Study of Geology

Geologic Time Scale  Table of Contents Introduction The Geologic Time Scale Precambrian Era Paleozoic Erai Mesozoic EraCenozoic Era Conclusion. * Objectives After attending this lesson, the user would be able to highlight the various periods of the earth's history. The origin and evolution of life that have happened during different periods will also be known. ✰   Introduction While studying the physical geology and history of the planet earth, it is necessary to know about the Geological Time Scale, in detail. The study of the geological time scale is necessary to every student of earth, atmospheric and all life sciences. The origin and evolution of the Earth took place over a period of billions of years. The evolution of life on earth is also a part of that prolonged Earth's history. It is a fact that the planet earth has evolved as one of the planets from the common nebulae. Due to this reason, the age of the

Sedimentary rocks Introduction All rocks on the surface of the Earth are exposed to the effects of erosion. The products of erosion accumulate to form sediments. Young sediments are unconsolidated (loosely connected) but with time they become consolidated and form sedimentary rocks. Sediments form on the surface of the Earth (most often underwater) and occur in layers – with the youngest layers at the top. The thickness of sediments on the surface of the Earth varies widely, from totally absent (for example at mid-ocean ridges) up to a maximum of ca. 20 km. Sedimentary rocks cover ca. 80% of the surface of the Earth, but contribute less than 1% to its mass. Sediments are, however, economically very important because they contain the major energy sources – coal, oil, and gas. 6.2 Weathering There are two types of processes that cause the alteration of rocks exposed on the surface of the Earth – physical and chemical. Physical or mechanical alteration results in rocks breaking into

Structure Geology Definition:-                Structural geology  is the study of the three-dimensional distribution of rock units with respect to their deformational histories.  Type of Structure Geology  Some of the  types  of  geological structures that are important to study include fractures, faults, and folds.  Structural geologists make careful observations of the orientations of these  structures  and the amount and direction of offset along faults.