what kind of rock does the continental crust form?

Answer 1

By definition true continental crust is dominantly granitic in nature where as oceanic crust is basaltic. Depending on the age of the continental crust and it's geologic history the upper layers of the crust may be modified via sedimentary processes and large sequences or sediment deposited. Overall thickness of the the sedimentary (sandstone, limestone, shale, etc.) are usually thin compared to the entire thickness of the crust (average thickness is around 35 to 40 km). The crust may also be modified by metamorphic process during deep burial or collisions with other continents. Usually the older the continental crust the more complicated its history.

Answer 2

there's 2 kind of crust : continental crust and oceanic crust

Continental crust is also less dense than oceanic crust

The continental crust is the layer of granitic, sedimentary, and metamorphic rocks

Answer 3

Origin of the Earth's crust Earth is considered to have differentiated from an aggregate of planetesimals into its core, mantle and crust within about 100 million years of the formation of the planet, 4.6 billion years ago. The primordial crust was very thin, and was likely recycled by much more vigorous plate tectonics and destroyed by significant asteroid impacts, which were much more common in the early stages of the solar system. There is a theory that the Moon was formed by one such very large impact. The Earth has likely always had some form of basaltic oceanic crust, but there is evidence it has also had continental style crust for as long as 3.8 to 3.9 billion years. The oldest crust on Earth is the Narryer Gneiss Terrane in Western Australia at 3.9 billion years, and certain parts of the Canadian Shield and the Fennoscandian Shield are also of this age. The majority of the current Earth's continental crust was formed primarily between 4.6 billion years and 3.9 billion years ago, in the Hadean. The vast majority of rocks of this age are located in cratons where the crust is up to 70 km (40 mi) thick. The lower density of the continental crust as compared to the oceanic crust prevents it being destroyed by subduction. Crust formation is linked to periods of intense orogeny or mountain building; these periods coincide with the formation of the supercontinents such as Rodinia, Pangaea and Gondwana. The crust forms not so much by accumulation of granite and metamorphic fold belts, but by depletion of the mantle to form buoyant lithospheric mantle. Composition of the crust The common rock constituents of the Earth's crust are nearly all oxides; chlorine, sulfur and fluorine are the only important exceptions to this and their total amount in any rock is usually much less than 1%. F. W. Clarke calculated that a little more than 47% of the Earth's crust consists of oxygen. It occurs principally in combination as oxides, of which the chief are silicon, aluminium, iron, calcium, magnesium, potassium and sodium oxides. Silica is a major constituent of the crust occurring as the silicate minerals, which are the most common minerals of igneous and metamorphic rocks. From a computation based on 1672 analyses of all kinds of rocks Clarke arrived at the following as the average percentage composition by mass: Plates in the crust of the earth, according to the plate tectonics theory Plates in the crust of the earth, according to the plate tectonics theory Oxide Percent SiO2 59.71 Al2O3 15.41 CaO 4.90 MgO 4.36 Na2O 3.55 FeO 3.52 K2O 2.80 Fe2O3 2.63 H2O 1.52 TiO2 0.60 P2O5 0.22 total 99.22 All the other constituents occur only in very small quantities, and total less than 1%.[2]. Density for the upper crust varies between 2.69 g/cm3 and 2.74 g/cm3 and for lower crust between 3.0 g/cm3 and 3.25 g/cm3[1].

Answer 4

igneous?

Granite in the continental crusts

Basalt in the ocean crusts

Answer 5

From my dim memory ( like to answer w/out looking up the Ans), I think they are 1) Granite, 2) Sandstone and 3) Conglomerate...?

Answer 6

This is a big question. Igneous rocks: granites, diorites, basalts, andesites, dacites, tonelites, etc. Metamorphic rocks: amphibolites, granulites, hornfels, eclogites, etc. Sedimentary rocks: (all of them, both sili-clastics and chemical precipitates).