GEOMORPHOLOGY AND MINERAL EXPLORATION

Geomorphology and Mineral Exploration

 Geological structure is linked to mineral reserves. Geological features could be shown by the way the landscape looks in certain places.

Surface Expression of Ore Bodies

• Some ore bodies have clear surface expressions in the form of outcroppings of ore, gossan, or leftover minerals, or in the form of cracks, fractures, and zones of breccia.
• A slope that stands out, like the one in Broken Hill, Australia, could show where lead-zinc lodes are.
• Quartz lines could stand out because they are much less likely to wear away than the nearby rock that isn't silicified, like in Chihuahua, Mexico.
• Some veins, like calcite veins, and mineralized areas may be shown by depressions or signs of sinking.

Weathering Residues

• A lot of minerals that are important to the economy are left over from past or present geomorphic cycles. Geomorphology can help you find these minerals.
• Some ores of manganese and nickel, clay minerals, caliche, and iron ore may be left over after ageing. The rocks on the surface of the earth are always being worn down and worn away by weathering and erosion. The results of rock weathering may be useful in business.
• Commonly, weathering products that are left behind form on pleneplain or nearly pleneplain surfaces.
• Most of the time, these minerals can be found on top of surfaces that have been worn away by erosion since the Tertiary period.
• When aluminous minerals break down in the earth's crust, they leave behind bauxite. This can be either a small amount of solid aluminous material in dolomites and limestones or the minerals themselves.

Placer Deposits

• Placer deposits are made up of heavy metals that have been mixed together by chemical weathering or erosion of metal formations.
• Placer deposits of minerals are the result of specific geomorphic processes and may have their own unique geographic expression when they are found in certain topographical places.
• The type of rock that makes up the ground floor may affect how the placers are deposited.
• Residual placers, also known as "seam diggings," are left over from the weathering of quartz veins or stringers. They are usually small and break up into lodes.
• This type of placer is between residual placers and alluvial placers because it is made when leftover materials creep down slope.
• People have found these kinds of gold placers in California, Australia, New Zealand, and other places.
• The koelits are colluvial placers, and the kaksas are alluvial placers. Alluvial placers in Russia, Colombia, and other places give us about a third of the world's silver.
• Some of the most valuable minerals that can be found in alluvial placers are gold, tin, and diamonds.
• People find diamonds in the Vaal and Orange River districts of South Africa, the Lichtenburg area of South Africa, the Belgian Congo, and Minas Geraes,
• Brazil, by collecting rocks that have been washed from rivers. It is where about 20% of the world's diamonds are found.
• Gold has been found in Australia and Lower California, Mexico, in aeolian placers. Bajada placers grow in the gravel rim of a pediment and in the alluvial fans that meet at the bottom of a bajada.
• You're more likely to find them near the base of a mountain than on the flatter slopes of a basin fill.
• Gold and pearls have been found in beach placers in California and Alaska.
• Zircon has been found in India, Brazil, and Australia, and ilmenite and monazite have been found in Travancore, India.
• You can help find placers by digging and doing geomagnetic tests. Most of the time, a magnetic scan will be useful because magnetite is often found near gold.
• If the bedrock is a basic type with a stronger magnetic field than the placer gravels, magnetic 'lows' may show where the filled paths are.
• W.D. Thornbury says, "Knowledge of the bedrock geology, application of geophysical surveying, test drilling, and interpretation of aerial photographs are all important parts of the search for these buried placers.
• But the most important thing to know about this search is the geomorphic history of the area.

Oil Exploration

• Many oil fields have been found because of how striking their landscapes are. Mineral oil is thought to have been made when organic matter broke down and composted.
• Once the oil is formed, it gets stuck in rocks under structure traps or sedimentary traps.
• The permeable and impermeable layers are brought closer together by bent sedimentary layers called anticlines and synclines.
• Mineral oil is well-preserved in the upper permeable beds and the lower impermeable beds.
• Mineral oil is usually found in rock structures that are porous and allow water to pass through them.
• Below these rocks are layers of rocks that don't let water pass through them. Mineral oil can be found in sandstone and limestone because they are porous and allow oil to pass through them.
• The bed that doesn't let water through is made of rock. Tones may show an anticlinal or domal structure in places with thick tropical woods that make it impossible to see the land's surface.
• Oil is being looked for today by using more minor signs of geological features that are good for oil to build up.
• One such method is using overhead photos to look at the drainage of a landscape. It is necessary to have a complex understanding of how water drains in a certain place; a geomorphologist would likely have this knowledge.
• It is especially helpful to do a drainage study in places where rocks have low dips and the terrain has little relief.
• Leverson says that a lot of oil and gas sources are connected to unconformities, which are old erosion surfaces.
• This means that a petroleum geologist has to deal with areas that are underground.
• When old erosion surfaces shrink permeable beds and are then covered by layers, they turn into stratigraphic traps. Most of these happen along fault lines.