Basaltic Rocks Make Up Most Of The Seafloor
Are denser than basaltic compositional rocks.
Basaltic rocks make up most of the seafloor. Examples of igneous rock are basalt granite and andesite fig. Basaltic magmas that form the oceanic crust of earth are generated in the asthenosphere at a depth of about 70 kilometres. The tholeiitic and the alkali basalts. The slow cooling at depth allows large crystals to grow.
Make up most of the seafloor. Forces are applied equally in all directions. If you could slice through the earth from it s inner most core at 6 371 km beneath the surface of the planet to its outer shell you would find a variety of solid dense metals in the hottest interior perhaps as hot at 4 300 c or 7000 f that are surrounded by an outer core of liquid metals continuing to move outward into the mantle you would then encounter solid rock towards. Most of the rocks of the earth s crust are igneous although sedimentary rocks usually cover them.
This hot rock melts as the divergent boundary pulls apart and the molten rock erupts onto the sea floor. Igneous rocks with an andesitic composition. Other articles where basaltic magma is discussed. Are denser than granitic compositional rocks.
Here convection currents deliver hot rock from deep in the mantle. Porosity is a measure of the volume of open space in rocks and unconsolidated geological materials such as alluvium and soils a. Learn more about basalt in this article. Basalts at oceanic divergent boundaries.
Basaltic rocks make up most of the sea floor. Most of earth s basalt is produced at divergent plate boundaries on the mid ocean ridge system see map. Basalt extrusive igneous volcanic rock that is low in silica content dark in color and comparatively rich in iron and magnesium. Intrusive igneous rocks are often characterized as coarse grained because.
Basalts may be broadly classified on a chemical and petrographic basis into two main groups. The mantle rocks located at depths from about 70 to 200 kilometres are believed to exist at temperatures slightly above their melting point and. The rock cycle is the transition of rocks among three different rock types over millions of years of geologic time fig. Have a similar texture.
Are found primarily in continental interiors. Basalt is an aphanitic fine grained igneous rock that is relatively low in silica and alkali metals it has less than 10 feldspathoid by volume with at least 65 of the rock consisting of feldspar in the form of plagioclase this places basalt in the basalt andesite field of the qapf diagram basalt is further distinguished from andesite by its silica content of less than 52. Confining pressure where. Granite and gabbro.
Basalt is the most common type of igneous rock and it covers the ocean floor and thus exists.