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The Bailey Peninsula is an anomaly: a north-facing peninsula in a ribbon lake (Lake Washington), in which the lake was cut by southward flowing subglacial river flow.

I am untrained in the field (as you will quickly detect...) but I nonetheless find myself wondering, and speculating.  I am posting here in hopes that my speculations can be brought down to earth, corrected by those who really know some local geology.

Derek Booth's 1994 paper, 'Glaciofluvial Infilling and Scour...' suggests that the peninsula had to withstand 'locally intense linear scour'.  Is it plausible that the more resistant elements of the Blakeley Formation  -- which can today be seen in the peninsula, especially on the north facing cliff on the west side of Andrews Bay -- provided this resistance?

Even more speculatively, I wonder whether, during the period of highest subglacial river flow, the Bailey Peninsula was actually an island, with some flow to the east across what is now the isthmus, as well as through the stronger, deeper channel to the west, on the Mercer Island side.

I will be grateful for any comments, even the most deflating!

Cheers,

 - Paul Shannon
   Institute for Systems Biology
   Seattle

This may be outside this forum’s area of interest, but I was wondering if the local glacial geology literature mentions what I’m calling ‘Glacial Lake Mineral’?  When I pushed the 7.5 quads together centered on Mineral and Alder Lake, it appeared the Nisqually River might have been damned by the Puget Lobe (when > 1800’ high) and diverted down today’s Tilton River to Morton and the Cowlitz.  If so, a lake of at least ten square miles with a half-dozen fairly large, steep islands may have filled and drained a number of times.  There’s also a very odd-looking ‘capture’ canyon connecting Alder Lake to the upper Little Deschutes River that may have been the initial drain as the ice dam relented.

Hi. I'm also new; a few references that may help you track down localities:

Hendriksen, D.A., 1956, Eocene stratigraphy of the lower Cowlitz River-eastern Willapa Hills area,
   Southwestern Washington:  Washington Division of Mines and Geology Bulletin, no. 43,                122 p., (incl. geologic map, scale 1:83,333)   


Tabor, R.W., Frizzell, V.A., Jr., Vance, J.A., and Naeser, C.W., 1984, Ages and stratigraphy of lower
    and middle Tertiary sedimentary and volcanic rocks of the Central Cascades, Washington:
    Applications to the tectonic history of the Straight Creek Fault: Geological Society of
   America, v. 95, no. 1, p. 26-44.


Vine, J.D., 1962, Stratigraphy of Eocene rocks in a part of King County, Washington: Washington
   Division of Mines and Geology Report of Investigations, no. 21, 20 p


I couldn't call them 'good' sites, but here around Ashford, coal and fossil leaves are common just below the Toh/Tpg contact.  Try the end of USFS Rd #59 or about three miles up Rd #85.

Hi, new to the forum.  I found in college and again with work great sites of fossilized palms and serrated leaves in Chuckanut Drive in Bellingham and again in Maple Valley, near Black Diamond.  I would give you the coordinates, but that Maple Valley site is paved and built upon.  I have a sort of side project of performing leaf margin analisis on fossilized plants to determine climate conditions, and was wondering if anyone knew of other areas one could find some.  Thanks!

I recently dug some infiltration pits near Hwy 101 and Steamboat Island Road, which is mapped as Qgt, which I found thinly deposited in two test pits, but found in all test pits what is well described as NRCS "extremely gravelly coarse sand" which appears to be there either due to strange hydraulics during the glacial advance in the area, or quite possibly another jökulhlaups which seems likely due to the Schnider Creek Valley being pointed right at this area.

The drama plays out on the Summit Lake 24k Quad.

I drive by a current development site daily on my way to and from work that is on the corner of Atlas Road and Barker Road just outside of Brier to the southeast.

They have been digging a pond, and it better be detention, not infiltration, as I saw water ponded. Knowing the site was in the Vashon Till, I found this reason to stop for a visit.

It turns out the bottom of the pond is in the top of the advance sands here, and I found a varved clay/silt at the contact. I can only suspect this is from the time of glacial advance when Lake Washington was greatly expanded from what it is today.

The location appears to have 3-4 feet of recessional material, 10 feet of till, with 2-3 feet of varved clays, to the advance sand. Quite a nice exposure. If you are interested, you should move quick, as they are likely to be buttoning it up for the October 1 deadline.

Kathy and I are going to attend GSA in Denver, hope to see everyone there. Here are the titles of our presentations.

Ref: Abstract No: 132422
Title: DELINEATING BURIED PEAT BOGS IN SEATTLE, WASHINGTON USING A BOREHOLE DATABASE

Ref: Abstract No: 127169
Title: QUENCH TEXTURES, LITHIFICATION, AND MODES OF CRYSTALLIZATION IN A COOLED SLAG BLOCK FROM A SMELTER AT NORTHPORT, NORTHEASTERN WASHINGTON STATE

When we send out the deliverable, we get very little feedback from the end users. Please let us know how you use it, and specifically, would it be a bad thing if we started migrating toward geodatabase format. That would mean, no included tools for viewing on the CD, just data. Please tell us what you think.
Aaron

Still more spammer/hacker activity. So we are working on some new things. Hang in there.

Hi all! I've been leading "the Cougar Mtn field trip" for almost 12 years now (for UW, BCC, NSCC, TLC, etc etc etc). I think I know the geology of the area pretty well (though I wonder whether I've kept up to date, given all the new mapping y'all do!). But, I'm definitely NOT a biologist. Does anyone know of accessible references/information about the fossils of the Blakeley Fm? I've seen the usual mussels, gastropods, etc, and today I found what looks like a barnacle! Any assistance greatly appreciated! Reply here or directly to gwjones@bcc.ctc.edu with specific subject line. THANKS!  ~Gwyn Jones