rocks Flashcards
rocks are all made of different minerals
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. The elements that make up a crystal and the conditions present during the crystal’s growth determine the arrangement of atoms and molecules and the shape of the crystals.
crystals
is the way light interacts with the surface of a crystal, rock, or mineral
Lustre
the quality or condition of being hard
hardness
of a mineral is the color of the powder produced when it is dragged across an un-weathered surface.
streak
is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth’s crust, and then transports it to another location
erosion
when there is buildup of tiny pieces of broken rocks
Clastic
when components of water evaporate and previously dissolved minerals are left behind.
chemical rocks
occur as a result of the accumulation of any form of animal or plant remains like bones.
organic
remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form.
fossil
rocks that cool down thrown through the air. ( magma or lava
igneous rocks
rocks that form on top of the earths surface
extrusive rocks.
a pale rock that forms when frothy lava cools in the air. Pumice often floats on water as it is very light and full of holes that once contained gas.
pumice
a rock that cools down quickly by gassy lava
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. It sometimes has holes that once contained volcanic gases
basalt
a smooth rock that feels like glass and breaks into pieces easily (black rock)
obsidian
igneous rock, that comes by magma from the earths crust
intrusive rocks
intrusive rock mass that measures more than 100 kilometres across
batholiths
a very shiny, crystal like rock large enough to see and forms slowly.
granite
flat, open land beside a river where sediments are deposited during floods
floodplains
large bodies of ice that move down slopes and push boulders, rocks and gravel in front of them
glaciers
deposit left by movement of a glacier
moraines
a sedimentary rock with medium-sized grains. The sand grains are cemented together by silica, lime or other salts.
sandstone
a fine-grained, sedimentary rock without layering
mudstone
a fine-grained sedimentary rock formed in layers by the 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. It consists mainly of calcium carbonate.
limestone
a sedimentary rock formed from dead plants and animals that were buried before rotting completely
Coal
a 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 (or both)
metamorphism
rock formed from another rock that has been under great heat or pressure (or both)
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
is a basic concept in geology that describes transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous.
rock cycles
rocks mined to obtain a metal or other chemical within them
mineral ore
extraction of natural resources from the Earth
mining
study of the possible effects of a planned project on the environment
environmental impact statement
restored to its previous condition
rehabilitaded
waste rock removed from below the topsoil. This rock is replaced when the area is restored.
overburden
mining that scours out soil and rocks on the surface of the land
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
the buckling of rocks. It is caused when rocks are under pressure from both sides.
folding
a scientist who studies fossils
palaeontologists
the age of a rock compared with the age of another rock
relative age
animal that eats other animals
carivores
animals that eat dead plant and animal material
scavengers
cavity 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
fossils that provide evidence, such as footprints, that an organism was present when the rock was formed
trace fossils
describes volcanoes that are no longer active. Extinct volcanoes have not erupted for thousands of years and show no sign of future eruption.
extinct
