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Chemical Signatures of Asteroid Impacts

Cross-section of the Earth

Topic

  • Evolution
  • Extinction
  • Earth Science
  • Earth History
  • Geology
  • Math & Computational Skills
  • Data Analysis

Resource Type

  • Activities
  • Lessons

Level

High School — General
Saved By
5 Users
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Description

This activity allows students to analyze the chemical data that led researchers to conclude that a layer of clay at the boundary between the Cretaceous and Paleogene rock layers (the K-Pg boundary) contained an extraordinary concentration of iridium. It supports concepts presented in the short film The Day the Mesozoic Died.

After watching the film, students will calculate the chemical signatures of two K-Pg (formerly referred to as K-T) boundary samples and compare them to those of a chondrite, a rock that originated from space, and a typical basalt, a rock that originated from Earth’s mantle. Students then evaluate elemental ratios to determine how well the evidence supports the conclusion that the iridium signal in K-Pg sediments was produced by an extraterrestrial impact.

Student Learning Targets

  • Calculate and use ratios to identify the source of a sample based on its chemical composition.

  • Evaluate the hypotheses, data, analyses, and conclusions in a scientific or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information.

Estimated Time

One to two 50-minute class periods.

Key Terms

basalt, C1 chondrite, Cretaceous Period, differentiated, iridium, “parts per” notation, platinum-group elements, Tertiary Period, ratio

Terms of Use

The resource is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license. No rights are granted to use HHMI’s or BioInteractive’s names or logos independent from this Resource or in any derivative works.

Version History

Date Published 03.05.12

NGSS (2013)

HS-ESS1-6, HS-PS1-5; SEP4, SEP6

IB Environmental Systems and Societies (2017)

1.3

Common Core (2010)

ELA.RST.9–12.4, ELA.RST.9–12.7, ELA.WHST.9-12.9
Math.N-Q.1, Math.A-REI.2, Math.A-REI.3; MP1, MP2

Materials

Student Handout (PDF) 256 KB
Teacher Materials (PDF) 190 KB

Additional Materials

a scientific calculator

Use This Resource With

Video Resource
The Day the Mesozoic Died

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Other Resources About the K-Pg Extinction

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Activity for The Day the Mesozoic Died
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Distribution of Elements in Earth’s Crust
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Calculating Iridium Fallout From an Asteroid Impact
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Weighing the Evidence for a Mass Extinction: In the Ocean
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Following the Trail of Evidence
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Determining the Size and Energy of the K-T Asteroid
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Weighing the Evidence for a Mass Extinction: On Land
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Finding the Crater
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Interactive Videos
Interactive Assessment for The Day the Mesozoic Died
Title screen of the film
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The Day the Mesozoic Died
Image of a prehistoric mammal taken from the film.
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Activity for Out of the Ashes
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Out of the Ashes: Dawn of the Age of Mammals

Other Related Resources

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Computer image of the meteor hitting the earth from the activity
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Calculating Iridium Fallout From an Asteroid Impact
Computer illustration of the asteroid that struck Earth
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Determining the Size and Energy of the K-T Asteroid
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Card Activities
Finding the Crater
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Distribution of Elements in Earth’s Crust
Image of John Shea simulating stratigraphy
Clips
Stratigraphic Principles
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Animated Life: Pangea
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Click & Learn
The Making of Mass Extinctions
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Phenomenal Images
Written in Chalk
Overlapping globes, the icon of EarthViewer
Click & Learn
EarthViewer
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Discovering the Wallace Line
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