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    This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.
    Northwest Geology Field Trips, by Dave Tucker, is licensed under a Creative Commons Attribution-Noncommercial- Share Alike 3.0 United States License. You can use what you find here, repost it with attribution to the author, "remix" it for your own purposes, but may not use it with the intent of making money off of it.

    EDUCATORS: Please feel free to use anything you find here that is useful to your mission educating people about Earth science. E-mail me if it would help to have a larger or higher-resolution version of any of the images. tuckerd at geol dot wwu dot edu

Field guide to Iceberg Point (Lopez Island, San Juans) geology

Quartz veins crosscutting the sheared sandstone at Iceberg Point. As always, click to enlarge the photo.

White quartz veins cross-cut sheared sandstone at Iceberg Point. As always, click to enlarge the photo.

I have at long last published a new geology guide on the Northwest Geology Field Trips website. This one visits Iceberg Point, the beautiful and wild southwest tip of Lopez island out in the San Juans. Your visit to Iceberg Point requires a pleasant nearly-level stroll of around 2 miles (round trip). The geologic guide visits rocks sheared by subduction and accretion and the unconformity between those rocks and the overlying till. Plus, it just a great place for a day trip.

I have been distracted for months (years!) getting Geology Underfoot in Western Washington written and sent off to the editor. I visited more places for the book than I could submit to the publisher, and this is one of the ones I had to omit. It remains a great geo-trip. Wish I could have written more than one volume, but the publishers were having none of that. Sigh. So, I’m going to gradually put some of the ‘deleted’ book vignettes on this website. Thanks to all subscribers to this website; you have apparently been patient during this long hiatus. Don’t go away!

CLICK HERE TO GO TO THE ICEBERG POINT GEOLOGY GUIDE

Fragrance Lake addendum: Where quartzite in the till comes from

Broken surface of quartzite.

Broken surface of quartzite.

I’ve been asked about the source for the quartzite clasts in Puget Lowland glacial till. They are diagnostic of a British Columbian provenance for the Puget Lobe of the Vashon advance, and the great glaciations that preceeded that one. Go to the quartzite page, where I discuss the source for these pebbles, and attempt to confuse everyone because there are two kinds of quartzite.

Geology guide to Fragrance Lake Trail (Larrabee State Park)

The Christmas Girls had just finished decorating all the sign posts as I pulled into the parking lot. Very festive! Click to enlarge.

The Christmas Girls had just finished decorating all the sign posts as I pulled into the parking lot. Very festive! Click to enlarge.

I’ve written up a geology guide to the popular Fragrance Lake trail. You’ll find it here. Even if the hike is mostly in glacial till, there are interesting stones in it, and the Chuckanut cliffs are always worth a peak. I do some armwaving about the origin of the big cliffs above the lake, too.