MS - ESS1.C (A) - Geologic History of Earth - FINAL (RC - 1/23/2014)

Module: Geologic History of Earth

DCI: ESS1.C (A) The geologic time scale interpreted from rock strata provides a way to organize Earth’s history. Analyses of rock strata and the fossil record provide only relative dates, not an absolute scale.

PE: MS-ESS1-4 Construct a scientific explanation based on evidence from rock strata for how the geologic time scale is used to organize Earth’s 4.6-billion-year-old history.

[Clarification Statement: Emphasis is on how analyses of rock formations and the fossils they contain are used to establish relative ages of major events in Earth’s history. Examples of Earth’s major events could range from being very recent (such as the last Ice Age or the earliest fossils of homo sapiens) to very old (such as the formation of Earth or the earliest evidence of life). Examples can include the formation of mountain chains and ocean basins, the evolution or extinction of particular living organisms, or significant volcanic eruptions.] [Assessment Boundary: Assessment does not include recalling the names of specific periods or epochs and events within them.]

The ideas we see in this standard are: 

- rock strata provide data that we can use to understand the geologic history of the Earth. 

- when scientists analyze rock strata and the fossil record, they can organize things according to relative dates but not an absolute scale. 

The PE tells us to 'construct' a scientific explanation which means we will have to provide evidence from rock strata and ask students to come to some conclusion about the relative ages of the fossils in the rock strata or of the rock layers themselves.  

We don't believe this means that students should know names and dates of certain eras or that they should know which types of fossils would belong to a certain era.  We can ask general questions about the types of evidence used to organize the Earth's history into time periods, or we can have kids use diagrams to make their own explanations.  We will provide diagrams if you'll let us know what you're looking for. 

Possible Question Starters: 

"The boundary between one geologic era and the next typically coincides with changes in which of the following?"

correct answer -  the fossil record of living things

incorrect answer - the size of particles in the rock 

"Several layers of rock are illustrated in their unchanged positions.

The fossils of the oldest living things in this region would be found in which rock layer?"

correct answer - Z