Geology Interview Preparation Guide

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The earth has only very recently been accurately dated. Until astonishingly recently, the earth was thought to be anywhere between a few hundred thousand and a few million years old. Now it is thought that the Earth is 4.6 billion years old, and was formed by interstellar dust coming together and being attracted to an increasingly strong gravitational force. Incidentally, life is thought to have arisen relatively early in the earth's existence - just 3.5 - 4 billion years ago!

Usually the triangulation method is used, making three measurements, and then using simple geometry/maths to locate the positioning.

Over time it developed an atmosphere that changed in time as liquid water gathered on the surface of the earth and created an atmosphere with clouds of water and levels of certain gases that protected the planet below and made it the temperature that it is, which is obviously fit for life as we can tell by looking around us.

The earth has changed massively since it was formed. Earth was a ball of rock that was hit and changed by loads of impacts and meteor impacts.

Factors such as the volume and surface area of the lake together with average wind speed and temperature at the surface are the factors that can be used to work out how much evaporation there is at the surface.

Specifically gases that are found in the magma correspond to having been formed at pressures many times greater than those in the outer core have, and rather therefore indicate that it was formed elsewhere.

Minerals or small particles of rocks, become rocks through pressure and temperature, often deep inside the earth’s core, or simply through pressure for instance on the seabed.

Wherever many small things become something big it is usually through compression, temperature, or pressure.

The opposite process - large things being worn into smaller particles - usually comes through another sort of force. Either weathering, erosion - action by wind, rain, and water - is responsible.

Gradually many rocks are eroded by movement of ice and water over them or the wind action also to become finer and finer and form little grains - e.g. of sand or of soil.

Various ways and techniques can be used. With many mountains, the rock in the mountain can be sampled and then a dating technique applied to find the age.

For instance, radiometric dating may be used to find the age of the rock. These techniques exploit the half-life of naturally occurring radioactive isotopes of elements present in tiny quantities to help work out how old something is.

With some mountains other techniques may be used, for instance at a plate boundary scientists may be able to wind back time to work out when the plates must have collided and formed mountain ranges such as the Himalayas.

Limestone is formed from pressure applied over time to dead creatures in the sea. Oil is formed because of sedimentary processes and which is one of the most important resources.

Fossils are created amongst periods of rock formation, and caused by the gradual accumulation of sediment over millions of years at the bottom, most commonly, of the seabed.

The heat and compression deep within the earth’s magma are what cause these unique and interesting layers of striation.

Depending on the particular stresses and strains, heat and pressure applied, and the individual rocks and minerals there in that composed the material, they react differently and this is what causes the banding.

The asthenosphere is a layer of the earths crust. There are various definitions here is one of them from a geology resources definition list:

"A layer of soft but solid, mobile rock comprising the lower part of the upper mantle from about 100 to 350 kilometers beneath the Earth's surface."

Things as if climate and food availability will make a big difference if it is too cold, too dry then people will need to move.

In addition, the amount of food is important too. Other factors might be human and political ones - such as a tough regime in charge of a country or if there is a war and so on then people will want to move too.

Igneous rocks are formed through volcanic action and because of volcanic activity.

Sedimentary rock takes a long time to form and is dead bits of animals laid down in the sea and compressed over millions of years to form rock; anywhere you see sedimentary rock you are seeing the remains of creatures that were once in the ocean a long time ago.

Metamorphic rock is formed through a combination of heat and pressure inside the earth.

Igneous rocks form in quite a different way to metamorphic rocks.

Igneous rocks form due to heat and volcanic activity specifically they form when molten rock cools and becomes solid.

However, metamorphic rocks are existing rocks - perhaps igneous ones - that have been changed by great pressure and often-great heat into metamorphic rocks.

This is caused by the magma - the molten rock - that is underneath each of the plates of the earth and causes them to move and flow along.

This is the major cause of this phenomenon to the best of our current geological understanding.

Igneous rocks are those that form from volcanoes and volcanic activity.

Sedimentary rocks are laid down over great time in oceans and are the results of compression on dead organic matter like small sea animals and so on.

Metamorphic rock is a change that occurs to igneous or sedimentary rock in the earth's crust due to the immense heat and pressure there acting on those rocks and chemically and physically changing their properties.

Sedimentary rocks have a clue to their origin in the name - sediment.

They are the products of lots and many dead marine creatures, which piled up on the sea floor as they were formed in water. These piled up together over a period and the pressure of them all caused the formation of rock.

By offering more rights and giving better treatment, more freedom and better options it was hoped to reduce the conflict and pre-empt problems from occurring because of this.

Radon is a radioactive gas that is associated with certain rocks, so perhaps this is a measure of the geology of the area, as in the rocks that are present in that location?