Describe the roll of gravity and distance from the Sun in the formation of the I

Question

Describe the roll of gravity and distance from the Sun in the formation of the Inner and Outer Planets of our Solar System. Describe how the Earth's internal structure and surface features were formed over time. Describe the role of temperature and pressure in the formation of minerals and geologic factors that may affect changes in temperature and pressure. Describe how minerals are formed in the 2 branches of Bowen's Reaction Series (Continuous and Discontinuous Series) Define Mineral Paragenesis and describe from start to finish how minerals become ore deposits, including: 1) source of minerals: 2) creation and movement of mineral fluids: 3) types and causes of mineral deposits: and 4) how minerals become localized.

Explanation / Answer

Paragenesis is the formation of ore deposits from the minerals. Paragenesis is the sequence in which the minerals are formed in an ore deposit. This processes happens mainly due to the variations of pressure in the tempeature and pressure. Depending upon whether an ore deposit formed at the time of and together with the enclosing rock, or was introduced into it by subsequent processes ore deposits are of two types

Syngenetic - A deposit formed at the same time as the rocks in which it occurs.

Epigenetic - A deposit introduced into the host rocks at some time after they were deposited.
           And depending upon the rock types and the minerals the following are the main types of ore deposits
1. Magmatic Deposits: These deposits are formed by the direct crystallization of the moltan magma.Ore deposits with silicate and sulfide magmas. As a magma cools, sulfides coalesce as droplets and due to higher density settle out. Most common sulfides are iron sulfides, but nickel, copper and platinum also occur. Megma is the direct source of the minerals here.
2. Pegmatitic Deposits: Pegmatites are very coarse grained igneous rocks. Commonly form dike-like masses a few meters to occasionally 1-2 km in length. Economic ore deposits are associated with granitic pegmatites since felsic magmas carry more water. Residual elements such as Li, Be Nb, Ta, Sn and U that are not readily accommodated in crystallizing silicate phases end up in the volatile fraction. When this fraction is injected into the country rock a pegmatite is formed. Temperatures of deposition vary from 250-750°C.
3. Hydrothermal Deposits: Hot aqueous solutions are responsible for the formation of these types of ore deposits. These types of ore forms fluids range in temperature from 50°C to 650°C.source and nature of the solutions, means of transport of the metals and mechanism of deposition is done by the water so these types of deposits are mainly saline in nature.
4.Metamorphic Deposits: These types of deposits are formed by the re-crystallization of matamorphic rock. the source of mineral for these deposits are metamorphic rocks. Pyrometasomatic deposits developed at the contact of plutons and host rock. Generally, host rock is a carbonate and new minerals formed are the calc-silicates diopside, andradite and wollastonite. Temperatures involved are thought to be 300-500°C, but pressure is probably quite low.
5. Volcanic Exhalative Deposits: Some ore deposits often show spatial relationships to volcanic rocks. They are conformable with the host and frequently banded suggesting sedimentary processes. Principal constituent is pyrite with lesser chalcopyrite, aphalerite, galena, barite and Ag-Au. These ores are associated with volcanism and the source of the ore fluids is of magmatic origin.
           Mineral deposits form because some medium serves as a concentrating and transporting agent for the ore minerals and some process subsequently causes the transporting agent to precipitate or deposit, the minerals. The variation the temperature and pressure is the main factor to form ore deposits. Different types of minerals are found on earth's surface these mineral get deposited and re-crytallize due to high pressure and temperature causes to form another form of minerals called minerals deposits. These deposition can be caused by boiling, a drop in temperature, by mixing with a cooler solution, or by chemical reactions between the solution and a reactive rock.
           This minerals became localize because most of the time these minerals are formed by the deposition and re-crystallization of local rock.

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