Geology Index
Last edited: May 5, 2026Lectures
SU-EARTHSYS11 MAY042026
Last edited: May 5, 2026metamorphism
Metamorphism: protolith + heat and pressure => changes in the mineral composition / orientation in solid states until energy-minimizing state “comfortable with each other and their surrounding.”
Given 25 deg C per KM, we know only 250-850 deg c is required for it: so, only need about 10km required for metamorphism.
protolith
starting point of the rock, from shale, etc.
why heat?
Heat causes atoms to vibrate rapidly: stretching, bending, breaking chemical bonds. Atoms detach from neighbors, form new bonds with more stable different atoms.
SU-EARTHSYS11 MAY0620206
Last edited: May 5, 2026stratigraphy
How do we understand what different stratum look like for historical dating, etc.,
uniformtarianism
“the past history of our globe must be explained by what seems to be happening right now.”
- an unconformity: a gap in the stratographic record
- if you look at the layers of the earth, if the lower older layers is not flat but the top layers are flat, then the lower layers have been squeezed / deformed in time
basic principles
- superposition: lower is older
- original horizontal: original is flat, tilt is later
- original continuity: if there’s a hole, it was a block before and something cut it
- cross-cutting relationships: if something cuts another thing, the thing that cuts it must be younger
unconformities
if there is some point where there’s a “sharp turn”, we call that an unconformity.
SU-EARTHSYS11 MAY182026
Last edited: May 5, 2026There’s So Much Oil in the Ground
oil
“Fossilized Sunshine” photosynthesis => plant elements => preserved sedimentary rocks.
- small critters
- phytoplankton
- plant matter
maturation process
Carbon-rich organic features, deposited. Increased pressure. Eventually compressed into…
kerogen
A solid, seminary rock that’s carbon rich. With enough pressure, carbons join up and then you get a chain.
Oil: C16H34, C7H16 etc.
increase pressure
….oil gets squeezed out from the kerogen, and then density differences makes it rise.
Houjun's Academic Home Page
Last edited: May 5, 2026👋 Howdy, I'm Houjun Liu!
I’m a third-year coterminal MSCS and BSCS student in the Computer Science Department at Stanford University, grateful to be advised by Prof. Mykel Kochenderfer. In the course of my research, I have also had the fortunate opportunity to work with Stanford NLP under Prof. Chris Manning, CMU TalkBank under Prof. Brian MacWhinney, and Prof. Xin Liu at UC Davis Engineering. I am affiliated with the Stanford NLP Group and Stanford Intelligent Systems Lab. I’m also visiting Microsoft Research Frontiers as a research scientist.