Sunday, 19 February 2012

Ratho Quarry

 It was nice and sunny and still today and as it was a weekend I had the day off so Joanna and I headed along to Ratho Quarry in the afternoon. I was wanting to try something hard so as my first objective looked abit wet I headed over to Artho (E4 6a/b) and geared up. Artho takes a steep corner with two thin cracks at either side in the back wall of the quarry. The start is the same as Petes Wall (E2 5c) until a hanging block where Petes Wall heads left and artho continues up the corner. I got to this point and really didn't want to continue up Artho so I bailed onto Petes Wall. This was however by no means easy as after an off balanced traverse there were some quite thin moves, for the feet atleast, up the corner. I hung around here for a while, which felt abit silly as the gear was pretty good and I could pratically reach the safety of a big ledge. After abit of huffing and puffing I did get up the route.
The traverse out of Artho (Photo credit: Joanna Lisowiec)
The scary crux of Petes Wall (Photo credit: Joanna Lisowiec)
While belaying Joanna on Petes Wall I noticed that the bottom of the quarry is made up of nice clean cracks while the top has lots of rounded breaks, like grit stone or cairngorms granite. This got me wondering about how it was formed. The Dolerite which the quarry is composed of will have been intruded in the past, probably around the same time as Arthurs Seat was an active volcano, as a sill. The change in texture of the rock could imply that the crack shows a cross section through two overlying sills, with the top one being intruded earlier and at a great depth, so that once the overlying sediments have been eroded away it could expand so producing the rounded seems which it shows. Although it does seem quite unlikley that two rocks of very similar composition will have formed at significantly different periods in exaclty the same place with no other strata between them what I do think is likely is my explanation for the formation of the seams. Please note that any explanations of rock formation which I give in my blog are just my random musings and should not be taken as correct, or anything like that really. 
It was Joannas lead next and she climbed Fledge (VS 5a) which takes a corner crack just left of the climbing arena's fire escape. It was getting dark and as it's a weeked ratho closes early, and when ratho closes they close the gate to the car park, we made a move and went home.
Things seem to be looking promising for a good trad season, I'd usually only be ticking E2's once I've properly warmed up on lots of easier things.

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