Directions for the Matrix Project

Matrix Instructions

You have received a 1 Kilo bag of "matrix" from a mastodon site in Dutchess County , New York . Everything in the bag is at least 11, 000 years old. Some of the twigs, leaves and shells look very recent. They have been well preserved by being sealed in an acidic bog for 11,500 years. We have found that a kilo will keep 20 or so students busy for 2 -3 sessions at about 30 minutes each. In your bag there is likely to be a mixture of peat, which is brown, organically rich material, and marl, a gray, clay-like material containing small shells.

Session #1

Required Supplies - newspapers, paper plates, toothpicks, one or more embroidery hoops with a piece of scrim (or other gauzy curtain material), or a clean fine mesh, grease splatter screen, jars with wide mouths and tight fitting lids, and a scale. Other useful items include a magnifying glass, a low power microscope, and an overhead projector.

1. Separate into groups of 3-5 students. Push some desks together and cover with newspaper. you may want to begin by placing a small amount of matrix on the glass of an overhead projector and identify different items such as rock and shell material.

2. Give each group a few tablespoons or chunks of matrix. The peat (brown material) may be broken up with your fingers and looked through. The marl (gray, clay-like material) should have the visible shells picked out with toothpicks. Then place the chunks of marl in a jar of warm water filled to about a 1/2 inch from the rim and put on the lid. Set this aside to soak, occasionally swirling the water and matrix around gently until the material has completely fallen apart. In the meantime, sort the rest of the material into 4 piles. A, Wood, cones and leaves B. Rocks C. Shells D. everything else

3. Examine the wood, cones, and leaves. You may find a group of twigs of similar length (1/2"-1 1/2"). Some of these may be crushed on one end and broken on the other. we believe mastodons ate spruce twigs this way, grabbing the short green twigs, and breaking it off. This group of twigs, which you have on your desk, most likely passed through the stomach and intestines of a mastodon.

4. Collect the wood, cones and leaves from each group and put it in a ziplock bag , weigh the bag and return to PRI. Use your tweezers or toothpicks to put the shells into a bag. How may different kinds of snail shells did you find? How many different kinds of clams? Did you find any charophytes? Any ostracodes?

5. When the marl in the jar is completely separated, pour through scrim lined embroidery hoop or a fine screen. Dry on paper and treat as above.

Session #2

You will need water to wash rocks, an old toothbrush, paper towels to dry them, coffee filters ,a colander or funnel and plastic ziplock bags.

6. Separate the rocks into 4 piles. B1-Big , gray rocks (Big means larger than a 25cent piece) B2-Little gray rocks B3-Black, shiny rocks B4-All other rocks.

7. Students may want to wash off their rocks to see the colors. You can just wash them off under a faucet. You can, if you want, run the wash water through the coffee filter, let the material dry overnight and examine the materials left in the filter with a magnifying glass Examine B3. These black rocks are probably chert. They are found today in limestone layers between Rochester and Albany, New York. They were carried south to Dutchess County by a glacier. Chert may be the remains of fossilized sponges that lived over 400,000,000 years ago in a salty ocean. Visit http:// www.geo.cornell.edu/glasssponge. Chert was used by early people in North America to make knives and other tools. Look closely at the edges of the chert to see if you can find any edges that may have been "worked" by early North Americans. Bag the B3 rocks, weigh them and return to PRI.

8. The B4 rocks-those with colors of red, white, etc.-were also carried by glaciers to Dutchess County. Many are igneous or metamorphic rocks. They are common rocks in Canada and the Adirondack Mountains. B4 rocks are called "glacial erratic." They may tell us the exact path the glacier took on its way from Canada to Dutchess County. Please bag , weigh and return to PRI.

9. Put all the B1 rocks together and weigh them , record the weight on the attached sheet. Look carefully at the B1 rocks. these rocks are likely to be sedimentary or metamorphic rocks. They are hardened sediments from the bottom of an ancient ocean, some of which have been subjected to high pressures and temperatures (metamorphosed). Some may have impressions of shells and other fossils. In New York State, these shale fossils are probably hundreds of millions of years old. Remember, the mastodon and the wood in your bag is " only" 11,500 years old. B1 rocks with fossils should be bagged, weighed, and returned to PRI.

10. Do the same sorting and examination of B2 rocks which are the same material as the B1 rocks. record their total weight on the attached sheet. If any of these small rocks contain what appears to be fossils, bag them separately before returning to PRI. Session #3: You will need a bowl of water, a spoon, some coffee filters, colanders or funnels, and paper towels. You may want to have some small bottles(pill bottles or film canisters are good) to protect small or delicate items.

11. Take about 1/2 teaspoon of "dirt" from bag D and dump into a bowl of water. Rocks and ivory will sink. Insect fossils, hair and other organic material will float. Use your spoon , fingers, toothpicks, tweezers or coffee filters to collect the floating material. Let this dry and examine with a magnifying glass. Place all interesting materials-seeds, hairs, small shells, insect parts, etc. in the containers, weigh them and return to PRI.

12. When all of D has been "wet-sorted", pour the bowl of dirty water through a coffee filter, let the material at the bottom of the filter dry, and examine. Look for brown-colored pieces of bone; creamy-colored pieces of tusk (ivory). Bag up the interesting discoveries and return them to PRI. Please send to us all sorted material including (twigs, leaves ,seeds, all rocks and interesting things you found , hairs, bones, insect parts, etc) You may wish to use the pictures we included and additional information on our web pages to help you identify the items that you have found. After you have completed this final step you will have some remaining dirt. If you wish, you may keep this dirt and use it for an additional experiment. Try growing some local wild seeds or commercial vegetable or flower seeds. Plant some in the mastodon dirt as well as in dirt from other sources (i.e.: your backyard, potting soil etc...). Compare the result. Please send us the names of your students/researchers. Material discovered will become part of PRI's permanent collection. A class photo would also be welcome. Please take a moment to fill out the questionnaire sheet.