Can a sedimentary rock become an igneous rock without changing first to a matamorphic rock?

Answer 1

Yes, of course there can. Igneous rocks are produced by fire - volcanoes, mostly. Sedimentary rocks are laid down in layers, usually on a seabed. The two processes are, in nearly every case, completely independent. there is, however, one case in which a rock can be both igneous and sedimentary - when a series of volcanic eruptions produce bast quantities of ash, which floats on the breeze, comes down into the sea, sinks to the bottom and forms - sediment.

Answer 2

Igneous rocks are formed by heat, partially melting solid material. The heating and melting process is slow and any sedimentary deposits taken into the melting environment will indeed be first metamorphosed in the process.

Sedimentary rocks can be caught up as inclusion in moving/intrusive magmas (as xenoliths) if the melt cools slowly then these inclusions can dissolve into the magma. However, because of the slow movement and gradual intrusion of magma into the host rock above it, metamorphosis is most likely to occur from a gradual increase in temperature, not the rapid melting and cooling into new igneous rock.

One of the only ways that sedimentary rock can directly become igneous is through a meteor impact event. In this case, a silicate sedimentary rock can turn into a volcanic glass almost instantly through melt and solidification.

Answer 3

Yes.