A New Class of Plate Tectonics – Lithospheric Dripping
Crinkles and divots in the surface of Earth on Türkiye’s Central Anatolian Plateau are the smoking gun for a newly discovered class of plate tectonics. Beneath a depression called the Konya Basin, Earth’s crust is slowly dripping deeper into the planetary interior, a process that is gradually shaping the surface geology of not just the basin, but the plateau that surrounds it. It’s called lithospheric dripping, a phenomenon that has only recently been discovered here on Earth, and geologists are still figuring out the different ways it manifests. When the lower portion of Earth’s rocky crust is heated to a certain temperature, it starts to go a little gooey. Then, like honey or syrup, it slowly oozes downward – a bit like a pitch drop experiment, but much bigger and slower. As this drop descends, it pulls the planetary crust down with it. This creates a depression, or basin. Then, when the drop detaches into the mantle, the surface rebounds, bulging upwards, with a widespread effect. The Central Anatolian Plateau is known to be uplifting over time. Previous research suggests that it has gained around a kilometer (0.6 miles) in altitude over the past 10 million years thanks to the release of a crusty drip. But then there’s the Konya Basin, which is subsiding downwards at a rate of around 20 millimeters (0.8 inches) per year. That doesn’t sound like much, but a sinking patch of ground in a region that is rising upwards warrants further investigation. The broader region of the plateau is in the throes of the rebound phase of the lithospheric drip process, after having dropped its gooey molten load into the mantle. The Konya Basin? That’s a smaller, second drip forming. “As the lithosphere thickened and dripped below the region, it formed a basin at the surface that later sprang up when the weight below broke off and sank into the deeper depths of the mantle,” says Earth scientist Russell Pysklywec of the University of Toronto. “We now see the process is not a one-time tectonic event and that the initial drip seems to have spawned subsequent daughter events elsewhere in the region, resulting in the curious rapid subsidence of the Konya Basin within the continuously rising plateau of Türkiye.” Excerpt from a Science Alert article By Michelle Starr
Postmortem on the southern Cordilleran Ice Sheet
(21Feb2024) On 18 March 2924 at 7:00pm the Puget Lobe Chapter io the IAFI will have Dr Ralph A Haugerud give his presentation “the Postmortem on the Southern Cordilleran Ice sheet. Death of an ice sheet can have many causes, as shown by retreat of the southern Cordilleran ice sheet about 15,000 years ago. East of the Cascades, the margin of active south-flowing ice retreated north as less snow fell and more melted. West of the Cascades, the Juan de Fuca lobe of the ice sheet appears to have floated away in response to rising sea level, perhaps without a proximal climatic cause. Collapse of the Juan de Fuca lobe diverted ice from the Puget lobe, which consequently stagnated at its margin and rapidly melted back. Later Sumas ice readvance in the Fraser Lowland may reflect stabilization of the remnant ice sheet by grounding as local sea level fell, followed by climate-driven retreat. Ralph Haugerud received B.S. and M.S. degrees in Geology from Western Washington University and a Ph.D. in Geological Sciences from the University of Washington. Since joining the USGS in 1986, he has worked in the North Cascades Range, the Salish Lowland, and the Columbia Plateau. From 1990 to 2014 he was technical lead for the Puget Sound Lidar Consortium, and he has been instrumental in developing the GeMS standard for representing geologic maps in a Geographic Information System (GIS). His current efforts focus on the structure of Eocene strata in central Washington, features formed by glacial Lake Missoula outburst floods, and regional map compilation. The in-person portion will be at Bellevue College Bldg R, Rm R103. See separate post for location details. For this meeting only there will be NO “Zoom” available.
Journey Through Time: Explore Drumheller Channels
Nestled in the heart of Washington state, the Drumheller Channels offer a unique glimpse into earth’s history, carved by the immense power of Ice Age Floods. This National Natural Landmark is a must-visit for anyone seeking breathtaking landscapes, remarkable geological formations, and a chance to understand the power of nature. Witness the Scars of Ancient Floods: Drumheller Channels are a remarkable example of the Channeled Scablands, a vast landscape sculpted by cataclysmic floods that roared across the region millennia ago. Hike or bike through dry riverbeds, past towering basalt cliffs, and over rolling hills, all remnants of these powerful events. Imagining the colossal force of water that once flowed through these channels is an awe-inspiring experience. Explore Diverse Landscapes: The Channels offer a variety of landscapes, each offering its own unique charm. Hike along the McManamon Trail for panoramic vistas of the Scablands, or venture into the Crab Creek Unit to discover hidden waterfalls and basalt columns. For a unique perspective, climb to the top of “Nick’s Columns” and marvel at the vastness of the Channeled Scablands. A Haven for Wildlife: The diverse ecosystem within the Drumheller Channels provides a sanctuary for various wildlife species. Birdwatchers can spot over 23 species of ducks and geese, while sharp-eyed visitors may catch a glimpse of deer, coyotes, and even bald eagles. The Channels are also a vital nesting ground for many birds, making it a crucial habitat for preserving regional biodiversity. Connect with the Past: Explore the fascinating human history of the Drumheller Channels. The region has been inhabited for thousands of years, with evidence of Native American presence found throughout the area. Learn about the early settlers who braved the rugged landscape and contributed to the development of the region. A Place for Recreation and Reflection: Whether you’re an avid hiker, a passionate photographer, or simply seeking a peaceful escape, Drumheller Channels has something for everyone. Hike through scenic trails, enjoy a picnic amidst the breathtaking scenery, or simply relax and soak in the tranquility of nature. Plan Your Visit: The Drumheller Channels are open year-round and offer free access. Several trailheads provide easy access to various sections of the Channels. The Ice Age Floods Institute offers valuable resources, including maps, trail descriptions, and educational information. Be sure to pack sturdy shoes, appropriate clothing for the weather, and plenty of water for your adventure. Come experience the grandeur and wonder of the Drumheller Channels. Witness the power of nature etched into the landscape, explore the diverse ecosystem, and connect with the rich history of this remarkable place. It’s a journey through time that will leave you with a lasting sense of awe and appreciation for the natural world.
Let Your Feet, and Your Imagination Roam at Rowena Crest and Tom McCall Preserve
Scenic Rowena Crest and the Tom McCall Preserve area provide an incredibly scenic place to let your feet, and your imagination wander as you look out on a major chokepoint along the Ice Age Floods path. The wildflower displays are amazing during the Spring, but several compelling flood-related features are visible from the vantage of the Rowena Crest Viewpoint any time of year. Rowena Crest lies nearly 700 feet above the Columbia River at the upstream end of the Rowena Plateau, a miles-long plateau that the river flows along. Just upriver from the plateau is the narrow section of the Gorge known as the Rowena Gap The drive to the viewpoint on old Hwy 30 from either east or west is a spectacular ride through a wonderous section of the Columbia River Gorge. A roundabout parking area at the viewpoint, with a safety wall above a sheer cliff, provides a great observation point eastward toward Rowena Gap. At Rowena Crest it’s easy to imagine what it might have been like to witness the approach of those massive floods. There is not yet scientific evidence that humans were in the area to bear witness to the Ice Age Floods, but there is solid evidence of humans in the Americas by that time. And there is growing concensus that if they came in during a glacial maximum, they would have come in by a coastal route that offered plentiful food and shelter for their journey. The mouth of the Columbia River would have been the first major waterway path inland that might have led them to settle in the area of the Floods. Your village might have been situated across the Columbia at the mouth of the Klickitat River where the town of Lyle now sits. If you were foraging, or just relaxing, atop Rowena Crest on a late summer day, you might have felt the ground begin to temble as if there were a small earthquake, but the trembling would have slowly increased for a few hours. Eventually you would have heard a low roaring sound that also grew over an hour or more before you could see turbulent brown muddy water begin flooding across the broad basin to the east. Then the roaring flood of water, only a few feet deep at first, would have entered the narrows, now called Rowena Gap, and sped on, crashing against the promontory you’re standing on and being diverted toward your village which was quickly washed away by the muddy torrent. But the muddy flood waters would have kept rising, unlike the Spring floods you’re used to on the Columbia, becoming a hundred feet deep, then two hundred as the levels just kept rising. Soon a huge whirlpool formed in the flood waters near the base of the promontory and a giant eddy formed where your village had been as flood waters flowed backward up the Klickitat River even as the bulk of the water continued downstream on the main stem of the Columbia. As the flood waters reached 400 and 500 feet deep and kept coming, suddenly to your right a huge block of the promontory broke off and slumped down into the rampaging flood waters. Now you would have begun running south toward higher ground, climbing higher and higher as the still rising flood waters poured across the plateau and plunged into the small creek valley to the west, tearing away at the valley walls and massively widening that little valley. Eventually the flood waters stopped chasing you upward as you climbed higher, 200 then 300 feet above the now submerged promontory. Now as you turned and looked out across that expanse of muddy water you could see massive white blocks of ice being carried along on the flood waters, similar but inconceiveably larger than the ice blocks carried on the river during the Spring floods. But the flood waters didn’t begin to recede that day, nor the next, as they might in the Spring floods. In fact it was almost half a lunar cycle before they began to slowly recede, exposing a mud coated Columbia River valley that was now noticably wider, with layers of shear vertical rock walls extending over 1000 feet above the normal river level below. As you began the recovery from the floods devastation, your family returned from from their hunting and gathering in the high mountain meadows, and you have an incredible story to pass along to them and your ancestors. This story is easy to imagine as you look out to the east from Rowena Crest. The onrushing Ice Age Floods waters easily flowed over the low relief of the broad Dalles Basin to the east, but the major Rowena Gap created a chokepoint in the path of the floods as they made their way through the Columbia River Gorge. This “hydraulic dam” forced the flood waters to build to over 1000 feet deep in this area, flowing hundreds of feet deep over Rowena Crest while forming a temporary lake in The Dalles basin. It is estimated that many of the 40-100 Ice Age Floods may have taken up to a month to completely flush through the system to the Pacific Ocean, but the duration of the flood waters at any point along the path probably lasted less than a couple of weeks. But this was more than enough to create several major floods features visible from this vantage point. At Columbia River level below and east of the promontory is a round Kolk pond that was created by giant whirlpools in the flood waters as they were deflected around the Rowena Crest promontory. Other similar Kolk features can also be seen on the Dallesport area to the east, and along the hiking path atop Rowena Crest where they are marked by surrounding groves of oak trees. grew Across the Columbia, the floods deposited a huge eddy gravel bar that the entire town of Lyle, Washington is built upon. The Klickitat River was backed up for miles
Mima/Desert/Biscuit Mounds – An (Possible) Explanation
If you’ve visited the Rowena Crest Viewpoint at Tom McCall Preserve, west of The Dalles in the Columbia River Gorge, you may have noticed the many dome-shaped earthen mounds that cover the Rowena Plateau. These mounds are broadly circular and are surrounded by collections of basalt rock fragments. If you’ve visited the spring wildflower mecca of Catherine Creek on the Washington side of the Gorge, you may have also wondered at what caused the stripes of black rock extending down the slopes above the area. Tens of thousands of similar soil mounds cover large areas of the high desert lands of north-central Oregon, often in swarms that number in the hundreds. These mounds can be round or elongated, can range from a dozen feet to more than 60 feet in diameter atop the rocky Columbia River Basalt bedrock, and are typically surrounded and separated from each other by rings or stripes of basalt rock fragments. The mounds also appear similar to those at Mima Mounds Natural Area Preserve near Olympia, WA. There have been many suggested causes for the creation of these mounds, from burial mounds, to Pleistocene pocket gophers, to plants or glacial sun cups trapping wind-blown sediment, to sorting by earthquake vibrations, to turbulence at the base of ice-age floods flowing over the landscape. Research by two Oregon graduate students, Clark Nelson of Oregon State University and John Baine Pyrch of Portland State University, independently came up with what may be the most likely explanation for the origins of these enigmatic features. Their theses suggest desert mounds and their rock rings formed through a process of natural sorting, where fine soil material is pushed up into mounds and associated rocks are pushed out to the edges to form rings through countless cycles of wetting/drying and freeze/thaw during the wetter and colder period of the late Pleistocene. Clark Nelson cut a trench through a mound that exposed layers of soil and volcanic ash whose lack of mixing discounts the pocket gopher theory. Nelson also found that slope angle less than or greater than 10 degrees determined whether the features would form rounded mounds vs. elongated stripes. Pyrch showed the strips to be distinct from common talus slopes, because no obvious source of rock exists at the head of the talus stripe. He also observed that rocks within these stripes are sorted, unlike talus slopes, suggesting the same ice age freeze-thaw origins as soil mounds and rock rings. You can read more detailed articles about these enigmatic features in these articles: Mystery of the Desert Mounds Great Pyramids of the Gophers: Mima Mound Mystery Solved Similar processes are also thought to be responsible for the “patterned ground” found in periglacial environs. However these various types of features may have formed, we can be certain how the few mounds in the center of the parking circle at Rowena Crest Viewpoint came to be. They were man-made during the construction of the viewpoint and made to look like the mounds that cover the Rowena Plateau. At least one origin has a definitive answer.
Steamboat Rock
Steamboat Rock lies at the very northern end of the Grand Coulee. At over 1 mile long, ⅔ mile wide, and 800 feet high. The basalt-topped butte standing alone in the middle of the coulee, almost completely surrounded by the waters of Banks Lake is an incredible sight. It was left behind by erosion of both the Ice Age Floods that carved the Grand Coulee, and the Okanogan Lobe of the ice-age continental ice sheet. Because this area is near the thinning outer margin of the Columbia River Basalt extent, it’s easy to see Columbia River Basalt directly overlying older granitic basement from the trails around the base. A steep climb on a well constructed trail leads to the broad top of Steamboat Rock where the views are truly expansive, encompassing a full 360° panorama. It’s also easy to find granitic erratics and glacial till atop the butte that attest to the fact that the Okanagan Lobe overrode Steamboat Rock during the most recent Ice-Age glacial advance. The campgrounds at the State Park are spacious and well laid out. There is easy access to both the trails and to Banks Lake for fishing, boating and swimming. Most of the water in Banks Lake has been pumped up from the Columbia River’s Lake Roosevelt, and impounded by a dam 20 miles south at Coulee City. Banks Lake is a key element in the Columbia Basin Project that supplies water for the verdant agricultural areas to the south in an otherwise quite dry, high desert environment. Some other interesting places to explore in the area include Northrup Canyon, Grand Coulee Dam, and the quixotic Gehrke Windmill Garden just north of Electric City.
Frenchman Coulee
Frenchman Coulee Ice Age Floods National Geologic Trail Frenchman Coulee is a short drive north and west from the Silica Road exit 123 off US-90, along the Old Vantage Road. It is one of the most beautiful features left behind by the great Ice Age Floods. Several of those massive floods, up to 700 ft (213 m) deep, created Frenchman Coulee, its Potholes Coulee neighbor to the north, and scoured the bizarrely eroded surface of Babcock Bench, preferentially eroding weaker rock out of the top of the Grand Ronde Member of Columbia River Basalt. Frenchman Coulee is actually a dual coulee and cataract system, Frenchman Coulee and Echo Basin, separated by a remnant rock blade that sports tall basalt columns attracting rock climbers like bees to flowers. The Feathers is probably the most popular climbing area in the region. Hiking trails, some barely discernible, lead along and atop the rock blade, affording spectacular views of both coulees. Frenchman Coulee also has a waterfall in the eastern section of the Coulee that is accessible by foot. Other hiking and biking trails explore the floor of the coulee and continue over 15 miles north along Babcock Bench, perched high above and adjacent to the Columbia River, past Potholes Coulee and on to Crescent Bar. Quick Facts Location: Old Vantage Highway, Quincy, WA 98848 A primarily destination for hikers, mountain bikers and rock climbers with the fascinating rock formations of the Gorge making for a great challenge
Ginkgo Petrified Forest
Ginkgo Petrified Forest State Park Interpretive Center Ginkgo Petrified Forest State Park is a registered National Natural Landmark, lyng just north of US-90 at exit 136, and west of the Wanapum Lake portion of the Columbia River at Vantage, WA. Established in 1935, it is home to a rare and vast collection of petrified trees. The park covers 7,124 acres, including an interpretive trail, on which visitors can hike and see protected displays of several of the petrified tree species. The abundance of tree species discovered here make it one of the most diverse collections of petrified trees in North America. The trees are thought to have been carried down the flanks of ancient volcanoes from various ecological zones by floods and lahars., and then deposited and buried in an ancient lakebed. Slowly, cell-by-cell, the tree cells were replaced by dissolved minerals in the groundwater, resulting in exact rock replicas of the trees. The park comprises three primary locations. Drive a couple of miles up the Old Vantage Highway to the Ginkgo “Trailside Museum”, constructed by the Civilian Conservation Corps in the 1930s, and recently updated with a new interpretive exhibit. From here, 1.25 miles of the Trees of Stone Interpretive Trail wind past more than 20 petrified logs protected in their original settings with signage about the petrified wood. Birders look for golden eagles, sage thrashers, Say’s phoebes and many other species. Elk and bighorn sheep also frequent this area. A total of 3 miles of hiking trails are at this site. Perched on a cliff face carved out by Ice Age floods, Ginkgo Petrified Forest Interpretive Center overlooks the Wanapum Lake portion of the beautiful Columbia River. The access road is marked by a small sign on Main St. just north of the small town of Vantage. The interpretive center was constructed by the Civilian Conservation Corps during the Great Depression and was later expanded in 1951.The air-conditioned Center museum features a beautiful collection of more than 30 varieties of petrified wood, videos and park volunteers to inform visitors about the history behind this unique and unusual petrified forest. They can also tell about the powerful Ice Age Floods, responsible for the visually captivating surrounding landscape. Outside the Center, visitors can enjoy the day-use/picnic area, view the scenic river, touch petrified wood and learn more about the Ice Age Floods. Ginkgo Petrified Forest State Park is also home to the Wanapum Recreation Area about 3 miles south of US-90, which features 27,000 feet of freshwater shoreline and hosts a 50 site, full hook-up campground, a day use area with a swim beach, and a boat launch. Quick Facts On the Ice Age Floods National Geologic Trail Location: 4511 Huntzinger Rd, Vantage, WA 98950 99371 MANAGED BY: Washington State Parks A Discover Pass is required for vehicle access to state parks for day use. For more information about the Discover Pass and exemptions, please visit the Discover Pass web page.
6 New ‘Nick On The Rocks’ Episodes
6 new short episodes of ’Nick On The Rocks’ aired on PBS this past winter! Each of these gems are short enough to be taken in by even the busiest of us, and yet have enough information to whet the appetite of even the most intensive of us. Nick is masterful in his presentations and who he draws in to help. Watch them all, you won’t be disappointed. Lake Chelan – Battle of the Ice Sheets (w/ Chris Mattinson) Click HERE to watch. 5 minutes. Chasing Ancient Rivers (w/ Steve Reidel) Click HERE to watch. 5 minutes. Seattle Fault (w/ Sandi Doughton) Click HERE to watch. 5 minutes. Bridge of the Gods Landslide (w/ Jim O’Connor) Click HERE to watch. 5 minutes. Columns of Basalt Lava Click HERE to watch. 5 minutes. Ancient Volcanoes in the Cascades (w/ Daryl Gusey) Click HERE to watch. 5 minutes.
Castle Lake Basin
Castle Lake fills a plunge-pool at the base of a 300-ft tall cataract at the opposite (east) end of the Great Cataract Group from Dry Falls, above the east end of Deep Lake. A set of steel ladders put in place during the construction of the Columbia Basin Irrigation Project allow for a safe descent into the basin. In the basin are great views of giant potholes, the flood-sheared face of Castle Rock, as well idyllic Deep Lake. The Castle Lake Basin lies along the east end of the Great Cataract Group. At the base of the cataract is lovely blue-green Castle Lake plunge pool nestled into the rock bench below. Castle Lake lies within a single recessional cataract canyon eroded down to a flood-swept, pothole-studded rock bench that stands 100 feet above Deep Lake. This is the same rock bench of Grande Ronde Basalt where dozens of potholes occur at the opposite (western) end of Deep Lake. Castle Rock itself is an isolated butte along the west side of the Castle Lake basin. It is a faceted butte escarpment nearly sheared off by monstrous flood forces moving across the cataract.