GEOL 102 1st Edition Lecture 4Outline of Last Lecture I. FossilsA. Any evidence for a previous life formII. SandstoneA. Is from the sedimentary rock familyB. Pieces put together III. Things that could have moved the mountains at devils lakeA. Glaciersa. Would cause striationsi. Scratches on the rocksb. Would cause various types and sizes of rocks to be placedB. Rivers a. Would have to look for ripplemarks, sediment that doesn’t belong, river fossils, or rounded rocksC. Earthquakesa. Would look for jagged line, find tops elsewhere, fault line D. Volcano a. Lava flows, volcanic rock, beds of lava flows, jagged pieces of rock, volcanic ashIV. Origin of the Earth and Geologic timeA. Used to understand the difference between relative and absolute geologic timeB. Geologic scaleC. Used to understand what rocks tell us about the age of the earth V. Devils LakeA. Quartzite formation hypothesisa. Loose grains of sand deposited by running water, then something happened to turn it into the hard rock we see todayVI. DispositionA. Particles set down by some sort of currentThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.a. In ex. After a floodB. When running water is at work it tends to deposit things in a layera. Layer will be sub horizontalVII. Erosion A. Opposite of depositionB. Pick up and moveVIII.Ripple Marks A. Associated with grains moving from currentIX. Metamorphic rockA. (change Shape) B. Under high temperature and pressureC. Recrystallization (no melt) Outline of Current Lecture I. Beach deposita. Look for sand, shells, fossils, logsb. Marine Fossil shells would appear II. Historical Events for Devils Lakea. Deposit sand (by H2O)i. In layers, flat lineb. Buried sand i. Increases temp. and pressure to form quartzite ii. “cooking”c. Mountain buildingi. Lines go from horizontal to vertical d. Erode mountainse. Deposit conglomeratei. Increase sea level (beach)f. Deposit sandstone (includes marine fossils)i. Sea levels continued to increaseg. Sea level dropped III. James Hutton a. Founded first angular conformity in the late 1700’s i. Angular conformity represents erosion and burial of a mountain ii. Siccar Point IV. Principles a. Principle of superposition i. In any stack of layered undisturbed rocks, the oldest rocks are at the bottom and the youngest are at the topb. Principle of cross-cutting relationshipsi. Any feature cut by something is older than the thing cutting it V. Geological time sale (calendar) a. Precambrain Era i. Oldest b. Palezoic Era i. “Paleo” old ii. “Zoic” live iii. Oldest life c. Mesozoic Era i. “mezzo” middle ii.