An Abundance Of Geology

Day 337: Once above verdant Summerland, hikers enter a bleak terrain where trees do not grow, wildflowers are sparse, rocks are abundant and snowfields linger all year. Many would say that this landscape is ugly and boring, but in fact it is one of the most geologically-rich areas of Mount Rainier National Park. Here, ancient glaciers have scoured exposed domes and prehistoric lava flows have congealed into hexagonal columns of andesite which tower above the rugged floor of the landscape, and metamorphic processes are in evidence at every turn. One of these processes was what engaged my interest on this day: a matrix studded with quartz-filled vesicles known as amygdules poised somewhere between Summerland and the spine of Panhandle Gap.

My attention had been caught by this marvel of geology over forty years ago when I passed through the area for the first time during a hike of the Wonderland Trail. A rockhound then, I was intrigued but not sufficiently resourced to track down the mechanism which created it. Like my specimen of diaspore, this phenomenon went on the shelf (mentally, if not physically) for future analysis. Recently, it was brought to my attention again by one of our Park geologists who not only explained the origin of amygdules, but posed a challenge to seek them out below Panhandle Gap. Since I already had a speaking acquaintance with the rock in question, it seemed only logical that I should be first to meet the challenge. However, the ointment had two flies in it: weather, and the busy Labor Day weekend.

I am a morning person by nature. Holiday or not, I knew I could find parking at the trailhead if I arrived early enough. I rose at 3:30, drove two hours, hiked the first mile of the trail by headlamp and thus managed to be well ahead of the hordes. After fiddling around at Summerland for a while, I headed on up into amygdule country and once on site, took measurements and calculated strain ratios to determine how much the lava had been stretched as it cooled. I am pleased to announce that my conclusions met with the geologist's approval when I submitted them yesterday evening.

Then, because it was September Morn, I continued on to Panhandle Gap, one of my favourite places in the Park, bleak though it may be. I spent an hour there before a pair of hikers came through...and then another and another and another...and then I realized it was time to leave. Holiday notwithstanding, I'd managed to capture several hours of precious solitude, and I'd learned something in the process. What good will it ever do me? Probably none, but I have the immense satisfaction of knowing that now if I ever need to hold forth on the subject of amygdules, I can do so convincingly and correctly.