When we reached the end of Level 6 in STP 1, we were twenty inches below the datum point (about seventeen inches below the actual ground surface). We hadn't found any artifacts in Level 6, with the exception of a rock that may have been shaped in some way (it could even be a piece of molded cement), so we decided to close the unit. After tidying it up and taking measurements, we photographed the unit from multiple angles, and I drew a profile sketch of the northern side of the unit.
This was the result:
And this is my attempt to show the stratigraphy in a photograph of the eastern side of the unit:
As you can see, the soil is darker near the surface. This darker soil consists of organic layers that were at one time the surface of the ground, and accordingly contain cultural deposits. The gravel layer is from the nineteenth-century walkway that ran between the entrance to the cemetery and St. Mark's Church. The mottled soil below the gravel layer consists of organic soil mixed with light-colored alluvial soil. As you go down, the proportion of light-colored soil gradually increases until it is consistent throughout the layer.
Finally, here is STP 4, all ready to dig. I am very excited to see what this unit will uncover.
Three questions:
ReplyDeleteWhat exactly is a datum point and why is it three inches above the ground? I have guesses, but I'd rather get the answer from a professional.
Why are there so many American flags in America? Is it to convince the population that America really does exist, or is it maybe to fill the gaping maw of the American flag-making industry?
Why don't you wear jeans on site? Is it because washed knees are easier and/or cheaper to dry than washed clothes?
You make soil strata interesting, Madeline. Well done.
The datum is an arbitrary point established for the sake of knowing where other things are in relation to it. In this case it is the spike in the southwest corner of the unit. A string is tied to the spike and used to make all of the measurements, so instead of something being 20 inches below the ground, it's 23 inches below the datum.
ReplyDeleteWe do like our flags. But this site is particularly patriotic, since George Washington brought his troops there after the Battle of White Plains, and the soldiers who died were buried in the cemetery.
I resist the tyranny of pants for as long as I can into the colder seasons.