Science
Strand V
Use Scientific Knowledge from the Earth and Space Sciences in Real-World Contexts

 

Science/Strand V
Content Standard 1
All students will describe the EarthÕs surface; describe and explain how the EarthÕs features change over time; and analyze effects of technology on the EarthÕs surface and resources. (Geosphere)

 

Science/Strand V/Content Standard 1
Middle School

 

Science/Strand V/Content Standard 1/Middle School
Benchmark 2
Explain how rocks are formed.

Benchmark Clarification

Forces in the Earth form rocks in different ways.

Students will:

  • Describe occurrences that take place on and below EarthÕs surface, as rocks continually change (recycle)
  • Use the rock cycle as a guide to explain the interconnected relationships among sedimentary, metamorphic, and igneous rocks

Key Concept / Real World Context / Instructional Example / Assessment Example / Resources

 

Science/Strand V/Content Standard 1/Middle School/Benchmark 2
Key Concept
Rock cycle processes:

  • Melting, cooling, solidification (igneous rocks)
  • Intense heat and pressure creates a new class of rocks(metamorphic rocks)
  • Weathering, erosion, deposition, and cementation of sediments from igneous, metamorphic, or sedimentary rocks create a new class of rocks (sedimentary rocks)

Heat source is the breakdown of radioactive elements in the interior of the Earth

Materials:

  • silt
  • clay
  • gravel
  • sand
  • rock
  • lava
  • magma
  • remains of living things (bones, shells, plants)

 

Science/Strand V/Content Standard 1/Middle School/Benchmark 2
Real World Context
Physical environments where rocks are being formed:

  • volcanoes
  • ocean trenches
  • ocean thermal vents
  • mid-oceanic ridges
  • metamorphic environments within the EarthÕs crust
  • caves

Depositional environments:

  • ocean floor
  • deltas
  • beaches
  • swamps
  • lake bottoms

 

Science/Strand V/Content Standard 1/Middle School/Benchmark 2
Instructional Example

Benchmark Question: How are rocks formed?

Focus Question: How is the formation of rocks related to the rock cycle?

Note: This benchmark is best taught after a volcano unit.

Students will observe a variety of rocks. They will collect data on the shape and size of crystals or mineral grains, rock color, and the presence of rock layers. The teacher will ask what is similar and different about these rocks. From these data, students will develop charts and make generalizations to determine which of the three basic groups the rocks fit into. Care must be taken to differentiate sedimentary and metamorphic rocks. Foliated (layered) metamorphic rocks like schist and gneiss often look just like sedimentary rocks

Discussions about where rocks come from will help students infer the cyclical nature of the raw recycled materials necessary to form rocks. Students will demonstrate their understanding of the classification of rocks and how they are formed by drawing a preliminary diagram of the rock cycle and communicating their rationale to the class. Students also will question the conclusions of their peers. If students donÕt generate questions about incorrect rock cycles, the teacher will ask leading questions specific to the presented rock cycle. It is important that the teacher allow students to construct meaning on their own.

An accurate rock cycle should include the following ideas:

Igneous rock:

  • Can be broken down to form sediments
  • Can be exposed to pressure and heat to form metamorphic rock
  • Can re-melt to form magma or lava
  • Will form from cooled magma or lava

Sedimentary rock:

  • Can be broken down to form sediments
  • Can be exposed to pressure and heat to form metamorphic rock
  • Can melt to form magma or lava

Metamorphic rock:

  • Can melt to form magma or lava
  • Can be broken down to form sediments
  • Can be exposed to pressure and heat to form metamorphic rock

As a class, with teacher guidance, students will use their models and reasoning to complete a traditional rock cycle drawing.

Constructing: (SCI.I.1.MS.2), (SCI.I.1.MS.3), (SCI.I.1.MS.5), (SCI.I.1.MS.6).

Reflecting: (SCI.II.1.MS.1), (SCI.II.1.MS.3), (SCI.II.1.MS.5).

 

Science/Strand V/Content Standard 1/Middle School/Benchmark 2
Assessment Example

Create a model of the rock cycle that includes the three basic types of rocks; igneous, metamorphic, and sedimentary. Present this model to the class, sharing understanding of how the rock cycle is used to explain how rocks are formed.

(Give students rubric before activity.)

Scoring Rubric

Criteria

Apprentice

Basic

Meets

Exceeds

Construction of rock cycle model

Illustrates rock cycle that includes the three rock types and three processes that are accurate.

Illustrates rock cycle that includes the three rock types and four to six processes that are accurate.

Illustrates rock cycle that includes the three rock types and all processes are accurate.

Illustrates rock cycle that includes the three rock types with an accompanying explanation that is accurate. Examples of rocks are included.

Presentation of rock cycle model

Presents information that explains three processes from the model.

Presents information that explains four to six processes from the model.

Presents information that explains the complete rock cycle processes.

Presents information that explains the complete rock cycle processes and includes examples of rocks.

 

Science/Strand V/Content Standard 1/Middle School/Benchmark 2
Resources

Webliography.
http://mtn.merit.edu/mcf/SCI.V.1.MS.2.html

http://volcano.und.nodak.edu/

http://www.ucmp.berkeley.edu/exhibit/geology.html

Geology 202: Introduction to Geology: ŌThis site contains notes and self-directed exercises which complement the lectures and laboratories of Geology 202, Introduction to Petrology Ņ a course offered in the Geological Sciences Department of the University of British Columbia (UBC).Ķ
http://www.science.ubc.ca/geol202/

Organization of Igneous Rocks: a comprehensive guide to igneous rocks. At this easily navigated site, resources are available for igneous rock classification, keys for identification, landforms, phase diagrams, distribution, and a self test.
http://geollab.jmu.edu/Fichter/IgnRx/IgHome.html

Image Gallery: a search engine for rock imagery from UBC. A limited number of landforms images are also available.
http://www.science.ubc.ca/eoswr/cgi-bin/db_gallery/searchframe.html

EarthÕs Crust/Rocks & Soil. Bill Nye Video. Disney Educational. (800/295-5010).