Unit 01 · Earth's Structure & Plate Tectonics
This unit builds from the inside of the planet outward: the layers of the Earth and what each is made of, how the rigid plates ride the slowly flowing asthenosphere, the three kinds of plate boundary and what each one builds or destroys, and the lines of evidence — matching coastlines and fossils, seafloor spreading, paleomagnetism — that turned Wegener's rejected idea into the organizing theory of all of geology. Mastery means you can read a plate-boundary map as a record of moving lithosphere, not a diagram to memorize.
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| Earth's internal structure | Confuses the layers or thinks the whole interior is molten. | Names crust, mantle, and core but blurs composition layers with mechanical ones. | Distinguishes crust/mantle/core by composition and lithosphere/asthenosphere by behavior, and explains how we know (seismic waves). |
| Plate boundaries & motion | Cannot name the boundary types or thinks continents are fixed. | Names divergent, convergent, and transform but mixes up what each produces. | Predicts the landforms, earthquakes, and volcanism at each boundary type and gives a real-world example of each. |
| Evidence for plate tectonics | Treats plate tectonics as something to accept on authority. | Lists one line of evidence but cannot connect it to a mechanism. | Marshals matching coastlines/fossils, seafloor spreading, and paleomagnetism into the case that vindicated Wegener. |
| Earthquakes & volcanoes | Sees earthquakes and volcanoes as random or unrelated to plates. | Links them to plates in general but not to specific boundaries. | Explains where and why quakes and volcanoes cluster, and reads P- and S-wave arrivals to locate a quake. |
| Lab technique (triangulation / maps) | Cannot read a seismogram or a plate-boundary map. | Reads the traces but misplaces the epicenter or the boundary. | Triangulates an epicenter from three seismograms and interprets a plate-boundary map, defending each call. |
| Integration (cross-domain) | Treats the science as isolated facts; makes no cross-domain connection. | Names a link to history, reading, or writing but cannot defend why it matters. | Connects the unit to its anchor across History · Reading · Writing (plus chosen electives) and defends why the connection matters. |
“The Andes are there because an oceanic plate is subducting under a continental one — that’s a convergent boundary, so you get a trench, deep earthquakes, and a line of volcanoes. Wegener saw the matching coastlines and fossils a century ago; it took seafloor spreading and the magnetic stripes to explain how the continents actually moved.”
“The continents don’t really move, do they? And the inside of the Earth is all melted lava the whole way down.”
You demonstrate this unit through earthquake-triangulation and plate-boundary map work plus short oral checks where you reason from the evidence aloud — not a multiple-choice test. A criterion counts as mastered only when you can both read the map and justify the geology behind it. Mastery is demonstrated, not awarded.
A 5-page clipboard packet — unit overview, key terms, the mastery rubric, anchor examples, and a score sheet you can print and grade against.