In a curious way I was much reminded of Alan Garner, whose name is only different by one letter, the Garner of Red Shift rather than Weirdstone. Geology, place, history, above all language and the particular vocabularies associated with various forms of expert knowledge; I can't think of another book whose idiom quite so precisely and magically as this one captures a whole world with all of its dimensions. Stuart Kelly's review at the Guardian fortunately saves me the trouble of trying to write a better description here!
Not sure if the feel will translate in a short excerpt, but here are a few sentences I especially liked (they are unusual in the context of the novel as a whole, there is almost an aphoristic quality to the final sentence - not Warner's usual habit - which is why it stood out, though it is quite distinct from the Flaubert-Hollinghurst-St. Aubyn lineage of satirical summing-up):
The bike struggled with their combined weights on the hairpin corner at the top of the King's Way and he had to turn the handlebar gear down to second with the bright headlight of an impatient car behind them before he indicated left and pulled in.
This lay-by, so insignificant in their previous lives, had now become their place of meeting. The need was less furtive and romantic than that the engine on the new bike struggled to take them both up the longer and steeper hill within the Brae Estate -- as Simon had discovered on his birthday. Almost all Simon's comments on any future Nikki and he would share involved reference to a more powerful, anticipated motorbike.