More than happens in most cities in the United States, Seattleites regularly feel the influence of geology. Driving our glacially carved hills; worrying about an earthquake from one of the three tectonic zones of weakness that underlie the region; paying for a new seawall and SR-99; or enjoying the views of the surrounding mountains: as my wife tells me, geology did that. And, yet, unlike cities such as Portland, New York, and Denver, Seattle has very limited rock at the surface. I am okay with this.
I love this post thank you. I've been to, over or around these formations a number of times on bike rides but will henceforth view them differently.
As a young rock climber living in Seattle I quite resented the absence of exposed rock. Being surrounded entirely by gravel was frustrating. Nowadays, being able to go tread on some 42 million year old volcanic sediments is nearly as exciting. I mean... how far down does the formation go? It must be, after all, the "tip of the iceberg". And these pairs of formations... because the Duwamish used to flow between them?
Are all rocks in the area roughly the same age? Granite vs basalt?
I love this post thank you. I've been to, over or around these formations a number of times on bike rides but will henceforth view them differently.
As a young rock climber living in Seattle I quite resented the absence of exposed rock. Being surrounded entirely by gravel was frustrating. Nowadays, being able to go tread on some 42 million year old volcanic sediments is nearly as exciting. I mean... how far down does the formation go? It must be, after all, the "tip of the iceberg". And these pairs of formations... because the Duwamish used to flow between them?
Sophie Bass' book is a great narrative of Seattle. Seattle with all its faults is still geologically fascinating! (See you at the MOHAI next month!)