midterm 2 Flashcards
earth’s formation led to which two metals in the core
iron and nickel
molten matter crystallization is?
a common process in earth’s interior or at its surface, a loss of atom mobility and distinct trend to form more rigid structures.
what are the four processes resulting in the formation of minerals
molten matter crystallization
transition from liquid to the solid phase
biological activities of organisms (bacteria) can lead to precipitation.
other structures are formed from pre-existing ones through ion and atom rearrangement.
what is a mineral?
a mineral is any naturally formed chemical substance having a definite chemical composition (but not fixed) and a characteristic crystal structure. In nature minerals can have impurities. Humans can make artificial minerals. (Consider as naturally formed substances for course)
what are mineraloids?
amorphous naturally occurring substances.
an important property of a mineral?
a mineral cannot be broken into different mineral substances using classical methods.
what are the 5 mineral properties
colour, lustre, crystal faces/crystal form, twinning, and transparency.
sillicates
silicates have silicone oxygen core and are more frequent nonmetallic minerals in the universe.
what are the three groups that non-silicates are divided into?
metals, semi metals and non-metals.
sulfides
minerals formed by a metallic element and sulphur.
sulfosalts
mixed sulphides in which a semimetallic element is present together with a metallic one.
oxides
compounds formed from various metallic elements and oxygen and in which the oxygen plays the role of an anion. The oxides occur in a variety of environments, being often encountered in all the three rock families, igneous, metamorphic anf sedimentary. Properties are extremally varied.
geode
empty space, certain concentration and temp can begin crystal precipitation.
what are the two categories of igneous rocks and describe them.
intrasive - formed inside earths crust
extrasive - formed at the surface of earth, having large sized minerals due to extra time to grow.
4 types of igneous rocks according to size
phaneritic - large sized visible minerals, slower process of crystallization.
aphanitic - extrusive, volcanic consists of small sized minerals & fast crystallization. formed through lava.
glassy - indicates the molten material crystallized very rapidly & had no time for crystal compound to arrange themselves (extrusive)
fragmental - consists of pyroclastic material ejected as lava from a volcano and can be igneous and sedimentary.
what is a sill ?
molten matter injected horizontally across rocks.
what are the two main types of extrusive igneous rocks?
lava flows (aphanitic igneous rocks) and pyroclastic flows (fragmental igneous rocks)
vesicular basalts?
bubbles of gas trapped in highly viscous lava.
what does. metamorphic mean?
its the idea of how the rocks are transformed and the process, rather than the rock itself.
types of metamorphic rock tranformation
regional - mountain range
contact - continental masses way below in magma chambers towards the surface. marbles.
burial - plaines zones of continents. (rocks eroding and waters carrying minerals)
difference between ionic and covalent bonds
ionic - weaker which gives minerals with this lower melting points and prone to dissolution.
covalent - stronger bonds, higher melting points, can be dissolved with difficulty.
diamond crystal structure
atoms of carbon are in the corners of a tetrahedron, covalently bonded each atom to the other 4. toughest mineral in the world. transported by volcanic eruptions.
graphite crystal structure.
planar structure consisting of parrallel layers that contain hexagons defioned by carbon atoms covalent corners. weakest bonds in the mineral world.
six crystal systems ?
cubic, tertagonal, hexagonal, orthorhombic, monoclinic, triclinic.
who outlined the classification for minerals being chemical compounds.
J.J. Berzelius.
what is a halide?
a mineral in which the cation is a metallic element and the anion is a halogen.
what are carbonates?
minerals in which the cations consist of one or more metals and the anion is represented ny the radical.
six subgroups of sillicates are ?
neosilicates inosilicates sorosilicates phyllosilicates tectosilicates cyclosilicates
how do igneous rocks form?
through the molten matter solidification in the earths interior or at its surface.
the rate of heat loss during the process of magma or lava solidification determines what?
the general appearance of an igneous rock.
intrusive rocks
form through the magma solidification beneath the Earths surface, slow cooling process, large sized minerals, can be seen with unaided eye. granite is an example.
extrusive rocks
form through the lava crystallization at the earths surface through fast cooling. minerals are small and can only be seen under microscopes.
two classification of igneous rocks are?
crystallinity (ratio between large-sized minerals and amorphous mass in the composition of an igneous rock) and grain size.
the four kinds of igneous rocks recognized are? (pg 47)
felsic rocks
intermediate rocks
mafic rocks
ultramafic rocks
intruisve rock textures (3)
granular - consists of minerals which are relatively uniform in size, slow & contiunous magma cooling.
porphyritic texture - large sized euhedral and subhedral minerals. developed in ground mass.
poikilitic texture - contains smaller minerals enclosed
pluton
the term generally used for a body of intrusive rock. the largest plutons are batholiths.
concordants vs discordants
concordants are a body of igneous rocks that has boundaries parrallel or almost parrallel to the surrounding rock layering, discordant is if its boundaries cross adjacent rock layering.
the 2 groups of extrusive rocks are?
lava flows and pyroclastic rocks.
sedimentary rocks definition.
they accumulate at the earths surface from particles of pre-existing weathered & eroded rocks. the majority of sedminetary rocks are formed in sedimentary basins,
3 categories of sedimentary rocks
detrital, chemical and biochemical.
Clastic rocks
formed through the accumulation of fragments of pre-existing rocks (igneous, sedimentary and metamorphic) in a sedimentary basin. known as detrital or siliciclatic rocks..
four components of clastic rocks are?
clasts, matrix, cement, and pores.
what is the basic sedimentary structure and what is the fundamental reults of it?
bedding, and the results are layers which are subdivided function of thickness into beds and laminae.
clastic rocks accumulate in three depositional environments
continental, transitional, and marine
the most frequent minerals in evaporate rocks are ?
gypsum, anhydrute, and halite.
