Arctic Canada
Journal of Maps, 2017 We present the results of helicopter- and field-based geological mapping of Elu Inlet and Melville Sound, Kitikmeot Region of Nunavut, Arctic Canada. The area includes a ∼150 km-wide belt of Proterozoic sedimentary rocks that unconformably overlie the ...
Alessandro Ielpi +3 more
doaj +1 more source
Metamorphosed and deformed pillows from Losomäki: evidence of sub-aqueous volcanism in the Outokumpu association, eastern Finland [PDF]
Bulletin of the Geological Society of Finland, 1981 Pillow lavas, some highly deformed and now seen as banded diopside amphibolites and tremolite-epidote-chlorite rocks (»barren skarn»), occur within the lower Proterozoic Outokumpu rock association at Losomäki, 50 km N.W. of Outokumpu.
A.F. Park, D.R. Bowes
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Sustainable Development, EarlyView.ABSTRACT Colorado's geologic, pedologic, topographic, hydrological, and climatic contrasts create strong but under‐synthesized opportunities for sustainable agritourism. This review investigates how geodiversity, and the broader environmental heterogeneity within which it operates, can be used to diversify farm income, strengthen place‐based visitor ...
Bonface O. Manono
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Thermal and Compositional Anomalies of the Australian Upper Mantle From Seismic and Gravity Data
Geochemistry, Geophysics, Geosystems, 2020 To discern temperature and compositional variations of the Australian upper mantle, we apply an integrative technique, which jointly interprets seismic tomography and gravity data.
Magdala Tesauro +2 more
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Talc‐Tempered Pottery From Bala Hissar, Kabul: An Analytical Study
Archaeometry, EarlyView.ABSTRACT Potsherds of cooking ware excavated at Bala Hissar archaeological site in Kabul were studied using X‐ray fluorescence (XRF), scanning electron microscope‐energy dispersive X‐ray spectrometry (SEM‐EDS), Raman spectroscopy, X‐ray powder diffraction (XRPD), thermogravimetric analysis (TGA) and optical microscopy.
Parviz Holakooei +4 more
wiley +1 more source
Journal of Palaeogeography, 2014 Detailed zircon U–Pb dating and whole-rock geochemical analyses were carried out on the sedimentary rocks of the Paleogene Dainan Formation from Gaoyou Sag in the North Jiangsu Basin, East China. Whole-rock rare earth element characteristics suggest that
Chun-Ming Lin +5 more
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Boreas, EarlyView.A detailed morphometric analysis of 200 cirques across the western Putorana Plateau, central Siberia, was undertaken to investigate cirque development, reconstruct glaciers and infer palaeoclimatic conditions. Cirques are amphitheatre‐shaped landforms with mean length and widths of 936 and 1000 m, respectively, indicating a mature glacial landscape ...
Rachel P. Oien, Ethan Lee
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Morphometric convergence between Proterozoic and post-vegetation rivers
Nature Communications, 2017 It has been previously assumed that deep river channels could not have developed in the Proterozoic due to lack of vegetation. Here, the authors present remote sensing and outcrop data to show that large scale and deeply channelled river networks did ...
Alessandro Ielpi +3 more
doaj +1 more source