Sub soil? Or base of old driveway?

[Russel Sprout]

Hi

Over the last year or two we've been landscaping our garden to get it looking nice and to create more areas for growing veg. We created a new parking area which allowed us to dig up some of the old driveway and convert it into beds. I've been digging today in one of these beds to get ready for growing. I had previously put some top soil on the bed from elsewhere in the garden, so it now has a good few inches on top. However, beneath this is a light coloured sandy and stony "soil" and to my untrained eye I'm not sure if it is subsoil, or the base layer of the old driveway. Can anyone with more experience tell what it is by looking at these photos?

The old driveway was shingled. In fact, the shingle you can see at the top of the first photo IS the old driveway (we kept some of it as a path).

I'm thinking of bagging up some of the sandy / stony "soil" and getting rid of it so that the top soil is deeper in the bed. Does that sound like a good idea or a waste of time?

Any thoughts would be most appreciated.

Huge thanks

Max

[Snoop Puss]

Are you able to dig somewhere close to the old drive and compare?

Plus, out of interest, might you have any pipes that ran under the old drive? Might sand and stony soil have been piled in on top to fill the channel?

[DannyK]

Might be granite scalpings. These are used as a sub-base for drives and paths. They are usually worked in with one of those vibrating plate machines.

[Bigmallly]

I think as long as you don't plan to grow Parsnips or Carrots, I would just keep adding organic matter. Small stones are good for drainage.

[Snadger]

If it is dolomite 'penning' , as it looks to be,it will have a depth of no more than 300 mili (1 foot) if you dig through this and find another type of soil, it would signify it wasn't the original sub soil. My subsoil at my plot is similar but I don't hit it until 400 mil down..
Crushed dolomite is very alkaline so grow your brassicas there.

[Russel Sprout]

Hi again

Many thanks for the replies. An update to follow, but first let me reply to some of the points raised...

@Snoop Puss... I have some photos of some digging I did in a different area which was closer to where the driveway becomes lawn. The soil layers were different there, although still sandy:





I'll see about digging an area in the lawn, although I'm not too sure I'll be allowed as the digging has already gotten a little out of hand!

Pipes - due to the large area and the depth (see below) I don't think it will have anything to do with pipes.

@DannyK. I've no idea what granite scalpings are but I guess it could be (although see below RE depth).

@Bigmallly. That's encouraging and pleasing to hear. To get rid of a lot of this stuff would be quite some operation! I'm aiming to get rid of the first 25-30cm so that I have that kind of depth of top soil. And I'll be digging in some manure as well.

@Snadger (and everyone else)...

I have dug down further now in a nearby spot and the light coloured sandy stuff goes on and on. I'm down almost 4 foot, and 3 and a half foot of it is this same sandy stuff. I also initially thought if it was some kind of driveway base layer, but would it be anywhere near that thick/deep is so? Yet on the other hand it seems a little "unnatural" to be subsoil, although - to be honest - I'm not too familiar with such things so that's a very uneducated guess and I suppose it might be.

We are on a septic tank where we live, so it might have something to do with the soakaway???

Any more guesses or thoughts?

I'll dig a little deeper and take some photos to add to the thread.

Cheers

[Potstubsdustbins]

Hi,

If you google 'subsoil Norfolk' you will find an awful lot of info on the types of subsoil prevalent in your area, this may help you.

[DannyK]

The grey debris in bottom pic looks like remains of drive sub-base. It probably shouldn't be more than a few inches deep.

Paving Expert - AJ McCormack and Son - Sub-bases

[Snadger]

The subsoil looks fine, I would get rid of the stuff above it though!

[goosander]

The stuff is the hardcore either scalping's or type one. Need to remove it as the water will not get through it easy. We done well over 100 drives per year mainly block paving and if mine would clear the lot out.
Bob

[Russel Sprout]

Hi all

In answer to the last few posts:

If you google 'subsoil Norfolk' you will find an awful lot of info on the types of subsoil prevalent in your area, this may help you.

I tried that but it did not come up with a great deal of info.

The grey debris in bottom pic looks like remains of drive sub-base. It probably shouldn't be more than a few inches deep.

Paving Expert - AJ McCormack and Son - Sub-bases

Do you mean the bottom picture in the first post or in post #6?

The subsoil looks fine, I would get rid of the stuff above it though!

Which picture are you referring to please, and what section of the picture??

The stuff is the hardcore either scalping's or type one. Need to remove it as the water will not get through it easy. We done well over 100 drives per year mainly block paving and if mine would clear the lot out.
Bob

Do you mean the light creamy coloured stuff I was asking about in the first post/ If so, I don't think I'll be able to get rid of all of it. I dug down around 6 foot in total and it just went on and on. It's a large bed and to get rid of all of it would be a monumental task!!!


What confuses me is that the stuff that looks most "unnatural" (the light creamy stony stuff I originally asked about) is what I thought was some kind of sub base for the drive, but surely no-one would put this in to a depth of 5 foot +?

Scratches head!

Thanks for the help and replies.

[DannyK]

I meant bottom pic post 6.

Try your post code on this siteSoil-Net.com - SoilScapes interactive mapper

If that "unnatural" layer is a foot or two down I'd cover it up and forget about it. Here I hit solid clay at about a foot and my neighbours hit chalk and everything seems to grow ok.