Rocks Flashcards
all rocks are made up from …
minerals
the outermost layer of the Earth, includes the crust and uppermost part of the mantle
lithosphere
a very hot mixture of molten rock and gases, just below the Earth’s surface, that has come from the mantle
magma
material broken down by weathering and erosion that is moved by wind or water and collects in layers
sediments
elements found uncombined in the Earth’s crust
native elements
geometrically-shaped substance made up of atoms and molecules arranged in one of seven different shapes.
crystals
appearance of a mineral caused by the way it reflects light. A mineral can appear glassy, waxy, metallic, dull, pearly, silky or brilliant.
lustre
colour of a mineral as a fine powder, found by rubbing it onto an unglazed white ceramic tile
streak
a measure of how difficult it is to scratch the surface of a solid material
hardness
chemical sedimentary rocks occur when components of water evaporate and previously dissolved minerals are left behind
chemical rocks
sedimentary rocks occur when there is buildup of tiny pieces of broken rocks
clastic rocks
organic sedimentary rocks occur as a result of the accumulation of any form of animal or plant remains like bones
organic
is formed through the cooling and solidification of magma or lava
igneous
magma that comes out of the ground and makes it to the surface and solidifies
extrusive rocks
magma that doesn’t make it to the surface and solidifies inside of the crust
intrusive rocks
a pale rock that forms when frothy lava cools in the air
pumice
a dark, igneous rock formed from gassy lava that cools quickly
scoria
a property of a material or substance that easily scratches another
abrasive
a dark, igneous rock with small crystals formed by fast cooling of hot lava
basalt
a black, glassy rock that breaks into pieces with smooth shell-like surfaces
obsidian
rocks formed from sediments deposited by water, wind or ice. The sediments are cemented together in layers, under pressure
sedimetary rocks
the wearing away and removal of soil and rock by natural elements, such as wind, waves, rivers and ice, and by human activity
erosion
flat, open land beside a river where sediments are deposited during floods
floodplains
deposit left by movement of a glacier
moraines
large bodies of ice that move down slopes and push boulders, rocks and gravel in front of them
glaciers
a sedimentary rock with medium-sized grains
sandstone
a fine grained, sedimentary rock without layering
mudstone
a fine-grained sedimentary rock formed in layers by consolidation of clay
shale
a sedimentary rock with a particle size between that of sandstone and mudstone
siltstone
sedimentary rock containing large particles of various sizes cemented together
conglomerate
a sedimentary rock formed from the remains of sea organisms
limestone
a sedimentary rock formed by buried dead plants and animals
coal
sedimentary deposit formed when a salt lake or seabed dried up. Its main chemical is sodium chloride
rock salt
the process that changes rocks by extreme pressure or heat
metamorphism
rock formed from another rock that has been under great heat or pressure
metamorphic rocks
a metamorphic rock formed as a result of great pressure on limestone
marble
a coarse-grained metamorphic rock formed mainly as a result of great pressure on granite
gneiss
an idealized cycle of processes undergone by rocks in the earth’s crust, involving igneous intrusion, uplift, erosion, transportation, deposition as sedimentary rock, metamorphism, and further melting and igneous intrusion.
rock cycle
rocks mined to obtain a metal or other chemical within them
mineral ores
extraction of natural resources from the Earth
mining
study of the possible effects of a planned project on the environment
environmental impact statement (EIS)
restored to its previous condition
rehabilitated
waste rock removed from below the surface. This rock is replaced when the area is restored
overburden
mining that digs out soil and rocks on the surface
open-cut mining
mining that uses shafts and tunnels to remove rock from deep below the surface
underground mining
the time beginning about two million years ago during which early humans made implements of stone
stone age
a mixture of a metal with a non-metal or another metal
alloy
a fine-grained sedimentary rock which leaves a very sharp edge when broken
flint
a process in which tool stones such as flint or obsidian were struck with harder stones, such as quartzite, to shear large flakes that could be used to make small tools
percussion flaking
remains of an animal or living thing from the past or a former age
fossil
the term for when rocks are under pressure from both sides (buckling)
folding
a scientist who studies fossils
palaeontologist
the age of a rock compared with the age of another rock
relative age
in a rock that shows the shape of the hard parts of an organism; types of fungi found growing on the surface of foods
mould cavity
fossils that provide evidence, such as footprints, that an organism was alive when the rock was formed
trace fossils
a family or species that have no members alive
extinct
animal that eats other animals
carnivores
animals that eat dead plant and animal material
scavengers
