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    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.

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Error on latest Jackass erratic report

The Federal Way Jackass Group conglomerate erratics I reported on earlier today are about 6 miles further south than the purported one at Des Moines Beach Park. So, if you wish to document that one, it wouldn’t be further south, but still worth knowing about. I have corrected the original post. Dave

Federal Way- furthest south Jackass conglomerate yet

By Dave Tucker Neil Gilham sent these photos taken in Federal Way. The erratics sure look like conglomerate of the Jackass Group. Neil thinks that given the cost of moving these from elsewhere, these were probably dug up on site during the construction of these apartments. I don’t have the exact location, but they are […]

Another southern Jackass erratic sighting

Website subscriber Carl Johansen sends these photos of erratics from the Jackass Formation conglomerate on the beach on the east shore of Camano Island. Unfortunately, the beach is private. Earlier this winter, I asked people to keep their eyes open for any of these distinctive erratics south or west of Whatcom County. This is relevant, […]

Jackass conglomerate erratics on Orcas Island.

Alert reader Michael Yeaman of Eastsound, Orcas Island, has sent photos of Jackass Group conglomerate erratics on lovely Crescent Beach, just east of Eastsound. Recall I sent out a call for citizen scientists to be on the lookout for these- read that request here. The idea is to show whether these erratics are strictly indicative […]

Appeal to citizen scientists: Do you know of any Jackass conglomerate erratics ?

Dear readers, Have you seen erratic boulders of Jackass conglomerate? I’m specifically interested in learning of any sightings south of Whatcom County, on either side of Puget Sound, or on the shores of the Strait of Juan de Fuca. The easiest place to spot them is on beaches.There’s an idea out there that all these […]

Jackass Mountain conglomerate glacial erratic, Blaine, Washington

By Dave Tucker and Kitty King December 5, 201o Northwest Geology Field Trips subscriber Kitty King of Blaine alerted me to a glacial erratic in Blaine, which recently emerged when brush were cleared along H Street Road. The 2-meter-high rounded stone is one of those wonderful conglomerate boulders from the euphonious Jackass Mountain Formation in […]

Jackass erratic emerges from the bushes in Blaine, Washington

  Northwest Geology Field Trips subscriber Kitty King of Blaine alerted me to a 2-meter-tall glacial erratic in Blaine, which recently emerged when brush were cleared along H Street Road. See the field trip description here. The 2-meter-high rounded stone is one of those wonderful conglomerate boulders from the euphonious Jackass Mountain Formation in southern […]

Guided Geology Field trip to Point Whitehorn, Whatcom County

I will be leading two geology walks along the cobble beach and shoreline bluffs at Point Whitehorn in Whatcom County. Saturday, June 6   1 p.m. and 3 p.m. [the same walk, twice]. Highlights: Erratic boulders, lag deposits as coastal bluffs erode; glacial strata in bluffs. We will look for marine shells in the glacial deposits, […]

Geology hike on the Gold Mine Trail, Sumas Mountain, Whatcom County: conglomerates and a mining scam.

By Dave Tucker Geologic highlights: Two different conglomerates and a potential future conglomerate in the same place; An unconformity at the basal contact of the Chuckanut Formation Serpentinized ultramafic rock Ruins from an elaborate mining scam Sumas Mountain rises abruptly above the Whatcom County lowlands just east of the towns of Nooksack and Everson. The […]

Beach erratic in Des Moines (the one in Washington, not Iowa!)

Last spring I put out a call for intrepid readers to investigate a reported Jackass conglomerate erratic on the beach at Des Moines, between Burien and Federal Way. Thanks to Sandy Bowman and Bud Hardwick for independently investigating. Turns out the large rock is granitic, not conglomerate. Read the article. Consuelo Larrabee at the Des […]