نتایج جستجو برای: hard rocks

تعداد نتایج: 168880  

Journal: :IOP conference series 2022

Abstract At the location of Pamukkulu dam, it has engineering geological characteristics that are less supportive construction above it, especially for foundation dam. By taking data directly in field and by laboratory testing, information is needed regarding characterization mineralogy properties rocks. Mineralogical analysis was performed with petrography X-Ray Diffraction (XRD) while rock we...

2012
B. Coyner M. Nafi

We use the ultrasonic transmission method to measure P-, SH-, and SV-wave velocities for Chelmsford Granite, Chicopee Shale, and Berea Sandstone in different directions up to 1000 bars confining pressure. The velocity measurements indicate that these three rocks are elastically anisotropic. The stiffness constants, dynamic Young's moduli, dynamic Poisson's ratios, and dynamic bulk moduli of the...

2003
M. P. Golombek J. R. Matijevic E. N. DiMaggio R. D. Schroeder

Introduction: The Viking and Mars Pathfinder landing sites and a wide variety of rocky locations on the Earth show size-frequency distributions that follow an exponential when expressed in cumulative fractional area covered by rocks of a given diameter or larger versus diameter plots. Mars lander rock distributions have been fit by an equation of the form: Fk(D) = k exp [-q(k) D], where Fk(D) i...

Rock fragmentation is one of the desired results of rock blasting. So, controlling and predicting it, has direct effects on operational costs of mining. There are different ways that could be used to predict the size distribution of fragmented rocks. Mathematical relations have been widely used in these predictions. From among three proposed mathematical relations, one was selected in this stud...

2000
Jürgen Schieber

As pointed out in the introduction to this book, shales contain the lion’s share of earth history that is recorded in sedimentary rocks. Understanding their deposition is key to the reconstruction of past oceans, landscapes, climates, and climatic cycles. Yet, whereas students of sandstones and carbonates have been able to learn a great deal about the deposition of these rocks from studying bed...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه زنجان - دانشکده علوم 1392

سنگ های آتشفشانی شرق تالاب گاوخونی در 140 کیلومتری جنوب شرق شهر اصفهان و جزو کمربند آتشفشانی ارومیه- دختر قرار دارد. هدف از این مطالعه، بررسی ژئوشیمیایی، تعیین موقعیت و جایگاه تکتونیکی، شناسایی چگونگی فرآیندهای ذوب بخشی و در نهایت تعیین منشأ ماگمای سنگ های آتشفشانی شرق تالاب گاوخونی است. در منطقه مورد مطالعه سنگ های آتشفشانی شامل ریولیت، ریوداسیت، داسیت، آندزیت، توف آندزیتی و توف داسیتی هستند. ...

1997
Chris Stassen

The oldest rocks which have been found so far (on the Earth) date to about 3.8 to 3.9 billion years ago (by several radiometric dating methods). Some of these rocks are sedimentary, and include minerals which are themselves as old as 4.1 to 4.2 billion years. Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on North America, Greenla...

Journal: :Science 2009
Rasmus Andreasen Mukul Sharma

O'Neil et al. (Reports, 26 September 2008, p. 1828) presented neodymium-142 data for rocks from northern Quebec, Canada, and suggested that these rocks may represent the oldest preserved crustal section on Earth. We argue that the age of the rocks is based on a spurious correlation between rocks that are probably not co-genetic and negative (142)Nd anomalies that may be the result of an analyti...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید