Basaltic Rocks Make Up Most Of The Seafloor

Basalt is the most common type of igneous rock and it covers the ocean floor and thus exists.

Basaltic rocks make up most of the seafloor. The tholeiitic and the alkali basalts. Are denser than basaltic compositional rocks. Porosity is a measure of the volume of open space in rocks and unconsolidated geological materials such as alluvium and soils a. This hot rock melts as the divergent boundary pulls apart and the molten rock erupts onto the sea floor.

Basalt extrusive igneous volcanic rock that is low in silica content dark in color and comparatively rich in iron and magnesium. Basaltic rocks make up most of the sea floor a true b false. Have a similar texture. The rock cycle is the transition of rocks among three different rock types over millions of years of geologic time fig.

Examples of igneous rock are basalt granite and andesite fig. Most of the rocks of the earth s crust are igneous although sedimentary rocks usually cover them. Basalts at oceanic divergent boundaries. Igneous rock is formed by the cooling and crystallization of molten magma at volcanoes and mid ocean ridges where new crust is generated.

Igneous rocks with an andesitic composition. Most of earth s basalt is produced at divergent plate boundaries on the mid ocean ridge system see map. Forces are applied equally in all directions. Confining pressure where.

Basalts may be broadly classified on a chemical and petrographic basis into two main groups. The slow cooling at depth allows large crystals to grow. Intrusive igneous rocks are often characterized as coarse grained because. Are denser than granitic compositional rocks.

Learn more about basalt in this article. Make up most of the seafloor. Basaltic magmas that form the oceanic crust of earth are generated in the asthenosphere at a depth of about 70 kilometres. Basaltic rocks make up most of the sea floor.

Other articles where basaltic magma is discussed. The mantle rocks located at depths from about 70 to 200 kilometres are believed to exist at temperatures slightly above their melting point and. Obsidian exhibits a texture. 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.

Here convection currents deliver hot rock from deep in the mantle.