Rocks!
Transcript of Rocks!
Chert
• Sedimentary
• Formed from radiolaria shells
• Main mineral is quartz
• Chemical
• Chert can often be bioclastic
Pink Granite
• Igneous
• Formed below the surface
• Felsic
• Main minerals are Potassium Feldspar, Quartz
• Also contains plagioclase feldspar, biotite, amphibole
• Phaneritic
Gabbro
• Igneous intrusive
• Forms below surface
• Contains plagioclase feldspar, pyroxene, a little olivine
• Phaneritic
• Mafic
Basalt
• Igneous
• Aphanitic
• Forms above surface
• Minerals: Plagioclase feldspar, pyroxene, olivine
• mafic
Amygdaloidal Basalt
• Apanitic
• Igneous
• Forms above surface
• Crystals (mostly quartz) grow in vesicles after rock is formed
• Mafic
Andesite
• Igneous
• Aphanitic
• Intermediate
• Forms below surface
• Minerals: Plagioclase, pyroxene, amphibole
Granodiorite
• Igneous
• Phaneritic
• Formed below the surface
• Minerals: Potassium feldspar, quartz, plagioclase, biotite, amphibole
• Intermediate
Granite Porphyry
• Porphyritic
• Felsic
• Formed by two different rates of cooling (eg. started cooling below the surface then rose and finished cooling above the surface)
• Minerals: potassium feldspar, quartz, plagioclase, amphibole, biotite
• Large minerals are called phenocrysts and small minerals are called ground-mass/matrix
White Granite
• Igneous
• Formed below the surface
• Phaneritic
• You can see the quartz cleavage planes
• Minerals: quartz, plagioclase, amphibole, biotite
• felsic
Rhyolite
• Igneous
• Aphanitic
• Felsic
• Formed above surface
• Minerals: potassium feldspar, quartz, plagioclase
Syenite
• Igneous
• Phaneritic
• Formed below surface
• Felsic
• Minerals: Potassium feldspar, plagioclase, biotite, amphibole
Pumice
• Igneous
• Felsic
• Vesicular
• Formed from magma cooling so quickly that gas cannot escape and forms air bubbles within the rock
Quartz Sandstone
• Sedimentary
• Clastic
• Sand sized particles
• Well-sorted
• Made up mostly of quartz
• Medium velocity transport (eg. slow stream or at a shore)
Shale
• Type of mudstone
• Mainly made of the mineral clay
• Clay sized particles
• Clastic
• Low velocity transport (eg. calm lake)
Conglomerate
• Sedimentary
• Clastic
• High Velocity transport (eg. fast stream or river)
• Pebble/boulder sized particles
Fossiliferous Limestone
• Sedimentary
• Chemical: bioclastic
• Contains fossils from ocean shells
• Mainly composed of calcite
• soft
Rock Salt
• Sedimentary
• Chemical
• Composed of soft mineral halite
Potash
• Sedimentary
• Chemical
• Mainly composed of mineral sylvite (KCl)
• Soft
Gypsum
• Sedimentary
• Chemical
• Very soft, when you scratch it it makes white dust
Slate
• Metamorphic
• Has slaty foliations
• Formed from shale
• Formed from regional metamorphism, intense pressure and heat
• Parallel cleavage
Quartz-Garnet-Muscovite Schist
• Metamorphic
• Schistose Foliation
• Formed by regional metamorphism (intense pressure and heat)
• Slate morphs into this
Garnet-Chlorite-Biotite Schist
• Metamorphic
• Schistose foliations
• High temp and pressure
• Regional metamorphism
• Formed from slate
Biotite Schist
• Metamorphic
• Schistose foliations
• Regional metamorphism
• Formed from slate
Quartzo-feldspathic Gneiss
• Metamorphic
• Gneissic foliations
• Regional metamorphism
• Main minerals: potassium feldspar, quartz
Marble
• Metamorphic
• Regional metamorphism
• Formed from Limestone
• Main mineral is calcite
• soft
Granite Gneiss
• Metamorphic
• Regional metamorphism
• Gneissic foliations
• Main minerals: quartz, potassium feldspar, quartz
Chlorite Schist
• Metamorphic
• Schistose foliations
• Regional metamorphism
• Looks like chlorite but it is a rock not a mineral
• Main mineral is chlorite
Amphibolite Gneiss
• Metamorphic
• Gneissic foliations
• Regional metamorphism
• Contains amphibole and garnet
Greywacke
• Sedimentary
• Clastic
• Sand sized particles
• Poorly sorted
• Medium velocity energy source (slow stream or a shore)
• Composed of quartz, k-feldspar, and clay
Calcite
• Mineral
• Rhombohedral cleavage
• Soft
• CaCO3
• Fizzes when HCl is put on it
• Non-silicate
• Carbonate
• Vitreous to dull
Chlorite
• Mineral
• Soft
• Dark green colour
• 1 perfect basal cleavage
• Silicate
• Hydrous Mg-Fe-Al silicate
• Pearly vitreous
Potassium Feldspar
• Mineral
• Hard
• Two directions of 90o cleavage
• Silicate
• KAlSi3O8
• Vitreous
Plagioclase Feldspar
• Mineral
• Silicate
• NaAlSi3O8- sodium rich, lighter colour
• CaAl2Si2O8- calcium rich, darker colour
• 2 close to 90o
• Vitreous
• Hard
• striations
Amphibole
• Mineral
• Silicate
• Hard
• Cleavage at 56o and 124o
• Dark colour
• Hydrous Na-Ca-Fe-Mg-Al silicate
• Vitreous dull
Pyroxene
• Mineral
• Hard
• Two directions of cleavage at 90o
• Dark green to black colour
• Vitreous to dull
• Silicate
• Ca-Fe-Mg-Na-Al silicate
Olivine
• Rough (sugary) texture
• Mineral
• Silicate
• Hard
• Olive colour
• No cleavage
• Vitreous
• (Mg,Fe)SiO4
Garnet
• Mineral
• Hard
• No cleavage
• 12 sided crystals (generally reddish)
• Vitreous
• Fe-Mg-Ca-Mn-Al silicate
• silicate
Quartz
• Mineral
• Hard
• No cleavage
• SiO2
• Silicate
• vitreous
Magnetite
• Mineral
• Magnetic
• Metallic black lustre
• Non-silicate
• Fe3O4
• No cleavage
Pyrite
• Mineral
• Hard
• Metallic Yellow lustre
• Shiny
• Non-silicate
• Sulfide
• FeS2
• Poor cleavage
Galena
• Mineral
• Soft
• Very dense, heavy
• Metallic grey lustre
• Parallel cleavage to cube faces
• Non-Silicate Sulfide
• PbS
Chalcopyrite
• Soft
• Mineral
• Metallic brassy yellow lustre
• Non-Silicate Sulfide
• CuFeS2
• Poor cleavage
Biotite Mica
• Mineral
• Soft
• Basal cleavage
• Dark colour
• Pearly
• Silicate
• Hydrous K-Al-Mg-Fe silicate
Muscovite Mica
• Mineral
• Soft
• Basal Cleavage
• Lighter Colour
• Pearly
• Silicate
• Hydrous K-Al silicate
Now you know your ROCKS!!