Tuesday, July 15, 2008

Day 156. Mount Kinabalu (continued)

I woke at 1:45 am, got dressed, and met my guide at 2 am. We were going to see the sunrise at the summit, and it would take us three and a half hours to get there. I am more tired than I had thought (my legs kept twitching all night long, as if toying with the idea of having cramps, and my knees complain if I twist my leg when stepping up), but the hours spent at 3,000 m seem to have done their trick in acclimatizing me to the high elevation.

Step by step we went up, walking over steep bare rock, and indeed by 5:30 am we reached the summit, together with another 20 enthusiasts (4,060 m altitude). The view was grand, although the sunrise was blurred by the carpet of low-lying clouds that mantled the horizon. My camera decided this was a good time to run out of batteries (argh!), so I didn’t feel obliged to take pictures of every cloud. I could see the coast from here, so now I know how high 13,000 ft look like!

Still, from the couple of photographs I took, you can see that Mt. Kinabalu is indeed an intrusion, which has punched through the sedimentary sequence of northern Borneo. There is a little contact metamorphism, but otherwise little evidence of regional deformation and metamorphism. The intrusion itself has at least two cupolas, and is dominated by a hornblende granodiorite, crisscrossed by very cool dikes of a plagioclase tonalite porphyry. As you can see in the photo, the exfoliation is spectacular.

The question is, what is this lonely pluton doing here? Why is it uplifting? (as indicated by the height of the mountain, the youthful stage of erosion, and the enormous amount of unroofing that must have taken place for us to be able to see the intrusion). I will give to my students the homework to search in the web for info on the geology of Mt. Kinabalu, and we will discuss it when I get back home.

Alas, everything that climbs up must come down, so at about 7 am we started the descent. I can feel my knees complaining, and that dull pain in the ball of my left foot is beginning to be more sharply defined. By 8 am we were back at the lodge, where we had breakfast and a good hour of repose. At 10 am we recommenced our way down. Ouch, ouch. Every step down on the causeway of the giants is causing pain. Talk about a death march. It is beginning to rain, so the ground is becoming slippery. Careful now. Wow . . . thunk! I have slipped and a tree stump has connected solidly with my left ribs. “Are you OK”, asks a fellow hiker. What a question; of course I am not OK, I just fell and am looking like a fool. But of course I smile back and say “Yes, yes, I am fine”. So we keep going down, and by 3:30 pm we finally make it to the trailhead, where my $10 have guaranteed us a place on the bus. The best $10 I have invested in this trip!

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