نتایج جستجو برای: sedimentary rock

تعداد نتایج: 48134  

Journal: :Proceedings. Biological sciences 2009
Felix G Marx

The validity of biological explanations of patterns of palaeodiversity has been called into question owing to an apparent correlation of diversity with the amount of sedimentary rock preserved. However, this claim has largely been based on comprehensive estimates of global marine Phanerozoic diversity, thus raising the question of whether a similar bias applies to the records of smaller, well-d...

2015
J C Bridges S P Schwenzer R Leveille F Westall R C Wiens N Mangold T Bristow P Edwards G Berger

The Mars Science Laboratory rover Curiosity found host rocks of basaltic composition and alteration assemblages containing clay minerals at Yellowknife Bay, Gale Crater. On the basis of the observed host rock and alteration minerals, we present results of equilibrium thermochemical modeling of the Sheepbed mudstones of Yellowknife Bay in order to constrain the formation conditions of its second...

2018
Michael P Russell Victoria K Gibbs Emily Duwan

Sea urchins are dominant members of rocky temperate reefs around the world. They often occur in cavities within the rock, and fit so tightly, it is natural to assume they sculpted these "pits." However, there are no experimental data demonstrating they bore pits. If they do, what are the rates and consequences of bioerosion to nearshore systems? We sampled purple sea urchins, Strongylocentrotus...

2012
Oleg V. Mikhailov M. Nafi Toksoz

Measuring the electrical field induced by a borehole Stoneley wave is a new method for characterizing a rock formation around a borehole. Our field measurements demonstrate that the Stoneley-wave-induced electrical field can be detected in sedimentary rocks (dolomite in our experiment), and that the amplitude of this electroseismic phenomenon can be used to detect isolated fractures and permeab...

Journal: :Environmental science. Processes & impacts 2013
Doris Wagner Antoni E Milodowski Julia M West Joanna Wragg Hideki Yoshikawa

This study investigates the influence of microbes on fluid transport in sedimentary and igneous host rock environments. It particularly focuses on granodiorite rock (Äspö; Sweden) and mudstone (Horonobe; Japan) that were utilised during laboratory-based column experiments. The results showed that biofilms form on both rock types in low nutrient conditions. Cryogenic scanning electron microscopy...

Journal: :Journal of the Japanese Association for Petroleum Technology 1972

2016
D. Stöffler K. Metzler

Introduction: Shocked rocks are known from various planetary bodies of the solar system including Earth, Moon, Mars, and several types of asteroids. It was first recognized on Earth that stages of progressive shock metamorphism can be defined [1,2,3,4] and this concept was later on confirmed for lunar rocks [5] and meteorites [6,7,8]. Initiated by the IUGS “Subcommission on the Classification o...

2016
Yong-Xiang Li Kenneth P. Kodama

Magnetic anisotropy and the elongation/inclination (E–I) approaches have been increasingly employed as two important means for detecting and correcting the paleomagnetic inclination shallowing in sedimentary rocks that was first recognized 60 years ago. Both approaches are based on certain assumptions, and thus have advantages and intrinsic limitations in investigating shallow inclinations in s...

Sedimentary Copper mineralization has been observed in Monj and Jolany locations in Bavanat (Sanandaj – Sirjan metamorphic belt). According to current study, the host rocks for copper mineralization in this area are green sandstones, generally in subarkose and arkose groups. Age of these sandstones is middle Jurassic. Copper mineralization is observed in two forms, sulfides form including chalc...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید