Geology of Blaine-Birch Bay Area Blaine Middle Whatcom County, WA School / PAC l, ul G ant, G rmor Wings Over Water 2020 C o n Nest s ero Birch Bay Field Trip Eagles! H March 21, 2020 Eagle "Trees" Beach Erosion Dakota Creek Eagle Nest , ics l at w G rr rfo la cial E te Ab a u ant W Eagle Nest n d California Heron Rookery Creek Wave Cut Terraces Kingfisher G Nests Roger's Slough, Log Jam Birch Bay Eagle Nest G Beach Erosion Sea Links Ponds Periglacial G Field Trip Stops G Features Birch Bay Route Birch Bay Berm Ice Thickness, 2,200 M G Surficial Geology Alluvium Beach deposits Owl Nest Glacial outwash, Fraser-age in Barn k Glaciomarine drift, Fraser-age e e Marine glacial outwash, Fraser-age r Heron Center ll C re Peat deposits G Ter Artificial fill Terrell Marsh Water T G err Trailhead ell M a r k sh Terrell Cr ee 0 0.25 0.5 1 1.5 2 ± Miles 2200 M Blaine Middle Glacial outwash, School / PAC Geology of Blaine-Birch Bay Area marine, Everson ll, G Gu Glaciomarine Interstade Whatcom County, WA morant, C or t s drift, Everson ron Nes Wings Over Water 2020 Semiahmoo He Interstade Resort G Blaine Semiahmoo Field Trip March 21, 2020 Eagle "Trees" Semiahmoo Park G Glaciomarine drift, Everson Beach Erosion Interstade Dakota Creek Eagle Nest Glac ial Abun E da rra s, Blaine nt ti c l W ow Eagle Nest a terf California Creek Heron Glacial outwash, Rookery Glaciomarine drift, G Field Trip Stops marine, Everson Everson Interstade Semiahmoo Route Interstade Ice Thickness, 2,200 M Kingfisher Surficial GNeeoslotsgy Wave Cut Alluvium Glacial Terraces Beach deposits outwash, Roger's Glacial outwash, Fraser-age Slough, SuGmlaacsio mSataridnee drift, Fraser-age Log Jam Marine glacial outwash, Fraser-age Peat deposits Beach Eagle Nest Artificial fill deposits Water Beach Erosion 0 0.25 0.5 1 1.5 2 Miles ± Chronology of Puget Sound Glacial Events Sources: Vashon Glaciation Animation; Ralph Haugerud; Milepost Thirty-One, Washington State Dept. of Transportation, Quaternary Research Center, Waterlines; Brian Atwater, Britta Johnson, & Amir Sheikh; 2017, Retrieved June 15, 2017 Years Before Present Event 18,800 The weight of the ice begins to depress the earth crust. The Puget Sound troughs and basin had been created previously. Corderillian Ice Sheet has filled the Strait of Georgia southward out into the Strait of Juan de Fuca , where it floats on the ocean. The glacial front is north of the junction of the Hood Canal to Admiralty Inlet and fills the Whidbey Basin. The outwash plains fill the entrance of the Hood Canal, Admiralty Inlet and Possession Sound from north of Everett to the southern end of Whidbey Island . The ice continued to move southward at an average rate of 450 feet (140 m) per year. 18,300 Three freshwater lakes filled the basin. Nearly the entire length of the Hood Canal was open water. To the east the largest body of water filled the East Passage, the Dalco Passage (Tacoma) with a river like basin along the west of Vashon Island. A separate lake flowed from the Case Inlet and Nisqually Reach west of Tacoma through the narrows into the river running north through the Colvos Passage. The ice sheet continues it’s southward progression, separating the Hood Canal from the other basins in Puget Sound. The ice front is just north of Seattle and the outwash plain covers all of Elliott Bay , from just north of West Point south to Blake Island. 18,100 Three freshwater lakes that had been created early continued to exist, growing small as the ice front moved south. The ice sheet has created a uniform arched front running from Dosewallips River mouth, southeast across the Kitsap Peninsula, through Bremerton , arcing across the southern tip of Vashon Island , ending in the Green River valley in the area of Kent . Outwash plains fill the mid reaches of the Hood Canal, the Clifton Channel and 3 to 5 miles (4.8 to 8.0 km) in the Carr Inlet, Colvos Channel, Quartermaster Harbor, and the East Passage of Puget Sound and a similar plain in the valley 17,800 of the Green River from Kent to Auburn . A single freshwater lake extends across the glacial front cover the lower Hood Canal and the lower hills north of the Black Hills north of Olympia . A smaller body of water filled the valleys of the Puyallup and White Rivers . The ice front reached to just north of Olympia. The entire basin of the Puget Sound was filled with ice. A small outwash plain covered 2 to 3 miles (3.2 to 4.8 km) in an arch from the heights south of the Hood Canal south and eastward to the 17,500 Eastern bluffs of the Nisqually River mouth. A narrow band of water lay to the south of this plain and covered the area where Olympia now stands. The ice front reached its southernmost most point. It road along the east face of the Olympic Mountains , south to the plains north of the Black Hills, skirting their northern hills, reaching southward into the Black River Valley to its junction with 16,900 the Chehalis River . The front rested on the flanks of Mount Rainier, turning northward, joined by numerous small glaciers in the valleys of the eastern front of the Cascade Mountains . There was 3,000 feet (910 m) of ice over Seattle and the land was depressed 275 feet (84 m) near Pioneer Square. The ice began to retreat after 16,900 ya. By 16,600, it had returned to north of Olympia, as it was 1000 years earlier. 16,600 The ice continued to retreat. Still standing south of Tacoma, substantial freshwater bodies had formed. Lake Skokomish stood in the southern bend of the Hood Canal and the lower reaches of the Skokomish River . Early Lake Russell or a late version of Lake Nisqually . 16,400 Continuing to recede to the north, the ice front reaches from the south side of Tacoma in a northwest arc across the Kitsap Peninsula, exposing the southern hook of Hood Canal, reaching the Olympic Mountains near Quilcene Bay. 16,400 A large freshwater body formed. The ice front became anchored on the west among the Olympic Mountains near Quilcene Bay. Lake Russell spread across the southern basins of Puget Sound. Lake Hood drained across its southern outlets into Lake Russell. From Tacoma, the ice lay ice front lay 7 to 10 miles (11 to 16 km) to the north and lay across the Green River at Kent. 16,300 Within a very short period, the glacier retreated up to 15 miles (24 km) in a few decades. Bremerton and Renton are now ice free. 16,200 Continuing the advanced rate of retreat, Seattle becomes the southern tip of the ice sheet. The Hood Canal has fully joined with Lake Russell, leaving only the highest points the Kitsap Peninsula standing above the shore. The retreat appears to have slowed or halted with evidence that the ice sheet was thinning, rather than receding. The water levels of Lake Russell have dropped correspondingly. 16,100 The upper end of the Stillaguamish River has formed a freshwater lake. Lake Washington and Lake Sammamish appear as water bodies along the southern margin of the lake. The ice front has receded north opening the mouth of Hood Canal and lies just south of the southern end of Whidbey Island . 16,000 The length of the Stillaguamish River is a freshwater lake. Lake Sammamish has linked to Lake Washington along its present watercourse with Lake Washington draining across Lake Union and then only through the Duwamish River at its south end. 15,900 The ice front has receded north into the Strait of Juan de Fuca, linking the Puget Sound Basin to the ocean. The Duwamish-Green River Valley was salt-water reach of the sound. The Stillaguamish River is also a salt-water branch of the sound. Except for the Duwamish-Green River saltwater embayment, the modern waterways have formed into the waterways known today. The Whidbey basin has taken a rudimentary form, with the Stillaguamish River flowing into Port Susan Passage 7,500 and Skagit Bay has appeared. 5,500 Mt. Rainier's northern crest collapsed sending a lahar down the White River . This creates the Auburn delta in the Duwamish Embayment, separating the Puyallup River valley from the Green River valley. 2,100 An eruption of Mt Rainier send sand lahars down White River to its junction with he Duwamish at Tukwila. 1,100 Duwamish valley earthquake lifts the Duwamish valley by 20 feet (6.1 m) draining what was left of the salt-water embayment, creating the Duwamish delta and what has become the Port of Seattle. Chronology of the Fraser Glaciation in the Northern Puget Lowland/Southern Fraser Lowlands From Booth, D. B, et. al. The cordilleran ice sheet, 2003 The Cordilleran ice sheet most recently advanced out of the mountains of British Columbia about 25,000 years ago. It flowed west onto the continental shelf, east into the intermontaine valleys of British Columbia where it probably merged with the western edge of the Laurentide ice sheet, and south into the lowlands of Washington State. In southern British Columbia and western Washington, the Puget lobe filled the Fraser Lowland and the Puget Lowland between the Olympic Mountains and Cascade Range. The Juan de Fuca lobe extended east along the Strait of Juan de Fuca ending some 100 km west of Washington’s present coast.