Term
| Three reasons why Antarctic Geology is important |
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Definition
The three reasons why antarctic geology is important:
1. Antarctic geology is linked to geopgraphy across many continents as antarctica was once the center of a large continent called Gondwana
2. Antarctic rocks, along with rocks in other places, contain a record of the past that gives insight to the future for things like climate change
3. antarctic geology is the key to accessing mineral/oil resources |
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Term
| how do we "see" antarctic rocks hidden below ice? |
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Definition
| we use ice-penetrating radar to see below the ice |
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Term
| the plate boundary where the antarctic plate meets the surrounding ocean floor is what kind of plate boundary? |
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Definition
| the margin of the antarctic plate where it meets the ocean plate is a passive margin |
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Term
| 10-220 MYA, _____ dominated more of the plate boundaries around antarctica |
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Definition
| 10-220 MYA, more of antarctica's plate boundaries were subduction zones |
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Term
| where is the only antarctic plate boundary where subduction is still taking place? |
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Definition
| the only antarctic plate boundary where subduction is still taking place is where the drake plate is subducting below the south shetland islands |
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Term
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Definition
| what is important to note is the saw-toothed boundary between the drake plate and shetland plate. This indicates that the drake plate is subducting below the shetland plate |
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Term
| the south shetland islands are interacting with the ____ plate and the _____ plate and are the site of ____ island, an active volcanic zone |
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Definition
| the south shetland island are converging with the drake plate (the drake plate is oceanic, so the drake plate is subducting) while they diverge from the antarctic plate. The south shetland islands are the site of deception island, which is a an active volcanic zone |
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Term
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Definition
| the red splotch with the arrow is decpetion island, a rare antarctic volanco |
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Term
| what is the ocean-ocean boundary we discussed in class? |
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Definition
| we discussed the south sandwhich islands being subducted under oceanic crust |
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Term
| what kind of plate are the south sandwhich islands on? what is occuring to that plate? |
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Definition
| the south sandwhich islands lie on oceanic plate. That oceanic plate is subducting under another oceanic plate |
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Term
| what is the transform plate boundary we discussed in class? |
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Definition
| the transform plate boundary that we discussed in class is where the antarctic plate and scotia plate are moving past one another |
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Term
| volcanos not near plate boundaries are related to what? |
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Definition
| volcanos in the middle of plates are caused by rifting/stretching of the crust or mantle hot spots |
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Term
| what is the mid-plate volcano in antarctica? |
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Definition
| the mid-plate volcano in antarctica is mt. erebus |
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Term
mt erebus is definitly related to _____
mt erebus may be related to _____ |
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Definition
mt erebus is definitely above rifting in the antarctic plate
mt erebus may be above a mantle hot spot |
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Term
| does the entire antarctice plate sit directly under the continent of antarctica? |
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Definition
| the antarctic plate includes the continent and some surrounding ocean |
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Term
| today's antarctic plate is surrounded mostly by ____ margins except for one small _____ boundary |
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Definition
| today's antarctic plate is surrounded mostly by divergent boundaries except for one small convergent boundary, where the drake plate is subducting under the shetland islands |
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Term
| why are parts of antarctica below sea level? |
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Definition
| parts of anarctica are below sea level becuase of rifting and stretching |
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Term
| rifting and stretching has led to some of the antarctic continent being ____ |
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Definition
| rifting and stretching has led to some of the antarctic continent being below sea level |
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Term
| what is the difference between the creation of volcanic and plutonic rocks? |
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Definition
the difference between the creation of volcanic and plutonic rocks:
1. volcanic rocks come from magma that reached the surface before it cooled
2. plutonic rocks come from magma that cooled under the ground |
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Term
| extrusive igneous rocks have what name and what size grains? |
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Definition
| extrusive igneous rocks are called volcanic and have fine grains |
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Term
| intrusive igneous rocks are called what and have what size grains? |
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Definition
| intrusive ingenous rocks are called plutonic and have coarse grains |
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Term
| 3 volcanic rocks we talked about, in order of darkest to lightest |
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Definition
the three volcanic rocks we talked about in order of darkest to lightest:
basalt → andesite → rhyolite |
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Term
| what are the three plutonic rocks we learned about in order of darkest to lightest? |
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Definition
the three plutonic rocks we learned about in order of darkest to lightest:
gabbro→ diorite → granite |
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Term
| vertical magma intrusions are called what? |
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Definition
| vertical magma intrusions are called dikes |
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Term
| horizontal magma instrusions are called what? |
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Definition
| horizontal magma instrusions are called sills |
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Term
| what are the batholiths and stocks? |
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Definition
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Term
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Definition
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Term
| name of a sedimentary rocks depends on ____ |
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Definition
| name of a sedimentary rocks depends on the grain size |
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Term
| chalk and limestone are formed by what process? |
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Definition
| chalk and limestone are created by the process of soluble substances precipitating out of water |
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Term
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Definition
| chert is silica-rich ooze on the ocean floor |
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Term
| what do we call silica-rich ooze on the ocean floor? |
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Definition
| silica rich ooze on the ocean floor is called chert |
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Term
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Definition
| that is conglomerate, a type of sedimentary rock composed of grains of many sizes |
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Term
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Definition
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Term
when mudstone undergoes heat and/or pressure, it metamorphises into _____
when sandstone undergoes heat and/or pressure, it metamorphises into _____
when igneous rock undergoes heat and/or pressure, it metamorphises into _____ |
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Definition
when mudstone undergoes heat and/or pressure, it metamorphises slates
when sandstone undergoes heat and/or pressure, it metamorphises into schist
when igneous rock undergoes heat and/or pressure, it metamorphises into gneiss |
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Term
| slate is metamorphic rock that was once ____ |
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Definition
| slate is metamorphic rock that was once mudstone |
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Term
| schist is metamorphic rock that was once ____ |
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Definition
| schist is metamorphic rock that was once sandstone |
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Term
| gneiss is metamorphic rock that was once _____ |
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Definition
| gneiss is metamorphic rock that was once igneous rock |
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Term
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Definition
| that Gneiss, a metamorphic rock that comes from igneous rock |
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Term
| four strategies to rank rocks in terms of age, in other words relative age |
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Definition
four strategies to find the realtive ages of rocks
1. law of superposition
2. fossils
3. cross cutting relationships
4 unconformities |
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Term
| what is the only way to find the absolute age of a rock? |
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Definition
| the way to find the absolute age of a rock is by looking at radioactive decay |
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Term
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Definition
| folded sandstones and shales |
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Term
| if a rock is cross cutting along a layer, what does that tell you about it's age? |
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Definition
| the cross cutting rock is younger than any of the layers it cuts through |
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Term
| unconformities represent _____ in the geological history of an area |
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Definition
| unconformities represent gaps in the geological history of an area |
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Term
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Definition
| gabbro has large, visible grains. it is black |
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Term
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Definition
| granite has large, visible grains. it is light colored |
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Term
| what does slate look like |
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Definition
| slate is what they make chalkboard out of |
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Term
| what is the difference between gneiss and schist? |
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Definition
| Schist breaks and flakes more. Gneiss has pretty swirls |
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Term
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Definition
| pumice has low density and has bubbles |
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Term
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Definition
| basalt is black with small grains. no definining features |
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