Dirt in lowcountry SC (possibly NC, GA as well) , which was underwater years ago.

[raccoon]

The dirt is black and sandy. Dig about a foot down and you get to some yellow sandy dirt. My theory is the black dirt has formed since the area was above water.

I've googled but can't find anything that specifically says this.

Anybody out there know about this?

[angrycarpenter]

1. I don't know much about the science of it

but I have dug a lot of holes in the panhandle of Florida. There the surface black layer was silt deposited by fresh water and the yellow sand was deposited when the area was saltwater beach. I don't know if your soil is coastal but that is the way it was there.

[raccoon]

2. The soil I was talking about where I grew about probably 40 miles from the coast.

Up to around Columbia, SC was underwater in prehistoric times.

[angrycarpenter]

3. A good test is if it turns to black talcum powder when dry.

then it is silt, otherwise I would say that it is normal soil formed by organic decomposition. The area I lived had been flooded by the river countless times and the top soil was mostly river silt.

[semillama]

4. Check this website

http://websoilsurvey.nrcs.usda.gov/app/

This is the USDA's online soil survey, which I use all the time.


Hit the green button, which should open a new tab. Now (if their map server isn't being wonky), enter in your state and county, and use the zoom tool to zoom into your location. There's a button on the right end of the toolbar with the zoom buttons called "AOI" (stands for area of interest) and draw a box around your location. A little box will appear saying "Creating AOI". When the AOI appears, click the "Soil Map" tab next to the "Area of Interest" tab, which will show you the soil types mapped for your area. Look at the soil map and determine which soil type corresponds to your location, and then click that soil type in the map unit legend on the left. A window will pop up and you'll see a description of the soil. Look under the heading "Description" for the "Parent material" and it should tell you in what conditions the soil formed.

PM me if you need any help with the application.

Or, alternately, just tell me where the general location is and I can look it for you.