Rocks and minerals

What are igneous rocks and how are they formed?

Igneous rocks are formed by the cooling of molten rock (magma or lava).

How do crystals form?

When minerals solutions can no longer absorb dissolved minerals

What factors affect the crystal size in igneous rocks?

fast cooling leads to small crystals, while slow cooling results in large crystals.

What are some examples of igneous rocks?

basalt, granite, obsidian

How are sedimentary rocks formed?

weathering, erosion, transportation, deposition, and compaction of existing rocks, and can also form from fossilization or precipitation of dissolved minerals.

What are the three types of sedimentary rocks?

The three types are clastic (formed from rock fragments), chemical (formed from mineral precipitation), and organic (formed from living matter).

Examples of sedimentary rocks?

sandstone(clastic), limestone(chemical), coal(organic)

How are metamorphic rocks formed?

When existing rocks are changed by heat and/or pressure without melting.

Where does pressure come from?

overlying rock layers

What are some examples of metamorphic rocks?

marble, quartzite, slate

What is the difference between extrusive and intrusive igneous rocks?

Extrusive form from lava that cools quickly on the surface, while intrusive form from magma that cools slowly beneath the Earth's crust.

State the rock cycle

Magma cools & solidifies -> igneous rocks -> weathering an erosion -> sediments -> sedimentary rocks -> heat & pressure -> metamorphic rocks -> melting -> magma (repeats)

What are ways we can explore for minerals using remote sensing? Explain.

Aerial photography -> wide area coverage, overlapping photos for 3D views. Satellite recording -> detects radiation patterns, works in all weather, data processed for location mapping

What are ways we can explore for minerals using geophysics?

use seismic waves -> shock waves travel through rock strata, reflects back to sensors

How do we evaluate mining for rocks and minerals?

assess ore size, grade, and tonnage, drill for rock samples (grid), feasability study

What are sub surface mining?

shaft mining which is expensive and used for high value ores.

What is surface mining?

open-cast,open-pit, open-cut, string mining. used for sand, gravel, stone, with quarries.

What factors affect the viability of mining operations?

geology, exploration costs, climate, environmental impact, accessibility, and demand/supply

What is the difference between greenfield and brownfield sites in mining?

A greenfield site has never been mined before and has low discovery chances, while a brownfield site has been previously mined but can still be profitable.

What economic considerations are important in mining?

quality and quantity of deposits, working life of the mine, transportation costs, and processing requirements.

What are the economic impacts?

Government taxes ore extraction. long term agreements can prevent sudden tax hikes. profit depends on global demand and prices.

What are the PPP impacts of mineral extraction?

dust and toxic chemicals cause lung diseas and skin/organ harm. noise disturbs animals and people. water pollution causes health issues and kill aquatic life. provides jobs for locals. boosts local economy.

What are the ecological impacts?

habitat loss when vegetation is cleared and land is destroyed. animals lose food/shelter which impacts the food chain. decrease in biodiversity due to less plant growth.

What is an Environmental Impact Assessment (EIA)?

An EIA is conducted before obtaining a mining license to evaluate social, political, environmental, economic, and demographic factors and to plan for damage mitigation.

What are some strategies for managing mining impacts?

Strategies include safe waste disposal, land restoration(reshape, add soil/fertiliser,replant), bioremediation(use organisms to clean pollutants), and reuse sites for reserviors, landfills, and recreation

What does sustainable mining entail?

Sustainable mining meets current needs without compromising future needs, ensuring environmental protection, social equity, and economic stability.

How to evaluate if the environment is bearable?

life cycle assessment

How to evaluate if its socially equitable?

human health and living standards assessment.

How to evaluate if its technologically feasable?

technological risk assessment

How can mining efficiency be increased?

open-pit mining, processing mine waste twice, chemical and biological treatment of waste, and enhancing machine performance, recovering and refining metals (uses less energy), engineering solutions and laws for handling waste.

What are the environmental impacts of surface versus deep shaft mining?

Surface mining causes more land and ecosystem damage, while deep shaft mining has less surface impact but can still lead to pollution.

What is the role of transportation in mining economics?

Transportation costs are crucial; rail is cost-effective for bulk shipping, and some ores are refined at the mine to reduce transport costs.

What are the characteristics of non-foliated and foliated metamorphic rocks?

Non-foliated metamorphic rocks do not have a layered appearance, while foliated metamorphic rocks exhibit distinct layers due to pressure.