Basaltic Rocks Make Up Most Of The Sea Floor True False

One magma can produce several different igneous rocks having different mineral compositions.

Basaltic rocks make up most of the sea floor true false. The pressures at depth causes them to have a rough texture d. Most of earth s basalt is produced at divergent plate boundaries on the mid ocean ridge system see map. False t f the particles in breccia are primarily silt sized. Basalt is a major rock type that occurs in virtually every tectonic setting.

Here convection currents deliver hot rock from deep in the mantle. It is thinner denser younger and of different. This hot rock melts as the divergent boundary pulls apart and the molten rock erupts onto the sea floor. True t f lignite and bituminous coals are sedimentary rocks.

The slow cooling at depth allows large crystals to grow. 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. Basalts at oceanic divergent boundaries.

The average rock density is about 2 7 g cm3 composition is comparable to the felsic igneous rock granodiorite. True t f glassy igneous rocks form when magma cools too fast for mineral grains to grow. The density is about 3 0 g cm3 composed mainly of the igneous rock basalt. False t f slate is associated with high grade metamorphism.

Oceanic crust is the uppermost layer of the oceanic portion of a tectonic plate it is composed of the upper oceanic crust with pillow lavas and a dike complex and the lower oceanic crust composed of troctolite gabbro and ultramafic cumulates. Granite and gabbro. Obsidian exhibits a texture. Learn more about basalt in this article.

Oceanic crust is about 6 km 4 miles thick. The tholeiitic and the alkali basalts. Basaltic rocks make up most of the sea floor. True t f basaltic rocks make up most of the sea floor.

Basalt is clearly the most common volcanic rock on earth and basaltic rocks including gabbro diabase and their metamorphosed equivalents are the most common rocks in the crust 2 basalt is also common on the moon and other rocky planets of the solar system. The topmost layer about 500 metres 1 650 feet thick includes lavas made of basalt that is rock material consisting largely of plagioclase and pyroxene oceanic crust differs from continental crust in several ways. Continental exceeds 70 kilometers under some mountainous regions while oceanic crust ranges from 3 to 15 kilometers. It is composed of several layers not including the overlying sediment.

Basalt extrusive igneous volcanic rock that is low in silica content dark in color and comparatively rich in iron and magnesium. The crust overlies the solidified and uppermost layer of the mantle the crust and the solid mantle layer together constitute oceanic lithosphere.