This paper presents new valuable field data and a comprehensive approach to the determination of the rock mass classification and tunnel support systems for tunnels in unconsolidated sedimentary rocks as a special soil condition. The main objective of this study is to investigate and present the characteristics of the unconsolidated sedimentary rock by using the point load tests and slake durab...

There is a great need for more precise absolute ages for sedimentary rocks. We have been actively involved in developing techniques to directly date sedimentary rocks, rather than using associated igneous rocks, or using relative dating techniques. Sedimentary phosphate nodules (i.e. coprolites) are ideal candidates for absolute dating of sedimentary rocks. Phosphates occur commonly within the ...

The causes of mass extinctions and the nature of taxonomic radiations are central questions in paleobiology. Several episodes of taxonomic turnover in the fossil record, particularly the major mass extinctions, are generally thought to transcend known biases in the geologic record and are widely interpreted as distinct macroevolutionary phenomena that require unique forcing mechanisms. Here, by...

Two laboratory experiments were conducted to evaluate the amount of P utilization from two different types of sparingly soluble phosphate rock by aquatic biotic communities. The first type was Mussoorie Phosphate Rock or MPR (sedimentary in origin) and other was Purulia Phosphate Rock or PPR (igneous in origin). The two trials were with eight different treatment combinations. Among various trea...

An integrated nomenclature scheme is proposed to capture the inherent heterogeneity of fine-grained sedimentary rocks at the 102 to 1023 mm scale and to assist the evaluation of these rocks as sinks of organic carbon, barriers to fluid flows, and reservoirs of oil and gas. This scheme incorporates previous knowledge and the latest field, petrographic, and laboratory observations. We propose to ...

a r t i c l e i n f o a b s t r a c t Rock alteration and rind formation in analog environments like Antarctica may provide clues to rock alteration and therefore paleoclimates on Mars. Clastic sedimentary rocks derived from basaltic sources have been studied in situ by martian rovers and are likely abundant on the surface of Mars. However, how such rock types undergo alteration when exposed to...

A number of subjective and objective methods have been proposed, and are in use, to determine the roundness of sedimentary rock particles. Roundness, which is one of three properties describing the shape of a particle, is a measure of the extent to which the corners and edges of a particle have been worn away. The objective roundness measures are mainly based on the Fourier transform. In this p...

________________________________________ Introduction __ ___________________________________ Area covered.__________________________________ Aeromagnetic survey.___________________________ Gravity survey.________________________________ Acknowledgments--.. __1________________________ Geology __ __ ____________ _ Rock units_____________________________________ Carboniferous and older rocks._____...