An archeologist who wrote a book on Iowa artifacts gave area residents insights into the authenticity of their items Saturday.
Toby Morrow, author of "Iowa Projectile Points," detailed some of the history, geology and physiology of several items brought in by amateur treasure hunters at Grimes Farm Conservation Center as part of the Artifact Roadshow.
Something many people don't realize, Morrow said, is that anything that has been in the ground for at least 50 years must be documented as required by federal archeological standards.
T-R PHOTO BY DAVID ALEXANDER
Toby Morrow, archeologist and author, demonstrates how a rock looks like a knife, but explains that it is simply a peculiar shape during the Artifact Roadshow at Grimes Farm Saturday. Included are examples of artifacts area residents brought out for Morrow to inspect.
"Sometimes we find scattered junk in a field," he said. "We don't know how old it is until we go to the artifacts."
Morrow is an archeologist with Wapsi Valley Archaeology, Inc.
For three hours, Morrow paced along a table full of items, mostly arrowheads, handling each item and giving some details about whether it is what it appears to be, which he said, is not as intuitive as it might seem.
For instance, a few banal-looking stones, he said, were actually axe heads while another, shaped like a dagger with hand grooves in it, was nothing more than a peculiarly shaped rock.
"We are not just looking at the shape of a rock. It doesn't matter if it fits in your hand. Almost everything will fit in your hand," he said. "What we need to look at is not the shape but the part of it that would have done something."
He told one woman that of all the items she brought she had only brought one artifact, and it wasn't likely to be what she thought. Morrow said it was likely a chipped piece of chalkboard. One of the most common types of artifacts archeologist find in this area is graphite pencils, which were not widely used until about 1890.
Several processes can cause rocks or other items to look as if they were manmade - limestone becoming gnarled around tree roots then being partially dissolved by organic acid, for example. But crafted items carry a distinct signature: rotational markings, carving, etc.
This stretch of Marshall County, Morrow said, is the second most important pre-historic site in the state for finding artifacts. Because rock has always been so abundant in this area, ancient people likely threw away more artifacts than are even available in other areas.
He demonstrated why some tools were made from certain types of rocks, detailing the physical makeup that makes them ideal for crafting implements.
"This rock," he says holding up a grayish stone, "Will hold a hard edge pretty well. That's why you see axes made of it."
Another archeological misnomer concerns "arrowheads." Morrow said about 99 percent of what people call arrowheads are actually tiny spears or darts used like a miniature catapult.
Wapsi Valley Archaeology, Inc. offers archaeological and historical investigations, including archaeological survey, site evaluation, excavations, historical research, grant proposal preparation and preservation planning.