Дисертації з теми "Late Archaean"
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Robertson, S. "Late Archaean crustal evolution in the Ivisartoq region, southern west Greenland." Thesis, University of Exeter, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353048.
Повний текст джерелаOpiyo-Akech, Norbert. "Geology and geochemistry of the late Archaean greenstone associations, Maseno area, Kenya." Thesis, University of Leicester, 1988. http://hdl.handle.net/2381/35080.
Повний текст джерелаHapugoda, Hapugoda Udage Sarath. "Late Archaean and Early Proterozoic crustal evolution of the Georgetown Block, Northeast Queensland, Australia /." St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16503.pdf.
Повний текст джерелаBrewer, M. A. "The petrology of the Late Archaean gneisses and granites, Nunatarssuaq, Ivisartoq region, southern West Greenland." Thesis, University of Exeter, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370924.
Повний текст джерелаHofmann, Axel. "Sedimentology and tectonic history of late Archaean sedimentary successions in Zimbabwe a study in greenstone belt geology /." [S.l.] : [s.n.], 2001. http://ArchiMeD.uni-mainz.de/pub/2002/0026/diss.pdf.
Повний текст джерелаWoodhouse, Ailsa Jane. "Provenance of late archaean metasedimentary rocks on the southern Gawler craton : implications for its early crustal development /." Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09SB/09sbw889.pdf.
Повний текст джерелаSwain, Greg Martin. "Provenance and tectonics of the late Archaean mulgathing complex, central Gawler Craton : geochronological, geochemical and isotopic evidence for plume-arc interaction /." Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09SB/09sbs9715.pdf.
Повний текст джерелаHalimat, Olubukola Ibrahim. "Actinobacterial and archaeal diversity in lake Magadi, Kenya." University of the Western Cape, 2013. http://hdl.handle.net/11394/4253.
Повний текст джерелаMicroorganisms of the class Actinobacteria and domain Archaea are interesting from a biotechnological perspective owing to their metabolic attributes as producers of secondary metabolites and resilience under harsh environmental conditions respectively. Lake Magadi is a soda lake well studied in terms of its geology and limnology. Research attention has also been drawn to the microbial populations which thrive in this unique habitat but currently there are no reports on the assessment of its microflora using molecular methods. This study aimed to assess the actinobacterial and archaeal communities within Lake Magadi, Kenya a hypersaline –highly alkaline habitat using metagenomic methods as a preliminary study to identify potential candidates for exploitative biology Samples from two sites dubbed Lake Magadi station 2 (LM2) and Lake Magadi salt pan 4 (LMS4) within the Lake Magadi were analyzed using the 16S rRNA gene as a phylogenetic marker. Cluster analysis of taxon-specific 16S rDNA PCR-DGGE profiles revealed moderately heterogeneous actinobacterial and archaeal populations across the sample sites under investigation which is probably a reflection of the differences in abiotic conditions at the study sites. This observation was also confirmed from the multi-dimensional scaling (MDS) plot. PCR-based clonal libraries of actinobacterial and archaeal communities of both study sites retrieved a total of thirty-two clones (twenty actinobacterial and twelve archaeal) were sequenced. Analysis of the sequences revealed cultured and uncultured signatures of microorganisms typical of hypersaline and or highly alkaline niches. A few (3) sequences presented novelty (<96%) in identities with any previously identified organism. It was concluded that the species dominance at site LMS4 [situated within the salt flats of Lake Magadi and site for exploration of trona and its mineralized extensions (nacholite and gayllusite)] is likely to be dictated by anthropogenic stress since most of the microbial signals associated with the study site are typical of saline and or alkaline environmental samples exposed to especially mining but also agricultural and waste management practices. Isolation studies also revealed previously identified strains peculiar to hypersaline brines and sediments. The strains retrieved were affiliated to the taxonomically diverse genus Bacillus and Halomonas sp. The true applications and potential opportunities these isolates have for biotechnology have been well documented. Observations made from the culture dependent and culture independent methods suggests strongly that study site LMS4 is subjected to environmental conditions more severe than at site LM2. This study is a guide for future studies as it provides primary information on the haloalkaliphilic representatives of the actinobacteria phylum and domain Archaea within the soda lake environment. It can serve as a pedestal for investigation into the molecular machinery that supports the haloalkaliphilic lifestyles of inhabiting microorganisms and consequently give leads as to how they can be commercially exploited.
Carter, Alan Henry Charles. "Fluid-rock interaction and gold deposition within a late Archaen shear zone, Dalny Mine, Zimbabwe." Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277295.
Повний текст джерелаSchlais, Michael J. "Detection and Characterization of a Unique Ammonia Oxidizing Archaea; Cultured from Lake Superior." Bowling Green State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1416483554.
Повний текст джерелаLanyon, Clare. "16S rRNA gene sequence analysis of non-methanogenic Archaea in a hypereutrophic freshwater lake." Thesis, University of Liverpool, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402322.
Повний текст джерелаVert, Joshua Christopher. "Hypersaline Lake Environments Exhibit Reduced Microbial Dormancy." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/4050.
Повний текст джерелаClevinger, Curtis C. "Nitrifiers and their contribution to oxygen consumption in Lake Erie." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1385130018.
Повний текст джерелаShtarkman, Yury M. "Metagenomic And Metatranscriptomic Analyses Of Lake Vostok Accretion Ice." Bowling Green State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1438867879.
Повний текст джерелаOrland, Chloé Shoshana Jessica. "Assembly and functioning of microbial communities along terrestrial resource gradients in boreal lake sediments." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/284909.
Повний текст джерелаBorrel, Guillaume. "Diversité des archées et implication de la composante procaryote dans le cycle biogéochimique du méthane en milieu aquatique continental : études taxonomiques et fonctionnelles dans la colonne d'eau et les sédiments anoxiques du lac Pavin." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00932300.
Повний текст джерелаReboul, Guillaume. "Metabarcoding and metagenomic approaches to decipher microbial communities in suboxic environments Microbial eukaryotes in the suboxic chemosyn- thetic ecosystem of Movile Cave, Romania Hyper- diverse archaea near life limits at the polyextreme geothermal Dallol area Performance of the melting seawater-ice elution method on the metabarcoding characterization of benthic protist communities Core microbial communities of lacustrine microbialites sampled along an alkalinity gradient Environmental drivers of plankton protist communities along latitudinal and vertical gradients in the oldest and deepest freshwater lake Ancient Adaptive Lateral Gene Transfers in the Symbiotic Opalina-Blastocystis Stramenopile Lineage Marine signature taxa and microbial community stability along latitudinal and vertical gradients in sediments of the deepest freshwater lake." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL041.
Повний текст джерелаMicrobial ecology is the science of micro-organisms and their biotic and abiotic interactions in a given ecosystem. As technology has advanced, molecular techniques have been widely used to overcome the limitations of classical approaches such as culturing and microscopy. Indeed, the development of Next Generation Sequencing (NGS) technologies in the past twenty years has largely helped to unravel the phylogenetic diversity and functional potential of microbial communities across ecosystems.Nonetheless, most of the environments studied through these techniques concentrated on relatively easily accessible, tractable and host-related ecosystems such as plankton (especially in marine ecosystems), soils and gut microbiomes. This has contributed to the rapid accumulation of a wealth of environmental diversity and metagenomic data along with advances in bioinformatics leading to the development of myriads of tools. Oxygen-depleted environments and especially their microbial eukaryote components are less studied and may lead to future phylogenetic and metabolic discoveries.In order to address this, we conducted analyses on two poorly studied suboxic ecosystems: Movile Cave (Romania) and lake Baikal sediments (Siberia, Russia). In this task, we aimed at unveiling the taxonomic and functional diversity of microorganims in these environments.To do so, I first evaluated the available bioinformatics tools and implemented a bioinformatics pipeline for 16S/18S rRNA gene-based metabarcoding analysis, making reasoned methodological choices. Then, as a case study, I carried out metabarcoding analyses of the water and floating microbial mats found in Movile Cave in order to investigate its protist diversity. Our study showed that Movile Cave, a sealed off chemosynthetic ecosystem, harbored a substantial protist diversity with species spanning most of the major eukaryotic super groups. The majority if these protists were related to species of freshwater and marine origins. Most of them were putatively anaerobic, in line with the cave environment, and suggesting that in addition to their predatory role, they might participate in prokaryote-protist symbioses.In a second study, I applied my metabarcoding pipeline to explore unique and relatively unexplored environment of Lake Baikal sediments. I first applied a metabarcoding approach using 16S and 18S rRNA genes to describe prokaryotic as well as protist diversity. Overall, the communities within these ecosystems were very diverse and enriched in ammonia-oxidizing Thaumarchaeota. We also identified several typical marine taxa which are likely planktonic but accumulate in sediments. Finally, our sampling plan allowed us to test whether differences across depth, basin or latitude affected microbial community structure. Our results showed that the composition of sediment microbial communities remained relatively stable across the samples regardless of depth or latitude.In a third study, we applied metagenomics to study the metabolic potential of communities associated to Baikal sediments and to reconstruct metagenome-assembled genomes (MAGs) of dominant organisms. This revealed the considerable ecological importance of Thaumarchaeota lineages in lake Baikal sediments, which were found to be the major autotrophic phyla and also very implicated in the nitrogen cycle. Chloroflexi and Proteobacteria-related species also appeared ecologically important.This PhD thesis reveals the taxonomic diversity of poorly studied suboxic ecosystems and therefore contributes to our knowledge of microbial diversity on Earth. Additionally, the analyses of surface sediment samples in lake Baikal adds new light on freshwater-marine transitions. The metagenomic analyses reported here allowed us to postulate a model of nutrient cycle carried out by microorganismsin these sediments. Overall, this work sheds light on the microbial ecology of oxygen-depleted environments, and most notably lake Baikal surface sediments
Woodhouse, A. J. "Provenance of Late Archaean metasedimentary rocks on the southern Gawler Craton: Implications for its early crustal development." Thesis, 2002. http://hdl.handle.net/2440/123522.
Повний текст джерелаGeochemical, whole rock Sm-Nd and detrital zircon U-Pb isotopic data from Archaean metasedimentary successions in the southern Gawler Craton indicate derivation from Late Archaean sources. Detrital zircons from the upper amphibolite-grade Wangary Gneiss have dominant U-Pb age groupings at 2500-2580 Ma and 2600-2720 Ma, with a few analyses ranging up to 2950-3150 Ma. Steep LREE enrichment REE with (La/Yb)N = 46 – 58 and low abundances of compatible trace elements point to a major felsic source component, with REE patterns typical of Na-rich granites. Detrital zircons from the metasedimentary dominated Hall Bay Volcanics (2500-2560 and 2660-2710 Ma) show a similar range of detrital zircon ages to the Wangary Gneiss, suggesting both sequences were derived from a temporally similar Late Archaean source terrain. The Carnot paragneisses and the Hall Bay Volcanics metasedimentary rocks show comparative HREE enrichment ((La/Yb)N = 7.4-12.5 and (La/Yb)N = 10.2-15.7 respectively), suggesting a greater input of mafic or intermediate material relative to the Wangary Gneiss. The correspondence in detrital zircon ages between the Wangary Gneiss and Hall Bay Volcanic metasedimentary rocks suggests both units form part of the same succession. Existing zircon U-Pb data provides no evidence for input of Early Archaean crust into the Wangary Gneiss, Hall Bay Volcanics or Carnot paragneisses, which is further substantiated by Sm-Nd depleted mantle model ages that range from 2900 to 3200 Ma in all metasedimentary rocks. The overlap of detrital zircon and depleted mantle model ages suggests that all three successions in the southern Gawler Craton comprise a single basinal succession. The geochemical compositions of the late Archaean sequences in the southern Gawler Craton are consistent with derivation from a bimodal terrain with variable mixing of three distinct sources: (1) intermediate-felsic volcanics; (2) mafic rocks and (3) highly fractionated Na-rich felsic rocks (tonalites-trondhjemites). These source regions are currently unidentified in the Gawler Craton, however, source terrains for the late Archaean sequences may be preserved in association with the 2500-3000 Ma age crust in rifted off components of the Gawler Craton in Antarctica. Although speculative at this stage, deposition of the Late Archaean sequences in the southern Gawler Craton is likely to have occurred on a rifting margin to a Late Archaean terrain. Sedimentation was terminated during collisional closure of the basin system leading to the 2500-2400 Ma Sleafordian Orogeny.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2002
Hofmann, Axel [Verfasser]. "Sedimentology and tectonic history of late Archaean sedimentary successions in Zimbabwe : a study in greenstone belt geology / Axel Hofmann." 2001. http://d-nb.info/963778617/34.
Повний текст джерелаFinn, Gregory Clement. "Geochemical and isotopic evolution of the Maggo Gneiss component from the Hopedale Block, Labrador : evidence for Late-Middle Archaean crustal reworking /." 1988. http://collections.mun.ca/u?/theses,109660.
Повний текст джерелаHuang, Hsing-Hua, and 黃星華. "Isolation and Characterization of Methanogenic Archaea from Saline Meromictic Lake at Siberia." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/56088076326794241356.
Повний текст джерела國立中興大學
生命科學系所
104
Methane is important greenhouse gas, and northern lakes are the significant methane emission sites. And these accumulated methane are mainly contributed by the methanogenic archaea. To investigate the biodiversity of methanogens at northern lakes, sediments samples were collected from two saline meromictic lake Shira and Shunet. After anaerobic enrichment and serial diluted sub-transfer, partially purified cultures and pure isolates were obtained. Based on 16S ribosomal RNA gene sequences analysis, Clostridiales, Acholeplasmatales, Synergistales, Bacteroidales, Methanosarcinales, Methanomicrobiales and Methanobacteriales were detected from methanogenic enrichment cultures or pure isolates from Lake Shira and Shunet. A psychrotolerant, methylotrophic novel Methanolobus species, strain YSF-03, was isolated from sediments of Lake Shira. Cells of strain YSF-03 were non-motile, Gram negative, irregular cocci, 0.8-1.2 μm in diameter. The substrates for methanogenesis used by strain YSF-03 were methanol and trimethylamine. The temperature range of growth for strain YSF-03 was 0oC to 37oC with optimum growth conditions were 30-37oC, pH 7.0-7.4 and 0.17 M NaCl. The DNA G+C content of the genome of strain YSF-03 was 42.0 mol%. Phylogenetic analysis revealed that strain YSF-03 was most closely related to Methanolobus profundi MobMT (98.15% 16S rRNA gene sequence similarity). Genome relatedness between strain YSF-03 and Methanolobus profundi MobMT was computed using both genome-to-genome distance analysis (GGDA) and average nucleotide identity (ANI) with values of 23.5% and 79.3%, respectively. Based on morphological, phenotypic, phylogenetic and genomic relatedness data, it is evident that strain YSF-03 represents a novel species of the genus Methanolobus. It is expected that these methanogens from northern lakes contribute to taxonomy information on psychrophilic methanogenic archaea.
Wernke, Steven A. "An archaeo-history of Andean community and landscape the late prehispanic and early colonial Colca Valley, Peru /." 2003. http://www.vanderbilt.edu/wernke/WernkeDissertation2003.pdf.
Повний текст джерелаBiswas, Soumya. "Prokaryotic Biodiversity of Lonar Meteorite Crater Soda Lake Sediment and Community Dynamics During Microenvironmental pH Homeostasis by Metagenomics." Doctoral thesis, 2016. http://hdl.handle.net/11858/00-1735-0000-0028-880D-1.
Повний текст джерела