quiz three Flashcards
What era is before the Cambrian
The precambrian is made up of the archaean/proterozoic
the oldest rocks are about
4 million years old (older than life)
where can you find the oldest rocks/grains
oldest rocks are in Canada but not older grains can be found in australia
what is the earth like at this 4.6 gA ago time
constant meteorite bombardment, very gassy cannot breathe
how and when does water enter the scene
water comes in at 4.4 Ga. the meteorite bombardment slows
when does life originate on earth/ what is it called
3.8 ga - the abiogenesis
what is the miller-urey
an experiment that was to try and recreate what the earth’s atmosphere was like
miller-urey takeaways
he was able to make amino acids. 12/20 of the most common have now been found
and where did this life originate
in deep sea vents or something similar
when are the earliest fossils from
3.5 ga
what were early fossils like
prokaryote body fossils
stromatolites
the trace fossils of microbial life - I guess the first fossils?
how are stromatolite formed
sediments trap the little microbial organisms in place. T
time period of the stromatolites
-so the atmosphere is low oxygen content
- but this is when the super continent breaks apart, also snowball earth
first animal fossils
edicarians
impressions of something that is soft
alive for like the 600-550 period
CAMBRIAN EXPLOSION
appearances of many different species in an instant
lagerstatte
not sure exactly what it is but since its a shale
so its a series of like really well preserved fossils;
when did the east coast form
in the Cambrian
taconic orogeny
1st step, the accretion of the taconic island arc
Acadian orogeny
2nd step, accretion of the avalonia island arc
Alleghanian orogeny
collision of Gondwana back into everything else
3 major ingredients feel like this will be a question
solar energy, sphericity, the fact earth is spinning (Coriolis effect)
where do you find coals
places where there is precipitation as well as warmth
where do you find evaporites
where it is dry and coastal
where do you find the sand dunes
where it is dry and continental
warm currents come from….
low latitudes
cool currents come from…
high latitudes
reefs
warmth + downwelling
oil
upwelling productivity
