Empirical Evidence of Catastrophic Geology: Case 4

The Ricobayo dam is a 320-ft tall concrete arch dam constructed in 1929-1933 in northwest Spain.  The original spillway was originally a simple 1300-ft long channel cut in the rock (unlined channel) that discharged over a rock cliff.  Floods (high water levels) occurred in 1934-1936 and scour (loss of rock mass) was observed within the spillway channel and plunge pool.   100 meters of granite rock along the spillway was scoured away during this time (80 ft in 1935 and 100 feet in 1936 to start), creating an entirely new downstream valley profile.

  

(Photo was reproduced from an article by George Annandale, P.E.).  The Ricobayo spillway consisted of granite with vertically dipping joints and 10 to 20 degree off horizontal joints.  The plunge pool of the spillway was relatively stable after a certain depth of scour had occurred (80 feet), due to the presence of harder rock starting at a certain elevation, although the concrete lining was destroyed by forces from a flood in 1939 and again in 1962.  The fractured/jointed condition of the rock permitted water infiltration and a reduction of effective stresses within the joints that facilitated loss of rock mass.  This case history reminds us of the power of water and the ability to alter topography and geologic profile very quickly.  A more recent photo of the dam is provided below.  Note the huge vacant rock space.

Paleontology: Dinosaur Footprints in Leander, Texas

In Leander, Texas, along the stream bed of the South Fork of the San Gabriel River, dinosaur (extinct reptile) footprints are evident in the exposed limestone.  This location is west of the US183 and San Gabriel River intersection right at the first bend in the stream valley.

The geology consists of inter-bedded limestone rock, marly (clayey) limestone, sandy clay-marl, weak limestone material, and nodular limestone sedimentary deposits categorized as the "Walnut Group" geologic formation that includes "Cedar Park Limestone", "Bee Cave Marl", and "Bull Creek Marl" members.  The layers of marl and weak limestone materials are erodible, so the currently exposed dinosaur footprints are in a limestone rock layer (resistant).  The stream valley walls show evidence of inter-bedding as the overlying layers have eroded while the currently exposed rock layers have remained more resistant to stream flood water erosion and weathering.

The photo shows the largest tracks, assumed to be from a theropod or ornithopod type dinosaur.  There are some other smaller tracks scattered around also from 3-toed (tridactal) dinosaurs.  This geologic formation was either deposited during the ascending phase of one creationist geologic model when footprints would have been made in soft (yielding) soil and quickly buried and preserved by the next event of sedimentation, or during the Cretaceous age of the uniformitarian model of millions of years, depending on which paradigm someone is working under. If working under the creationist model this strata was likely buried under subsequent sediment layers but then subsequently exposed after the abative geologic phase eroded off alot of the overlying strata and river floods finished off the rest to expose the site in its current condition.

Chert vs Flint

Chert rock is common in the "Edwards" geologic formation here in central Texas.  A more common layman term is "flint".  Chert is a rock (not a mineral) composed of microscopic quartz crystals (microcrystalline).  Chert has a smooth surface and fractures with a conchoidal shape.  Chert is found as nodules (subrounded mass) or layers of limited horizontal extent within limestone rock.  Chert occurs in many colors such as white, yellow, red, brown, green, blue, gray, and black.  The yellowish, red, and brown chert is commonly called "jasper", while the dark gray to black chert is commonly called "flint".

The conchoidal fracturing is what made "flint" a popular rock type for carving an otherwise very hard material and making arrow heads, spear tips, or knives.  The image at right includes an arrowhead made of chert found in Georgetown.  The other two items are very dark gray to black chert rock fragments (flint).

Empirical evidence of catastrophic geology: Case 3

The Washington State scablands........Lake Missoula glacial dam breach and the massive flood and its geological effects.

The following is reproduced from Sean D. Pitman's website, a great historical piece:

J Harlen Bretz

And The Great Scabland Debate

Sean D. Pitman, M.D.

© April 2004

Introduction

One of the most interesting debates in the history of geology has to do with the origins of the Channeled Scabland region in eastern Washington State – so named by J Harlen Bretz because of the region’s distinctive channels with intervening “scabs” of loess or soil covering the underlying basaltic rock.  But how, exactly, were these channels and scabs formed?  Were they formed over millions of years of time by process of erosion currently active in the region or were they formed by some other means?

By the time of the early twentieth century, the most prominent scientists of the day were decidedly “uniformitarian” in their thinking.^1,2 That is, they believed that the regular observed processes of usual geologic events acting over vast periods of time were able to explain most if not all of the observed geologic record.   J Harlen Bretz, who earned his Ph.D. in geology from the University of Chicago, was the first geologist to seriously challenge this notion, but it was by no means an easy. The process to change the prevailing dogma of the day was a tremendous struggle for Bretz despite his use of a great deal of very good evidence – and that is what is most interesting about this story.

The Evidence for a Catastrophic Flood

Many people think that scientists are dispassionate in their investigations, conclusions and their general search for truth.  As we will soon discover, most scientists have always been very passionate people who, just like most of the rest of us, do not like to admit a long-held error even in the face of otherwise overwhelming evidence.

Bretz’s interest in the Scablands was first aroused in 1910 by the newly published Quincy topography map of the area. This map clearly revealed great potholes now known as the Potholes Cataract. During this same year, Joseph Thomas Pardee published a paper describing the geomorphological evidence for a great glacial lake occupying the intermountain basins of western Montana during the late Pleistocene.  He described the prominent horizontal shorelines or “strandlines” previously noted by T. C. Chamberlin.  This lake, which was to eventually play a prominent role in this story, was named for Missoula Montana, where its strandlines were particularly prominent. ²

Bretz began the field research of the Scablands in 1922 with the help of a few advanced geology students.  He continued these summer outings over the course of seven years, traveling largely byfoot.  What he saw was truly remarkable.  For example, the cliffs of Dry Falls are 3.5 miles wide and drop some 400 to 600 vertical feet.^1,4 By comparison, Niagara Falls is only a measly 1.5 miles wide and drops just 165 vertical feet. Bretz took note of the very steep sides of the channels and their relatively straight pathways as well as the presence of very large gravel bars deposited by water.  Also, throughout the scablands Bretz saw huge islands of land protruding from the surrounding landscape with streamlined features as if they were carved by massive torrents of water. ²

Bretz first presented his initial observations in 1923 to the Geological Society of America.  In that first paper he simply described what he saw on his various field trips.  He deliberately took special care not to present any sort of explanation or interpretation for his observations.  He did note, however, that the observed channel erosion required large non-specified quantities of water.  On the other hand, in his second 1923 paper Bretz decided to stir up his fellow geologists just a little bit. In the second paper Bretz presented his theory that a truly huge catastrophic flood was in fact the creator of the most prominent features of the Scabland region. ²

Uniformitarian Bias Blinds Scientists

Of course this conclusion was less than enthusiastically received by Bretz’s fellow geologists.  In fact, Bretz was openly and vigorously ridiculed for presenting such a ludicrous notion as a flood model for the scablands since this region had obviously been carved out over millions of years by uniformitarian processes.  In support of this derision, Pardee’s brief 1922 paper concerning the scabland region near Spokane, Washington (the Cheney-Palouse Scabland Tract) was used to discredit Bretz.  In that paper Pardee proposed that unusual glaciation, acting over very long periods of time, created the Scablands.

However, when Bretz went to visit this area a couple years later he found that Pardee’s “glacial” deposits were actually flood bars.  What is even more interesting is that, after hearing of Bretz’s ideas, Pardee seemed to change his mind.  He actually wrote to Bretz in 1925 suggesting that Bretz consider the draining of a glacial lake as a possible source for his suggested cataclysmic flood.  In reference to this communication, Bretz wrote the following to J. C. Merriam:

Mr. Pardee of the Federal Survey, who has seen much of the scablands, has suggested that his glacial Lake Missoula might have afforded the water for these enormous rivers if it were suddenly drained out across the plateau.  This comment indicates that his former view of the scablands by land ice and concomitant subglacial drainage under ordinary climatic melting has been abandoned.  Even our ultraconservative in Pleistocene geology, Dr. Alden, wrote that the phenomena I describe certainly appear to be river work “if you could only show where all the water came from in so short a time.” ²

Later, in a 1943 correspondence with Hobbs, Pardee himself wrote:

The “drift” referred to in the article Science consists of bouldery deposits which at that time (1922) I interpreted as a gravelly till transported and deposited by glaciers that extended far over the Columbia Plateau.  The principal feature of the deposits that suggests glacial action is the presence of large boulder, some of them of foreign origin.  From information of the region that has been made available since 1922, however, I have concluded that the deposits are more likely the work of flood waters, such as postulated by Bretz, rather than of glacial ice.  That is — I do not regard them as conclusive evidence of glaciation.  On the other hand the deposits are indirectly, if not directly, related to glaciation and may have been formed by streams that gouged out the channels and basins under an ice cover as you suggest.²

It seems then that Pardee actually considered the flood hypothesis with Lake Missoula as the source, but was probably dissuaded from pursuing such a heretical notion any further by Alden and Kirk Bryan (Pardee’s superiors at the time).  This idea is at least consistent with Pardee’s silence when Bretz presented his rather shocking catastrophic flood idea at the now infamous 1927 “scabland debate”. ²

Sometime before 1927 geologists were catching on to the seriousness of what Bretz was suggesting.  If true, Bretz’s theory would undermine the very foundation of Uniformitarianism.  Just as anticipated, the general outcry against any hint of a catastrophic model was very loud indeed.  In fact, there was a very strong desire to publicly discredit and humiliate Bretz.  So, to this purpose, Bretz was asked to present his ideas in public forum to the Geological Society of Washington.  Bretz himself was rather unaware of the underlying purpose of this gathering or just how hostile his audience actually was to his ideas.  Unawares to Bretz, six “challenging elders”, as Bretz later referred to them, were chosen to counter Bretz’s claims and beat him in public debate.⁶

The first to speak in response to Bretz’s presentation was W. C. Alden.  Alden suggested that many of the features Bretz observed could be explained as collapsed lava caves.  He also noted that a flood large enough to create the features observed by Bretz would require an incredible volume of water, and he confidently declared that such a volume of water was simply impossible to achieve.  Therefore, another source for the origin of these features must be responsible.  Other challengers agreed arguing that the relatively small rivers already existing in the region were in fact responsible, in their current state given enough time, for the observed formations.  Instead of a catastrophic flood of magnificent proportions sweeping over the region in a few days they suggested that the rivers took several million years to carve out the scabland features and that Bretz should abandon his ludicrous catastrophic notions.⁶

Bretz was not easily defeated however.  He came to this meeting very well prepared with a great deal of evidence to support his position.  He countered all six speakers by pointing out that the channels and bars found in the scablands were much too large, even for a very swollen Columbia River to create over millions of years.  The great weight of observational evidence suggested in fact that a huge amount of water traveling at tremendous speed had carved out the entire region in just a few days.^2,5,6

Despite the overwhelming evidence in support of Bretz’s interpretations, the “six elders” would have none of it.  Nothing would convince them of such a catastrophic model, especially since Bretz was unable to identify or explain the source of so much water.  Though the uniformitarian hypothesis did not fit the observed evidence nearly as well as Bretz’s catastrophic model, no one would openly admit to believing Bretz and thus be forced to admit that holy Uniformitarianism was nothing more than an empty dogma.

Though Pardee was at this debate, he said nothing in Bretz’s defense.  He simply sat silently listening to the debates.  Perhaps if Pardee had spoken up earlier, things might have been different for Bretz.  But, as it was, the Uniformitarianism of the geology community was not going to even consider a catastrophic origin for the scabland formations.  After all, everybody knew that such geological features were perfectly consistent with slow formation over very long periods of time – even without considering the rather overwhelming fieldwork evidence that Bretz was presenting.  So, the opposition against Bretz was vigorously continued for many many years.

As Long as it’s Not Noah’s Flood

It was not until June 18, 1940 that things began to slowly change for Bretz.  At the American Association for the Advancement of Science in Seattle Washington, many papers were presented in a session entitled, Quaternary Geology of the Pacific, which strongly supported a non-catastrophic origin for the channeled scablands.  A post-meeting field trip was also organized during which Richard Foster Flint of Yale University proposed to demonstrate the evidence for the non-cataclysmic model.  Bretz was invited to attend both the meetings as well as the field trip, but he refused.  Perhaps he was just tired of being constantly held up to public ridicule after so many years?  In any case, Flint gave a fine synopsis of his complex argument of proglacial outwash along with stream aggradation and incision.  Flint boldly proposed that the surface form of the scabland flood bars was that of “non-paired stream-cut terraces in various states of dissection.”  E. T. Hodge followed with his scenario of involving glacial erosion associated with complex damming and diversions by river ice.  I. S. Allison then countered Flint just a bit by comparing Flint’s “fill” hypothesis with his own “ice-jam” uniformitarian hypothesis.  Finally, Pardee, the eight speaker of the session, spoke benignly about the “Ripple Marks in Glacial Lake Missoula.”  ²

In a low key manner Pardee described the huge “ripple marks” of Camas Prairie in northwestern Montana, with heights of up to 15 meters and spacings of as much as 150 meters, as well as his old theory that Lake Missoula was the source of the water that obviously created the unusual current beds found in the Montana prairie region.  He went on to suggest that about 2,000 km³ of water were held in the lake and that the evidence showed that a glacial dam had once blocked off the mouth of this lake.   He presented convincing evidence, to include severely scoured constrictions in the lake basin, huge bars of current-transported debris, and giant current ripple marks, which all strongly suggested that the ice dam had been breached in a very dramatic fashion.^2,3,5,6 Pardee went on to propose that the way this occurred was that the ice dam had blocked the water until the water became deep enough to lift up the ice dam and allow the blocked water to rush out with almost unimaginable force so that the lake was completely emptied within just 48 hours.  He suggested that the lobe of the Cordilleran Glacier was the actual plug or dam that blocked the Clark Fork River.  This ice dam caused the formation of Lake Missoula (4,150 feet above sea level) to reach a depth of about 2,000 feet over some 3,000 square miles.⁵ When the ice dam failed, 500 cubic miles of water rushed out of Lake Missoula at 50 to 60 miles per hour (or 9.46 cubic miles per hour), which translates into a 2,000 foot wall of water smashing with Herculean force all the way to the pacific ocean.⁴

Bretz Vindicated

Today it is believed that this huge flood of water rushed across Idaho’s northern Rathdrum Prairie and into eastern Washington where it divided into three huge flows, each up to 600 feet deep traveling at 45 miles per hour. ⁵ To understand a bit of this magnitude, this flow was ten times more massive than the flow of all the rivers in the entire world today.  As this flood raged across the Spokane Valley and out across the loess-covered basalt plateau, it carved out the 20-mile-wide Cheney-Palouse Tract, the 14-mile-wide Crab Creak Channel, and the 50-mile-long Grand Coulee as well as numerous cross or “braded” channels.  When blocked by Horse Heaven Hills on the west and the Blue Mountains to the south, the water raced to Walula Gap where the Columbia River heads west to the Pacific Ocean.  Since this gap was too narrow to allow the massive flood to flow through fast enough, the flood waters reversed themselves up the Snake River all the way past Lewiston, Idaho.  Eventually however, the water drained down to the Pacific and flooded Oregon’s Willamette Valley along the way.  During this time, Portland would have been under some 400 feet of water.⁵

Of course, Pardee’s evidence for the origin of massive amounts of flood waters was just what Bretz needed.  This evidence was just enough proof for Bretz to confirm the source for and cause of the watery cataclysm that he knew must be there somewhere.  The rest all fell into place since all the information to back up the effects of such a cataclysm had already been ready and waiting for many years.  Interestingly enough though, Pardee did not himself state the obvious connection of the Lake Missoula features to the Channeled Scabland features of Washington State. Some have suggested that he generously left that point for Bretz to make.²

In 1952 Bretz made yet another field trip to the scablands and returned with even more evidence to include detailed maps, aerial photographs, and sedimentological information.  In his subsequent 1956 paper, Bretz concluded that the most convincing evidence for a cataclysmic flood proved to be the presence of giant current ripples on bar surfaces.  These ripples clearly showed that bars up to 30 meters high were completely inundated by phenomenal flows of water.  Numerous examples of giant current ripples were found on the same bars that Flint had interpreted as normal river terraces.  As it turns out, Pardee’s recognition of the giant current ripples of Lake Missoula was followed by Bretz’s documentation of 15 more scabland ripple fields and then by Baker’s and Nummedal’s identification of 100 more rippled areas.  Such features could only have been produced by the flow of very deep water at velocities of truly enormous catastrophic proportions.  This was the beginning of early acceptance and painful recognition of the validity of Bretz’s position by geologists.²

Bretz’s remarkable work was built painstakingly over many years, but he had to fight great opposition for many decades for its final acceptance.  Finally, in 1979, the geological establishment publicly acknowledged Bretz’s work by awarding him the prestigious Penrose Medal – the most prestigious honor in the field of geology.³ Bretz was in his late 90s, and had been holding the line for more than 50 years before finally realizing general acceptance of his “insane” catastrophic model for the formation of the Channeled Scablands of eastern Washington State.

References

1. Allen, J. E., Burns, M., Sargent, S. C., Cataclysms on The Columbia, Timber Press, (1986),Samuel Strok book review for Geology 103 at Bellevue Community College – Winter, 2003 (http://scidiv.bcc.ctc.edu/rv/103/reviews/docs/Strok.ncl )
2. Baker, V., Joseph Thomas Pardee and the Spokane Flood Controversy, GSA Today, 5:(9), September 1995 (http://gsahist.org/gsat2/pardee.htm )
3. Helfferich, C., Boulders, Braids, and J Harlen Bretz, Alaska Science Forum, Article #1160, November 17, 1993 ( http://www.gi.alaska.edu/ScienceForum/ASF11/1160.html )
4. Spokane Astronomical Society, 1998 (http://www.webmaker-nw.com/bustomars/mars-dry-falls-1.html )
5. Kids Cosmos, 2001 (http://www.kidscosmos.org/kid-stuff/mars-trip-scablands.html )
6. Newman, J., Missoula Floods, Oregon Field Guide, Episode 1001, 2002-2004 (http://www.opb.org/programs/ofg/episodes/1001/missoula/index.php )

Empirical evidence of catastrop. geology: Case 2

Mount Saint Helens is an active volcano in Washington State.  A series of eruptions began in 1980 when a large landslide and powerful explosive eruption created a large crater, and ended 6 years later after more than a dozen extrusions of lava built a dome in the crater. Larger, longer lasting eruptions appear to have occurred in the past and are likely to occur in the future. Although the volcano seems to have returned to a period of quiet, scientists closely monitor Mount St. Helens for signs of renewed activity.

The first sign of activity at Mount St. Helens was a series of small earthquakes that began on March 16 1980. After hundreds of additional earthquakes, a steam explosion on March 27 blasted a crater through the volcano's ice capped summit. Within a week the crater had grown to about 1,300 feet in diameter and two giant crack systems crossed the entire summit area. By May 17, more than 10,000 earthquakes had shaken the volcano and the north flank had grown outward at least 450 feet to form a noticeable bulge. Such dramatic deformation of the volcano was strong evidence that molten rock (magma) had risen high into the volcano.

On May 18, 1980 at 8:32 a.m., a magnitude 5.1 earthquake caused the volcano's bulge and summit to break away in a huge landslide - the largest in recorded history. The landslide depressurized the volcano's magma system, triggering powerful explosions that ripped through the sliding debris. Rocks, ash, volcanic gas, and steam were blasted upward and outward to the north. This lateral blast of hot material accelerated to at least 300 miles per hour, then slowed as the rocks and ash fell to the ground and spread away from the volcano; several people escaping the blast on its western edge were able to keep ahead of the advancing cloud by driving 65 to 100 miles an hour! The blast cloud traveled as far as 17 miles northward from the volcano and the landslide traveled about 14 miles west, down the North Fork Toutle River.

The lateral blast produced a column of ash and gas (eruption column) that rose more than 15 miles into the atmosphere in only 15 minutes. Less than an hour later, a second eruption column formed as magma erupted explosively from the new crater. Then, beginning just after noon, swift avalanches of hot ash, pumice, and gas (pyroclastic flows) poured out of the crater at 50 to 80 miles per hour and spread as far as 5 miles to the north. Based on the eruption rate of these pyroclastic flows, scientists estimate that the eruption reached its peak between 3:00 and 5:00 p.m. Over the course of the day, prevailing winds blew 520 million tons of ash eastward across the United States and caused complete darkness in Spokane, Washington, 250 miles from the volcano.

During the first few minutes of this eruption, parts of the blast cloud surged over the newly formed crater rim and down the west, south, and east sides of the volcano. The hot rocks and gas quickly melted some of the snow and ice capping the volcano, creating surges of water that eroded and mixed with loose rock debris to form volcanic mudflows (lahars). Several lahars poured down the volcano into river valleys, ripping trees from their roots and destroying roads and bridges. The largest and most destructive lahar was formed by water seeping from inside the huge landslide deposit through most of the day. This sustained flow of water eroded material from both the landslide deposit and channel of the North Fork Toutle River. The lahar increased in size as it traveled downstream, destroying bridges and homes and eventually flowing into the Cowlitz River. It reached its maximum size at about midnight in the Cowlitz River about 50 miles downstream from the volcano.

A 320 ft thick deposit was laid at the bottom of Spirit Lake due to the eruption and the flooding caused by the main rockslide debris that displaced the water, creating huge waves that scoured the basin and created the thick deposit (Meyer, W. and P. J. Carpenter. 1983. Filling of Spirit Lake, Washington. U.S. Geological Survey Open File Report 82-771).

Stratified layers up to 400 feet thick formed as a result of landslides, pyroclastic flows, , etc., during the Mt. St. Helens eruption. Fine laminae from only a millimeter thick to layers more than a meter high formed in just a few seconds each. A deposit more than 25  feet in thickness, and containing upwards of 100 thin layers accumulated in just one day on June 12, 1980.

Rapid erosion was caused by mudflows, landslides, and waves of water. On March 19, 1982, a small eruption melted the snow that had accumulated in the crater over the winter, and a resulting hot mud flow carved a system of canyons up to 140 feet deep and 17 miles long in a single day. The deepest of the canyons has affectionately been called the "Little Grand Canyon" of the Toutle River. The small creek that now flows through the bottom would appear to have carved this canyon over a great length of time, but this unique event has demonstrated that rapid catastrophic processes were instead responsible. The picture to the right above shows a 100-ft deep canyon carved into the pumice plain by August 1984.  I think the photo is by Steven A. Austin (geologist).


One prominent fast erosion feature is Loowit Falls. Loowit Falls is one of two major waterfalls that occurs along the the north flank of Mount St. Helens. When the mountain erupted in 1980, it created a catchment basin in the resulting crater. Beginning in the winter of 1980-1981 the Crater Glacier began to form and is currently the largest glacier on Mount St. Helens, as well as the youngest and fastest growing glacier in the United States. Once the glacier began growing, it also began melting and its meltwater has channeled largely into what is now Loowit Creek. Mt Saint Helens receives 183 inches of rain and snow each year (wet climate). As Loowit Creek intersects the blasted out north slope of the mountain it carved out the rugged Loowit Canyon, with Loowit Falls found at its head. National Geographic in May 2000 stated "Spilling from the crater, Loowit Falls reshapes the north slope of the volcano. You would expect a hardrock canyon to be thousands even 100's of thousands of years old, but this was cut in less than a decade.  Loowit Canyon formed in a matter of about 15 years and over that time Loowit Falls has constantly changed in appearance. When surveyed in 2011 the waterfall cut stood 186 feet tall. Imagery available in Google Earth shows the brink of Loowit Falls has retreated upstream by 40 feet since 1994. Some time between 2006 and 2009 a smaller but significant lower tier of the falls was buried almost entirely by a landslide and over the years there has been an increase in rockfall debris collecting at the base of Loowit Falls. Loowit Canyon is incredibly unstable and the height and appearance of the falls will continue to change in the coming decades. The falls have existed only since 1981 and with the rapid advance of the Crater Glacier there is a possibility that the stream may either be diverted or the glacier may even cover the falls and spill into Loowit Canyon at some point. 

Loowit Canyon is over 100 feet deep and was gouged in part through old hard volcanic rock (andesite).  This rock was not eroded over millions of years, mudflows eroded the canyon in just a few months in 1980.

Pumice (relatively porous, low density, lightweight rock formed from volcanic flow) is relatively more erodible than other rock types, but is not soil, so the erosion rate from recent water flow and the catastrophic erosion from the mudflows (lahars) is still impressive.