Relive Important Archive Articles

A large number of important articles get buried over time as new articles are added to our website, so here’s a chance to review and relive some of our most important articles. We think you might enjoy reviewing these timeless features.

Beryllium-10 dating of late Pleistocene megafloods and Cordilleran Ice Sheet retreat

Balbas et. al. use cosmogenic beryllium-10 dating methods to further constrain the timing of ice sheet retreat, as well as the potential pathways for megafloods from both Lake Missoula and Lake Columbia. Read this fascinating Geology article summarizing their findings. Balbas2017 – Missoula Flood Chronology In summary, our new chronological information suggests the following: (1) Blockage of the Clark Fork river by the Purcell Trench lobe by ca. 18.2 ka, resulting in Missoula floods following the Columbia River valley. (2) Blockage of the Columbia River valley by the Okanogan lobe before 15.4 ± 1.4 ka, which shunted Missoula flood water south across the Channeled Scablands. (3) The final Missoula floods at ca. 14.7 ± 1.2 ka, signaling retreat of the Purcell Trench lobe from the Clark Fork valley, yet these floods entered a glacial Lake Columbia still impounded by the Okanogan lobe. (4) Down-Columbia floods at ca. 14 ka from breakouts of glacial Lake Columbia, signaling the retreat and final damming of the Columbia Valley by the Okanogan lobe

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Glacial Lake Missoula

This feature-filled video by Tom Foster and Nick Zentner explores the evidence for Glacial Lake Missoula, and provides a treasure trove of places to visit and sights to see when you plan your field trip to the area.

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The Cerutti Mastodon Site – A Bretz Type Controversy of Our Time

In March, while visiting San Diego, I went to the San Diego Museum of Natural History in Balboa Park and toured the remarkable Cerutti Mastodon Site exhibit. This controversial exhibit of a mastodon site is notable for its claim that the mastodon’s bones were broken by humans 130,000 years ago, making it far older than any other such site in North America. The signs at the beginning of the exhibit read as follows; “The Cerutti Mastodon discovery. A San Diego find reveals the earliest evidence of of human life in North America. In 1992, paleontologists from the San Diego Natural History Museum were surveying a highway construction site to identify and salvage any fossils that might be unearthed. “Field paleontologist Richard Cerutti spotted some bones and tusks. Exploring further, the team discovered that these were bones of a mastodon-an extinct relative of elephants. “But Richard noticed something unusual. The bones were mysteriously broken and the pieces separated. “It took 22 years for scientists to solve the riddle. Once they did, they realized that this local site is evidence of human presence on this continent 130,000 years ago-much earlier than we thought possible. “In 2014, scientists made a new discovery about the age of the Cerutti Mastodon Site. How did this happen? Scientists figured out the age of the mastodon bones using radiometric dating. It’s a way of telling how old a rock or fossil is by measuring its radioactive isotopes. “A radioactive isotope transforms into an isotope of a different element over time. If you know the rate at which the “parent” isotope transforms into its “daughter” isotope, measuring the parent-daughter ratio tells you how old the material is. “Scientists used a method that measures the ratio of the radioactive isotope uranium-234 to its daughter isotope thorium-230. Dramatic improvements in this method have made it a highly accurate means of dating very old materials- up to 500,000 years. In 2014, scientists used this method to date bones at the Cerutti Mastodon Site. “The results were clear. The bones are approximately 130,000 years old.” More than two decades after the Cerutti mastodon’s discovery in southern California in 1993, USGS scientist Dr. James Paces was sent several bones of unknown age. The specimens were important because they came from a site with abundant evidence of processing by ancient humans. Advances in analytical capabilities and the understanding of processes that incorporate natural uranium and its decay products in fossil bone provided archaeologists with a radiometric dating tool that, at least in some cases, could confidently and accurately determine ages for these older materials. After analyzing nearly 100 subsamples from multiple specimens, Dr. Paces determined that the mastodon bones—which were still fresh when someone fractured them using hammerstones and rock anvils—were covered with sediments 131,000 years ago, give or take about 9,000 years. This result indicates that some form of archaic humans arrived in the Americas more than 100,000 years earlier than scientists had thought possible. Following the dating of the bones officials at the Natural History Museum began making plans for a permanent exhibit about the discovery. The exhibit opened in 2017. It is very thorough and includes bones, alleged hammerstones, and anvil rocks from the original mastodon site as well as numerous photos and interpretive panels. When J Harlen Bretz first announced in the 1920’s his theory that the scablands of eastern Washington State had been carved out by a cataclysmic flood he met stiff opposition. What he was proposing was so far out of the mainstream of geological thinking of the time that many scientists couldn’t accept it. Schooled in uniformitarianism they believed that earth’s landforms were all created by slow gradual processes operating over time and that an event of the magnitude Bretz was proposing just wasn’t possible. They tried to come up with alternative explanations for the facts Bretz presented that fit in with their current frame of reference. Yale University geologist Richard Foster Flint famously said of certain flood features in the scablands that they presented “a picture of leisurely streams with normal discharge.” The claim by San Diego’s Natural History Museum that the Cerutti site is 130,000 years old is likewise far outside what many scientists of our time are ready to accept. Other similar sites are much younger. For example Sequim’s famous mastodon site is only 13,800 years old. If the San Diego Natural History Museum is correct it totally rewrites the history books about humans in North America. It places humans in North America during a previous interglacial period. It would establish that humans had long since been in North America during the time of the comparatively recent ice-age floods. Critics of the Natural History Museum, and there are many, point to things like what they consider to be a lack of lithics from the site. Others speculate that the signs of bone breakage observed at the site may have been caused by some other creature besides humans or by modern day construction equipment. But the Natural History Museum counters that none of the critics have provided a satisfactory alternative explanation for the evidence that they’ve presented. Cerutti and his team of researchers and the San Diego Natural History Museum remain unequivocal in their conclusion: The Cerutti Mastodon Site is a 130,000 year old archaeological site. – by Mark Sundquist, Puget Lobe Chapter “Ideas without precedent are generally looked upon with disfavor and men are shocked if their conceptions of an orderly world are challenged.” J Harlen Bretz 1928 “Extraordinary claims require extraordinary evidence – each aspect requires the strongest scrutiny,” Chris Stringer

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DECIPHERING THE CHANNELED SCABLANDS FIELD WORK CONTINUES

In August, Scott David, a postdoctoral researcher and Karin Lehnigk, a 2nd year PhD candidate from the University of Massachusetts visited the scablands for a week to do field studies. Karin was in search of granite erratics. Samples of these were taken to be processed for Beryllium-10 exposure dating, a robust geochemical technique which enables researchers to determine how long the object sampled has been sitting on the surface of the Earth. This information combined with computer simulations of a range of flood sizes is to test the hypothesis that the earliest floods through the Cheney-Palouse Scabland Tract were also the largest. Scott was in search of potholes. Measuring the geometry of potholes and the rocks that comprise them in a variety of locations, he is using these measurements in numerical and physical modeling experiments to explore what erosion mechanisms could generate these massive features. Were they produced by retreating waterfalls, rocks circulating at the base of the flow, large scale turbulence, or some combination of these mechanisms? The results of the study should provide insight into how the remarkable canyons that comprise the Channeled Scablands formed. On a Friday afternoon, I met up with them in Ritzville and proceeded to some granite erratics near Cow Creek southeast of town to take samples. They spent the night at our house in Washtucna and were thrilled to have hot showers, a home-cooked meal and soft beds. The days before they slept in tents on a gravel parking lot. The next morning, Chad Pritchard from EWU joined us as we took measurements from four pot-holes along the south side of Washtucna Coulee between Washtucna and Hooper. They also took granite samples from the Midcanyon Bar near Lyons Ferry before returning to the Grand Coulee area. The results of their studies were not available at time of printing. Article by Lloyd Stoess in The Scablander

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23,000 Year Old Human Footprints Found in New Mexico

Articles in Science Alert and the New York Times report on a well documented age for many sets of human footprints as old as 23,000 years in the ancient lake shore sands of White Sands, New Mexico. “The footprints were first discovered in 2009 by David Bustos, the park’s resource program manager. Over the years, he has brought in an international team of scientists to help make sense of the finds. Together, they have found thousands of human footprints across 80,000 acres of the park. One path was made by someone walking in a straight line for a mile and a half. Another shows a mother setting her baby down on the ground. Other tracks were made by children.” Beginning in 2019, two United States Geological Survey (USGS) research scientists, Dr. Jeffrey Pigati and Kathleen Springer, began working on the site and found ancient seeds of ditch grass associated with various sets of footprints. The oldest footprints so far have been found in seed beds radiocarbon age-dated as old as 22,800 years, and the youngest footprints dated to about 21,130 years ago. Some scientists still have concerns the seeds might have absorbed older carbon from the lake waters. But in general this research is strongly indicative that humans were present in the Americas long before the generally accepted 15,600-year-old footprint found in Chile or the 13,000 year age of human tools found near Clovis, NM. If humans were well established in New Mexico 23,000 years ago, they must have started spreading down from Alaska long before that. “That starts to wind back the clock,” said Dr. Reynolds of Bournemouth University. Some researchers feel the migration might have been along the coast during the last major ice advance of the Pleistocene, while others argue people could have traveled inland more than 32,000 years ago, before Ice Age glaciers reached their maximum extent and blocked off that route. Regardless of the possible migration route, this new evidence opens up new possibilities that humans may have been present in our local area even before the earliest of the Ice Age Floods, about 18,000 years ago. While the floods could have wiped away most traces of early people in the area, the window of human habitation may be much greater than scientifically documented to date.  

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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 and left, huge blocks of the promontory broke off and slumped down into the rampaging flood waters. Now, even more fearful, 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 inconceivably 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 noticeably 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. 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

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Palagonite Maar Near Hood River

Palagonite Maar Just west of Hood River is a distinctive, short (<500 m) section of stratified orangeish oxidized volcanic tephra and highly fractured lava bombs.  This mixture of oxidized volcanic particles ranging down to sub-micrometer sizes mixed with the larger lava bombs is a palagonite tuff. This deposit is the result of a “phreatic” eruption when lava erupted explosively from a volcanic vent through water, like a lake or groundwater. The rapid heating expansion of water to steam blew the rising lava out of the vent as tephra (volcanic rock fragments) ranging from ash-size to volcanic bombs (blobs of lava) up to several inches in diameter.  Rapid oxidation of the water-quenched tephra turned the iron content to rust, producing the orangeish color of the tephra. The lava bombs were heavily fractured due to rapid cooling of the blob as it came in contact with the water and as it flew through the air. The tephra deposits dip inward on either side of a central gap toward the gap, with NE dips in the western section and NW dips in the eastern section, forming an inverted cone that converges downward toward the central gap. This feature is a “maar” deposit; an inverted cone of tephra and lava resulting from rapidly rising magma interacting with groundwater causing a steam-driven explosive eruption that builds the surrounding maar.  The vent of this maar was in the area of the central gap.

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WA-DNR Website Features Phenomenal LIDAR Images

Washington State Geological Survey is collecting, analyzing, and publicly distributing detailed information about our state’s geology using the best available technology – LIDAR – an acronym for Light Detection And Ranging. The main focus of this new push for LIDAR collection is to map landslides, but there are innumerable additional benefits and applications of this data both inside and outside of the field of geology. A number of amazingly beautiful and revealing images are featured on the WA-DNR Flickr website, along with a trove of information about the technology and it’s applications. LIDAR is a surveying method that measures very precise distance to a target by illuminating that target with a pulsed laser light and measuring the reflected pulses with a sensor. Differences in laser return times and wavelengths can then be used to make digital representations of the target. LIDAR is expensive, but it can easily remove vegetation/grass/trees as it uses an emitting source and interferometry criteria to find the “last echo return” that is assumed as the ground, even in very dense scenarios (forests, corn fields, etc). LIDAR uses ultraviolet, visible, or near infrared light to image objects. It can target a wide range of materials, including non-metallic objects, rocks, rain, chemical compounds, aerosols, clouds and even single molecules. LIDAR is widely used for many different applications. Some (but by no means all) of those uses include: Geology and Hazards, Forestry, Graphics, Navigation, Meteorology and Fir,e Land-use planning, Archaeology and Agriculture. In geology, bare earth models allow closer study of geomorphology, which is the study of the origin of the topography of the earth. Floods, faults, landslides, erosion, and glaciers leave their mark on the landscape, and while these marks can be hidden by dense vegetation, they can’t hide from LIDAR. LIDAR can be used in the field of archaeology to find things hidden by the forest canopy. Large features that would be indistinguishable on the ground are readily apparent in a LIDAR survey, leading archaeologists to sites they might not have otherwise found. For example, intensity returns can be used to detect features just below the surface that affect plant growth.

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