Mr. Rodriguez's Online Earth Science Classroom

Earth Science Crafts and Cooking

How to Make a Salt Dough Ocean Floor

By L. M. Rodriguez

Using the formula below, you will construct and label a model of the Atlantic Ocean basin floor from the East Coast of North America to the West Coast of Africa (please refer to page 401 of your textbook).  This model will include the Continental Shelf, Continental Rise (Slope), the Abyssal Plains, the Mid-Ocean Ridge, Sea Mounts, Guyouts and Hydrothermal Ridges.  Painting is optional but WILL have an effect on your final project grade.

What You Need:

1 large bowl

1 poster board or cardboard (8x11 max)

1 cup of salt

1 1/4 cups warm water

1 mixing spoon

3 cups flour

On a sheet of cardboard, draw an outline of the Ocean Basin. Spread the salt dough onto the outline, making sea mounts and other geographical features such as Mid-ocean ridges, etc.. Allow the map to dry, and then paint.

My only suggestion is to add the water slowly (cold water works o.k. too-the salt is just a little bit grainier) because the weather conditions determines how much water you need, just make the flour a dough consistency, too dry and it will crack easily when moved. You can also work with your hands wet to help shape the dough as you work as dry hands drawi the water out of the dough. Also, make sure the cardboard is thick, because tag board or something thin will warp with the wet dough and the kids will be unhappy. We have made them on old leftover pieces of plywood too--I can't remember now how well the dough stuck to it-- that was a while ago, we've always used cut up thick cardboard boxes since then. Also, it will probably take several batches of dough depending on the size of your map- so be sure to have enough flour on hand.

I would allow 2-5 days for the map to dry, depending on the amount of moisture in the air. If you have a gas oven with a pilot light you can put it in there for a couple of hours to help. I think I heated my electric oven to around 250 and then turned it off--I put in the maps after it had cooled some-just to let the warm air dry the maps out a bit more. I painted them with poster paints and they turned out very bright, another time a student did one with water colors (minimal water, as dry a brush as possible) and the colors came out very washed out and faded. I inspected a few of the ones my students did last spring and they used some kind of thick, foam board (like the stuff you might use to make a science display) and they held together very well. Have fun!

Grading Rubric

Project:  Ocean Floor Model