نتایج جستجو برای: sedimentary structure

تعداد نتایج: 1577589  

2013
Xinhu Li Yuan Guo

The method of sedimentary cycle division is studied based on comprehensive research and activity analysis of well logging, combined with wavelet analysis and characteristics of stratigraphic cycle. Based on the method above, this paper divided stratigraphic cycles and finely classified the tratifigraphic by taking H1518 in HSS oilfield as an example. The result shows that sedimentary cycle can ...

2015
Shigekazu Kusumoto Yasuto Itoh Keiji Takemura Tomotaka Iwata

In the two-dimensional discrete element modeling of displacement of sedimentary layers caused by faulting within the basement, we attempted to move a rigid basement as if it were an elastic basement by controlling its motion through application of dislocation solutions. An advantage of our modeling procedure is that we can discuss displacement fields of sedimentary layers in connection with fau...

Journal: :Science 2014
S M McLennan R B Anderson J F Bell J C Bridges F Calef J L Campbell B C Clark S Clegg P Conrad A Cousin D J Des Marais G Dromart M D Dyar L A Edgar B L Ehlmann C Fabre O Forni O Gasnault R Gellert S Gordon J A Grant J P Grotzinger S Gupta K E Herkenhoff J A Hurowitz P L King S Le Mouélic L A Leshin R Léveillé K W Lewis N Mangold S Maurice D W Ming R V Morris M Nachon H E Newsom A M Ollila G M Perrett M S Rice M E Schmidt S P Schwenzer K Stack E M Stolper D Y Sumner A H Treiman S VanBommel D T Vaniman A Vasavada R C Wiens R A Yingst

Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicate...

2003
Scott M. McLennan

Terrestrial planetary surfaces, other than Earth, are overwhelmingly basaltic in character. Because of this, among the most intriguing and significant results from recent studies of Mars are the occurrences of high-silica rocks at the Pathfinder site and orbital thermal emission spectroscopy evidence for a global petrological dichotomy with andesites dominating the entire northern hemispheric p...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2012
Jens Kallmeyer Robert Pockalny Rishi Ram Adhikari David C Smith Steven D'Hondt

The global geographic distribution of subseafloor sedimentary microbes and the cause(s) of that distribution are largely unexplored. Here, we show that total microbial cell abundance in subseafloor sediment varies between sites by ca. five orders of magnitude. This variation is strongly correlated with mean sedimentation rate and distance from land. Based on these correlations, we estimate glob...

Journal: :Astrobiology 2011
John Grotzinger David Beaty Gilles Dromart Sanjeev Gupta Mitch Harris Joel Hurowitz Gary Kocurek Scott McLennan Ralph Milliken Gian Gabrielle Ori Dawn Sumner

Processes that operate at planetary surfaces have the potential to record a history of planetary evolution in the form of sedimentary rocks. This is important because our experience on Earth shows that sediments and sedimentary rocks are the dominant archive of high-resolution proxies of present and past tectonic, climatic, and biological processes. Our understanding of the evolution of Earth’s...

Journal: :Marine geology 1986
J C Walker

Time resolved data on the carbon isotopic composition of carbonate minerals and the sulfur isotopic composition or sulfate minerals show a strong negative correlation during the Cretaceous. Carbonate minerals are isotopically heavy during this period while sulfate minerals are isotopically light. The implication is that carbon is being transferred from the oxidized, carbonate reservoir to the r...

S. H. Vaziri

Middle to Upper Triassic (Upper Ladinian to Lower Carnian) deep-sea sedimentary rocks crop out across a large area west of Nakhlak village, Central Iran and have been named Ashin Formation. The up to 304m thick, turbiditic, siliciclastic Ashin Formation consists of alternating turbiditic, thin- and medium-bedded calcareous sandstones, purple, fine-grained volcaniclastic sandstones, and mostly g...

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