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Showing 1 to 20 of 403 for “"carbonates"”.
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U-Th Dating of lacustrine carbonates
Carbonates are prevalent in many modern and ancient lacustrine settings, but reconstructions of past lake levels or environments from such materials have been hindered by poor chronology. Uranium-thorium (U-Th) dating has the potential to fill a gap in current geochronological tools for such …
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Petrology and geochemistry of the Killdeer carbonates
… been replaced by zeolites, quartz varieties, and carbonates. Authigenic minerals include calcite, dolocmite, opal, chalcedony, megaquartz, pyroluaite(?), rare clay, and zeolites.</p> <p>Clinoptilolite is the most common zeolite occurring in most of the rock types. Offretite and chabazite occur in …
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Lipase catalyzed transesterification of plant oils with dialkyl carbonates
Dialkyl carbonates, especially dimethyl- and diethyl carbonate, have been explored as raw materials for lipase-catalyzed methyl and ethyl ester synthesis and as organic solvents for oilseed extraction. Palm kernels and other potential tropical oilseeds were used as raw materials for this study. The …
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HlGH RESOLUTION PALAEOMAGNETIC ANALYSES OF CRETACEOUS SHALLOW WATER CARBONATES
… borehole cores of Lower Cretaceous shallow water carbonates from Southern Italy was obtained and studied lithologically and palaeomagnetically. It was found that the rocks are organized in cyclic lithofacies representing depositional environments from subtidal to supratidal and their magnetic …
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Poroelastic properties of carbonates: a case study on Indiana limestones
… I estimate dynamic and static stiffnesses of carbonates as they often differ due to various effects, such as velocity dispersion, heterogeneity of the rock, and amplitudes of applied strain. The studied materials include carbonate rocks with similar mineralogy and porosity, but varying …
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Investigating the Fate of Mg-bearing Calcium Carbonates During Early Diagenesis
… facilitates Mg incorporation into calcium carbonates under conditions that approximate early diagenesis and burial. The study compares Mg-incorporation in carbonate precipitated from a solution with the composition of an idealized Silurian seawater in the presence of functionalized (-COOH) …
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Multi-functional polymers from polyamines and functional five-membered cyclic carbonates
… reaction of functional five-membered cyclic carbonates with polyamines. The functionality of the polymers defines their properties and their application: multi-functional poly(ethylene imine)s for antimicrobial polymer and primer polymer for textile finishing were prepared. The main concept …
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Calcite cements in carbonates of the Sverdrup Basin, Canadian Arctic Archipelago.
Calcite cements from the Upper Paleozoic sequences 2, 3 and 4 of the Sverdrup Basin (Canadian Arctic Archipelago) are the subject of this study. On a micro-scale, petrography with light microscopy, cathodoluminescence (CL), scanning electron microscopy (SEM) and staining helped to identify two main …
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Sedimentology, Diagenesis and Reservoir Characteristics of Eocene Carbonates Sirt Basin, Libya
ABSTRACT The reservoir quality of Middle Eocene carbonates in the intracratonic Sirt Basin (at the northern margin of the African continent) is strongly influenced by depositional facies and various diagenetic modifications. This thesis investigates the petrography, sedimentology, diagenetic …
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Analysis of cyclic shallow-water carbonates: Cambrian Highland Peak Formation, eastern Nevada
Several methods of analysis were used to test the robustness of sea level signals recorded in Middle to lower Upper Cambrian shallow-water carbonate rocks in the southwestern United States and to refine stratigraphic correlation of this interval. Embedded Markov chain and cycle architectural …
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Experimental investigation of imbibition in oil-wet carbonates under low IFT conditions
Natural reservoir drives and waterflooding in naturally fractured carbonate reservoirs with an oil-wet matrix generate very low oil production. Surfactants enhance oil recovery in these reservoirs by altering wettability and reducing interfacial tension (IFT). The main purpose of this research was …
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High resolution sequence stratigraphy of late Mississippian carbonates in the Appalachian Basin
The late Mississippian carbonates in the Appalachian Basin, U.S.A., were deposited on a huge, south-facing ramp during long-term Mississippian transgression that formed the Mississippian supersequence. The St. Louis- to Glen Dean interval consists of up to twelve fourth-order depositional sequences …
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Multifunctional chitosans obtained via polymer-analogous reaction with functional five-membered cyclic carbonates
… with ethylene carbonate or functional ethylene carbonates was studied. The results show that due to the low reactivity of the amino group in glucosamine repeating units this procedure is not viable. The carbonate coupler is a bifunctional molecule bearing two amino-reactive groups, which can be …
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Depositional constraints on lacustrine carbonates from the Winnemucca Dry Lake Basin, Nevada, USA
… paleoenvironmental histories, lacustrine carbonates are also important hydrocarbon reservoirs. Enormous quantities of oil and gas are stored in such reservoirs in South America, Africa, and China, and exploration continues for new lacustrine plays. Accordingly, understanding the …
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Trace elements in marine biogenic carbonates: analysis and application to past ocean chemistry
Trace elements in marine biogenic carbonates may be used as proxies for past ocean<br/>chemistry provided that there is an established relationship between the trace element<br/>proxy and a parameter of interest, this relationship is preserved within biogenic<br/>carbonate, and the trace element …
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