Geophysical Survey

July 17, 2012  

By Tabitha Hubbard

Dr. Sauck conducting geophysical survey

       Today everyone was once again excited to get into the field. This morning Dr. William (Bill) Sauck of the Western Michigan University Department of Geosciences began conducting a geophysical survey of an unexplored area of the Fort site. Previously we cleared the area and placed stakes marking the perimeters of the survey site.  We had two squares for the survey; one was 10 x 10 meters and the other 20 x 20 meters.  Dr. Sauck conducted the survey with a magnetic gradiometer, which detects items with a magnetic reading under the surface. Some items that give off a magnetic reading are iron, fired pottery, and burned stones. Each member of the field school got the opportunity to assist with the survey. We marked out one-meter units across each square. Then Dr. Sauck walked the units with the gradiometer. He did get a few readings; one was specifically located near a tree. We will not know the exact details of the magnetic survey until the data is processed. He will prepare a map showing the results, which will help us to determine locations most likely containing features or large amounts of artifacts.

Stone Projectile Point

            While the survey took place, some people continued to clear the fort site. We still have some clearing to do, but we are steadily working through it. 

Although the temperature reached about 100 degrees today, we found ways to stay cool. The trees in the area mostly shade our site. My pit in particular receives a breeze from the river.  By the afternoon, Dr. Sauck finished the survey and everyone returned to the shade and continued excavating his or her pits on the Lyne site. The deepest unit is at forty centimeters below datum and the shallowest is approaching thirty centimeters. Most people have encountered fewer artifacts at these depths. The most notable find today was a stone projectile point, which dates to the Late Woodland period (A.D. 1000-1700). One group found a stone core at about 32 cm below datum; the stone appears to be the same as some of the flakes previously found.

Now, everyone is relaxing in the air-conditioning working in lab. Some people are washing artifacts from our excavations. Most of the groups have continued to sort artifacts into types, such as bone, flakes, and charcoal. The remaining people are either working on putting data into Past Perfect, which is our data management program. Finally, others are doing household chores, so we keep our living quarters tidy. 

I am looking forward to getting back to my unit tomorrow.