Geology 112 Word Scramble
|
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
| Question | Answer |
| The Hadean Time? | First 600 Ma, B4 first rocks, time of huge impacts |
| Oldest rocks | 4.0 Ba |
| Oldest mineral? | Zircon (western australia) 4.2 Ba |
| Zircon? | A mineral in granite, i.e. the main rock in continents |
| The oldest rocks? | Ultra hot pillow lavas (1600 degrees c) Proves the was already an ocean and earth was hotter below the surface |
| Source of gas and water? | 60 - 70% of the gas from volcanos is water vapour, rest is CO2 and N2 |
| How did oceans form? | Condensation of water vapour |
| Composition of early atmosphere? | 60% carbon dioxide, 30% Nitrogen, 10% argon |
| Composition of current atmosphere? | 78% Nitrogen, 21% Oxygen, 1% others |
| Evidence for oxygen poor atmosphere? | Pyrite and uraninite pebbles in ancient conglomerates. Palaoisols are all grey (acient soils), and early oceans had dissolve oxgyen in them which is impossilbe with oxygen in the atm. |
| Where is oxygen produced? | Small amounts in upper atm as UV light splits water vapour up. (photodissociation. Also Photosynthesis. |
| Evidence for dissolved iron in oceans? | Banded Iron formations, formed in shallow marine environments bewteen 3.5 - 2.0 Ba |
| Progression of Oxygen? | 3.8 Ba microbes producing O2 in the ocean and precipitiaing BIF's. BIF's stopped at 2.0 Ba and red beds were formed on land, indication oxygen in atm. |
| Plants invaded continents? | 0.4 Ba. |
Created by:
shiftyleigh
Popular Earth Science sets