EARTH 7 Lecture Notes - Lecture 4: Pilbara Craton, Geologic Time Scale, Nuclear Membrane
Earth’s Age
- Lord Kelvin - Earth can’t be older than 20-40 Ma (wrong because he didn’t know about
another source of heat -- radioactivity)
- Darwin - can’t be true, earth needs to be older
- Radioactivity not discovered until 1896
- First absolute ages published in 1907
- Earth rocks/minerals, moon rocks, and meteorites all suggest that the Earth and Solar
system formed ~4.5 billion years ago
The geological timescale
You should know!:
- The age of the earth (4.5 Ga)
- The range of the precambrian (4500-540 Ma)
- The range of the paleozoic (540-
- The
Everything need to know for midterm contained on one page
A brief history of life
First good evidence, 3.5 Ga
- Living stromatolites in shark bay, australia
- Fossil stromatolites from warrawoona, australia
- Fossil bacteria from ~3.45Ga Kelly Group, Pilbara Craton, Western Australia
The Rise of Atmospheric Oxygen
Banded Iron Formations
- Fe dissolved in the ocean reacted w/ O2, forming world-wide iron oxide deposits (2.5-
1.8Ga)
What’s a Eukaryote?
Prokaryotes v. Eukaryotes
Eukaryotes
- More complex than prokaryotes
- Nuclear envelope
- Organelles (mitochondria = powerhouse of the cell)
3 Domains of Life
Prokaryotes:
- Bacteria
- Archaea
Eukarya:
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lord kelvin - earth can"t be older than 20-40 ma (wrong because he didn"t know about another source of heat -- radioactivity) Darwin - can"t be true, earth needs to be older. Earth rocks/minerals, moon rocks, and meteorites all suggest that the earth and solar system formed ~4. 5 billion years ago. The age of the earth (4. 5 ga) The range of the precambrian (4500-540 ma) Everything need to know for midterm contained on one page. Fossil bacteria from ~3. 45ga kelly group, pilbara craton, western australia. Fe dissolved in the ocean reacted w/ o2, forming world-wide iron oxide deposits (2. 5- Organelles (mitochondria = powerhouse of the cell) Tons of single cellular things + multicellular. Origin of eukaryotes come from separate bacteria that were one pre living. More complex cell, more efficient as predator one of the early eukaryotes engulfed purple bacteria, purple bacteria had ability to use oxygen to make energy become mitochondria.
