Use these targets, vocabulary, rubrics, examples, and score sheet with the instructor's approved lesson and procedure. This is an assessment companion, not a complete lesson or safety authorization.
Student lessons, data, and worked answers: Unit 04 learning pathway.
The student demonstrates the following:
Five science criteria plus separately reported integration (Page 3).
Use halving, fractions or logarithms at the agreed level.
The student reasons from the evidence to an order and an age (Page 4).
Retain count units, initial daughter, closure assumptions and transfer.
You are making a decision, not adding up points. For each criterion, decide whether the work is Developing, Proficient, or Mastery — the column language tells you which. A criterion counts as mastered only when the student can both order the evidence and justify the age it points to. Each student has three tokens per term; each token retries one rubric criterion. Approved accommodations, equipment failures, and approved absences are handled separately and do not consume these tokens.
Accept listed synonyms; use the distinction column to resolve near-matches.
| Canonical answer | Accepted synonyms | Common confusion / discriminator |
|---|---|---|
| Relative dating | ||
| Superposition | oldest layer on the bottom | In undisturbed layers, the base is the oldest — not the top |
| Cross-cutting | a feature is younger than what it cuts | An intrusion or fault is younger than the rock it cuts through |
| Inclusions | fragments are older than their host | A chunk inside a rock predates the rock around it |
| Unconformity | a gap in the rock record | Missing time — erosion or non-deposition between layers |
| Absolute dating | ||
| Half-life | time for half the parent to decay | Constant for an isotope; not “half the time left” |
| Radiometric dating | dating by isotope decay | Uses the parent-to-daughter ratio; not a guess |
| Parent / daughter isotope | decaying atom / its product | The ratio, plus half-life, gives an absolute age |
| Absolute age | an age in years | A number, vs. relative age (just the order) |
| Fossils & deep time | ||
| Index fossil | widespread, short-lived species | Pins a layer to a narrow time; used to correlate rock |
| Geologic column | standard sequence of rock & time | Eons/eras/periods; the framework for correlation |
| Correlation | matching rock across distant sites | Uses index fossils and layers to line up far-apart rock |
| Deep time | the immense scale of Earth's age | ~4.6 billion years; a million and a billion are not the same |
| Criterion | Developing | Proficient | Mastery |
|---|---|---|---|
| Relative chronology | Cannot order the supplied events. | Orders layers but needs help with cross-cutting evidence. | Defends the L-A-U-I sequence and distinguishes relative order from the numerical age constraints supplied. |
| Dating quantities | Confuses fraction, half-life or initial daughter. | Calculates with help but omits clock assumptions. | At the agreed level, defends halving, corrected isotope fractions or logarithmic ages/bounds with units and closure assumptions. |
| The geologic column & fossils | Sees fossils and layers as unrelated curiosities. | Names eras or index fossils but cannot use them to correlate rock. | Uses index fossils and the geologic column to correlate and date rock across distant sites. |
| Deep time | Thinks geologic time is intuitive and the Earth is young. | Recites the Earth's age but cannot place events in proportion. | Places major events on a scaled timeline and reasons correctly about durations that dwarf human experience. |
| Decay-model reasoning | Calls model fractions laboratory measurements. | Reads the model but overlooks daughter correction or retention. | Distinguishes the single-daughter teaching clock from real isotope systems and explains a failure of its assumptions. |
| Integration (cross-domain) | Makes no supported connection between the source and the science. | Uses the source but needs help connecting evidence, writing, or limitations to the science. | Independently connects History, Reading, and Writing using a cited source, appropriate evidence, a limitation, and a scientific explanation. |
Ask why initial daughter must be subtracted and which event the clock could date. This single-daughter model is not a laboratory dating procedure; no radioactive materials are used.
Read these before you grade. They show what Mastery and Developing actually sound like, plus the edge cases where you should coach rather than decide on the spot.
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | Relative chronology | Dev / Prof / Mast | |
| 2 | Dating quantities | Dev / Prof / Mast | |
| 3 | The geologic column & fossils | Dev / Prof / Mast | |
| 4 | Deep time | Dev / Prof / Mast | |
| 5 | Decay-model reasoning | Dev / Prof / Mast | |
| 6 | Integration (cross-domain) | Dev / Prof / Mast |
☐ No ☐ Yes — for criterion: __________
Tokens left this term after this session (choose one): ☐ 3 ☐ 2 ☐ 1 ☐ None left
Dev = Developing · Prof = Proficient · Mast = Mastery · Unsure between two levels? Circle the lower one and note what a re-do would need.