This site is newly developed and will help you with your Earth Science homework.
I hope to update the site on a regular basis to give you a general direction that we are heading toward in class.
The site will include assignments, both long and short term.
I will add helpful sites, links, and tutorials.
Class notes for the first week of November.
We are currently studying Chapter 4 in the textbook. To this point we have discussed Igneous Rock- "rocks born of fire". There are many types of igneous rocks; pumice, granite, obsidian,rhyolite,basalt, and scoria, to name a few. What is really important for you to understand is the various ways in which these rocks are formed.
We first need to know where the magma which formed the rock cooled-
intrusive igneous rock- cooled underground
extrusive igneous rock- cooled above ground
If the magma cools below ground then it would have been a slow cooling process. This time would allow for larger crystals to grow. Remember last chapter we discussed the three ways crystals formed. The very first way was magma cooling! This is seen here.
If the magma reaches the surface we then call it lava. Lava will cool relatively quickly. This quick cooling doesn't allow for large crystal formation. So, we would expect to see fine grained crystals in an extrusive igneous rock.
The second important charicteristic to look at is the composition of the magma. Magma comes in three basic flavors!(Never try to taste magma-1400 C)
Basaltic magma- is very dark in color and heavy. This is due to it containing large amounts of Fe(iron) and Mg(magnesium)
Granitic magma- is lighter in color(greyish) and lighter in weight due to it containing larger amounts of Si(silicon) and O(oxygen).
Andesitic magma- is truly a mixture of the two magma types above. Andesitic magma contains various amounts of; Fe, Si,O, and Mg.
Today in class we talked about metamorphic rocks! There are two types of metamorphic rocks- Foliated and non-foliated.
Foliated rocks have visible bands or layers of mineral grains. While in non-foliated rocks there are no visible bands.
ex. marble- non-foliated
Gneiss some foliated, some not
We also discussed sedimentary rocks. They are formed from the weathering and erosion of existing rocks or the decomposing of plants or other organic material.
They are classified by their composition into the following types:
A.) detrial (clastic) -> worn down or broken away
B.) chemical -> dissolved minerals or evaporation
C.) organic -> peices of living things
ex. conglomerate, breceia, siltstone, sandstone, shale
It takes 300 million years and 2.1m of plant matter to make .3m of bituminous coal .
1.) coastal plains
2.) interior plains
3.) Appalachain highlands
4.) interior highlands
5.) intermontane plateau and basin
6.) pacific valley and mountain system
7.) Rocky mountains
8.) Superion uplands (elevated land)
1. folded mountains- formed from pressure from the sides which causes them to fold
2. upwarped montains- pressure from sides and bottom cause these to form.
3. Volcanic mountains- formed by magma pushing up from beneath the earths surface.
4. fault block mountains
Types of maps
globe- most accurate
robinson projection- poles are distorted
conic projection- most accurate but only show small areas like road maps
Topographic maps- show elevation and landforms like mountains, rivers and valleys
topographic maps have contour intervals that tell how how much you are stepping up between two contous lines.
They must have a compass rose, a key, an index contour(marked lines), and a scale that tells how much an area on the map is worth in real life.
Rules for topographic maps
1.) the closer the lines the steeper the elevation rise in real life
2.) contour interval
3.) hatch marks going in mean depression in land
4.) Contour lines bend upstream on rivers on topographical maps.
-Topex Poseidon- radar , high frequency radio waves (topographic experiment)
-Landsat satellites- hundereds of mirrorswith detectors to measure electro-magnetic rariation from the earth