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Mahaney W.C.,Quaternary Surveys | Barendregt R.W.,University of Lethbridge | Allen C.C.R.,Queens University of Belfast | Milner M.W.,MWM Consulting | Bray D.,University of Lethbridge
Cretaceous Research | Year: 2013

Coprolites from the Beechy Member of the Cretaceous Bearpaw Formation, southern Saskatchewan, presumably deposited by one or more species of mosasaur or large fish/shark, were recovered and analyzed using SEM/EDS. The data reveal the presence of pseudomorphous coccoid bacteria, potential filamentous bacteria, bacterial endospores and filamentous fungi. No recorded fossil plant or bone material could be identified, either within the highly compressed coprolitic mat-flattened full coprolite bolus - of recovered marine sediment encased in a mixed mat of hematite-apatite primary minerals heavily coated with Ca-smectite and nontronite, or the full coprolite bolus. The presence of fossil bacteria with morphological characteristics similar to those of endospores in other environments suggests that only robust microbial forms such as these survive diagenesis, partly with some carbon still intact, the remainder replaced with silica and iron. The data support the view that coprolites can serve as a useful source of information on the ancient microbial world. © 2012 Elsevier Ltd.

Mahaney W.C.,Quaternary Surveys | Milner M.W.,MWM Consulting
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2011

Red pine (Pinus resinosa) growing in sandy soil of Glacial Lake Whittlesey age (~. 13-12. ka) in the town of Waterford, Ontario, Canada, north of Lake Erie, was struck by lightning in a fierce thunderstorm, May, 2010. The lightning strike was strong enough to destroy television sets and telephones in nearby houses and two red pines were struck, one split down the middle from above the bole to near the crown. Samples of bark and inner tissue were examined to determine the composition of black silt-size specs seen on the severed material. In addition to minerals found in abundance in the local soil, C clots/spherules, disrupted cellulose structures, blackened tissue, fused disfigured Si and metallic sheets of Na, the latter sourced from melted albite (Na-rich plagioclase), were analyzed. Many silt and sand size particles, sourced from the local soil were presumably electrically-levitated along and within the bark by the lightning discharge. Iron-rich micas, other Fe minerals and a great range of light minerals moistened by torrential rain were among the silts and sands transported to great height and embedded in the bark. © 2011 Elsevier B.V.

Mahaney W.C.,Quaternary Surveys | Mahaney W.C.,York University | Hancock R.G.V.,McMaster University | Milan A.,York University | And 4 more authors.
Geomorphology | Year: 2014

Macrofabric analysis of till sections in south-central Ontario confirms that clast orientation yields information related to changing ice dynamics during the Wisconsinan glaciation. Test stations in six sections yield unimodal to multimodal macrofabrics that indicate ice flow direction, ranging from SE-NW vectors when ice was thin and flowing radially to variable NE-SW, NNE-SSW, and N-S vectors when ice thickened. Ice loci appear to range from the Lake Ontario basin and southern Quebec (thin ice), Labrador Ungava (thicker ice), and Hudson Bay (thickest ice). The north-south fabric may identify the intergrowth of Keewatin-Labrador ice, presumably the maximum ice thickness of the Last Glacial Maximum (LGM). The preliminary data support the theory that topography directed ice movement during preliminary and closing stages of glaciation in southern Ontario, while thick ice generated flow vectors largely unaffected by underlying topography; hence, leading to clast azimuthal variations reflecting changing ice loci with glacier growth. The fabrics analyzed suggest that inferring difference between ductile and brittle lodgement tills is possible as well as to identifying possible glacial tectonic action/overburden loading that disturbs the least friction-fit position of clasts in till. The changing dynamics within till sheets are supported, in part, by variations in glacial crushing seen in SEM imagery that depict a range of microtextures from full-scale fractures under brittle conditions to those indicating less viscous transport under ductile regimes. To some degree, changes in flow direction are further supported by geochemical variations that relate to bedrock/regolith up-glacier controlling Ca-dilution and variable concentrations of Rare Earth Elements (REEs). © 2013 Elsevier B.V.

Mahaney W.C.,Quaternary Surveys | Hart K.M.,Dublin City University | Oreilly S.S.,Dublin City University | Allen C.C.R.,Queens University of Belfast | And 4 more authors.
Planetary and Space Science | Year: 2012

Bulk paleosol samples collected from a Middle to Early Miocene moraine in the New Mountain area of the Dry Valleys, Antarctica, yielded Coleoptera exoskeletons and occasional endoskeletons showing considerable diagenetic effects along with several species of bacteria, all lodged in a dry-frozen but salt-rich horizon at shallow depth to the land surface. The till is at the older end of a chronologic sequence of glacial deposits, thought to have been deposited before the transition from wet-based to cold-based ice (∼15 Ma), and hence, entirely weathered in contact with the subaerial atmosphere. It is possible, though not absolutely verifiable, that the skeletons date from this early stage of emplacement having undergone modifications whenever light snowmelt occurred or salt concentrations lowered the freezing temperature to maintain water as liquid. Correlation of the Coleoptera species with cultured bacteria in the sample and the likelihood of co-habitation with Beauveria bassiani found in two adjacent, although younger paleosols, leads to new questions about the antiquity of the Coleoptera and the source of N and glucose from chitinase derived from the insects. The skeletons in the 831 section may date close to the oldest preserved chitin (Oligocene) yet found on Earth. While harsh Martian conditions make it seemingly intolerable for complex, multicellular organisms such as insects to exist in the near-surface and subaerially, life within similar cold, dry paleosol microenvironments (Cryosols) of Antarctica point to life potential for the Red Planet, especially when considering the relatively diverse microbe (bacteria and fungi) population. © 2011 Elsevier Ltd. All rights reserved.

Mahaney W.C.,Quaternary Surveys | Mahaney W.C.,York University | Voros J.,York University | Krishnamani R.,The Rainforest Initiative | And 4 more authors.
Geografiska Annaler, Series A: Physical Geography | Year: 2016

The Neem tree, the oil of which has a long history of pesticide, fertilizer and medicinal use in India, has been studied extensively for its organic compounds. Here we present a physical, mineralogical and geochemical database resulting from the analyses of two Neem soil profiles (epipedons) in India. Neem tree derivatives are used in the manufacture of a variety of products, from anti-bacterial drugs and insecticides to fertilizers and animal feeds. A preliminary geochemical and mineralogical analysis of Neem soils is made to explore the potential for chemical links between Neem tree derivatives and soils. Physical soil characteristics, including colour, texture and clay mineralogy, suggest the two pedons formed under different hydrological regimes, and hence, are products of different leaching environments, one well-drained site, the other poorly drained. Geochemically, the two Neem soils exhibit similarities, with elevated concentrations of Th and rare earth elements. These elements are of interest because of their association with phosphates, especially monazite and apatite, and the potential link to fertilizer derivatives. Higher concentrations of trace elements in the soils may be linked to nutritional derivatives and to cell growth in the Neem tree. © 2016 Swedish Society for Anthropology and Geography.

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