Help figuring out terrain type with jar test

Hi, I have some small terrain that was an old now unused plantation. I thoguht it would be cool to make a simple natural building as a beginner, and decided to do the jar test.
Maybe some small superadobe building or similar, open to anything really.

However after mixing well with water and leaving for 3 days, there is no clear division of earth types? If you look closer there is a difference right in the middle.
The lower half has some small points, and the upper half is more smooth. But normally the diagrams show 3 types and they are clearly separated so not sure how to interpet this.
Any help would be appreciated! Thank you!  

welcome to the forums Arnau!

I wonder if your mix needs more water?
In the picture it doesn't look as liquid as needed in order for the layers to sort themselves out.

I agree with Judith, I think that the soil material needs to be re-suspended in a larger volume of water. At worst case, it would reconfirm what you are seeing and makes the mystery all the more interesting!

Judith Browning wrote:welcome to the forums Arnau!

I wonder if your mix needs more water?
In the picture it doesn't look as liquid as needed in order for the layers to sort themselves out.

I agree, needs more water

For such test I was using 3 times more water than soil. Shaking for 10 minutes and left for 3 weeks.

Thanks for posting this, Arnau! I was about to do the same and have similar questions.

Next up, some advice on how to interpret the results! I'm sure some searches on the jar test will turn that up.

I agree with the others that you need a lot more water.

The jar test u7sually show clay, sand and silt.

Yours looks like it is all clay.

Cristobal Cristo wrote:For such test I was using 3 times more water than soil. Shaking for 10 minutes and left for 3 weeks.

Based on my experience with my local dirt, and a good amount of reading about the general topic, 3 weeks is way longer than you need to get a general idea. After a few minutes, sand will settle out. After a few hours, silt will settle out. If it's been more than a day, and there are still clay particles in suspension, then you've got an unusually fine clay but the final ratio probably won't change significantly if you leave it longer.

Some say that adding soap will make things settle out faster. I have not noticed a difference with my local dirt.

All that said, I generally think that the jar test is a bit over-sold. Different particle sizes settle out at different rates, yes, but any given dirt is composed of a broad gradient of particle sizes. It's not like it's 30% particles of exactly 50 nanometers, and 40% exactly 10 micrometers, etc. So there's no good reason to expect sharp distinctions between sand/silt/clay which will be obvious to someone who's never looked at this sort of thing before.

In my opinion, it's more useful to do tests that are more specific to what you're actually trying to do with this dirt. If you're trying to make adobe bricks, for example, just go ahead and make two or three of them, and after they're completely dry, drop them from hip height onto the ground. If they don't break, then they're strong enough to build a wall out of them.

Okay one more thing to add. If I really had to, I would look at your jar and say that the bottom 1/3 or so has sand particles in it, and above there it's mostly clay. The sand stands out because you can see black specks and shiny specks, whereas the clay particles are microscopic so it all blends into one averaged-out color. Silt is somewhere in the middle and not as easy for me to distinguish based on a photo.

My soil mixture was still cloudy after a week. Of course I could estimate the clay contents at this time, but was not in hurry and after 3 weeks the water got cleared. Possibly my clay has finer particles that keep cloudiness longer.

Ty for the detailed answers guys! I will try to do it again with more water, better shaking and leaving it more time, will report if soemthing happens. Ty again!

You need at least 1/3  soil and 2/3 water for the test
Its called "the soil test" not a 'terrain' test.

A note on cloudiness, organic material will stay suspended in the water longer than the inorganic. I did a jar test with some imported soil that had compost mixed into it and it took MONTHs for the opaqueness of the water to clear to a semi-clear rate. Don't expect the water to be clear anytime soon if it looks dirty.