Initial Publication Date: August 18, 2014

Analyzing Sediment Cores


The JOIDES Resolution core description laboratory is one of the most exciting places to be during a scientific drilling expedition. Scientists in the core description lab are the first to look at sediments that have been buried beneath the ocean for thousands, or even millions of years! Sedimentologists in the core description lab work as a team describing and characterizing the cores, with the goal of unraveling the depositional history of sediments to reveal clues about the earth's past. Like detectives, Expedition 341 sedimentologists use visual descriptive information including color, sediment grain size, fossils, and other information to piece together clues about the climate history of Southern Alaska.

In this activity you will put your observational skills to work as you and your teammates take on the role of sedimentologists in the core description lab. In addition to visual descriptive information, you will use proxy data, including microfossils and Earth's paleomagnetic record to determine the ages of the sediments as you build evidence to interpret the Earth's past climate.

By the end of this lab, you should be able to:

  • Describe physical characteristics of sediment cores.
  • Use visual descriptive information to make inferences about past climate in S. Alaska.
  • Determine the ages of sediment cores using microfossils and paleomagnetic data.
  • Explain how oxygen isotopes can be used as a proxy for past climate.

Keeping Track of What You Learn

In these pages, you'll find two kinds of questions.

  • Checking In questions are intended to keep you focused on key concepts. They allow you to check to be sure the material is making sense. These questions are often accompanied by hints or answers to let you know if you are on the right track.
  • Stop and Think questions are intended to help your teacher assess your understanding of the key concepts and skills. These questions require you to pull some concepts together or apply your knowledge in a new situation.

Your teacher will let you know which questions you should answer and turn in.