Geological dating problems
The power of the theory of plate tectonics lies in its ability to combine all of these observations into a single theory of how the lithosphere moves over the convecting mantle.
Advances in seismology, computer modeling, and mineralogy and crystallography at high temperatures and pressures give insights into the internal composition and structure of the Earth.
In this diagram based on seismic tomography, subducting slabs are in blue and continental margins and a few plate boundaries are in red.
The blue blob in the cutaway section is the Farallon Plate, which is subducting beneath North America.
) is an earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time.
Geology can also include the study of the solid features of any terrestrial planet or natural satellite such as Mars or the Moon.
These advances led to the development of a layered model of the Earth, with a crust and lithosphere on top, the mantle below (separated within itself by seismic discontinuities at 410 and 660 kilometers), and the outer core and inner core below that.
Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure.In practical terms, geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, and providing insights into past climate change.Geology is a major academic discipline, and it plays an important role in geotechnical engineering.Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates.Geologists use a wide variety of methods to understand the Earth's structure and evolution, including field work, rock description, geophysical techniques, chemical analysis, physical experiments, and numerical modelling.