Enough clay soil?

Good Afternoon!

I plan on making a circular COB with an eight foot diameter, stone footings, glass bottles, and at least 1 window, uncertain of the height (I am 6" and will want to stand up of course).

I know there are may be other factors involved to get an adequate answer, to which I can add more details to this post, but I am wondering if I will have enough clay soil? I am having a hard time looking at the volume that I have and picturing how much will go into the project. This will be my first venture into the cob - thanks for your support!

Mathew, its a simple matter of maths.
Assuming you will have an internal diameter [d]of 8ft, a wall 18 inches wide [w] and at least 9 feet tall [h]
The wall area can be calculated as follows;
∏d x h= area,   3.142 x 8 = 25 square ft
area x w = volume. 25 x 1.5 = 37.7 cubic ft

I have not allowed for the window and door openings.
You may waste that volume anyway with broken bits, droppings etc.

You can calculate the volume required as John suggests. The more important question is, what is the makeup of your soil? What you show looks like it has a lot of organic litter in it, maybe sticks, leaves, or bark. It needs to be mostly mineral soil, about 1/4 clay with the rest being sand and gravel, to be structural and durable. Straw added to the mix will give it tensile strength so cracks don't spread; they act like tiny rebars spread throughout the wall.

@John - thank you for breaking down the math for me - much appreciated. I'll head out when it stops raining and measure or dig up some more

@Glenn - I suppose I'll put a few samples in a jar and really see about the soil itself, but based on looks and feel, is quite heavily clay based. Where you mention organic litter, I was chopping wood there. I have started to sift dirt with a 1/2 inch screen at the second location to get out some of the rocks, roots, and other organic matter. I picked up some play sand for a firepit and was hoping to mix it in with the soil along with straw.

I was also debating straw bale if the consistency or amount of clay soil was not correct.

I appreciate all of your responses and the help!

That's a good explanation for the "organic" look of the surface. For making mass cob, there is no need to remove small stones. Anything up to golf ball size or so will not interfere in any way with the structural wall building. For finish layers, you do need to eliminate anything larger than coarse sand.
My native clay, glacier deposited and found in random pockets, is naturally ideal for mass cob, with around 1/4 clay and the rest sand, gravel, and small to medium stones.