Teach the Earth > Hydrogeology > Hydrogeology, Soils, Geochemistry 2013 > Teaching Activities > Sedimentation Rates from Pb-210 data

# Sedimentation Rates from Pb-210 data

This activity was selected for the On the Cutting Edge Reviewed Teaching Collection

This activity has received positive reviews in a peer review process involving five review categories. The five categories included in the process are

• Scientific Accuracy
• Alignment of Learning Goals, Activities, and Assessments
• Pedagogic Effectiveness
• Robustness (usability and dependability of all components)
• Completeness of the ActivitySheet web page

#### Summary

In this exercise, students use a data table of depth, porosity, Pb-210 activity, CaCO3 concentration, 14C age and d13C values to calculate mass accumulation rates, linear sedimentation rates, CaCO3 dissolution and contributions of terrestrial vs aquatic organic matter in a hypothetical coastal sediment core.

## Context

#### Audience

upper-level elective sedimentary geochemistry course

#### Skills and concepts that students must have mastered

isotope mixing models
dimensional analysis and unit conversions

#### How the activity is situated in the course

This is the first in a sequence of problem sets in the course.

## Goals

#### Content/concepts goals for this activity

Using radio-isotope data to calculate mass accumulation and sedimentation rates in sediments.
Using concentration data to estimate rates of change in mineral abundance in sediments.
Using stable isotope data to construct mixing models.
Interpreting sedimentation rates and sources in the context of possible environmental change.

## Description and Teaching Materials

This is a one-page stand-alone problem set. Students complete the calculations and return their answers. I typically give students 1-2 weeks to complete this problem set.

Problem Set: Sedimentation Rates, Reactions and Sources (Microsoft Word 2007 (.docx) 176kB Apr15 13)

## Assessment

This assignment is assessed based on simply grading of the answers. Typically, students have not encountered this type of quantitative problem set prior to my class, and many have challenges completing the assignment. I spend class time going through the solutions to the problems.