Geologia

Geology is the study of the earth. It includes not only the surface processes which have the earth’s surface, but the study of the ocean floors, and the interior of the earth.
Important point: Theearth has evolved (changed) throughout its history, and continue to evolve.
The earth is about 4.6 billion years old; human beings have been around for on past 2 million years.
* The firstmulti-celled organism appeared about 700 million years ago.
* Thus, mankind has been witness to only 0.043% of earth history.
A river deposits about 1mm of sediment (mud) each year.
Why study theearth?
We’re part of it. Dust to dust. Humans have the capability to change construction from houses to roads to dams are affected by the earth, and thus are some geologic knowledge.
Most surface rocksstarted out as igneous rocks-rocks produced by crystallization from a liquid.
If a rock becomes very, very hot, it may reach its melting temperature, that is, the temperature at which it begins tochange from a solid to a liquid.
Las rocas ígneas (latín ignius, "fuego") se forman cuando el magma (roca fundida) se enfría y se solidifica. Si el enfriamiento se produce lentamente bajo lasuperficie se forman rocas con cristales grandes denominadas rocas plutónicas o intrusivas, mientras que si el enfriamiento se produce rápidamente sobre la superficie, por ejemplo, tras una erupción volcánica,se forman rocas con cristales invisibles conocidas como rocas volcánicas o extrusivas. La menor parte de los 700 tipos de rocas ígneas que se han descrito se han formado bajo la superficie dela corteza terrestre. Ejemplos de rocas ígneas son la diorita, lariolita, el pórfido, el gabro, el basalto y el granito.
En otras palabras podemos decir que las rocas volcánicas o extrusivas, pertenecen a lacategoría de rocas ígneas.
1. Rocas plutónicas o intrusivas:
Se forman a partir de magma solidificado en grandes masas en el interior de la corteza terrestre. El magma de enfría lentamente lo...