⚛️ Sedimentary Rocks & Stratigraphy — printable rubric packet (Geology Unit 03). Print 8.5×11 portrait. Every page is designed for clipboard use while you grade at the bench.
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▲ Page 1 — Unit overview
Bright Minds Geology · Course Pack
Sedimentary Rocks & Stratigraphy — Unit Packet
Overview
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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 03 learning pathway.

Unit learning targets

The student demonstrates the following:

How this unit is assessed

Mastery rubric

Five science criteria plus separately reported integration (Page 3).

Bench & stratigraphic column

Identify rocks and order a set of beds by the stratigraphic principles.

Oral check

The student defends the sequence of time the layers record (Page 4).

Lab notebook

Rock ID, depositional environment, and the ordered column kept distinct.

How to read a Bright Minds rubric

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 name the rock and defend the sequence of time it records. 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.

▲ Page 2 — Key terms
Sedimentary Rocks · Vocabulary
Key Terms — What Counts as Correct
Vocabulary
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Accept listed synonyms; use the distinction column to resolve near-matches.

Canonical answerAccepted synonymsCommon confusion / discriminator
Sediment to rock
Compactionburial squeezingWeight of overlying layers presses grains together
Cementationmineral glueDissolved minerals precipitate and bind the grains
Lithificationsediment turning to rockThe whole compaction + cementation process, in order
Rock origins
Clasticfragment / detrital rockBroken pieces cemented together; e.g. sandstone, shale
Chemicalprecipitated rockFrom minerals left as water evaporates; e.g. rock salt, some limestone
Organicbiological rockFrom living matter; e.g. coal, shelly limestone
Depositional environmentwhere it was laid downRead from grain size and sorting — beach, river, deep sea, swamp
Stratigraphy
Superpositionoldest on the bottomIn undisturbed layers, each bed is younger than the one below
Original horizontalitylayers start flatTilted beds were deformed after deposition
Cross-cuttingcuts are youngerA fault or intrusion is younger than the rock it cuts
Unconformitygap in the recordMissing time — erosion or non-deposition, not a normal layer
▲ Page 3 — Mastery rubric
Sedimentary Rocks · Mastery Rubric
Six Criteria — Developing / Proficient / Mastery
Rubric
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CriterionDevelopingProficientMastery
Sediment to rock: compaction & cementationCannot describe how loose sediment becomes rock.Names compaction or cementation but not both, and not in order.Traces weathered sediment through burial, compaction, and cementation into solid rock.
Clastic, chemical & organic rocksGroups all sedimentary rock together.Sorts a few rocks but confuses the three origins.Classifies sandstone, shale, limestone, rock salt, and coal by clastic, chemical, or organic origin.
Depositional environmentCannot connect observations to an environment.Uses one property as a unique environmental diagnosis.Combines grain size, sorting, structures, and composition to compare plausible depositional environments and their limits.
Stratigraphic principlesCannot order the supplied relationships.Applies superposition without checking orientation or disturbance.Uses appropriate relative-dating principles, a scaled log, and stated structural assumptions to order events and calculate thicknesses.
Unconformities & preserved accumulationTreats the record as complete and uniform.Identifies a gap but assigns its duration without evidence.Explains erosion/non-deposition, calculates assigned preserved rates, and identifies effects of compaction, hiatuses, and missing records.
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.
What “Mastery” requires
The student names the rock and its environment and orders a set of beds by the stratigraphic principles, defending the sequence of time — unprompted.
What does not pass
Reading a tilted bed as if it were laid down tilted ignores original horizontality — that is Proficient on criterion 4, even if the rock IDs are right.
Grading it at home

The split between Proficient and Mastery is layers as time: not just naming a rock, but using the principles to order a cliff face and explain any gaps. Ask “which is older, and how do you know?”

▲ Page 4 — Anchor exemplars
Sedimentary Rocks · Calibration
Anchor Exemplars — To Calibrate Your Ear
Anchors
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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.

Reading a stratigraphic column

▶ Mastery
“The supplied sorting and structures constrain possible environments, but a sandstone name alone does not prove a beach. Superposition needs the stated upright sequence. The truncation shows an interruption, not its numerical duration.”
▶ Developing
“It’s just striped rock. The layers are however old. I don’t know why there’s a gap in the middle.”

Integration — Steno & reading the record

▶ Mastery
“Steno realized the bottom layer was laid down first — that’s superposition, the idea that lets us read a cliff like a diary. The same logic dates fossils by the bed they sit in.”
▶ Developing
“Steno studied rocks.” (A fact, with no link to superposition or reading the record.)

Edge cases — coach, don’t fail

▶ Tilted beds read as original
Treats steeply tilted layers as if deposited that way. Coach original horizontality: layers start flat, so tilting came later. Common, fixable.
▶ Environment guessed, not read
Names “a river” with no evidence. Coach grain size and sorting — well-rounded, well-sorted grains point to a beach, not a guess.
▲ Page 5 — Score sheet (clipboard)
Sedimentary Rocks · Score Sheet
Unit Score Sheet — One per student
Score Sheet
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Student: ______________________________________    Date: _______________    Guide: _________________________

Mastery criteria — circle one per row

#CriterionDecisionNotes
1Sediment to rock: compaction & cementationDev / Prof / Mast
2Clastic, chemical & organic rocksDev / Prof / Mast
3Depositional environmentDev / Prof / Mast
4Stratigraphic principlesDev / Prof / Mast
5Unconformities & preserved accumulationDev / Prof / Mast
6Integration (cross-domain)Dev / Prof / Mast

Bench & column — technique check

Used a token this session?

☐ 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.