Antarctic Lab Prep.

The Earth System

Preparation for the Antarctic Research Facility Lab

The Antarctic Research Facility (ARF) stores the largest collection of marine sediment cores in the world. What's sediment, what's a core? That's what these pages are here to help explain. Follow Step One and Step Two. Some common terms that you may hear in lab will be italicized. After completing Step Two move on to Step 3: you should be able to answer all of the questions on the Knowledge Sheet.

Step One

Click on each one of the links below. They'll take you to other pages that will help to explain some of the basic Earth processes at work that make and deposit sediment, which is what core samples (a.k.a. cores) are made of. Researchers take the cores and analyze the sediment to learn about past climate changes (among other things).

What is sediment anyway?
Sediments, those particles on the ocean floor, are made up of dead plankton and small pieces of rock. Small plankton are very abundant in Antarctic waters.

When tiny plankton called Foraminifera, a.k.a. "Forams" die, they sink to the bottom, leaving their hard calcareous (CaCO3) skeletons to accumulate.
Diatoms & Silicoflagellates are about the size of a sand grain. Unlike Forams they have silicious skeletons, skeletons made of silica (SiO2).
Radiolaria are another type of plankton that have a silicious skeleton. The skeletons rain down when the organisms die (sometimes after passing through a fish) and collect as sediment on the ocean floor.
Your average 'small piece of rock'.

How and where is sediment deposited, how does it get into a core sample? The organic particles (Forams, Radiolaria, Diatoms, etc.) come down directly out of the water. The other sediments such as: pebbles, sand, silt, etc., come from streams (in the Summer) and ice-rafts, icebergs that shed sediment as they melt. They settle to the bottom, build up, and solidify to some extent. After several thousand years of this, core samples can be extracted by the intrepid scientist. Here's a basic diagram of a general offshore depositional environment that is similar to that of coastal Antarctica (although there are no glaciers or sea ice in this diagram). Note the location of the continental shelf and slope.
Cores look like this:
- Southern Ocean (Antarctic) core sample
- marine cores from other regions
Cores often contain fossilized remnants of plankton. Here is one example: calcareous nannofossils. Other sizes of plankton and plankton with silicious skeletons get fossilized too.
This external site will help explain: What are these cores for and how are they collected?

Step Two:

Now you have some idea of how sediment is formed and how cores are collected. There some basic principles that scientists apply in order to deduce what information is hidden in the cores. Review the following sites. Be very sure you understand the general concepts and terms in italics:

Explanation of important stratigraphic terms, including unconformity, absolute age, etc.
A United States Geological Survey (USGS) site on geologic time that includes information on index fossils and the basic principles of geology.
The Geological Time Scale from the USGS helps illustrate the length of the Quaternary Period and its two epochs relative to the overall age of the Earth.

Step Three:

Read and answer the questions on the Lab Knowledge Sheet.

Related Sites

These optional sites may be useful in your preparation, or just interesting.

-Get the lay of the land with pictures of Antartica taken near McMurdo Station. Check out the diatoms page under the "Streams" general heading.
- More pictures of plankton than you can shake a stick at.
-The Geologylink geologic glossary has definitions of some basic geological terms (although not for the plankton).
-The FSU Antarctic Research Facility