4 laws of relative dating
Earthquake seismology has largely been responsible for defining the location of major plate boundaries and of the dip of subduction zones down to depths of about 700 kilometres at those boundaries.In other subdisciplines of geophysics, gravimetric techniques are used to determine the shape and size of underground structures; electrical methods help to locate a variety of mineral deposits that tend to be good conductors of electricity; and paleomagnetism has played the principal role in tracking the drift of continents.The combination of weathering and erosion leads to the wearing down or denudation of mountains and continents, with the erosion products being deposited in rivers, internal drainage basins, and the oceans. The unconsolidated accumulated sediments are transformed by the process of diagenesis and lithification into sedimentary rocks, thereby completing a full cycle of the transfer of matter from an old continent to a young ocean and ultimately to the formation of new sedimentary rocks.Knowledge of the processes of interaction of the atmosphere and the hydrosphere with the surface rocks and soils of the Earth’s crust is important for an understanding not only of the development of landscapes but also (and perhaps more importantly) of the ways in which sediments are created.The allied field of geophysics has several subdisciplines, which make use of different instrumental techniques.
Minerals as basic constituents of rocks and ore deposits are obviously an integral aspect of geology.
Geomorphology is concerned with the surface processes that create the landscapes of the world—namely, weathering and erosion.
Weathering is the alteration and breakdown of rocks at the Earth’s surface caused by local atmospheric conditions, while erosion is the process by which the weathering products are removed by water, ice, and wind.
Paleontological research of the fossil record since the Cambrian Period has contributed much to the theory of evolution of life on Earth.
Several disciplines of the geologic sciences have practical benefits for society.