What is the difference between basaltic and granitic magma

Yosemite Valley in the Sierra Nevada and Mt. Rushmore are two notable examples of granitic rocks. But granitic "basement rock" can be found just about everywhere east of the Rockies if you're willing to dig through the dirt and sedimentary rocks at the surface.

Granite is intrusive, which means that the magma was trapped deep in the crust , and probably took a very long time to cool down enough to crystallize into solid rock. This allows the minerals which form plenty of time to grow, and results in a coarse-textured rock in which individual mineral grains are easily visible.

Granite is the ultimate silicate rock. Relatively small amounts of iron and magnesium occur, but since they have generally higher densities it's not surprising that there isn't very much in the granite. Due to the process of differentiation , most of the heavier elements are moving towards the core of the earth, allowing the silicon and oxygen to accumulate on the surface.

And accumulate it has. We call this purified material felsic because of the relatively high percentage of silica and oxygen. Basalt is extrusive. The magma from which it cools breaks through the crust of the earth and erupts on the surface.

We call these types of events volcanic eruptions , and there are several main types. The volcanoes that make basalt are very common, and tend to form long and persistent zones of rifting in nearly all of the ocean basins.

Basalt is an igneous rock aphanitic fine-grained that is relatively low in silica and alkali metals. This kind of igneous rock consists of rock minerals such as porphyritic, phenocrysts containing larger crystals formed before the extrusion that brought the magma to the surface, embedded in a finer-grained matrix. These phenocrysts usually are of augite, olivine, or a calcium-rich plagioclase, which have the highest melting temperatures of the typical minerals that can crystallize from the melt and are therefore the first to form solid crystals.

Basalt is used for a huge variety of purposes. Basalt is cut into dimension stone. The lean slabs of basalt are cut and polished for use as building veneer, monuments, floor tiles, and other stone objects. It is also crushed for use as an aggregate in construction projects. These crushed rocks is used for road base, concrete aggregate, railroad ballast, filter stone in drain fields, asphalt pavement aggregate, and many other purposes.

Granite is an igneous rock that is light-colored with grains large enough to be visible with the unaided eye. It is composed of quartz and feldspar rock-forming mineral with minor amounts of mica, amphiboles, and other minerals. Basalt sometimes also contains vesicles. High silica content acidic Gabbro. Medium silica content. A layer of gabbro is found in the ocean crust, unerneath the basalt layer 0.

The lunar highlands have many gabbros made largely of potassium feldspar - also known as plagioclase Peridotite. Small crystals. Medium silica content intermediate. A fine-grained volcanic rock of granitic composition. Dark, dense. Ocean crust Density 2. Low silica content. They have been identified as major surface rocks on the dark lunar planes and much of Mars, Venus and the asteroid Vesta.