The Las Vegas Review Journal's Sunday edition has a front page article explaining a moraine has been found in nearby Kyle Canyon, in the Spring Range about 50 miles from Las Vegas. It invites members of the public to a guided tour the next Saturday to see for themselves. I did. I was not convinced.

But before you are prejudiced by my ramblings, read the newspaper article. I will illustrate it with my own pictures, set off rom the text with lines like this one:

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Sunday, June 09, 2002
Copyright © Las Vegas Review-Journal
Scientists see signs of glacier in mountains

Ice sheet may have covered big part of Mount Charleston 20,000 years ago
By KEITH ROGERS
REVIEW-JOURNAL

It was the odd-shaped hump along a wash on Mount Charleston that got Nick Saines to wondering. What if the rock that's now a favorite skiing and hiking spot for Las Vegans was once a massive glacier?

"There's something unusual about it, just by its shape," he said, recalling his thoughts 10 years ago on a hike when he first came across the feature.

Although it might be hard to imagine an ice sheet hundreds of feet thick in the desert climes of Southern Nevada, Saines and a couple of colleagues now think they have uncovered enough evidence that a glacier crowded the limestone face of Mount Charleston, 45 miles northwest of Las Vegas.

A glacier could have existed during the end of the Ice Age about 20,000 years ago, they believe.

Scientists over the decades have wondered about the possibility that a glacier, perhaps several of them during the Ice Age going back 1.6 million years, covered part of the mountaintop, the centerpiece of the Spring Mountain range.

A scientific paper co-authored by Saines, University of Nevada, Las Vegas geoscience professor Rik Orndorff and geologist John Van Hoesen spells out the evidence. The paper is undergoing review for the journal Quaternary Research.

They say the proof lies in what's called a moraine, the rocks, boulders and sediments that remained on the surface as the alpine ice sheet slowly melted. That's where Saines ran across the hump more than a mile east of Mount Charleston's Big Falls.

"This deposit bears the hallmark of features of a glacial provenance and indicates that the Spring Mountains were the southernmost glaciated range in the Great Basin," the three wrote in a summary of their paper.

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Nick Saines explains the moraine's features to the public tour that was held the Saturday after the newspaper article. The feature of discusion here is the water-flow deposit left on the lee side of the dam this moraine created across Kyle Canyon. Water flowed over the dam, leaving a deposit with well-sorted characteristics on top of the south side of the dam, downstrem, until the dam broke, and then the dam was washed away except for this remnant.

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On a hike to the moraine Wednesday, Orndorff and Saines pointed to rocks they said had been scratched and rounded from movement of a thick sheet of ice.

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There is no doubt that this rock was scratched as it moved across other rock while captured in the ice of a downward sliding glacier. During Saines' explanation of the origin of this rock I asked him if he had entertained an alternate hypothesis, one I was trying to develop while listening, with the help of a geomorphologist I knew on the tour. The alternatibve explanation was that this rock was created very high but brought down here with this material by a catastrophic (on a small scale) flood of material off the higher mountains? The geomorphologist I consulted on the tour thought a debris-flow event could also result in an unsorted deposit like this with samples of rock from higher elevations. Saines answered that we should always be open to alternative hypotheses and look for evidence to support or contradict them. Hence this website. I have pretty good indications, from web-based literature describing other debris-flow incidents, that the alternate hypothesis I suggested with the help of my geomorphologist friend on the tour has merit.

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Flanking a wash that runs through Kyle Canyon, erosion from past floods cut through the moraine, offering a cross-sectional view of it.

"We think this deposit is a piece of a deposit that extended across the valley," Orndorff said.

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This is the alleged remnant of a moraine that formed a dam across the bottom of Kyle Canyon, left by a glacier that terminated at this point. It is indeed made of poorly sorted material including boulders as well as very fine materials, characteristic of a moraine. Material left by the water of the overflow on the top left (south) of the remnant, by contrast, is sorted. [My acquaintance and coworker who was on this tour, and is a real geomorphologist, disagrees on this fanciful interpretation and suggests it is not all that well sorted and looks more like colluvium, a gravity-driven, rather than water-driven, rearrangement of material off the top of the pile of deposited material.] A moraine is made of material left as a glacier recedes, meaning it is a pile of rock and finer material that has been scooped up by the glacial (like a huge earth-mover with a blade of) ice as it moves roughly and heavily downhill over the terrain.

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Saines, project manager for SCS Engineers in Las Vegas who once charted glacier deposits for the Vermont Geological Survey, has come across unusual rock features before, including the Great Unconformity. Now a roadside geological park at the foot of Frenchman Mountain on the Las Vegas Valley's east rim, the Great Unconformity is among a few places in the world where geologists can observe an outcropping where red granite formed by heat and pressure and sandstone deposited by a shallow sea lie next to each other. It represents a period of about 1.2 billion years that appear to be missing between the rock layers.

At Mount Charleston, Saines said, thousands of hikers probably have walked past the moraine without realizing they were looking at a clue to Southern Nevada's distant past.

"Let's go back into the Ice Age and back in time," Saines said, heading toward the spot at an elevation of 8,330 feet. "Imagine a sheet of ice hundreds of feet high."

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This is a look to the west from the location of the postulated moraine. The newspaper article's interviewees are asking us to imagine hundreds of feet of ice lying in this valley all the way to the tops of the mountains in the background. My alternative view is that there were indeed glaciers, ones that terminated somewhat below where the present, small snowfields still exist that are visible in this photo.

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During that period, he said, the climate must have been much wetter than today. After all, it takes abundant snowfall that accumulates winter after winter, turning the bottom layers into a solid ice sheet that begins moving under the force of its own weight. The 4-plus inches of precipitation that typically fall on the Las Vegas Valley now wouldn't be enough to sustain a buildup of snow in the Spring Mountains.

But back then, snowpacks lasted long enough to create a glacier. Caught in this glacier were pieces of bedrock that became rounded and polished by its moving ice and scratched by other rocks and gravel crashing into it. As the glacier melted and receded, rocks and sediment were left piled in its path.

Besides the different terrain, animals now extinct roamed the landscape at lower elevations, including creatures such as ground sloths, mammoths, saber-toothed tigers, ancient camels and wolves.

If the alpine glacier existed 20,000 years ago, from that point in time it would have been some 10,600 years until Nevada's oldest known human inhabitant, Spirit Cave Man, walked in what is now the state, based on the mummified remains of the man found in a cave east of Fallon in 1940.

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It is of interest, to me, that Spirit Cave man lived at the end of the last ice Age, and fished in a marshland left by Lake Lahontan's retreat. There is an excellent publication on Spirit Cave man, showing he is so well preserved he is actually called a mummy, with hair, flesh, and his last meal all identifiable. The publication is mentioned on the Nevada State Museum website, on that page is a link to an artist's drawing of the person in his burial position:

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Evidence of animals that lived near the end of the Ice Age have been found closer to the Las Vegas Valley. About 45 miles southwest of the valley at Devil Peak, three women exploring a cave in 1990 found the 9-foot-long skeleton of a Shasta ground sloth. Scientists believe this creature had pale yellow or brown-colored hair covered with green algae. The sloths, so-named for the first such sloth fossils found in 1909 in a cave at Mount Shasta, Calif., had long, sharp claws to defend themselves against large prehistoric cats.

Orndorff has spent much of his career as a geomorphologist studying the interaction between glaciers and climate. Some of his work has focused on so-called "pluvial lakes," those that changed in size as the climate changed. A long time ago, one of those lakes, Lake Lahontan, between Carson City and Fallon, was bigger than Lake Erie, he said.

One of his students, Kuwanna Dyer, a geology major at UNLV, will search for more evidence of glaciers on Mount Charleston, hoping to document evidence left by several smaller ice sheets the scientists believe are depicted in aerial photographs.

Saturday, the Southwest Section of the Association of Engineering Geologists will hold a field trip to the moraine that is open to the public. The group plans to leave from the Mary Jane Falls parking area in Kyle Canyon at 10 a.m. for the hour-long hike.
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These last two pictures show the meeting place and the start of the public, guided tour the Saturday after the newspaper story ran. Pretty good turnout for a hot day in the valley. All the pictures on these pages came from that tour.

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This story (at the time this website was built), was located at:
http://www.lvrj.com/lvrj_home/2002/Jun-09-Sun-2002/news/18919295.html

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The next page amplifies my concerns about some of the newspaper article's explanations, the same concerns already mentioned in the figure-captions above. You get to that next page by going to the top of this page and hitting the "home" button, or simply hitting your previous key on your browser.