Bell ringer: start here (while attendance happens)
Phenomenon hook · 5 min

Two satellite views of Pallikaranai Marsh, thirty years apart: 1988 (vast marsh extending much further) and 2018 (heavily encroached).
Task: What changed? What forces (natural and human) caused that change? What story does this place tell?

Two Google Earth satellite views of the same stretch of south Chennai: in 1988, Pallikaranai Marsh is a broad dark wetland with open ground around it; in 2018, dense urban development covers most of the frame and presses in on a much smaller green remnant of the marsh.
Google Earth Timelapse comparison by Raj Bhagat Palanichamy, 1988 (left) vs. 2018 (right). Imagery: Google Earth / Landsat, Copernicus. Via NewsMeter.

Answer in your Field Notebook, dated.

Today we are learning

I can identify mechanical and chemical weathering processes in field photos, distinguish them from erosion, and name a specific weathering process happening at AISC.

I can: tick as you go (for you, not for marks)
full course map →
AI Partners available for today's work
Remember: every AI use gets documented. → AI Documentation Template

What today is about

The first process. Everything else in the unit follows from this one.

Weathering is the rock-breaking step: before anything moves (erosion) and before anything settles (deposition), rocks have to come apart. Mechanical weathering (frost wedging, root prying, thermal stress) breaks rock physically; chemical weathering (dissolution, oxidation, hydrolysis) changes the rock chemically. In tropical Chennai, chemical weathering dominates: deep, persistent, humid conditions break rock down through chemistry more than through physics.

Today's anchor question ("what stories does the landscape tell us?") is the question driving the whole unit. Today we start with the smallest story: how a single rock breaks. By Block 9 you'll be telling the biography of an entire Chennai location.

This unit also introduces the Field Geologist, an AI partner that knows the nine Landscape Biography locations and thinks like someone standing at your site with a notebook. It asks what you observed before it discusses what anything means. Read its opening message on the partner page before your first conversation.

Before you start the work

Start with the Watch: projected for everyone. The Interact is a quick warm-up that follows it, and the Read is your reference for the photo-ID work. Notes go in your Class Notebook as a Power outline.

Taking notes? Power 1 seeds for today
mechanical vs. chemical weathering · the format
Placeholder
Watch (6 min)
TBD: short demo of mechanical vs. chemical weathering: frost wedging vs. root prying vs. dissolution vs. oxidation, with field photo examples for each.
Placeholder
Read (10 min)
TBD: weathering vocabulary handout (mechanical / chemical / biological) with definitions, visual cues, and tropical-specific examples.
Placeholder
Interact (5 min warm-up)
TBD: photo-ID warm-up: 4 weathering-process images projected one at a time, 30 seconds each to name the process. Then the choice board.

Everyone does this

Meet your new partner
The Field Geologist: observation-first coaching for reading landscapes. Read the opening message and example exchange before you bring it your location.
Vocabulary support
The U2 pre-teach: 15 terms with definitions and sentence stems. Several are in today's block.

Today's work: choose one path

All four paths end the same way: a labeled photo set or photo response that identifies specific weathering processes. The path you pick is about where you do the work.

Sketch first: no words

Sketch first, no words (5 min, alone): one drawing that shows the DIFFERENCE between weathering and erosion. Compare with a partner (3 min): can they tell which side is which without you explaining? Note it in your Field Notebook, dated; today's work sharpens exactly this distinction.

Learning Intention: I can identify mechanical and chemical weathering processes in field photos, distinguish them from erosion, and name a specific weathering process happening at AISC.
A
8-photo identification (default)
Pair work. Eight unfamiliar field photos. For each, identify the dominant weathering process and the single best piece of visual evidence. Pair discussion encouraged; submit one annotated set per pair.
Pairs · Default
B
AISC campus weathering walk
Walk the AISC campus (or specific zone Ms. Jayanthi/Mr. Ignash assigns). Photograph 3 weathering processes on the way. Label each with mechanism + evidence. Stretch: identify one example of chemical weathering specifically.
Solo · Stretch
C
Tropical-specific deep dive
Research how laterite forms in tropical climates. Why is laterite so common in South India? Produce a half-page explainer with one diagram. Useful prep for Block 5's tropical-landscapes content.
Solo · Choice
D
Peer-help station
Stuck on distinguishing weathering from erosion? Come to the peer-help table. Pair with a student who's solid on the distinction. Use the vocabulary handout. Ms. Jayanthi/Mr. Ignash floats. Cap ~6 students at a time.
Pairs · Practice

Open your Class Notebook and type today's entry header as Heading 2:

A: Oct 15 | U2 B1 | Weathering: How Rocks Break DownB: Oct 16 | U2 B1 | Weathering: How Rocks Break Down

What you're submitting today

Whichever path you chose, the artifact is the same shape: weathering processes named, with evidence.

Exit ticket: AISC weathering observation

Name one specific weathering process happening on AISC's own grounds. Describe what you'd see if you went to look at it. One sentence is fine; the point is specificity, not length. "Chemical weathering" is too generic. "Iron oxidation rusting the metal railing by the science block back door" is the move.

Submit via Google Classroom (link posted in August)

Rubric link: Weathering vocabulary is K/U bedrock for the Landscape Reading. Specificity is what separates the bands. See the rubric: K/U 7-8 says "discipline-specific vocabulary used accurately throughout."

One question before you leave

Three to five minutes. Your answer is saved to your reflection journal, where you can read back everything you have written this year.

The reflection style this block is the unit-opening "I used to think... now I think..." move.

Today's reflection is in Google Classroom, under Reflection Journal.

Link posted in August

Sign in with your school account. Your teacher can see what you write here.