The outcrops
we do stop at consist of tourmaline garnet leucogranites and
augen gneiss. As we move southward along the gorge, the
vegetation becomes more abundant and verdent.
For the rest of the trip, Mr. He is very reluctant to
stop, worried about last stretch of road to Zhangmu. This is most
unfortunate because the geology is spectacular. We drive thought
the high Himalayas, which as dominated by high-grade metamorphic
rocks, gradually moving out of the mountains' rain shadow.
Crossing a high pass, we enter the upper reaches of the Po Chu
river gorge. The outcrops
we do stop at consist of tourmaline garnet leucogranites and
augen gneiss. As we move southward along the gorge, the
vegetation becomes more abundant and verdent.
The
road snakes along a precipitous gorge as it makes its way to
Zhangmu. In places the roadbed has slipped away, leaving
crescent-shaped bites in the pavement. The drop is terrifying,
but the scenery is magnificent with waterfalls cascading down the
vertical sides of the gorge. Over a distance of tens of
kilometers, the climate has changed dramatically. The leaves of
the abundant foliage glisten with moisture. The damp air is a
wonderful contrast to the dust and aridity of the upper gorge and
a dramatic demonstration of the magnitude of the Himalayan rain
shadow.
The town of
Zhangmu is built on an old landslide that produced a break in the
steep walls of the gorge. The road twists through town in a
series of tight switchbacks. It appears that an earthquake could
send the entire place down into the gorge. The floors of the
hotel have large cracks that are evidence that the building is
constructed upon a gradually slumping slope.
The following morning, we awake to a downpour. Rain has
flooded the hotel lobby. We climb into the back of a truck
covered with a tarp, for a crowded damp ride to the border. Those
in front sit on the piled luggage, but have no view and poor
ventilation. Those in back stand, clinging to the metal frame
supporting the canvas roof. I am one of the latter, and peer out
the back of the truck into the rain, while being gassed by
exhaust. Mr. He and Professor Lin stand waving from the
checkpoint at our departing truck.
