Shifting Plates

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[   ] Crust is Created

[   ] Crust is Destroyed

[   ] Crust is Neither

| Write landforms:

Word Bank: Fault Lines • Severe Earthquakes

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Check Your Understanding:

1. What causes earthquakes at a transform boundary?

[   ] A. Plates lock with friction, then suddenly snap

[   ] B. Magma shoots straight into the clouds

[   ] C. The ocean dries completely up

2. Where is brand-new ocean floor formed?

[   ] A. At mountain peaks in the Himalayas

[   ] B. Along divergent mid-ocean ridges

[   ] C. Deep inside underground caves

Plate Boundaries Investigation • 6th Grade Earth Science (Support Edition) Page 1 of 2

Part 3: Real-World Tectonic Detective

Circle the correct boundary and outcome for each real Earth feature.

Student ID:

CASE 01: The Himalayas Asia

Two continental plates are crashing head-on into each other.

Boundary Type (Circle one): Convergent  |  Divergent  |  Transform

What forms here? (Circle one): Giant Mountains  |  Deep Ocean Trench

CASE 02: San Andreas Fault California

Two plates are grinding side-by-side past each other.

Boundary Type (Circle one): Convergent  |  Divergent  |  Transform

What forms here? (Circle one): Frequent Earthquakes  |  Active Volcanoes

CASE 03: Mid-Atlantic Ridge Atlantic Ocean

Two ocean plates are slowly pulling apart under the sea.

Boundary Type (Circle one): Convergent  |  Divergent  |  Transform

What forms here? (Circle one): New Seafloor Crust  |  Continental Desert

CASE 04: Mariana Trench Pacific Ocean

A heavy oceanic plate dives down beneath another plate (subduction).

Boundary Type (Circle one): Convergent  |  Divergent  |  Transform

What forms here? (Circle one): Super Deep Trench  |  Flat Prairie Land

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Part 4: Boundary Diagram Challenge

Follow the 2 simple steps

Look at the two tectonic plates below. Complete the two steps:

[ Plate A ] GAP [ Plate B ]

Draw motion arrows (← | →) or (→ | ←)

Rising Magma from Mantle

Step 1: Draw two arrows in the diagram showing the plates pulling apart.

Step 2: Name this boundary:

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Part 5: Scientific Argument (Claim • Evidence • Reasoning)

Sentence Starters Provided

The Mystery Question: A student says, "Earth is constantly making new rock at divergent boundaries, so Earth must be getting bigger and bigger like a balloon!" Is this student correct? Fill in the blanks:

[CLAIM] I (agree / disagree) with the student.

[EVIDENCE] While new crust is created at divergent ridges, old crust is pushed down and melted at (convergent / transform) boundaries.

[REASONING] This means Earth does NOT grow bigger because crust is constantly being (recycled / lost in space) at the same speed!

Plate Boundaries Investigation • 6th Grade Earth Science (Support Edition) Page 2 of 2

Check Your Understanding Answers: 1 = (B) Oceanic crust is denser and colder; 2 = (C) Divergent Mid-Ocean Ridge.

Plate Boundaries Teacher Guide • 6th Grade Earth Science Page 1 of 2

Part 3-5 Solutions, Rubric & Differentiation

Scoring guidance and inclusive instructional scaffolds.

Assessment Support

KEY

Part 3: Real-World Case Files Solutions

CASE 01: Himalayas

Boundary: Convergent (Continental-Continental)

Landform & Event: Fold mountain range (Everest), frequent powerful earthquakes, NO volcanoes.

CASE 02: San Andreas Fault

Boundary: Transform (Strike-slip)

Landform & Event: Linear fault line, offset rivers, intense shallow earthquakes, NO volcanoes.

CASE 03: Mid-Atlantic Ridge

Boundary: Divergent (Oceanic-Oceanic)

Landform & Event: Submarine mountain ridge, rift valley, seafloor spreading, underwater hydrothermal vents.

CASE 04: Mariana Trench

Boundary: Convergent (Oceanic-Oceanic Subduction)

Landform & Event: Deepest ocean trench on Earth, volcanic island arc, deep-focus earthquakes.

Part 5 CER Exemplar & 3-Point Rubric

Target: Grade 6 Standard

Exemplar Student Response:

[Claim] I disagree with the statement that Earth is expanding. [Evidence] While new crust is continuously formed at divergent boundaries like the Mid-Atlantic Ridge, old oceanic crust is simultaneously pushed downward and melted at convergent subduction zones, such as the trenches around the Pacific Ring of Fire. [Reasoning] Because the rate of crust creation at divergent boundaries is balanced by the rate of crust destruction at convergent boundaries, the total surface area and volume of the Earth remain constant over geological time.

Differentiation & Inclusive Scaffolds

Support / ELL / IEP Scaffolds

• • Use physical gestures: flat palms pushing together (convergent), pulling apart (divergent), and sliding thumbs (transform).
• • Provide sentence starters for Part 5: "I disagree because while new rock forms at ______, old rock is destroyed at ______."

Advanced / Extension Challenges

• • Hotspot Investigation: Challenge students to research why the Hawaiian Islands have volcanoes despite being in the middle of a plate!
• • Pangea Reversal: Calculate how many millions of years until the Atlantic Ocean closes back up at 2.5 cm/year.

Plate Boundaries Teacher Guide • 6th Grade Earth Science Page 2 of 2