rocks and minerals Flashcards
(37 cards)
what dose the term rock refer to?
A combination of one or more mineral.
what is an Igneous Rock?
Rock made during a volcanic process.
What dose the term mineral refer to?
A naturally occurring inorganic substance
with a specific chemical composition.
What is a crystal and how is it made?
crystals are solids in which all of the atoms
are arranged in repeating patterns.
Those found in rocks form when solutions of minerals cannot absorb any more dissolved minerals.
Some of each mineral type precipitates out of solution to form the centre of a crystal. More mineral ions precipitate onto the surface, and the crystal becomes larger until the solution disappears.
Quick cooling = small crystals, slow = large.
what is magma?
molten rock beneath the surface of the earth.
Explain the three states of matter?
Solid: firm and stable in shape, cannot flow or be compressed (squashed), as particles have little space to move, or to move into
Liquid: flows freely and take the shape of its
container, as particles can move around each other, but cannot be compressed, because particles are close together and have no space to move into
Gas: flows freely and will expand to fill the whole container, as particles can move quickly in all directions, and can be compressed, because their particles are far apart and have space to move into
what is a solution?
a solid dissolved in a liquid
what dose Precipitates mean?
When a substance comes out of a solution.
what is an Ion?
An atom in which the number of positively
charged protons are not equal to the number of negatively charged electrons.
what is a Sedimentary Rock, give examples?
A rock formed from material derived from
the weathering of other rocks or the
accumulation of dead plants and animals.
Builds in layers.
E.g. limestone, sandstone, shale.
what is a metamorphic rock, give examples?
A rock formed from existing rocks (igneous,
sedimentary and other metamorphic rock)
by a combination of heat and pressure.
E.g. granite (igneous) to gneiss
shale (sedimentary) to slate
limestone (sedimentary) to marble
The conditions to make metamorphic rock destroy any fossils that might be in the rock.
what is the rock cycle?
A representation of the changes between
the three rock types and the processes
causing them.
what is ore?
A rock with enough of an important metal or mineral to make it worth mining, and
producing a profit.
what is prospecting, explain; remote sensing, field surveys, and geophysical analysis?
A process of searching for minerals.
- Remote sensing: cheaper when covering very large area.
- Field surveys: geochemical analysis - where chemicals in the samples are identified.
- geophysical analysis - a series of vibrations (seismic waves) are sent through the Earth’s surface and are reflected back to sensors
on the surface.
Explain more about remote sensing?
A process in which information is gathered
about the Earth’s surface from above.
Aerial photos
Satellites:
- Picking up mineral deposits unique
radiation patterns
Or
- Reflected signals from the surface of the
Earth
What does the term geochemical refer to?
The chemical properties of rocks
what does the term geophysical refer to?
The physical properties of rocks.
A type of mining used when the mineral is
either exposed on the surface or overlain by
only small amounts of overburden
what is overburden?
The rock and soil overlying an economically
viable mineral deposit.
what is open pit mining?
Open-pit mining is a surface mining technique that involves extracting minerals or rock from the earth by removing the soil and rock above the mineral deposit.
what is surface mining?
Surface mining, including strip mining, open-pit mining and mountaintop removal mining, is a broad category of mining in which soil and rock overlying the mineral deposit are removed, in contrast to underground mining, in which the overlying rock is left in place, and the mineral is removed through shafts or tunnels.
what is strip mining?
Strip mining is a form of surface mining that is employed to strip away a layer or seam of soil, natural vegetation, and rocks (known as overburden) to extract the mineral deposits underneath.
what is subsurface mining, pros and cons?
A type of mining used when the deposit is
covered by a deep layer(s) of unwanted rock.
Pros:
- Less environmental impact; only a small area of
land is cleared of vegetation, but mine waste will build up above ground.
Cons:
- Expensive
- Dangerous
- Can cause land collapse
Whether you use a shaft, sloping or drift mine depends on how deep you need to go.
what is deep mining and what are some things that can go wrong?
Mining that goes more than 1500m below the surface. Deep rock mass is characterised by high in situ stress, high temperature, and high water
pressure.
Compared with shallow resource extraction, deep mining may be associated with disasters such as
rockbursts (when the opening of mine workings relieves neighbouring rocks of tremendous pressure, which can literally cause the rock to explode, or trigger abrupt movement on nearby geological structures), large-scale caving, and large inrush of mixed coal, gas, and water.
what is a mine shaft?
Shaft mining refers to the method of excavating a vertical or near-vertical tunnel from the top down with no bottom access. . When the top of the excavation is the ground surface, it is referred to as a shaft; when the top of the excavation is underground, it is called a winze or a subshaft.
