Brian Sheehy asked some good questions about the soil composition of the courses to the south of London, and how this compares to the Parisian heath courses. Here, as best I am able, is a primer.
Most of the heath courses lie, in whole or in part, on a geological formation known as the Bagshot Beds. See
http://en.wikipedia.org/wiki/Bagshot_Formation for a more detailed explanation of this formation.
Clearly, this type of sandy soil is not the same as the pure sand that characterises links. It is much older - links, being the result of direct action by wind and water, can form and reform rather quickly, as the rapidly growing duneland around Rye in Sussex shows.. Although sand is a key feature of the formation, it is far from the only component.
The Bagshot beds reach the surface in several parts of southern England. The heaths of Hampshire and Dorset that are home to courses like Broadstone are an extension of this formation.
Another key geological component of this part of England is the chalk that underpins the North and South Downs. You see the escarpment of the North Downs very clearly from the M25; it's the steep slope that lies to the north of the motorway between junctions 7 and 5 on the borders of Surrey and Kent. The bedrock of the Downs is chalk, but the chalk is covered in places by a variety of different soils. The Beaverbrook GC course at Cherkley Court, a couple of miles from Walton Heath, that is currently under construction by David Kidd and his crew, is on the chalk, and anyone who has seen some of the photos of the early build that have appeared on social media will have seen the stark white chalk exposed by the topsoil stripping. Here, the chalk is very close to the surface. As an aside, the reason southern England is now producing excellent sparkling wines is that this chalk formation is part of the same geological seam that reaches the surface 150 miles or so further south in Champagne.
Back to golf courses. Sean Arble has observed many times on here that the drainage qualities of the heath courses are often overstated, and I think we can all agree with this. I have no doubt that soil composition has much to do with this, as do maintenance regimes and many other factors. A key one is topography. No-one who has played the Red course at the Berkshire in winter could have missed the fact that the first fairway, which is very flat and relatively low-lying, is typically one of the softest places on the course. Climb the slope to the second green, and the ground is noticeably firmer. Woking is another good example of this; the low areas of the course near to the railway line are invariably the softest, and when one climbs the ridge in front of the ninth green, it is easy to see a difference.
The native sands of the Bagshot formation, as people who have played those courses will have seen, are typically quite grey. There is an interesting contrast between this and the sands of (for example) the Dutch heath belt; when I visited Frank Pont during the early construction of Swinkelsche, on land that was denatured heath, I was struck by the remarkable contrast between the rich, dark topsoil - the result of a century's intensive manuring by agriculture - and the bright sand immediately below it. On the other hand, the sands at Morfontaine and Chantilly are darker, more akin to those in Surrey. Whether there is a geological connection, I can't say. But it wouldn't surprise me.