Archive for July 26th, 2009

The Final Quarry

July 26th, 2009

Black Hill, north of Ephraim, Utah. Research Day 12 (July 21).

Today was our last day collecting data in the Green River Formation, so we ended it by visiting one of the larger quarries in the area. Shortly after arriving at the quarry, though, Bill stumbled upon a baby rattlesnake, and it was angry, curled up and rattling under a small wackestone ledge. Bill couldn’t quite leave it alone the entire time we were at the quarry. This rattlesnake only added to the “wildlife” list that we saw in central Utah while hiking through the Green River Formation. It seemed like each day numerous Black Widow spiders were seen, and some of them were fairly large. In addition to rattlesnakes and Black Widows, we were treated to cottontail rabbits, deer, elk, ground squirrels, swarms of “Mormon crickets” (migratory grasshoppers), red harvester ants, and a rare fox sighting in the middle of one afternoon.

Phil turned out to be a "stratigraphic column machine", and here is completing a stratigraphic column through one portion of the largest quarry on Black Hill.

Phil turned out to be a "stratigraphic column machine", and here is completing a stratigraphic column through one portion of the largest quarry on Black Hill.

The Black Hill quarry proved interesting, because it was unlike its northerly counterpart on White Hill.  For example, the stromatolites here are much smaller than those that we observed on White Hill.  Our initial assumption is that the Black Hill quarry is stratigraphically younger than most of the quarries on White Hill.

The Black Hill quarry proved interesting, because it was unlike its northerly counterpart on White Hill. For example, the stromatolites here are much smaller than those that we observed on White Hill. Our initial assumption is that the Black Hill quarry is stratigraphically younger than most of the quarries on White Hill.

One feature that remained a constant within the Green River Formation was the presence of iron-rich layers that were used in correlation.  On Black Hill, these iron-rich layers were more numerous and sometimes thicker.

One feature that remained a constant within the Green River Formation was the presence of iron-rich layers that were used in correlation. On Black Hill, these iron-rich layers were more numerous and sometimes thicker.

More Tuff Mapping with the Trimble GPS

July 26th, 2009

Little Hill and Black Hill, north of Ephraim, Utah. Research Day 11 (July 20).

Today we set off with the same goal as we did on July 14 — mapping the large tuff bed with the GPS. So, it is the same procedure as last time, with Bill becoming a Human Antennae. This time, however, we are headed to the Little Hill / Black Hill cuesta complex, which is south of White Hill (where we mapped the tuff before). The weather was again beautiful today, with temperatures in the afternoon fluctuating between 99-102 F…a simply perfect day for walking out the tuff bed all day long.

View to the S of the Black Hill cuesta, with the Wasatch Plateau rising in the background.  Black Hill is geographically larger than White Hill, but it is only slightly higher, with an elevation of 6,402 ft.  Black Hill's perfect dip slope of the Green River Formation is shown off in this photo.

View to the S of the Black Hill cuesta, with the Wasatch Plateau rising in the background. Black Hill is geographically larger than White Hill, but it is only slightly higher, with an elevation of 6,402 ft. Black Hill's perfect dip slope of the Green River Formation is shown off in this photo.

Walking the tuff bed is not difficult at Black Hill, because the tuff was well exposed.  In this photo the resistant tuff bed is exposed along the Green River slopewash.

Walking the tuff bed is not difficult at Black Hill, because the tuff was well exposed. In this photo the resistant tuff bed is exposed along the Green River slopewash.

The view from the top of Black Hill was amazing, and it provided a perfect location to take a picture of White Hill, which lies immediately to the N.

The view from the top of Black Hill was amazing, and it provided a perfect location to take a picture of White Hill, which lies immediately to the N.

From the top of Black Hill, you can easily see the large landslide to the E.  The landslide originated toward the top of the Wasatch Plateau and spread into the adjacent Cane Valley.

From the top of Black Hill, you can easily see the large landslide to the E. The landslide originated toward the top of the Wasatch Plateau and spread into the adjacent Cane Valley.

Gal Hill: Hitting the Tuff Jackpot

July 26th, 2009

Ephraim, Utah. Research Day 10 (July 19).

Just a few blocks from where we are staying is a tame elk farm, whose southern border is a very small hill called Gal Hill. As soon as we drove by the hill, we knew that we had hit the jackpot. Most all other exposures of the uppermost large tuff in the Green River are covered by slopewash, but Gal Hill exposes the stratigraphy both below and above the large tuff bed that Bill was mapping in the region with GPS. We decided to spend the greater part of a day at Gal Hill, hoping that it might provide clues to changing lake conditions and facies migrations due to the influx of the tuff.

Scenic overview of Gal Hill, a small hill on edge of Ephraim.  In the center of the photo, the larger ledge is the resistant tuff.

Scenic overview of Gal Hill, a small hill on edge of Ephraim. In the center of the photo, the larger ledge is the resistant tuff.

Closer view of the tuff at Gal Hill.  At this locality, the tuff is much more planar that at other localities, and it appears to maintain a constant thickness throughout.  Immediately below the tuff bed is a zone of silicified stromatolites, some of which have been slightly deformed.

Closer view of the tuff at Gal Hill. At this locality, the tuff is much more planar that at other localities, and it appears to maintain a constant thickness throughout. Immediately below the tuff bed is a zone of silicified stromatolites, some of which have been slightly deformed.

Above the tuff bed, the silica content of the Green River Formation seems to increase, with a variety of chert lenses, concretions, and thin chert beds of various colors.

Above the tuff bed, the silica content of the Green River Formation seems to increase, with a variety of chert lenses, concretions, and thin chert beds of various colors.

At the top of Gal Hill, the Green River Formation has been bent both downward and upward and fractured, separated by vertical chert lenses.

At the top of Gal Hill, the Green River Formation has been bent both downward and upward and fractured, separated by vertical chert lenses.

Regional Reconnaissance for more Green River

July 26th, 2009

Manti, Salina, and Gunnison, Utah. Research Days 8-9 (July 17-18).

After finishing White Hill yesterday, we decided to spend part of the day (July 17) collecting more data and part of the day doing field reconnaissance for additional exposures of the Green River Formation that might help us with our research.

In the morning, we traveled to Manti, Utah, which is approximately 10 miles south of Ephraim. Manti is home to the Manti Temple, one of the Mormon temples in Utah. Interesting to geologists, though, is the fact that the Manti Temple is built out of the Green River Formation, and there is a large quarry in the hill immediately east of the Temple. “Temple Hill” provided a good exposure of the more massive quarry bed.

View of the quarry at Temple Hill.  The more massive quarry bed is approximately 8 ft thick here, and it is overlain by a succession of lime mudstones, wackestones, claystones, and shales.

View of the quarry at Temple Hill. The more massive quarry bed is approximately 8 ft thick here, and it is overlain by a succession of lime mudstones, wackestones, claystones, and shales.

Phil and Bill are working their way through Temple Hill's stratigraphy.

Phil and Bill are working their way through Temple Hill's stratigraphy.

After our adventures on Temple Hill, we headed south for Salina, Utah, home of Soldier Canyon.  This scenic view of Soldier Canyon shows the thickness of the Green River Formation in this area of Utah.  Surprisingly, though, we couldn't find as many tuff beds in this succession as we did farther north near Ephraim, Utah.

After our adventures on Temple Hill, we headed south for Salina, Utah, home of Soldier Canyon. This scenic view of Soldier Canyon shows the thickness of the Green River Formation in this area of Utah. Surprisingly, though, we couldn't find as many tuff beds in this succession as we did farther north near Ephraim, Utah.

This is a view of the Green River at the mouth of Twist Gulch, a small canyon just to the N of Soldier Canyon.  After a quick visit here, we decided to travel northwards toward Gunnison, Utah, to visit the Chalk Hills.

This is a view of the Green River at the mouth of Twist Gulch, a small canyon just to the N of Soldier Canyon. After a quick visit here, we decided to travel northwards toward Gunnison, Utah, to visit the Chalk Hills.

After a reconnaissance to the Chalk Hills one day, we decided to come back the next day to investigate the stratigraphy and possible presence of tuff beds.  The Chalk Hills were quite interesting and possibly could form the basis for another Wooster I.S. in upcoming field seasons.

After a reconnaissance to the Chalk Hills one day, we decided to come back the next day to investigate the stratigraphy and possible presence of tuff beds. The Chalk Hills were quite interesting and possibly could form the basis for another Wooster I.S. in upcoming field seasons.

The view from the base of the Upper Member of the Green River at the Chalk Hills was spetacular, even if the climb up and down was a little treacherous!

The view from the base of the Upper Member of the Green River at the Chalk Hills was spetacular, even if the climb up and down was a little treacherous!

The Behemoth Stratigraphic Column

July 26th, 2009

White Hill, north of Ephraim, Utah. Research Day 7 (July 16).

We returned to White Hill for our last day of work at this location. Today’s task was to measure a 362 ft stratigraphic column through part of the Lower Member and all of the exposed Upper Member of the Green River Formation. That’s a lot of limestone!! This was an important day, because this stratigraphic column will allow us to correlated all of our other stratigraphic columns by finding numerous other tuff beds in the Lower and Upper Members.

View of a portion of our 362 ft stratigraphic column of White Hill.

View of a portion of our 362 ft stratigraphic column of White Hill.

Phil and Bill, nearly at the top of White Hill, are discussing their measuring strategy.

Phil and Bill, nearly at the top of White Hill, are discussing their measuring strategy.

The guys are excited that they've finished their stratigraphic column at White Hill.  In the background are several other features:  Black Hill is the smaller cuesta just behind their heads, while the Wasatch Plateau rises to its 10,000 ft elevation.

The guys are excited that they've finished their stratigraphic column at White Hill. In the background are several other features: Black Hill is the smaller cuesta just behind their heads, while the Wasatch Plateau rises to its 10,000 ft elevation.

The Pavant and Canyon Ranges: Windows into the Sevier Orogeny

July 26th, 2009

Pavant and Canyon Ranges, Utah. Research Day 6 (July 15).

The old slogan for geologists is that the best geologists are the ones who have seen the most rocks. So, today, instead of spending time in the Green River Formation, we joined Ohio State’s field camp on their yearly visit to the Pavant and Canyon Ranges.

Because of my affiliation with OSU’s field camp through the years (this year I helped teach the first half of field camp), the Wooster Crew stayed in the same apartment complex in Ephraim as the OSU crowd. Each day, we were able to interact with other professors, TAs, and students. So, when we found out the day of their Pavant and Canyon Range trip, we decided to tag along. For their Junior I.S., both Phil and Bill read literature on the Sevier Orogeny in Utah, and today’s visit to these ranges enabled us to first-hand witness some of the figures published in this literature that we had read earlier in the spring.
The Pavant Range and the Canyon Range expose some of the large thrust sheets associated with the Sevier Orogeny, along with some additional small-scale faulting and folding due to the regional compression.

We welcomed the trip to the Pavant Range.  The photo above is a typical stream dissecting the canyon where the Pavant Thrust is exposed.  Temperatures in the Canyon were slightly cooler than what we had grown accustomed to back in Ephraim, where we had been working in 99 F temps for the past few days.  Everyone was tempted to wade in these cool streams during our lunch break.

We welcomed the trip to the Pavant Range. The photo above is a typical stream dissecting the canyon where the Pavant Thrust is exposed. Temperatures in the Canyon were slightly cooler than what we had grown accustomed to back in Ephraim, where we had been working in 99 F temps for the past few days. Everyone was tempted to wade in these cool streams during our lunch break.

Bill and Phil are posing in front of one of the small folds in phyllites associated with compression events in the Pavant Range.

Bill and Phil are posing in front of one of the small folds in phyllites associated with compression events in the Pavant Range.

The Wooster and OSU gang looks at some of the rocks exposed in the Pavant Range.

The Wooster and OSU gang looks at some of the rocks exposed in the Pavant Range.

This is another spectacular fold in the Pavant Range that shows several folding generations.

This is another spectacular fold in the Pavant Range that shows several folding generations.

Wooster makes it to the Canyon Range Thrust overlook!  Behind Bill is the famous exposure of the Canyon Range Thrust, where synorogenic conglomerates were deposited at the front of the thrust sheet.  The exposure is located in Oak Creek Canyon in the Canyon Range.

Wooster makes it to the Canyon Range Thrust overlook! Behind Bill is the famous exposure of the Canyon Range Thrust, where synorogenic conglomerates were deposited at the front of the thrust sheet. The exposure is located in Oak Creek Canyon in the Canyon Range.

Bill, The Human Antennae (…or our own Statue of Liberty)

July 26th, 2009

White Hill, north of Ephraim, Utah. Research Day 5 (July 14).

We devoted most of today to mapping the largest and most continuous tuff in the Green River Formation. Our goal was to walk completely around White Hill while mapping the tuff with a Trimble GeoXH Handheld. This was part of Bill’s project, so he was in charge of GPS data collecting, while Phil was the “point man” (i.e., he walked ahead of Bill, all the while trying to keep on top of the tuff even when it was in nearly covered intervals). Bill used an antennae with the handheld GPS; however, the only catch to our plan was that we did not have an antennae rod. So, Bill walked around White Hill with GPS and stylus in one hand and the antennae in the other, striking a pose like the Statue of Liberty. This enabled us to get sub-2 ft resolution, which is good data for his mapping project.

Bill is showing off his technique of taking GPS readings in one hand, while becoming the "Human Antennnae" with the other.
We started mapping the tuff at road level (~5,620 ft elevation) and ended the day at the top of White Hill (~6,381 ft elevation).  Due to the dip of the beds, it was a slow, steady climb throughout the day.  However, the view at the top of White Hill is gorgeous.  For example, the photo above is a view to the W of the Gunnison Plateau (San Pitch Mountains).  On a clear day in central Utah, you can see for miles.

We started mapping the tuff at road level (~5,620 ft elevation) and ended the day at the top of White Hill (~6,381 ft elevation). Due to the dip of the beds, it was a slow, steady climb throughout the day. However, the view at the top of White Hill is gorgeous. For example, the photo above is a view to the W of the Gunnison Plateau (San Pitch Mountains). On a clear day in central Utah, you can see for miles.

Working in the Quarries

July 26th, 2009

White Hill, north of Ephraim, Utah. Research Days 3-4 (July 12-13).

In the Green River Formation exposed in the Sanpete Valley, there are numerous large and small quarries that provide excellent exposures of the unit. In some places, the Green River contains massive bedding — perfect as quarry stone for buildings in the area.

Over the course of these next few days, we measured a 175 ft stratigraphic section through the Upper Member of the Green River Formation in one quarry, but then moved on to measure additional stratigraphic sections through three additional quarries. By the end of the two days, Phil and Bill were becoming experts at measuring sections.

Here is a scenic view of a portion of White Hill that contains two quarries.  These quarries, although small, provided evidence of the shoreline of the Green River lake in this area.

Here is a scenic view of a portion of White Hill that contains two quarries. These quarries, although small, provided evidence of the shoreline of the Green River lake in this area.

Bill is at the edge of one of the small quarries, trying to find both stromatolite beds and mudcracks within the Green River.

Bill is at the edge of one of the small quarries, trying to find both stromatolite beds and mudcracks within the Green River.

Some of the stromatolites in the Green River are only a few inches in height; others -- like the one pictured above -- are quite large and easier to recognize.

Some of the stromatolites in the Green River are only a few inches in height; others -- like the one pictured above -- are quite large and easier to recognize.

View of the top of one of the larger stromatolites (pencil for scale).  For some of the loose stromatolites, we could actually peal back the individual layers to see the textural features.

View of the top of one of the larger stromatolites (pencil for scale). For some of the loose stromatolites, we could actually peal back the individual layers to see the textural features.

View of the underside of the elusive mudcracks that we tried to find in situ.  Mudcracked slabs were abundant as float, but they proved to be difficult to find in place due to the platy bedding in the quarries.

View of the underside of the elusive mudcracks that we tried to find in situ. Mudcracked slabs were abundant as float, but they proved to be difficult to find in place due to the platy bedding in the quarries.

Here's a view of one of the larger quarries on White Hill.  Bill and Phil are in the photo for scale.

Here's a view of one of the larger quarries on White Hill. Bill and Phil are in the photo for scale.

The guys are busy trying to "mine out" a thin green tuff bed within the limestones of the Green River.  As Phil put it, finding this green tuff was "money", because it will help us correlate this quarry to other stratigraphic sections in the area.

The guys are busy trying to "mine out" a thin green tuff bed within the limestones of the Green River. As Phil put it, finding this green tuff was "money", because it will help us correlate this quarry to other stratigraphic sections in the area.

We ended the days working in the quarries with a beautiful double rainbow back at the Ephraim apartments in the evening, shortly after dinner.

We ended the days working in the quarries with a beautiful double rainbow back at the Ephraim apartments in the evening, shortly after dinner.

Cedar Adventure to Excursion Ridge

July 26th, 2009

Intro
Kelly and Colin standing on one of the lower ridges near Excursion Ridge.

Today we hiked up Excursion Ridge to collect yellow-cedar samples for Colin’s I.S. On the trek up to the cedar stand, we hiked up the road and passed the dam used for the Falls Creek hydroelectric project. They plan to harness the power of Falls Creek to provide summer power to Gustavus.

Dam
The dam on Falls Creek. They regulate the flow of the creek to provide power while still allowing enough water for the fish. It is a controversial project due to questions on power provided versus environmental impact.

The day was uncharacteristically beautiful, and the expedition turned out to be fruitful. We collected samples from 43 yellow-cedars, with at least two samples from each tree. While at the site, we also collected samples from lodgepole pines dominating the meadow to satisfy our scientific curiosity. All in all a very productive day.

Coring
Colin places a core into the straw after extracting it from the tree.

Meadow
The meadow located at the top of the sample site, dominated by lodgepole pines and covered by arctic cotton.

Lunch
Dr. Wiles and Kelly walk through the meadow to the lunch site.

Introducing Ourselves to the Green River Formation

July 26th, 2009

Ephraim, Utah.  Research Day 2 (July 11).

Field work began on one of the cuestas north of Ephraim, commonly called White Hill. This particular cuesta rises to a height of 6,381 ft in elevation — a good climb for our first day out in the field in the dry Utah heat. We used our first official day as a day of reconnaissance, examining several quarries located on White Hill and also examining a rather large tuff exposed around the cuesta. Phil is planning on conducting research primarily in the quarries in an attempt to stratigraphically correlate the Green River Formation locally, while Bill is going to research the multiple tuff beds present in the formation.

Below, Phil (left) and Bill (right) are eager to begin work in one of the quarries located on White Hill.  Although only 8:00 am, the morning temperatures are in the mid-70s, but they will rise to the mid-90s by the afternoon.

Below, Phil (left) and Bill (right) are eager to begin work in one of the quarries located on White Hill. Although only 8:00 am, the morning temperatures are in the mid-70s, but they will rise to the mid-90s by the afternoon.

The guys are hard at work examining the various lithologies, which range from lime mudstones to boundstones and everything in between.

The guys are hard at work examining the various lithologies, which range from lime mudstones to boundstones and everything in between.

View of the largest tuff that was erupted into the Green River lake.  In places, the tuff is up to 4 ft thick and represents a moment in geologic time.

View of the largest tuff that was erupted into the Green River lake. In places, the tuff is up to 4 ft thick and represents a moment in geologic time.

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