Category: Geology

How many cleavage does olivine have?

The specific gravity and hardness of the olivines are listed in the Table. There are at least two cleavages—i.e., the tendency to split along preferred crystallographic directions (perpendicular to the a and b axes in this case)—both of which are better-developed in the iron-rich varieties. Does olivine have a cleavage? Cleavage and fracture – Olivine

How are Corried formed?

How are corries formed simple? Corries form in hollows where snow can accumulate. The snow compacts into ice and this accumulates over many years to compact and grow into a corrie/cirque glacier. This then moves down hill because of gravity and the mass of the ice. How are corries and tarns formed? The glacier moves

Why are Stratovolcanoes more explosive?

Stratovolcanoes are more likely to produce explosive eruptions due to gas building up in the viscous magma. Andesite (named after the Andes Mountains), is perhaps the most common rock type of stratovolcanoes, but stratovolcanoes also erupt a wide range of different rocks in different tectonic settings. Why are stratovolcanoes more explosive than shield volcanoes? Due

Where was the center of the earthquake?

The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. Where was the center point of the earthquake? The hypocenter is the point within the earth where an earthquake rupture starts. The epicenter is the

What are P waves and S waves also called?

P-waves and S-waves are sometimes collectively called body waves. What type of waves are P and S waves? Types of Waves: Mechanical Body Waves: P and S waves are mechanical body waves. A mechanical wave is a wave that must travel through a medium, such as the ground or air. The energy of a mechanical

What is the crystal structure of feldspar?

Structure. The structure of a feldspar crystal is based on aluminosilicate tetrahedra. Each tetrahedron consists of an aluminium or silicon ion surrounded by four oxygen ions. Each oxygen ion, in turn, is shared by a neighbouring tetrahedron to form a three-dimensional network. What is the crystal of feldspar? Most feldspar crystals are tabular and flattened

What textures are possible in extrusive rocks?

Extrusive igneous rocks will have aphanitic, vesicular, glassy, or pyroclastic textures. What is the texture of extrusive rocks? Extrusive igneous rocks have a fine-grained or aphanitic texture, in which the grains are too small to see with the unaided eye. The fine-grained texture indicates the quickly cooling lava did not have time to grow large

Where exactly is the San Andreas fault line?

San Andreas Fault, major fracture of the Earth’s crust in extreme western North America. The fault trends northwestward for more than 800 miles (1,300 km) from the northern end of the Gulf of California through western California, U.S., passing seaward into the Pacific Ocean in the vicinity of San Francisco. Where does the San Andreas

What is converging tectonic plates?

Convergent (Colliding): This occurs when plates move towards each other and collide. When a continental plate meets an oceanic plate, the thinner, denser, and more flexible oceanic plate sinks beneath the thicker, more rigid continental plate. This is called subduction. What does converging tectonic plates produce? The impact of the colliding plates can cause the

What is viscosity in volcanoes?

Viscosity is the resistance to the flow of a substance. Viscosity is directly related to the amount of silica content. The more viscous the magma the more explosive the volcanic eruption will happen. What is the viscosity of the lava? Thus, basaltic magmas tend to be fairly fluid (low viscosity), but their viscosity is still

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