Oh, my darlings, will I have treats for you! Lockwood and I are in the midst of our geoextravaganza tour down the Oregon coast and across the Josephine Ophiolite. Lots of hot volcanic action round here, but there’s a huge metamorphic story to be told. There’s going to be a lot to absorb and process before I can relate that tale, but I’ll give you a bit of a preview here.
We’re going to linger lovingly over this location soon – you’re looking at a sandstone cape here, one with an enormous hole in it. There’s a story about the Columbia River Basalts, and a geologic puzzle that took some time to solve. This is a great place to show that science is a process.
We’re very close to the subduction zone here – this is about as close as you can get on land. We’ll discuss that, and the fact that this cape is rising at an incredible pace. By geologic standards, it’s screaming upward like one of those super-fast elevators in high rises. There’s also a fantastic jumble of rock round here – Oregon’s endless basalt finally ends, and we begin to see older rock, and the crazed mess the collision of various plates has made of it.
Further down the coast, almost to California, you see some spectacular sea stack scenery. This location is a little wayside where several arches have formed in a tiny area. It’s utterly enchanting. We’re going to explore how the sea creates these features, and why your children’s children may not be able to view them.
Now we’re in it. This is the Josephine Ophiolite, and this is a lovely sheeted dike complex. We’ll discuss ophiolite sequences in detail, but just think of this right now: standing here, you’re looking at rocks that formed far below the ocean crust. So many dikes of mafic magma pushed up that there’s no host rock left – it’s all dikes. Both of those facts cause my eyebrows to migrate into my hairline, and my mouth has uttered an abundance of “Oh, wows!” and “No ways!”
And I haven’t even shown you the absolutely magnificent serpentinite. Ya’ll are gonna love it.
Those who are yearning for the next Mount St. Helens post won’t have long to wait – it’s two-thirds done. We can have our volcano and our ophiolites, too. Stay tuned…