Parent plan · Week 12 · Earth’s History — launch and foundations — Earth & Space Science
Parent teaching plan · 36 weeksUnits to teach or revisit
Chapter 4 · Earth’s History
Assigned readings
This chapter follows the question: How do we know what happened before people could observe it?
This week’s goals
- Explain mechanisms with labeled figures and relevant records.
- Distinguish measured observations, illustrative models and conditional projections.
- Apply ideas independently and revise after feedback.
Read A geological history with missing pages before starting this chapter. Use the linked unit explanations and source records during the assigned sessions.
Five flexible sessions normally about 45 minutes. Assessment slots explicitly combine or extend sessions to the existing paper’s full time. Slow down and use consolidation sessions for reteaching when an explanation is not secure.
Session 1 · Geologic Time & the Rock Record — observe and build
Illustrative evidence case. Tilted older layers are cut by an erosional surface, with horizontal younger sediment above it. Other deposits are bracketed between dated volcanic layers.
Your task
Read the chapter context and the unit language notes. Make a first model, study the core explanation and Parts 1–2, and attempt their visual and reasoning checks.
- Read the assigned context and note two observations.
- Draw a first explanation with one uncertain feature.
- Study Parts 1–2 and trace each diagram label.
- Attempt checks before consulting guidance and record one revision.
Hint and response guidance
Read the stated evidence and diagram captions; separate quantities, reference frames and assumptions before deciding.
540/4,600 is about 0.117, or 12%. Equal-sized boxes for the eons would distort their relative durations. No. Different accumulation, compaction, erosion and nondeposition histories can produce different thickness-time relationships. A time inference needs more evidence.
- Use the stated evidence and units accurately.
- Explain a mechanism or evidence relationship.
- Show a labeled model, graph or intermediate calculation.
- State a limitation and a useful revision/test.
Session 2 · Geologic Time & the Rock Record — connect mechanisms
An unconformity is a discontinuity involving nondeposition or erosion. In the schematic, older strata were tilted and their upper portions removed before younger horizontal sediment accumulated. The missing record can include events and long intervals, but the geometry alone does not tell us their exact durations. Later metamorphism or intrusion can further modify what survives. Absence of a layer therefore does not establish that nothing happened during that time; it may establish that a continuous record is not preserved at this site.
Your task
Study Parts 3–4 and any source records. Complete the whole-unit application with a labeled diagram, calculations and a limitation.
- Define each new quantity and its unit.
- Compare the diagrams and stated evidence.
- Attempt the whole-unit application without copying guidance.
- Check intermediate reasoning and annotate a correction.
Hint and response guidance
Read the stated evidence and diagram captions; separate quantities, reference frames and assumptions before deciding.
Older deposition preceded tilting; erosion/nondeposition preceded the younger overlying deposit. The interval length and exact dates remain unconstrained without further evidence. No. The supplied relations give a bracket of 90–100 Ma. An exact estimate requires additional dating or a justified accumulation model.
- Use the stated evidence and units accurately.
- Explain a mechanism or evidence relationship.
- Show a labeled model, graph or intermediate calculation.
- State a limitation and a useful revision/test.
Session 3 · Geologic Time & the Rock Record — explain and transfer
Use the unit’s worked cases and changed independent application.
Your task
Study the illustrated worked case, attempt practice and the changed case, then revise the opening explanation and complete the exit response.
- Explain the worked diagram in your own words.
- Attempt varied practice and the independent changed case.
- Check evidence/calculations using the rubric.
- Return to the first model and explain a revision before the exit response.
Hint and response guidance
Read the stated evidence and diagram captions; separate quantities, reference frames and assumptions before deciding.
Its deposition is younger than 72 and older than 68 million years, subject to valid ash-event dates and order. Thickness does not imply constant accumulation; gaps and variable deposition can prevent an exact midpoint age.
- Use the stated evidence and units accurately.
- Explain a mechanism or evidence relationship.
- Show a labeled model, graph or intermediate calculation.
- State a limitation and a useful revision/test.
Session 4 · Fossils & Relative Dating — observe and build
Illustrative evidence case. A fault cuts two beds but is covered by an uncut younger bed. Matching fossil intervals occur in two different rock types at separate sites.
Your task
Read the chapter context and the unit language notes. Make a first model, study the core explanation and Parts 1–2, and attempt their visual and reasoning checks.
- Read the assigned context and note two observations.
- Draw a first explanation with one uncertain feature.
- Study Parts 1–2 and trace each diagram label.
- Attempt checks before consulting guidance and record one revision.
Hint and response guidance
Read the stated evidence and diagram captions; separate quantities, reference frames and assumptions before deciding.
Preservation and sampling are incomplete, and the organism may have lived elsewhere or left no recognizable remains. Compare habitat, preservation conditions and sampling before concluding absence. Faulting would precede E’s deposition, while following the beds it cuts. That brackets the fault relatively between older cut units and later uncut cover.
- Use the stated evidence and units accurately.
- Explain a mechanism or evidence relationship.
- Show a labeled model, graph or intermediate calculation.
- State a limitation and a useful revision/test.
Session 5 · Fossils & Relative Dating — connect mechanisms
An index fossil is useful for correlation when its time range is relatively short, its distribution is broad enough and it can be reliably identified. Correlation relates intervals in separate records; it does not require the same rock type or the same present elevation at both sites. Organisms prefer particular environments, so absence at one site may reflect habitat rather than a different time. Combine fossil ranges with other markers and check the completeness of each sequence. A broadly distributed organism living for hundreds of millions of years may be a poor narrow time marker.
Your task
Study Parts 3–4 and any source records. Complete the whole-unit application with a labeled diagram, calculations and a limitation.
- Define each new quantity and its unit.
- Compare the diagrams and stated evidence.
- Attempt the whole-unit application without copying guidance.
- Check intermediate reasoning and annotate a correction.
Hint and response guidance
Read the stated evidence and diagram captions; separate quantities, reference frames and assumptions before deciding.
Similar sedimentary rock can form at many times. A suitable reliably identified fossil with a narrow known range constrains time more specifically, with habitat and preservation qualifications. Map position is spatial, not temporal. Their ordering needs a cross-cutting contact, stratigraphic relation or appropriate numerical dates.
- Use the stated evidence and units accurately.
- Explain a mechanism or evidence relationship.
- Show a labeled model, graph or intermediate calculation.
- State a limitation and a useful revision/test.
Submit this week
- First and revised models with explained changes.
- Assigned independent practice or assessment attempt and corrections.
- Investigation records/graphs with units and limitations when scheduled.
Parent / teacher weekly conference
Assess explanations against the task criteria, discuss a real attempt before opening guidance, and adapt pacing to the learner. These home-study sessions do not certify NYSED laboratory eligibility.
- Can the learner explain each relevant diagram label?
- Are quantities, units and assumptions correct?
- Can the learner solve a changed case without copying?