Question

What do all rocks have in common? Rocks are made of how many minerals put together? How does Igneous Rocks form? What is the most unreliable source to identify a minerals property? Explain how each of the three kinds of sedimentary rocks form. List one example of each kind of rock. The meaning of the word "metamorphic" is The type of metamorphism that results from the heat of magma is called? Describes the processes by which sedimentary rock becomes metamorphic rock? Metamorphic rocks are often found in association with what geologic event?

Answer 1

Common in all rocks.

The color, composition, and texture are common in all rocks.

Rocks are made of minerals. Only a few minerals are rock forming and most rock is made from a combination of the commonest of these such as feldspars, quartz, mica, olivine, calcite, pyroxene and amphiboles. Most other minerals, of which there are over 3000 different types, are rarely present in quantities large enough to be considered rock forming.

Igneous rock is formed through the cooling and solidification of magma or lava. Igneous rock may form with or without crystallization, either below the surface as intrusive (plutonic)rocks or on the surface as extrusive (volcanic)rocks.

Color is probably one of the least reliable properties used in mineral identification. There are many minerals which have the same color, and many minerals have more than one color.

For example, hornblende, axinite, biotite, uraninite, pyrolusite, and aegerine are all black, or close to black. Sphalerite can be yellow, grey, brown, and black.

Things like hardness, cleavage, specific gravity, and crystal habit are much more diagnostic.

In most places on the surface, the igneous rocks which make up the majority of the crust are covered by a thin veneer of loose sediment, and the rock which is made as layers of this debris get compacted and cemented together. Sedimentary rocks are called secondary, because they are often the result of the accumulation of small pieces broken off of pre-existing rocks. There are three main types of sedimentary rocks:

Clastic: your basic sedimentary rock. Clastic sedimentary rocks are accumulations of clasts: little pieces of broken up rock which have piled up and been "lithified" by compaction and cementation.

Chemical: many of these form when standing water evaporates, leaving dissolved minerals behind. These are very common in arid lands, where seasonal "playa lakes" occur in closed depressions. Thick deposits of salt and gypsum can form due to repeated flooding and evaporation over long periods of time.

Organic: any accumulation of sedimentary debris caused by organic processes. Many animals use calcium for shells, bones, and teeth. These bits of calcium can pile up on the seafloor and accumulate into a thick enough layer to form an "organic" sedimentary rock.

The metamorphics get their name from "meta" (change) and "morph" (form).

The type of metamorphism that results from the heat of magma is called contact metamorphism.

Sedimentary rocks gets converted into metemorphic rocks Inside Earth there is heat from pressure . There is heat from friction ,these heat bakes the rock.

Baked rock does not melt, but it does change. It forms crystals. If it has crystals already, it forms larger crystals. Because this rock changes, it is called metamorphic.That change is called metamorphosis.

Metamorphic rocks are often found in association with what geologic event :mountain building