Nannofossils Reveal Seafloor Spreading Truth

Contributor
Jerry Cook and Virginia Jones
Type Category
Instructional Materials
Types
Lesson/Lesson Plan , Activity , Data , Graph
Note
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.

Reviews

Description

In this activity, students use information from the Deep Sea Drilling Project to look for evidence of seafloor spreading in the Mid-Atlantic Ridge.  Using temporal and spatial data obtained from core samples, students create and analyze a graph, looking for patterns in the data.  Through graphical analysis, students should discover that the older a core sample is, the farther it will be from the ridge.  This will be confirmed when students compare their graph to the map of drilling sites provided in the instructions.  The lesson plan also includes analysis questions and ideas for activity extensions. This activity would take one or two class periods to complete.

Intended Audience

Educator
Educational Level
  • Grade 8
  • Grade 7
Language
English
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

MS-ESS2-3 Analyze and interpret data on the distribution of fossils and rocks, continental shapes, and seafloor structures to provide evidence of the past plate motions.

Clarification Statement: Examples of data include similarities of rock and fossil types on different continents, the shapes of the continents (including continental shelves), and the locations of ocean structures (such as ridges, fracture zones, and trenches).

Assessment Boundary: Paleomagnetic anomalies in oceanic and continental crust are not assessed.

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
In Nannofossils, students graph and evaluate spatial and temporal data from the Deep Sea Drilling Project looking for evidence to support the concept of seafloor spreading. The temporal data, or age, of the sediments was determined by an analysis of the nannofossils found in the different core samples. This technique is briefly mentioned in the directions so it might easily be overlooked. Teachers should check to see that their students understand the concepts of relative dating and the importance of nannofossils prior to starting this activity in the classroom. By comparing their completed graphs to the map of the Mid-Atlantic Ridge, students will gather the needed evidence to support the theory of seafloor spreading.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
The Nannofossils activity incorporates the Practice of Analyzing and Interpreting Data since students are creating and analyzing a graph in which the two variables are Paleontological Age (temporal) and Distance From Ridge Axis (spatial). Prior to graphing the data, teachers may want to lead a discussion about what type of graph, line or bar, would most appropriately represent the data and which variable should be assigned to each axis (independent versus dependent variable). Being proactive in this regard may reduce some math anxiety on the part of students who may be unsure of how to proceed. Once this issue has been settled, teachers could decide, on a case by case basis, what level of assistance individual students may need in assigning a scale to the x and y axis. Once the graph has been completed, students can answer the questions provided in the activity as a means of analyzing the relationship between the two variables. Some of these questions may be difficult for younger students; teachers may consider having students work in groups in order for all students to achieve success.

Disciplinary Core Ideas

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
In Nannofossils, students graph data obtained from core samples to discover the relationship between sediment age, based on nannofossil analysis, and distance traveled from the Mid-Atlantic Ridge. The resulting straight line graph should lead students to understand that the older a sediment is, the farther it will be from the ridge and that this information provides evidence for seafloor spreading. The instructions also challenge students to use their graphs to determine the speed of seafloor movement; however, the calculations and analysis involved may be too sophisticated for younger students and the result is not necessary for a basic understanding of seafloor spreading.

Crosscutting Concepts

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

Comments about Including the Crosscutting Concept
The Crosscutting Concept of Patterns is utilized when students evaluate the relationship between the two variables, core age and distance from the ridge, found in their completed graphs. In order to facilitate student understanding, teachers might want to initiate a two part discussion before students tackle the analysis questions provided in the activity. Part one of the discussion would center on identifying patterns when analyzing the temporal and spatial relationship in their graphs. For example, what type of positive or negative relationship exists between the two variables? The second part of the discussion would encourage students to focus on the general pattern which can be observed when comparing their graphs to Figure 2 which shows the location of drill sites. Once students appear to have a general understanding of their data, they should begin to answer the analysis questions.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This activity is strongly aligned to all three dimensions of NGSS. In this lesson plan, students utilize the Practice of Analyzing Data by graphing and analyzing real world data from the Deep Sea Drilling Project to build their understanding of seafloor spreading. Their analysis incorporates the Crosscutting Concept of Patterns since the straight line observed in their resulting graphs provide support for the Disciplinary Core Idea that land patterns, based on fossil analysis, provides evidence of plate movement. Through their analysis, students will see that the older sediments are farther from the axis of the mid-Atlantic Ridge while newer sediments are closer, providing evidence that over the course of millions of years, tectonic plates have moved.

  • Instructional Supports: In this lesson plan, students engage in an authentic scenario using data obtained from the Deep Sea Drilling Project. The lesson uses grade appropriate, scientifically accurate information and includes ways for student to present their ideas through the graphs they create. The lesson does not provide any guidance for differentiation; in fact, teachers may need to design supports for students with limited math abilities. To make this activity more relevant, teachers should have students use a world map to identify the coordinates of the dig site as provided in Figure 2. Some extension activities have been provided.

  • Monitoring Student Progress: Teachers will be able to monitor 3D student performance since students must identify patterns when analyzing the data both in their constructed graphs and in Figure 2 in order to obtain evidence for seafloor spreading. The lesson, however, lacks teacher support since it does not provide embedded formative assessments, scoring guidelines or rubrics.

  • Quality of Technological Interactivity: This activity is a pen and paper exercise; there is no technological interactivity.