The Moon
October 4, 2006
Visible phase determained by:
-
Current phase
- Position of the sun in the sky (time)
- Position of the moon in the sky
At sunset: full is rising, first quarter is high in the sky, new is setting (third quarter sets at noon)
Moon is offset from Earth Sun by .5*
Orbital plane of moon around earth is different than that of the earth around the sun
Only solar eclipse when phase is new
penumbra = outershadow of moon (only part of the solar eclipse)
umbral shadow = inner shadow of moon (full eclipse) about 300km on earth at a time and never longer than 7 minutes
annular eclipse (when moon doesn’t completely cover the solar disk), umbral shadow is not complete
Lunar eclipse is longer (earth is bigger)
- Takes hours
- Penubral shadow has almost no effect
- At totality, it looks red due to refraction through earth’s atmosphere
Sed Rocks -Con’t
October 4, 2006
It takes 2 moles to weather ignious rocks, but only 1 mole is returned by the calcium carbonate. So silcate weathering consumes CO2
Lithification process
- Compaction
- Dissolution
- Precipatation
- Recrystalization
- Cementation
Facies Concept
- Unique to where a rock forms
- Sediment transported to shore line
- sand facies is very high energy
- finer grain caries through sand to mud
- very little carries out to the carbonate faces
- Sand stone to mud stone to lime stone
- Facies can only be ontop or below ajacent facies
- The order in which they’re array’d gives us the sea level history (transgression or Regression)
- Durring regression erotion takes place
Major depositional environments
- Weathering and erosion (proximal) -> source rock and climate
- Transportation and sedimentation (updip to fluvial) -> distance, gradient, energy level (lakes vs river)
- Shoarline (dunes)
- Deltas
- Deep Marine
- rate of sink matters
Eluvial system
- Fan (not clay because not enough time) basement stuff (felpars)
- Braided (broad and wide streams)
Eolian depositis ->
- fine grained (weathered by wind)
- between proximal and distal
- Dunes migrate ontop of eachother
Meandering streams
- Big and deep
- flood eluvial vally
- deposits silt and clay
- going down: High energy to low energy
Delta
- Sudden energy drop
- While global sealevel is rising, the mississippi is regressing because of sedemens
- Opposite gradiant: find to course grain due to regression
Reaf system
- Limestones and dolastones (from magnesium from lagoons)
- Both high and low energy (high from ocean, low from lagoon)
Turbidites
- Clay -> courser then back to cley suddenly
- Graded bedding
- Energy of the flow highest when it gets to the site
- head of flow is course tail is finer.
Important stuff that didn’t fit anywhere else
- Lacustrine Deposits: Varves
- Layering caused by lakes
- Diagenisis -> everything not metamorphic
- Basement = Igneous rocks
- felspar becomes clay, but it takes time
Metamorphic rocks -> represent changes that occer in solid state (prior to melting)
- Recrystalization
- Phase changes
- Neo Crystalization
- Pressure solution ->the contact (touching point) is desolved between grains
- Deformation -> contact is not desolved
- Tend to find them in Precambrian sheilds and occationally folded mountain belts (due to their tectonic activity)
- Temp, pressure, fluids
Lithosphere goes down into mantal to stenosphere
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September 21, 2006
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