Tag: lithosphere and asthenosphere

Igneous rocks form from molten rock, and rarely have fossils in them. Metamorphic rocks have been put under great pressure, heated, squashed or stretched, and fossils do not usually survive these extreme conditions. Generally it is only sedimentary rocks that contain fossils.

Igneous rock (derived from the Latin word ignis meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava.

Gypsum Products and Properties as a Building Material for Construction. Gypsum is one of the widely used construction material mainly in interior designing. Gypsum is used as surface materials. Its application is prominent in wall and ceiling construction.

Lithification is the process by which sediments combine to form sedimentary rocks. Compaction is a consolidation of sediments due to the intense pressing weight of overlying deposits. With compaction, sediment grains get squished together, reducing the size of the original pore space that divided them.

Plaster of paris originally was made from the extensive gypsum deposits of Montmartre in Paris.

Plaster of paris, consists of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry. Known since ancient times, plaster of paris is so called because of its preparation from the abundant gypsum found near Paris.

The igneous rocks are called primary rocks because these were originated first of all rocks during the formation of the upper crust of the earth on cooling, solidification, and crystallization of hot and liquid magmas after the origin of the earth. Thus, all the subsequent rocks were formed, whether directly or indirectly, from the igneous rocks in one way or the other.

• Rocks formed after evaporation of water are called evaporites. Gypsum is an example of evaporites.
  
• Plaster of Paris is manufactured from gypsum and thus it is a secondary product hence cannot be the right answer here.
• Thus option B ie gypsum is the right answer.

• Rocks formed by the cooling of molten rock are called igneous rocks. Among the given options only granite is an igneous rock while rest 3 are sedimentary ricks.
• Hence option C is correct.

The word igneous has been derived from a Latin word 'ignis', meaning thereby fire. The igneous rocks are formed due to cooling, solidification, and crystallization of hot and molten materials known as magmas and lavas. They were originated first of all the rocks during the formation of the earth.

Among the three major types of rock, fossils are most commonly found in sedimentary rock. Unlike most igneous and metamorphic rocks, sedimentary rocks form at temperatures and pressures that do not destroy fossil remains.