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A facies study of the Des Moines series in the Forrest City BasinMaderak, M. L. (Marion Louis) January 2011 (has links)
Maps in pockets bound with piece. / Digitized by Kansas Correctional Industries
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Geochemistry and stratigraphy of the Cretaceous/Tertiary boundary impact ejecta.Hildebrand, Alan Russell. January 1992 (has links)
An array of stratigraphic, chemical, isotopic, and mineralogical evidence indicates that an impact terminated the Cretaceous Period. The 180-km-diameter Chicxulub crater, which now lies buried on the Yucatan peninsula of Mexico, was probably formed by the impact. The impactor was probably a long-period comet. Shock devolatization of the thick carbonate/evaporite sequence impacted at Chicxulub probably led to a severe and long-lasting greenhouse warming and a prompt pulse of sulfuric acid rain. The fallout of crater ejecta formed two layers: a lower layer which varies in thickness following a power-law relation based on distance from the Chicxulub crater and an upper, globally-distributed, uniformly ∼3-mm-thick layer. The upper layer probably represents the fallout of condensates and entrained solid and liquid particles which were distributed globally by the impact fireball. The lower layer consists of brecciated rock and impact melt near the crater and largely altered tektites far from the crater. The clasts of this layer were probably ballistically transported. The Raton, New Mexico K/T boundary section preserves the fireball and ejecta layers in a coal-free nonmarine environment. Siderophile, chalcophile, and lithophile trace element anomalies occur similar to those found at marine K/T boundary localities. Soot occurs peaking in the 3-mm-thick fireball layer and the immediately overlying 3 mm of sediment, implying prompt burning of the Cretaceous forests. The Brazos River, Texas continental-shelf K/T sections preserve coarse boundary sediments which were probably produced by impact waves. Siderophile and chalcophile trace-element anomalies occur suggesting that the fireball layer and possibly part of the ejecta layer are interbedded with the coarse boundary sediments. The Beloc, Haiti deep-sea K/T sections preserve a thick ejecta sequence including altered and unaltered tektites and shocked minerals capped by the fireball layer. The thick K/T ejecta preserved at this and other nearby K/T localities require a source crater of Chicxulub's size and location. The composition of the tektites and shocked grains require an impact into recently extracted continental crust with a carbonate/evaporite component as found at the Chicxulub crater.
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Sedimentology and sequence stratigraphy of Brigantian Yoredale Strata in Northern England and Scotland, U.KBrightmore, Ian William January 2010 (has links)
This study provides a sequence stratigraphic framework within which to consider Brigantian Yoredale strata. The framework has been used to determine the relative effects of syn-depositional tectonics, eustasy and climate on Yoredale sequence stratigraphic architecture within the northern Britain study area. Seventeen high-frequency depositional sequences have been identified and correlated within Brigantian strata in northern England and the Midland Valley of Scotland. Examination of sequence thickness and lithofacies stacking patterns has allowed the spatial and temporal occurrence of syn-depositional tectonism to be constrained and the effects on sequence and lithofacies architecture defined. The overall effect of tectonics on Yoredale sedimentation and cyclicity are interpreted to have been minimal. The correlation of sequence boundaries between the two very different tectonic regimes of northern England and the Midland Valley of Scotland would suggest that tectonics was not the driving mechanism behind cyclicity as suggested by some workers. Correlation of sequences with coeval sequences in the Illinois Basin of mid-continent North America demonstrates a lack of correlation to a particular tectonic regime or depositional facies type. The close similarity of sequence architecture between the Illinois Basin and northern British basins is taken to indicate that the sequences were synchronous depositional events that resulted from high-frequency eustatic sea-level changes. Glacio-eustasy provides the most logical explanation for the observed sequence architecture and apparent synchronous development of sequences and sequence boundaries across the northern Britain study area and globally.
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Characterisation of Triassic mudstones from the central North Sea : sedimentological, mineralogical and pore system propertiesWilkins, Anne D. January 2016 (has links)
No description available.
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Stratigraphic and structural development of the St. Vincent tertiary basin, South AustraliaStuart, William Joseph January 1969 (has links)
iii, 260 leaves : ill., charts & maps in back pocket / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1970) from the Dept. of Geology, University of Adelaide
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The biostratigraphy and palaeoecology of South Australian Precambrian stromatolitesPreiss, Wolfgang Victor January 1971 (has links)
Precambrian stromatolites in South Australia are almost entirely restricted to the folded rock sequence of the Adelaide Geosyncline, a large, deeply subsiding basin with predominantly shallow - water sediments. The history of research into the age and fossils of the Precambrian rocks is reviewed, and a possible time - framework is suggested on the basis of available radiometric data. Stromatolites, laminated structures formed by trapping of detritus and precipitation of chemical sediment by algae and bacteria, have been studied by other workers from at least two points of views : most Western authors regard stromatolite morphology to be purely environmentally determined, while one Russian school maintains that it is largely controlled by the algae present, and that stromatolites evolve as a consequence of the evolution of the algae forming them. They concluded this from an empirical study of widespread stromatolites of different ages, which made possible the biostratigraphic subdivision and correlation of many Late Precambrian sections. The Russian methods of study and taxonomy have now been applied to South Australian stromatolites for the first time. Of the eighteen forms of columnar stromatolites described, five are identical or nearly identical to Russian forms. Nine forms are new, but sufficiently similar to Russia forms to allow inclusion in the same groups as these. Groups and forms must be defined on the basis of numerous characters, which may be given different relative weighting for different taxa. The taxa so defined have restricted ranges in geological time. Stromatolite correlation with the Russian sequence suggests that the Early Adelaidean ( i.e. pre - tillite ) beds are middle Riphean ; the Skillogalee Dolomite is youngest middle Riphean, i.e. older than the Late Riphean Bitter Springs Formation of Central Australia. The Late Adelaidean Umberatana Group assemblage, correlated with the youngest Late Riphean, has seven groups in common with the Bitter Springs Formation, but unlike the latter, it overlies the lower tillite. A comparison with available radiometric data shouts good agreement for the Umberatana Group, but some conflict with one recent age determination exists for the Early Adelaidean. A study of the environments of growth of South Australian stromatolites shows that at least three forms, of widespread distribution, grew under a variety of conditions of energy, oxidation, type of sediment influx, and possibly salinity. The taxa defined are stable under these varying conditions, but there are minor modifications due to differences in environmental energy. Skillogalee Dolomite stromatolites grew under varying energy conditions on a very extensive and level carbonate depositing platform, frequently under hypersaline conditions. Umberatana Group stromatolites inhabited a marine environment, either in marginal littoral zones in the south - western and north - eastern Flinders Ranges, or on off - shore carbonate banks interpreted to be related to rising diapirs. In both cases, stromatolites formed during episodes of shallowing water depth. / Thesis (Ph.D.)--Department of Geology and Mineralogy, 1971.
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Mesozoic magmatic activity in Hong KongWong, Po-wan, Kenny. January 2006 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.
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Paleo-oceanography of the subtropical southeastern Pacific during late Quaternary : a study of radiolaria, opal and quartz contents of deep-sea sedimentsMolina-Cruz, Adolfo 28 May 1975 (has links)
Micropaleontological data have been analyzed through mathematical
and statistical procedures, in order to: (1) establish the distribution
pattern of radiolarian assemblages in the surface sediments,
(2) establish the relationship of these assemblages with oceanographic
variables, (3) determine the faunal composition down-core with
respect to the faunal surface pattern, and (4) estimate water temperatures
and 1OO M PO₄ within the geological past. This, together with
the analysis of opal and quartz content of the sediments, has permitted
the inference of the paleo-oceanography of the subtropical southeastern
Pacific during the last 75,000 years. Factor analysis shows
that five major radiolarian assemblages (factors), accounting for
93.6% of the variance, reflect the mixed layer circulation and its
associated water masses. According to their position in the area,
these factors are called: (1) the Subtropical factor, (2) the Equatorial
factor, (3) the Peru (current) factor, (4) the Chile (current) factor,
and (5) the Backwater factor. The subtropical factor is correlated
with "warm" water temperatures, the Equatorial factor with opal
production, the Peru factor with coastal upwelling, the Chile factor
with "cool" water temperatures, and the Backwater factor with
mixing of water masses. The distribution pattern of quartz reflects
the position of the southeast trade winds which largely control the
oceanographic conditions of the subtropical southeastern Pacific. The
opal distribution resembles the patterns of surface primary productivity.
Opal content is "high" below the Equatorial Undercurrent. However,
it is "low" along the South American coast probably due to
dilution by terrigenous input.
Cores RC11-230 (8°48'S-110°48'W), V19-29 (3°35'S-83°56'W),
and Y71-6-12 (16°26'S-77°23'W) were used in the stratigraphic study.
Their stratigraphic control (correlation) is made through their δ ¹⁸O
records. The changes of quartz, opal and radiolarian assemblages
contents down-core are considered to be the result of shifts or
changes in intensity of the atmospheric and oceanic circulation.
Oceanographic changes have occurred in the subtropical southeastern
Pacific during the last 75,000 years, but they are not manifested at
each location in the same form. These changes have not been synchronous
with changes of global ice volume; rather, during pronounced
climatic changes, a sequence which is initiated by changes in the wind
circulation is observed. The oxygen isotope stage 4 is characterized
by mixing of water masses, "deep" thermocline and low concentration
of nutrients. The lower interval of isotope stage 3 is characterized
by weakened wind-driven circulation and "high" water temperatures.
The middle of isotope stage 3 is a time in which wind-driven conditions
become dominant in the region. Oxygen isotope stage 2 is
"cool" and has strong wind-driven conditions. The shift to the
present oceanographic conditions in the subtropical southeastern
Pacific occurred 11,000 years ago. / Graduation date: 1976
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Geology of the Buster Creek-Nehalem Valley area, Clatsop County, northwest Oregon /Olbinski, James Steven. January 1983 (has links)
Thesis (M.S.)--Oregon State University, 1983. / Typescript (photocopy). Some col. ill. and col. maps folded in pocket. Includes bibliographical references (leaves 168-178). Also available via the World Wide Web.
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The Middle Paleozoic stratigraphy of the central Rocky Mountain region ... /Tomlinson, Charles Weldon. January 1900 (has links)
Thesis (Ph. D.)--University of Chicago, 1916. / "Private edition distributed by the University of Chicago Libraries, Chicago, Illinois." "Reprinted from the Journal of geology, Vol. XXV, Nos. 2-4, 1917."
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