Search results
Results from the WOW.Com Content Network
Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure conditions than those in which the original rock was formed. This process is called metamorphism, meaning to "change in form". The result is a profound change in physical properties ...
The field of geology encompasses the composition, structure, physical properties, and history of Earth's components, and the processes by which it is shaped. Geologists typically study rock , sediment , soil , rivers , and natural resources .
Primitive rocks are common on the surfaces of many asteroids, and the majority of meteorites are primitive rocks." [1]: 145 Widmanstätten pattern in an iron-rich meteorite. An example of a primitive rock is the achondritic iron-nickel octahedrite mineral seen in the Widmanstätten pattern that is found in a number of iron-rich meteorites.
Solidified lava flow in Hawaii Sedimentary layers in Badlands National Park, South Dakota Metamorphic rock, Nunavut, Canada. Geology (from Ancient Greek γῆ (gê) 'earth' and λoγία () 'study of, discourse') [1] [2] is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. [3]
Sedimentology is closely linked to stratigraphy, the study of the physical and temporal relationships between rock layers or strata. The premise that the processes affecting the earth today are the same as in the past is the basis for determining how sedimentary features in the rock record were formed.
It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. [1] [2] A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form.
A facies encompasses all the characteristics of a rock including its chemical, physical, and biological features that distinguish it from adjacent rock. [ 2 ] The term "facies" was introduced by the Swiss geologist Amanz Gressly in 1838 and was part of his significant contribution to the foundations of modern stratigraphy , [ 3 ] which replaced ...
Petrology (from Ancient Greek πέτρος (pétros) 'rock' and -λογία 'study of') is the branch of geology that studies rocks, their mineralogy, composition, texture, structure and the conditions under which they form. [1] Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. [2]