Taken for Granite Trivia Quiz

Answer: Magma

Magma is generally formed via the partial melting of the Earth's crust and the upper mantle (athenosphere). The temperature range of magma is 700 - 1300 degrees Celsius, depending on its composition. Mafic magmas (high iron and magnesium) have a much higher temperature than felsic magmas (high silica).

Answer: Limestone

The White Cliffs of Dover are made of chalk - a type of limestone. This limestone is composed dominantly of coccoliths (phytoplankton with calcium carbonate 'shells') and was formed during the Cretaceous Period (145 million years ago - 65 million years ago).

Answer: Metamorphic rock

Gneiss is a metamorphic rock, which has formed under extremely high pressures and temperatures. Gneiss (pronounced 'nice') has a distinctive striped/layered appearance. The alternating layers are comprised of light-coloured felsic minerals (e.g. orthoclase) and dark-coloured mafic minerals (e.g. biotite). Gneiss is the highest grade regional metamorphic rock.

Answer: Gypsum

Frederic Mohs was a German mineralogist who developed one of the most well-known and frequently used systems of mineral identification. In 1812 he gathered ten of the most commonly available minerals and tested their 'hardness', placing them in order from softest (1 - talc) to hardest (10 - diamond); thus the Mohs hardness scale was born.

Answer: Continental rift valley

The Red Sea covers an area of approximately 450,000 sq km. The sea gets its name from the red-brown colour it becomes following the death of an invading algal bloom (trichodesmium erythraeum).

Answer: Sandstone

Uluru is approximately 700 million years old and was named Ayers Rock when white settlers first discovered it in 1873 - Sir Henry Ayers was the Chief Secretary of South Australia. It is believed that Indigenous Australians first lived in the area surrounding Uluru approximately 10,000 years ago.

Answer: Collapse of a volcano

This collapse follows a volcanic eruption, after the magma chamber has emptied. A caldera formed after the 1883 eruption of Krakatau and a new volcanic island (Anak Krakatau) emerged from the caldera in 1927. This island remains a site of active volcanism.

Answer: Window panes

Muscovite was mined in the 1700s near Moscow and used for window panes, due to its transparent nature. This glass became known as 'Muscovy glass'. Muscovy was the original European term used from the 1300s for the Principality of Moscow.

Answer: Pahoehoe and a'a

Hawaiian Shield volcanoes produce low viscosity, high temperature basaltic lavas. The two key controlling factors that determine whether a'a or pahoehoe lava flows occur are the viscosity and cooling rate following an eruption. Fast cooling, high viscosity lavas form the rough, blocky a'a and slow cooling, low viscosity lava forms the smoother, ropey pahoehoe.

Answer: Quartz and potassium feldspar

Granite is a coarse-grained intrusive igneous rock. The grain size of granite is determined by its cooling rate; slow cooling results in large grains/crystals. A batholith (or pluton) is a large granitic intrusion that exists below the Earth's surface and is formed when highly silicic magma intrudes pre-existing large scale weaknesses in the Earth's crust. Most batholiths are between 10 - 15 km thick.

The Idaho Batholith covers an area of 40,000 square kilometres.