I have always been curious about the deep soil profiles that were exposed on Wolverine Farm every time we cut a new road or opened a new gravel pit. Consistent through the length of the farm was the presence of two significant ash layers that I thought could be clues to the dates on the calendar on the left. This cut documents 8 feet of deposits on the edge of the Matanuska River. The most significant ash layer is 57 inches down from the top surface of the photo. It is about 1 to 2 inches of pinkish ash. The other ash layer is down 30 inches and is only about the width of a pencil at best. Since we are within a hundred miles of dozens of volcanoes I decided that probably these volcanoes had their own unique fingerprint which surely had been studied.
Sure enough I contacted the United States Geological Society and Dr Kristi Wallace who specializes on volcanoes of SE Alaska suggested that the heavy ash layer was probably from the eruption of the Hays volcano around 1500 BC. That event blew out more than 4 cubic kilometers of the earth's crust into the atmosphere. This was about the same time the Jews were experiencing the exodus out of Egypt.
Dr Wallace has promised to visit the farm later this spring to help us interpret our calendar.
Evident in this profile is the first organic matter that started to appear in the wind laid loess. Also evident in close proximity of the ash layers is clear evidence of large fires. Was the ash enough to kill off a lot of the vegetation and set up the fires? We want to study microscopically the loess itself to see if it changes from the top to the bottom and gives up any clues to source or age. Some of these banks have stood solidly for over 50 years. Studies of loess elsewhere suggest that our loess is the jagged triangular type that is more stable.
This is a story that you will hear more about in the future. Can anyone give us access to a microscope?