ESSC 101-Stephanie Welch/TEST 2
Igneous rock formation occurs................
primarily at or near tectonic plate boundaries
What are the types of volcanoes?
shield, cinder cone, composite
What is the definition of a mineral?
naturally occurring, inorganic solid with a specific chemical composition and a definite atomic structure
Contact metamorphism typically produces
non-foliated rocks (marble from limestone) forms close to earth's surface
Intermediate Rocks
--Between felsic and Mafic --Diorite - course grained intrusive intermediate igneous rock (oceanic-continental boundary) --Andesite - fine grained extrusive intermediate igneous rock (oceanic-continental boundary) --contains minerals -pyroxene & Amphibole (dark); and plagioclase feldspar & quartz (light)
Basic classification of metamorphic rocks
--Foliated -- a texture that gives the rock a layered appearance --Non-Foliated - does not exhibit a banded or layered appearance
What are the atomic structures in order from weakest to strongest?
--Isolated silicate structure --Single chain silicate structure --double chain silicate structure --sheet silicate structure --Framework silicate structure
Felsic Rocks
--Light colored rocks that are rich in elements such as aluminium, potassium, silicon, and sodium Rhyolite - fine-grained extrusive felsic rock Granite - course grained intrusive felsic rock (continental-continental convergnce) Obsidian - felsic volcanic glass
Medium grained Clastic rocks:
--Sandstone --made up from the grains of sand --most dominant mineral is quartz --may have iron oxide cementing grains together
Mafic Rocks
--Silica deficient rocks with high contents of: Magnsium; iron & calcium --made up predominantly of: plagioclase feldspar and pyroxene & olivine --Gabbro - course grained intrusive mafic rock --Basalt - fine-grained extrusive mafic rock (oceanic-oceanic boundary)
What happens in a flood volcanic eruption?
--Very low viscosity (basalts) --Creates extensive lava plateaus when it cools and solidifies. --Leaks out of the earth & fills in low lying areas (like the columbia river) --end up with individual layers that makeup the subsurface of the earth
Pre-existing rock to sediment
--chemical and physical weathering --Erosion --dissolution
Ultramafic Rocks
--makes up the mantle, contains less than 45% silica, Iron rich. --Composed of Olivine & Pyroxene --Peridotite - a course grained intrusive ultramafic rock
What happens in a submarine eruption?
--nearly always basaltic, pillow shape due to cooling under water --lava squirts out of the earth then rapidly cools and solidifies (This gives us evidence of how long water has been on earth)
Transportation of rock
--rounding of particles occurs due to abrasion during transport
What are the two most important elements of a mineral?
Atomic structure & specific chemical composition
crystallization of granite minerals from first to last
1. Biotite 2. Plagiclase Feldbar 3. Potassium 4. Quartz
What is granite composed of?
2 types of Feldspar, quartz & Biotite
Phanerozoic Climate Change
250 million years ago when Pangea started to break apart, an extensive amount of CO2 was released into the atmosphere from an extensive amount of volcanism. the atmosphere temps increased rapidly and caused a mass extinction.
composite volcano
A tall, cone-shaped mountain, high viscosity, high gas content and extremely explosive (Mt. Renier, Denali, Mt. Shasta, Mt. St. Helens: Within the Cascade Range)
What is the Hawaiian Islands made of?
Basalt
_____________________ is the main mafic igneous rock to form at ______________________________________
Basalt Divergent plate boundaries
Examples of Depositional Environments
Beach Swamps/Flood Plains River Channell/Delta
What are sedimentary structures?
Bedding Ripple Marks Mud cracks
Types of fossils
Body Trace
Course grained clastic rocks
Breccia Conglomerate
Course grain Clastic rocks are?
Breccia - angular gravel Conglomerate - rounded gravel
Breccia
Clastic, coarse sized grains, usually near-surface faults, angular clasts Could have fallen from a rock fall in the mountains)
The majority of sedimentary rocks are ......
Clastic/Detrial
Sedimentary rock classifications are.........
Clastic/Detrial Inorganic/Chemical organic/biochemical
Sedimentary Rock classification:
Clastic/Detrital Inorganic chemical Organic Biochemical
Chemical weathering of Feldspar and Micas:
Clay minerals
What rocks are formed at the oceanic/continental plate boundaries?
Diorite & Andesite
What are the mineral properties?
Color streak luster hardness cleavage fracture specific gravity magnetism chemical reaction
conglomerate gravel
Composed of rounded clasts that are pebble size or larger (could have formed at a river or stream)
What are the three types of rock metamorphism?
Contact regional shock
atomic structure of Amphoibole Group
Double Chain Structure
If a Diamond and Coal have the exact same composition, which one is harder and why?
Diamond it is covalently bonded in all directions
What is Volcanic Igneous Rock?
Extrusive
True or False Marble is the parent rock of Limestone
False
silica content from most to least
Felsic Intermediate Mafic Ultramafic
Crystal igneous rocks are mostly
Felsic intermediate Mafic
Crystal Igneous Rocks are mostly......
Felsic intermediate mafic
The composition of granite is called?
Felsic Composition
What makes up the continental crust?
Felsic igneous rock (Granite)
Volcanic Eruptive Types are:
Flood Eruptions Submarine Eruptions
_____________________ in sedimentary rock hold clues to the history of life
Fossils
What is the strongest silicate structure?
Framework
atomic structure of Quartz Feldspar group
Framework Silicate Structure
What rocks make up plate tectonics?
Granite & Basalt
Felsic flow
Granite lava - thick more viscose - harder to flow
Mississippi Bird's Foot Delta
Has 3 distributaries A tremendous amount of sediment comes to rest
What is Calcite Dissolution?
Hydrogen Cations replace others in minerals and allow them to dissolve in a solution. (Calcite dissolving into an acidic solution to form caves)
atomic structure of Olivine?
Isolated Silicate Structure
Mississippi Delta
It has distributaries Water is being diverted out
chemical sedimentary rocks
Limestone Chert - almost entirely of Silica Jasper/Flint - composed of crystal & silica Gypsium/Halite (Salt)
Sediment from chemical precipitation:
Loose solid particles originating from chemical precipitation from solution including secretion by organisms in water. (Calcite precipitation from sea water)
What are the special case bonding?
Metallic Bonding Van der Waals bonding Hydrogen bonding
Elements make up___________________
Minerals
Bowen's Reaction Series
Minerals form in a sequence with mafic rocks forming first deeper in the crust at higher temperatures and Felsic rocks forming last at lower temperatures higher in the crust forming more resistant rocks (like Granite)
from sediment to sedimentary rock
Movement of sediment by water, wind or ice.
mineral content of metamorphoic rocks are dependent on????
Parent rock composition
What are metamorphic rocks?
Parent rocks are "metamorphosed" by changes in composition and structure due to increased temp and pressure
Components of weathering
Physical & Chemical
ripple marks
Preserved in sand that was moved by wind, streams or waves
Deposition
Process in which sediment is laid down in new locations.
The most stable mineral on earth is?
Quartz
What mineral are most beaches made up of?
Quartz
What minerals makeup Granite?
Quartz Plagioclase feldspar potassium feldspar biotite
intraplate volcanism
Rising mantle plumes can produce localized hotspots and volcanoes (ex. Hawaii-basalt, Yellowstone-rhyolite)
Sedimentary rock analysis-----------------
Rock Type Fossils present sedimentary structures
extrusive igneous rock
Rock that forms when magma cools immediately above the surface of Earth
Minerals make up___________________
Rocks
Pre-existing rock to sedement
Rocks exposed at earths surface changed by weathering and erosion, broken into pieces to change their nature
Physical weathering of quartz:
Sand
Medium grained clastic rocks
Sandstone
"Fair Game" Sedimentary Rocks
Sandstone Shale/Mudstone Limestone Evaporites Coal
Fine grained clastic rocls
Shale Fissle Siltstone Claystone
fine grained clastic rocks
Shale Fissle Siltstone Claystone
atomic structure of Mica/Clay group
Sheet Silicate Structure
atomic structure of Pyroxene Group?
Single Chain Structure
cinder cone volcano
Steep sloping, small structure, intermediate viscosity, formed from the debre of a volcanoe
Factors controlling metamorphic rock characteristics are:
Texture Temp pressure tectonic forces foliation
What is physical weathering?
The breakdown of rocks without chemical change. Usually this is caused by abrasion. Actual process of desenegration
Where do Diorite & Andisite usually form?
The cascade range (Northern California, Oregon & Washington) Mt St Helens Mt Renier Mt shasta
What is Chemical weathering?
The process that breaks down rock through chemical changes
Lithification
The process that converts sediments into solid rock by compaction or cementation.
Yellowstone
Volcanic Felsic igneous rock that is very rare
What is a metallic bond?
a bond formed by the attraction between positively charged metal ions and the electrons around them
clastic rock
a sedimentary rock formed when rock fragments are squeezed together (sand & clay)
Bedding Structures
a series of visible layers within a rock *Most common type of structure*
Which word best describes a minerals tendency to break along planes of weakness? a. cleavage b. luster c. specific gravity d. fracture
a. cleavage
Why does basalt makeup most of the ocean floor? a. it forms at divergent plate boundaries b. basalt does not subduct at convergent plate boundaries c. basalt forms at transform plate boundaries d. none if the above
a. it forms at divergent plate boundaries
Contact metamorphism occurs
adjacent to magma bodies introducing pre-existing rock
Which of the following is the name of an angular course grained, clastic sedimentary rock? a. conglomerate b. breccia c. shale d. limestone
b. breccia
Which Silicate structure will result in a mineral that is hardest and has the fewest planes of weakness? a. sheet b. framework c. isolated d. chain
b. framework
What type of volcanic eruption contains the lowest viscosity lavas? a. strato volcano b. shield volcano c. cinder volcano d. volcanic domes
b. shield volcano
Mafic flow
basaltic lava - thin less viscose - flows easy
Mudcrack structures
became very dry over time, recording that time in history
How did the Indonesian islands form?
because of the subducting plate and the melting of the subducting plate
What is the cleavage of a mineral?
breakage along flat plains
shield volcano
broad shape, low viscosity lava (Hawaiian Islands) Indonesian Islands have all shield volcanoes
A mafic extrusive igneous rock is called? a. granite b. andesite c. basalt d. pumice
c. basalt
Which is NOT part of the definition of a mineral? a. inorganic b. solid c. man made d. specific structure
c. man made
Which of the following minerals is not typically found in granite? a. quartz b. feldspar c. pyroxene d. biotite
c. pyroxene
Non-Foliated Metamorphic Rock is named based on..........
composition (Quartzite)
What composition of igneous rocks are first to solidify from a rising magma plume? a. mafic b. intermediate c. felsic d. ultramafic
d ultramafic
Which of the following information about sedimentary rocks is useful when interpreting past environments? a. sedimentary rock type b. fossils c. sedimentary rock structure d. all of the above
d. all of the above
What types of minerals form as a result of the chemical weathering of feldspar and biotite from a granite? a. framework silicates b. calcite c. organic materials d. clay materials
d. clay minerals
What factor controls the composition of a metamorphic rock? a. type of metamorphism b. temperature c. pressure d. composition of parent rock
d. composition of parent rock
What rocks form at convergent plate boundaries?
different types if igneous rock
The violence of volcanic eruptions are controlled by?
dissolved gasses in the magma (the more trapped gas, the more violent the eruption
Trace fossils are
evidence of the activities of ancient organisms. Ex: footprints, animal trails, or animal burrows.
How is sedimentary rock formed?
from accumulation of fragments of other pre-existing rocks, sediment or from chemical precipitants
What is the fracture of a mineral?
how a mineral breaks
What are the 3 rock types?
igneous, sedimentary, metamorphic
Sedimentary rocks, structures and fossils give us------
important clues to the geological history of an area using rock type, including grain size, fossils and sedimentary structures
sediment
loose materials, such as rock fragments,mineral grains, and the remains of once-living plants and animals, that have been moved by wind, water, ice, or gravity.
Clastic/Detrital Sedimentary Rocks
made of fragments of other rocks( Sandstone, shale, conglomerate) Particularly found formed around continents
Divergent boundaries create.........................
mafic extrusive rock (basalt) that is later subducted beneath continents which is why ocean crust is mafic and continental crust is felsic
How is igneous rock formed?
magma / molten rock solidifies
intrusive igneous rock
magma cools slowly beneath Earth's surface
Limestone was metamorphosed from______________________
marble
regional metamorphism
metamorphism associated with large-scale mountain-building processes (results in foliated rocks)
Shock metamorphism results from:
meteorite impact (Brushy Creek in Louisiana is an impact sight)
Factors controlling metamorphism
parent rock, heat, pressure, fluids
Sedimentary rocks hold clues of_________________________
past environments
Pyroclastic means?
pyro - fire clastic - pieces
What is metamorphism?
refers to solid-state changes to rocks in earth's interior (no complete melting of the rocks occur to bring about these changes)
How is metamorphic rock formed?
rocks that are subjected to high temps and/or pressures (cooked but not melted) (Happens with mountain building)
What kind of rock are fossils found?
sedimentary rock
chemical sedimentary rock
sedimentary rock consisting of material that was precipitated from water by either inorganic or organic means
What is a covalent bond?
sharing of electrons
Sharing of oxygen atoms in _______________________ results in different ___________________ structures
silicate tetrahedra silicate
Silicon-Oxygen Tetrahedra
strongly bonded silicate ion basic structure for silicate minerals
texture of metamorphic rocks depends on......
temp and pressure
Body fossils are
the imprint of the organisms body after decomposition
What is the sedimentary structure?
the pattern formed after the deposition of sediment
Climate impact of volcanism
the release of dissolved greenhouse gasses (CO2, H2S, HCI) from a volcanic eruption can lead to long term warming of the atmosphere by trapping more heat close to the surface of the planet
Importance of the Mississippi River and Delta's?
they enabled Louisiana to be formed and continue to be built The river changes its path over time and builds out additional parts of Louisiana
Why are fossils not found in igneous and metamorphic rocks?
too much heat that would erase any evidence of the fossil
What is ionic bonding?
transfer of electrons
foliated metamorphic rock is named based on...........
type of foliation (Slaty, Schistose, Gneissic)