Running the Green River
a photo-diary by Jason Lennane
Geo River Trip Class (Geo 466)
New Mexico Tech, June 2001
Arriving at Melanie’s house around 7:15 I found her still packing and getting ready for the trip, so I didn’t feel too bad about being late. While packing the car she informed me that we would be picking up Bonnie and possibly even a fourth passenger. Therefore it was necessary to make some room in the trunk of the car.
(A quick note about packing for a river trip: Each person was assigned a 6400 cubic inch dry bag and a smaller dry bag. Naturally we weren’t expected to utilize the entire bag. However, when packing one discovers that given all that space it is hard not to fill it up. If the bag doesn’t look full you must have forgotten something, therefore it is necessary to put more stuff in the bag.)
Upon picking up Bonnie we attempted to put three of these large dry bags in my trunk. Unfortunately they wouldn’t fit without an excessive amount of effort. So Melanie and I pounded our shoulders and elbows into the bag, giving an effort that most football players would have found impressive.
With the car packed, and ready to pop at the seams, we set out for our rendezvous with the rest of our party in Albuquerque. The hour-long drive is one I travel frequently and is particularly beautiful early in the morning. The sun was already getting high and beautifully lit up the Rio Grande valley.
Meeting our party at the rendezvous point, and taking on another passenger, Marty, who fortunately left her bag in another vehicle, we were set to make our way to Sand Wash on the Green River, in Utah. We set off to the north heading for the Four Corners area and eventually on to the Devils Highway, Hwy 666. This particular stretch of road is quite breathtaking, as we passed the Jemez Mountains as well as many other ranges and beautiful geologic features including several volcanic necks such as Shiprock.
We stopped and camped that night about 50 miles from the start at Sandwash. I brought two sleeping bags on the trip intending hopefully to use my lightweight fleece bag if it was to be warm enough. Of course that night I froze. It was far too cold for a fleece sleeping bag, and I barely slept at all. Naturally I decided not to use the fleece bag and left it behind. Every night following it was warm and would have been perfect for the fleece bag. But instead I had my trusty 10-degree bag in which I sweated my butt off.
The food committee was packing and preparing the food. The rest of the committees prepared the boats and other supplies. Dennis and myself took to pumping up the boats (a true test of endurance). The boats were then framed and packed. Obviously the first packing wasn’t so smooth, however we got the hang of it quickly.
After packing the boats we had a quick lunch of sandwiches and Pringles, and then we set off on the Green River. I was in the boat captained by Dennis, along with Martie and Melanie. The river was slow and a lot of paddling was needed. We only traveled about a mile before we stopped for our first geo hike.
Stop 1: Approaching the thick brush at the shore the hum got louder and louder. Upon hitting the shore I jumped out of the boat in order to tie it off. Instead of making a classic marine beach landing, my foot sunk in the mud down to my thigh. I was stuck. I eventually got my foot free and managed to dig out my flip-flop. I finally got my things together just as everyone was hiking into the thicket. As soon as I set foot into the brush I was overcome by mosquitoes, millions of mosquitoes. This would be the trend for the next two days.
Once we managed to chomp through the brush we came upon an oil shale, which Kent attempted to ignite. The shale consists of ostrocod fecal pellets and smells like petroleum when it is ignited. It was deposited in a possibly brackish lacustrine environment. Kent told us a story about a guy who built his fireplace out of this oilshale and burned down his home. Moral: Smell your shale before you use it.
We also crossed a terrace, which indicates a rapid period of uplift, causing the river to down cut. The entire area is dipping slightly to the north.
Stop 2: Mini Maude, possible location where the Powell expedition camped. It was a small fast moving stream entering the Green. Excellent example of how a river can move its bed load. This tiny stream moves fast enough to move a cobble sized bed load. We were playing in the stream and letting it carry us, when someone’s keys actually got lost in the stream. Against all odds Rhonda actually found the keys.
We paddled down stream for a few hours and pulled off at a sandbar where
we decided to camp. At first there were no mosquitoes and it was quite
relaxing. We set up camp and had a terrific spaghetti dinner with fresh
mushrooms and Italian sausage and homemade pasta. For dessert we had cheesecake.
Everything was delicious. After dinner I sat down around the fire and out
came the mosquitoes, which forced me into my tent. I slept wonderfully,
never waking until the next morning.
Stop 1: Sumner’s Amphitheater. We pulled of by a steep bank and
began to climb. On our way up we observed laminar stromatolites, which
were deposited by cyano bacteria. These were deposited in a mid-Tertiary
lacustrine system.
Stratigraphically above the laminar stromatolites both columnar, laminar
and dome stromatolites could be found together. Capping off the stromatolites
is a reef breccia. As we continued to climb up we saw a white marlstone
and a gray limestone that often weathered to a brown. The limestone consisted
of ooiltes, and fish scales were present as well. There was also a white
mudstone and shale. These are the three main lithologies of the Green River
Formation.
A major portion of the trip was the identification and uses of certain plants. At this stop we observed Shadsdale, Snake Weed, and Squaw Bush. Shadsdale is salty and has an affinity for alkaline soils. Snake Weed smells like turpentine. Squaw Bush, also known as the lemonade tree, was used by the Indians to make a drink, which supposedly tasted like lemonade.
As we continued to hike up, Kent pointed out a Rincon, which is a butte, left by an abandoned channel and then incised by the river. We also talked about the regularly space butraces, which are controlled by the regional joint system.
Stop 2: This was a quick stop to observe some petroglyphs. Afterwards we went for a swim.
Today we hit our first rapids; however, they were quite small and uneventful,
yet still good practice for what’s to come. That night we camped
at a mosquito infested bank above the river. For dinner we had salmon,
corn on the cob and cheesy potatoes. The grub is great; I don’t eat
this well at home. After dinner I quickly jumped into my tent due to the
mosquitoes. Again I slept like a baby.
Stop 1: We stopped at a beach and made a short hike to a moonshiner's cabin. This cabin was very well preserved and many of the artifacts still remained.
Stop 2: We floated our way into the Colton formation, which
consists primarily of fluvial sediments such as shale and mainly sandstone.
Walking up an arroyo we noticed the large clasts in the walls indicating
that these were deposited by a debris flow. As we continued up we saw the
contact between a sandstone (stream) and the shale (floodplain). At this
point the Green River Formation and the Colton Formation interfinger each
other. This is where a large river was running into a lacustrine lake.
As the lake rises and falls, the river and the lake interfinger each other.
At this stop we also observed Alveolar weathering. This is the pitted
weathering in which water dissolves the cement and remaining sand blows
out.
Stop 3: This was a quick stop to view more petroglyphs.
Today was our first shot at any decent rapids. To more evenly power and control the boats, Melanie and I switched to the other paddleboat with Melanie taking over as captain.
Tonight night we camped on a sandy bar beside the river. It is excellent,
no mosquitoes, and just a few gnats which are hardly noticeable. We ate
stir-fry with rice and had cheesecake for dessert. We actually sat and
talked around the fire.
The night was very windy and I never took the time to put the rain fly
over my tent. This resulted in a fine-grained well-sorted sand horizon
covering everything in my tent including myself. However we ate delicious
chicken fajitas for dinner.
Stop 1: We climbed up the lower part of the Colton formation to a conglomerate with clasts of quartz, red white and black chert, weathered carbonate, and some volcanic clasts as well. This heterogeneous conglomerate was sourced from the southeastern Uncompagre uplift.
Stop 2: Abandoned hunting ranch. Butch Cassidy and the Sundance Kid stopped here to sleep on the way to their hideout.
Stop 3: A hard climb to a fossil bearing limestone, containing gastropods and pleisopods.
Finding a good camping spot was very difficult due to the presence of
dead and stinky fish everywhere. But eventually we located an odor-free
location and enjoyed curry and pot stickers for dinner.
Stop 1: We observed the Ferrar sandstone-- a sub-angular to sub-rounded fine-grained sandstone, and the Toucher Fm, which is also a fine-grained ss that is more mature.
Stop 2: We observed the contact between the Nelson Fm and
the Blue Castle ss. Below the Nelson Fm is a black mudstone with fine coal
stringers. The Black color is from organic material that hasn’t been oxidized.
This occurs because the material was deposited in a restricted basin, and
was buried rapidly in an anoxic environment. The Nelson formation represents
a distal swampy region of a foreland basin. The Blue Castle Fm has been
interpreted as a fluvial system.
Stop 3: Unload the boats pack the cars and get our butts
off of the river.
This trip was an excellent opportunity to observe geology in the field. It is always valuable to actually see and touch structures and rocks, which you may have only read about. This trip gave me the opportunity to do just that. The river also gave us the unique opportunity to view a large and unique stratigraphic section in a relatively short time. The rafting itself was also terrific because it was challenging at some points and made for an exciting ride. But often it was calm and slow and allowed the time to look around and enjoy the beautiful scenery.
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Last Updated: September 10, 2001 by Webmaster |