geology time notes 10-23 Essay

Submitted By amm666
Words: 1133
Pages: 5

Crystal Separation
-filter pressing
-crystal settling
-crystal flotation
What if the magma stays underground?
-magmatic stop-moving through ground (country rock) -wedging -breaking -melting
-plutonic
Batholiths- larger than 100km2 -most batholiths contain multiple intrusions
Stock-smaller 10km2 or less
Dike-path that is vertical
Still-is horizontal
Volcanoes
How to melt rock?
-add heat
-lower pressure on already on hot rock
-add water to already too hot rock.
-combinations of the above ^
-rock doesn’t melt uniformly

Volcanic processes and volcanoes
Volcanic processes- the escape of magma and other ejecta from the interior of the earth
3 major types of ejecta
Lava-liquid magma at or near the surface of the earth
Pyroclastic material tephra- ash, solid or solid when it hits the groups
Gas-H2o, CO2, SO2
Volcano type determined by proportions of each ejecta type amount of magma and magma viscosity
How it comes out? And how it flow?
Viscosity
Viscosity
Low viscosity - rapid flow
High viscosity- slow flow
Dependent upon 3 Factors
-Temperature of the magma -increase temperature-decrease viscosity
-Silica content of the magma -increase Silica content-increase viscosity
-Dissolved gas content of the magma -Increase dissolved gas content- decrease viscosity
Flow structuring- Pahoehoe and AA
Volcanoes
4 major types of eruption that build a mountain

Shield Volcanoes
/-All lava
-Divergent plate boundaries – tension or hot spots
-most common on earth
-usually undersea
-usually quiet eruption -Strombolian Hawaiian Pelean
-does not expoled
-relatively short with respect to width
-lava flows low viscosity/mafic chemistry
-Basaltic rock
-decompression melting

Compostie Volcanoes
-also called stratovolcanoes exp: mammoth mountain.
-made up of lava and pyroclastic material
/-convergent plate boundaries -subduction zones (only)
-most common on land
-explosive eruptions -Plinian Vulcanian
-relative tall with respect to their width
-lava flows high viscosity/intermediate chemistry
-andesitic rock
-nuee ardende- ash fall volcanic mud flow water and hear to the fraction
-diapir-malting blobs Volcano
-heating from frection
-it melts through the asthenosphere
-The more buoyant- able or apt to stay afloat or rise to the top of a liquid or gas
-newly air vents
-ash flow
-lahar-volcanic mud flow with ash -rain or river -snow melting
Cinder Cones
/-pyroclastic material
-beginning volcanoes
-no special plate tectonic setting
-usually “grow up” to become another volcano type
-explosive eruptions
-rarely taller than 300m
-at most one flow lava, if any
-chemistry depends upon plate tectonic setting

Volcanic Domes
-also called lava dome or plug dome
-lava
-usually happens in associated with composite volcanoes
-relatively quiet eruptions most of the time -high viscosity

Fissure Eruptions
-also called lava flood or flood basalt
-lave
-no mountain is built- plateau
-Relatively quiet eruption- must of the time
-Extremely low viscosity -Basalt rock
Weathering
Weathering –the disintegration and decomposition of rock by physical or chemical processes
Physical weathering-the mechanical process(es) that break rock into smaller pieces “using a hammer”
Chemical weathering-the process(es) by which minerals in the rock are changed into other minerals or dissolved
Chemical and physical weathering rein forces each other -the greater the chemical weathering the weaker the rock: the easier it is to break -the more breakage: the greater the surface area: the faster the chemical integration. Weather rates
Properties of the rock -composition/mineralogy -Structure of the rock – layers
Climate
-moisture; weat- huge affect on how rock decomposition
-acidity- agent of weather “water”
Duration
-burial in soil -bacterial action
-topography - the arrangement of the natural and artificial physical features