Layer-Cake Earth

Science and Children, National Science Teachers Association Sophie Warny Rebecca Tedford
Type Category
Instructional Materials
Experiment/Lab Activity , Lesson/Lesson Plan
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be "fully aligned," the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



Students learn about geologic sampling by taking 'core samples' from a layer cake. The activity gives specific directions on how to prepare the Earth cake, complete with raisin, pecan and chocolate chip fossils. Students use a rolled-up transparency film tube to carefully remove a core sample and observe the sediment layers and any fossils embedded in the sediment layers. At the end of the activity, a foil covering is taken off of the sides of the cake so that the students can observe the changes in sedimentary layers. 

Intended Audience

Educational Level
  • Upper Elementary
  • Grade 5
  • Grade 4
  • Grade 3
Access Restrictions

Available for purchase - The right to view, keep, and/or download material upon payment of a one-time fee.

Performance Expectations

4-ESS1-1 Identify evidence from patterns in rock formations and fossils in rock layers for changes in a landscape over time to support an explanation for changes in a landscape over time.

Clarification Statement: Examples of evidence from patterns could include rock layers with marine shell fossils above rock layers with plant fossils and no shells, indicating a change from land to water over time; and, a canyon with different rock layers in the walls and a river in the bottom, indicating that over time a river cut through the rock.

Assessment Boundary: Assessment does not include specific knowledge of the mechanism of rock formation or memorization of specific rock formations and layers. Assessment is limited to relative time.

This resource appears to be designed to build towards this performance expectation, though the resource developer has not explicitly stated so.

Comments about Including the Performance Expectation
Students observe sediment layers made of cake "core samples" and embedded food fossils, recording observations on their activity sheet. Students then use a key to analyze the age and environment of the fossils that they uncovered. The 'Earth' cake is made so that the layers do not match up across the whole cake, and so different groups will have different layer patterns. Some core samples will have a layer with shark teeth next to a layer with a dinosaur bone, supporting the theory that the landscape has changed over time.

Science and Engineering Practices

This resource appears to be designed to build towards this science and engineering practice, though the resource developer has not explicitly stated so.

Comments about Including the Science and Engineering Practice
Using the activity sheet, students record the color of each sediment layer, the thickness of each sediment layer, if fossils are present, and the order of the deposition during the lab. Using the unearthed fossils and a key to fossil symbols (included in article), the students then predict the the age of the sediment layer and past climate and environmental conditions based on the information in the table. To add more math and computation to this activity, the teacher could modify the lab sheet to include the actual years of the Tertiary, Jurassic, and Cambrian periods (rounded off to he nearest million), and have the students compare the ages of the layers to help them analyze and interpret the data.

Disciplinary Core Ideas

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
The lesson is includes a teacher background on geologic processes and how to determine which layer was formed before another layer. A table in the article gives the ages of three fossils, so the students can use the fossils to help date the different layers, as well. Students will find, however, that not all core samples are alike, and that a disruption has happened to the sedimentary layers in the cake 'Earth'.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
The lesson plan suggests that the day before the cake activity the teacher should introduce the concepts that (1) Rock layers are formed one at a time, with the oldest layer being at the bottom, (2) sediments are deposited over an area horizontally, (3) The layers in an area should all be the same, unless the sediment layer did not reach that area, and (4) Unless disturbed, the oldest animal and plant fossils should be at the bottom on the layers. This information will allow the students to note that the layers of the cake (if made according to the directions) have been disturbed, and that there has been a change to the order of the layers in some places. Examples of evidence from patterns, for example rock layers with marine shell fossils above rock layers with land fossils and no shells, indicates changes from a land to a water environment. The students can make their claim about what they think the Earth looked like long ago, and then support their claim by using the evidence that they found. A class discussion will reveal that not all core sample patterns were alike, and the disruption in the pattern can be used to discuss faults, erosion, and other factors that cause geologic change.

Resource Quality

  • Alignment to the Dimensions of the NGSS: The students are working in small groups to make sense of the phenomena of sedimentary layer patterns and the change in environments they indicate through a model.

  • Instructional Supports: This article has very detailed instructions for introducing geologic concepts, baking the Earth cake, and following up the activity with higher-order questioning. An activity sheet to record the core sample, the color of each sedimentary layer, the thickness of each layer, if fossils were present, and the order of the deposition is included. To make this activity more aligned to monitoring students progress it is suggested that students more formally analyze and interpret their data by drawing and writing down in their science journal what they see (how many fossils in each layer, color etc) as they take the core sample from the cake. This way they could be have meaningful reflection on the comparisons of the layers. In the introductory lesson, four geologic principles are introduced. While fourth grade students should have no problem understanding the concepts, especially if the cake and trash can analogies suggested are used, they are not developmentally ready to understand or use the scientific names for those principals. This lesson gives students the opportunity to share what they found with their classmates, and then try to put the separate parts of the puzzle into the completed whole 'Earth'. The lesson does not have suggestions for ESL students or struggling readers, and some of the vocabulary in this activity might be too advanced for lower level students.

  • Monitoring Student Progress: An activity sheet has the students draw a picture of the core sample and record details about each sedimentary layer. Adding some higher-level prediction questions to the activity sheet would allow the teacher to more fully grasp if the the student understands the concepts. An addition of a rubric evaluating if the core sample was taken correctly, if the proper information was recorded, and if reasonable predictions were made would be a good addition to this activity.

  • Quality of Technological Interactivity: There is no technology used in this activity.