Late Miocene to Quaternary slip history across the Qiulitag anticline in the southern Tianshan piedmont     

Julien Charreau  Amandine Sartgou  Dimitri Saint‐Carlier  Jrme Lav  Pierre‐Henri Blard  Stphane Dominguez  Sheng Li Wang  Gang Rao 《地学学报》2020,32(1):89-96

In this study, we reconstruct the Miocene to Quaternary shortening history across the Qiulitag anticline, a complex fault‐bend fold located in southern Tianshan. We studied the Yaha and Kuche sections, where we combined surface structural measurements and seismic imaging to model the stratigraphic horizons. The history of folding was reconstructed based on magnetostratigraphic analyses and eight cosmogenic burial ages in Kuche. Pleistocene deformation rates were also quantified in Yaha based on a deformed fluvial terrace that we dated to ~67 ka using a cosmogenic depth profile. Our results suggest that the fold grew at a mean slip rate of 0.9–1.3 mm/a in both sections but accelerated to ~2.5 mm/a during the Pleistocene in Kuche. These results support a migration of the deformation towards the basin during the Pleistocene and suggest that most of the present deformation in the Tianshan is accommodated across the external structures of the range.  相似文献   

The palaeomagnetism and magnetic fabric of cave sediments from Grønligrotta and Jordbrugrotta, Norway     

Mark Noel  Shirley St  Pierre 《Geophysical Journal International》1984,78(1):231-239

Summary. Twenty-four oriented specimens of laminated clay were obtained from vertical sections in two caves in northern Norway. Studies of the magnetic remanence and susceptibility anisotropy show that the magnetization is depositional in origin and due to magnetite. The palaeomagnetic record in one section is correlated with results from a Swiss lake sediment core to suggest an age of 9600–6800 yr bp for the cave clay. It is shown that the susceptibility lineation produced on gently sloping surfaces was predominantly controlled by gravity and cannot therefore be used directly to estimate the palaeoflow or palaeofield directions.  相似文献   

    

Douglas M. Hawkins  Noel Cressie 《Mathematical Geology》1984,16(1):3-18

Geological data frequently have a heavy-tailed normal-in-the-middle distribution, which gives rise to grade distributions that appear to be normal except for the occurrence of a few outliers. This same situation also applies to log-transformed data to which lognormal kriging is to be applied. For such data, linear kriging is nonrobust in that (1)kriged estimates tend to infinity as the outliers do, and (2)it is also not minimum mean squared error. The more general nonlinear method of disjunctive kriging is even more nonrobust, computationally more laborious, and in the end need not produce better practical answers. We propose a robust kriging method for such nearly normal data based on linear kriging of an editing of the data. It is little more laborious than conventional linear kriging and, used in conjunction with a robust estimator of the variogram, provides good protection against the effects of data outliers. The method is also applicable to time series analysis.  相似文献   

Culture, nature and landscape in the Australian region     

Noel Castree  Lesley Head   《Geoforum》2008,39(3):1255-1257

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Kaolin deposits in the lower cretaceous Baqueró formation (Santa Cruz Province, Patagonia, Argentina)     

M.F. Cravero  E.A. Dominguez 《Journal of South American Earth Sciences》1992,6(4)

Sedimentary kaolin deposits in the Lote 18 area (Santa Cruz Province, Patagonia, Argentina) have been mined since 1951. They constitute 30% of the country's production and are mainly used in the ceramic whiteware industry. The deposits belong to the Baqueró Formation (Lower Cretaceous) and unconfomably overlie either the ash-flow tuffs of the Chon-Aike Formation (Middle Jurassic), which are altered to kaolinite and minor illite, or the ash-fall tuffs of Bajo Grande Formation (Upper Jurassic-Lower Cretaceous), which are altered mainly to smectites. The presence of illite or smectite, as well as the kaolinite crystallinity, depends on the stratigraphic position of the kaolin horizons within the Lower Member of the Baqueró Formation and on the lithology of the underlying rocks. Kaolin beds composed of well-crystallized kaolinite at the base of the sequence overlaying Chon-Aike rocks are the purest. Kaolinite becomes less well cystallized with transport. Edge-to-face and swirl SEM textural patterns indicate the compaction of flocculated clays and clay movement during drainage and compaction. Mineralogical, petrological, and physico-structural evidence (i.e., form, extent, thickness) indicates that the kaolin deposits are sedimentary, formed by the transportation and deposition of previously formed kaolinite. Kaolin beds are ovoidal in plan and lenticular in profile, with thickness ranging from centimeters to 11 meters, and the culmination of fining-upward clastic sequences. Sedimentary facies analysis indicates that the kaolin deposits were formed in a fluvial environment from currents with a high suspended-load/bed-load ratio, as would result from deposition in ox-bow lakes.  相似文献   

Hot Enough for You? A Spatial Exploratory and Inferential Analysis of North American Climate-Change Projections     

Noel Cressie  Emily L. Kang 《Mathematical Geosciences》2016,48(2):107-121

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Investigation of the atmospheric mechanisms related to the autumn sea ice and winter circulation link in the Northern Hemisphere   总被引：1，自引：0，他引：1  

Martin P. King  Momme Hell  Noel Keenlyside 《Climate Dynamics》2016,46(3-4):1185-1195

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Local influence diagnostics for the retrospective problem in sequential population analysis     

Cadigan  Noel G.; Farrell  Patrick J. 《ICES Journal of Marine Science》2005,62(2):256-265

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Time varying rotary spectra     

Henry Crew  Noel Plutchak 《Journal of Oceanography》1974,30(2):61-66

A method for computing and displaying the temporal variation of rotary spectral estimates is described. The method is applied to time series measurements of highly nonstationary winds and currents. The results indicate approximately fortnightly modulation of diurnal wind energy and inertial current energy.  相似文献   

Confidence regions in ternary diagrams based on the power-divergence statistics     

Frederick Medak  Noel Cressie 《Mathematical Geology》1991,23(8):1045-1057

Watson and Nguyen (1985) and Watson (1987) consider the problem of plotting confidence regions in a ternary diagram, for a trinomial probability vector , based on Pearson's x². Their results are extended to the power-divergence family of statistics resulting in confidence regions of diverse shapes and sizes. The members of the family with the most accurate coverage probabilities are =2/3 and =1/2.  相似文献