REWRITTEN FIELD NOTES FOR UTAH TRIP
AUGUST 3 TO AUGUST 8, 1999
NORTHERN SAN RAFAEL SWELL AREA
MORRISON FORMATION

by

Edward L. Crisp

This trip was primarily an information gathering trip.  We (West Virginia University at Parkersburg and Marietta College) needed to find new exploration and excavation areas and sites in the Morrison Formation for continued study of the paleontology, stratigraphy, and sedimentology of this formation.  In addition, we would know in advance where to bring students for field studies classes (conducted in May of each year) without wasting time hunting for areas when the students are with us. We were still conducting field studies under an exploration permit issued by the Federal Bureau of Land Management (Salt Lake City State Office and Price Field Office) for the 1999 field season.

AUGUST 3, 1999

Left from Columbus airport about 3:00 p.m.  Arrived in Salt Lake City, Utah about 9:00 p.m.  Dr. Stone (Stoney) and Jon Duke were at the airport to pick me up.  It took us about 2 1/2 hours to drive to Hunington, Utah to the Village Inn.  We were all tired, so we went right to bed.

AUGUST 4, 1999

We all got up about 8:00 a.m. and went to breakfast at the Cactus Garden.  After breakfast we loaded up and went to the May 1999 Sauropod Vertebrae dig site, which is not too far to the east of the famous Cleveland-Lloyd Dinosaur Quarry (also only about a mile or two as the crow flies from our 1998 Camarasaurus/Stegosaurus dig sites).

The main reason to visit this locality was to do some more work at the clam bed site.  Stoney and I did measurements of the lateral extent of the bed.  We also collected some samples of the internal and external molds.  I then measured the section from the Jurassic Salt Wash Member of the Morrison Formation to the base of the Cretaceous Buckhorn Conglomerate Member of the Cedar Mountain Formation (this encompassed the entire Upper Jurassic Bushy Basin Member of the Morrison Formation at this locality).  I also collected samples of all the sandstone units within the Brushy Basin Member at this locality.

Note:  We had already submitted an abstract relative to the occurrence of clam fossils at this locality to the annual Geological Society of America Convention in Denver to be held during October 1999.  David Burton, one of my students at West Virginia University at Parkersburg, would be the senior author and would present the paper.  David had done most of the initial work at this location in May 1999 and was working on this as a research project as part of the WVUP 1999 Field Studies in Utah Course.

CLAM BED LOCALITY - May 1999 locality.  Brushy Basin Member of the Morrison Formation.






Measured lateral extent of clam bed outcrop – approximately 230 feet continuous with about another 100 feet to the west that is discontinuous.





Collected several samples of sandstone and clams.





There is another greenish sandstone about 2 feet above the top of the clam bed sandstone. This upper greenish bed has no clams in it. A light greenish gray mudstone separates the two sandstone beds.
 

Six of the clams were measured in the field for height and length, with the following measurements:

Height (in.)                         Length (in.)
 
1.0 4.3
1.6 3.5
1.5 4.0
1.0 3.0
1.4 2.5
1.3 2.3

 

EYELEVELING OF STRATIGRAPHIC SECTION AT CLAM BED LOCALITY

My eyelevel is 5 foot 6.5 inches.

Location 1. Salt Wash Member of the Morrison Formation near the base of the Brushy Basin Member. Also near the sauropod vertebrae location of May 1999.

Clean, very light gray, fine-grained sandstone with a high quartz content (may be an orthoquartzite, at least locally). Well cemented with silica. Thick bedded to massive, but weathers into thin (less than one inch) partings. No apparent cross-bedding at this particular location (However, I did not look around much at other outcrops in the vicinity).

Dipping to NW at about 10 degrees.

Location 2. Two eyelevels above location 1. About level of sauropod vertebrae of May 1999. Appears to be gray mudstone here.

Location 3. Three eyelevels above location 2 to the base of a thin, 1 foot bed of med. grained sandstone with a salt and pepper appearance.

Location 4. Two eyelevels above location 3. This location is very close to the top of an 8 inch layer of medium gray micrite.

Location 5. One eyelevel above location 4. Near top of another 1 foot micrite or hard mudstone.







Location 6. Base of a sandstone at 4 eyelevels above location 5. Conglomeritic at base – decreasing grain size upward. Fine grained at top. Cross-bedded. The mudstone below the sandstone has large chunks of rock incorporated into it. Lt. gray mudstone below the sandstone. The sandstone is 5 hammers thick (my blue handled geologic hammer).





Location 7. Three eyelevels above location 6. Right at the top of a medium grained sandstone (somewhat salt and pepper appearance). The sandstone is about 2.5 hammers thick.

Found one fair external mold and one fair internal mold in this sandstone (the sandstone is definitely in place). The molds are not as good as in the main clam bed sandstone (which is above this location). Saw some other faint hints of clam molds.

Location 8. Two eyelevels above location 7. Near top of fine grained olive green sandstone. About 2/3 of a hammer thick. Our clam bed was about ½ way between the last eyelevel to this location. Between the main clam bed and this thin sandstone is a light greenish gray mudstone. Already have a sample of this mudstone.

Location 9. Three eyelevels above location 8. Near base of the micrite bed that yields the prominent brown, limonite stained float on the hillside. Already have a sample of this that David Burton took in May 1999. The micrite bed is about 2 feet thick at this location.

Location 10. Seven eyelevels above location 9. At the base of a red, very fine grained, cross-laminated (sets less than one inch), sandstone for about 4 feet, then 3 feet of light tanish gray fine sandstone with no apparent cross-stratification.

Location 11. Five eyelevels above location 10. Near top of a fine grained red sandstone (very much like red sandstone at location 10). About three feet thick.

Location 12. Five and one half eyelevels above location 11. Base of the Cretaceous Buckhorn Conglomerate member of the Cedar Mountain Formation. The Buckhorn Conglomerate at this location yields large float blocks that fall down the hill and has the typical lithology of the Buckhorn, with large gravel fragments of black chert a very prominent component.

Note: For all the previous locations a sample was taken unless otherwise noted.

Photos of clam bed sandstone through polarizing microscope.  The large clast in photo C is about 1 mm.  All photos to same scale.
 
 
 

AUGUST 5, 1999

Arrived in Ferron about noon. Took road to east toward the coprolite locality. Turned off onto graded jeep trail. It had rained recently and the road was very slick. Managed to get to where the Jurassic Brushy Basin Member of the Morrison Formation was outcropping before sliding off the road. Got Stoney’s truck out of ditch, but continued to have trouble making any progress. Had to push the truck several times and shovel off the top of the mud from the road. The road was completely dry under about one inch of swollen smectite-rich mud. Finally came to a small hill that we could not get up. Stopped here to set up camp. Stoney, Jon Duke and I hiked along the Brushy Basin outcrop towards the coprolite locality (about 1.5 miles from the camp). We looked for fragments of dinosaur bone, but only found a few isolated fragments. I did find a chunk of rock that looked very similar to the theropod coprolites. Found it is a small streamlet about half-way from the campsite to the coprolite site.

Arrived at coprolite locality about 4:00 p.m. Stoney showed us the main coprolite. I walked over to an outcrop of the Jurassic Salt Wash member of the Morrison Formation to examine it.

Location 13. Salt Wash Member. Took some samples here. Photo 29 on digital camera.

Fine to coarse, very light gray sandstone (conglomeritic in places).




Stoney took us to the site of the sauropod cervical vertebrae. Pretty impressive. Stoney had exposed 2 of the cervical ribs. There appeared to be several vertebrae in a linear alignment. We then walked back to the campsite. Arrived about 8:00 p.m.


Stoney at the site of the cervical vertebrae.



Kimber had found some dinosaur fragments (pieces of small ribs, etc.) near the campsite and was very excited. Jason and Peter were out roaming about. They returned soon to say that they had also found some pieces of dinosaur bone, but did not retrieve any of them.

Peter built a fire from some of the wood that Kimber had brought with here. It was starting to get dark and looked like we were going to get rained on again. It did sprinkle a little and there was a little lightening and thunder. We grilled the steaks (that Stoney had bought that morning in Castle Dale) over the open fire. Jon made some flavored pasta and Kimber perked some coffee. We were all very hungry and the steaks were excellent. The sky cleared up and we could see the stars. Stony offered me the back seat of his truck to sleep in (in case it rained, I did not have a tent), Stony took the front seat.
 

AUGUST 6, 1999

Stony and I got up about 6:30 a.m. We had some cold coffee from the night before. Everyone else was still asleep in their tents (except Jon, who slept in the front seat of Kimber’s little blue pickup). It was a clear pleasant morning, hardly a cloud in the sky. Everyone else started getting up around 8:00 a.m. Kimber fixed eggs for Stony and Jon and made coffee for the rest of us. I had a couple of peanut butter sandwiches and the rest snacked on various things. Jon had not brought his insulin with him, so he really had to watch what he ate and could not eat very much. We broke camp and packed up the tents.

The road was still slick, so we had to wait for it to dry out. Stoney and I read some and talked about the environments of the Morrison Formation. About 11:00 a.m. the road was starting to dry out. With a little shoveling and pushing we got the truck up the little hill and off we went. Arrived adjacent to the coprolite locality about 12:10 p.m.

We parked along side the road. Stony and the rest went to the coprolite locality. Jon and I started a stratigraphic traverse that would take us from the Salt Wash to the base of the Buckhorn Conglomerate, tying in the 2 coprolite locations. The Salt Wash member crosses the road near where we parked. John and Cheri Bishop arrived.

Location 14. Salt Wash Member. Medium to coarse sandstone, conglomeritic lenses. Very light gray in color and cross-bedded. The outcrop near the road was 4 feet 8 inches thick. Photos 39-41 on digital camera. Photos 16 and 17 on regular 35 mm camera. Took several samples here.




Salt Wash at Location 14.


Location 15. Top of micrite (stains brown, limonitic). Top about one eyelevel below top of Salt Wash, but stratigraphically above the Salt Wash. About 1 foot thick.

Location 16. One eyelevel above top of micrite to the top of the first Brushy Basin sandstone. Medium to coarse grained with conglomeritic lenses, cross-bedded, light gray sandstone (looks similar to Salt Wash, but is stratigraphically above the Salt Wash).

Outcrop thickness 5 feet. Dips approximately 10 degrees to west (measured with a compass).

Location 17. Coprolite #1 location. One eyelevel + 3 feet 4 inches above location 16.




Drs. Stone and Crisp with the main body of the coprolite.


Gray 6 inch micrite about 6 inches below the bottom of the coprolite. The coprolite is in a red-brown mudstone. John Bishop took a sample of the mudstone above and below the coprolite.



Main body of the coprolite.


Location 18. Two eyelevels above location 17 (the coprolite location). Near the base of a fine to medium grained, light gray sandstone. About 10 feet thick. Very localized. To this point, most of the mudstone is gray with some brown and purple.


Sandstone at location 18. Photo 42 on digital camera.


Location 19. Five eyelevels + 8 inches above location 18. Second coprolite location. In brownish red silty mudstone. The mudstone is hard and nodular in places.

Location 20. One eyelevel above location 19 (second coprolite). Near top of a light gray, fine to medium grained sandstone. Three feet two inches thick. Appears to be localized, but covered with a lot of float. The top of this sandstone is right at the boundary with very classic looking Morrison variegated mudstone (about 11 color bands to next sandstone) with popcorn weathering.

After getting location 20, a thunderstorm blew up and it rained for a few minutes. Jon and I came down from the side of the hill to camp (Kimber and Peter had set up a shelter in the flatish area down hill of the coprolite location). We had some lunch and waited to see what the weather was going to do. While Jon and I had been doing the traverse, the rest of the crew had exposed much to the coprolite by digging away the hard mudstone surrounding it. The fresh mudstone is gray rather than brown red.

We decided to go to the cervical vertebrae site. John Bishop tried to find a way to get his truck to the site, but didn’t make it all the way to the site. We parked and walked on to the site. Began digging at ends of the bones that were exposed. Found what appear to be two more vertebrae to north of the two already partially exposed. Jason and John exposed more of the two that Stoney had first found. Picked up all the loose fragments around the vertebrae and put in zip-lock bags. We dug until about 8:00, then headed back to camp. Stayed for a little while, then all but Kimber and Peter (who stayed the night at the coprolite location) headed for Huntington. Went to the rooms first, so Jon could take some insulin, then went to our favorite restaurant in Huntington, the Cactus Garden. I had a Buffalo Burger, fries, and a salad. The service wasn’t quite as good as usual.

Oh, while we were going back to John’s truck from the cervical vertebrae site we found several areas with bone fragments on the surface. Jason found some bones that may be the upper part of a femur of a juvenile Allosaurus. John Bishop found a small centrum of something and gave it to me.

SATURDAY AUGUST 7, 1999

Stoney and I got up about 7:30 a.m. Shaved and got ready. We all left the motel about 8:30 a.m. and went to the Cactus Garden for our typical buffet breakfast. We then headed for the field. We stopped at the grocery store in Castle Dale to get supplies for Kember and Peter and to get hotdogs and chili for the evening meal. It was fair day at Castle Dale, so had to wait at the grocery store until the fair parade was over (the parking lot of the grocery store was the assembly area for the parade). After the parade, we went to the local hardware store to get some acetone to mix with glue, then headed on for the field. Stopped on the road east of Ferron and picked up some wood for the evening fire.

Arrived on location about noonish. Kimber and Peter were still alive and well.

Jon and I continued our traverse while the others worked at the coprolite location.

Location 21. Five eyelevels + 2 feet above location 20. Bottom of a fine to medium grained sandstone. Approximately 4 feet thick. Weathered color light gray to light lavender. Fresh color light gray. Occasional color banding. Fairly consistent grain size throughout. Cross-bedded. Laterally starts breaking up with mudstone between sandstone layers. Disappears to the north and south.

Location 22. From the top of the sandstone at location 21, one eyelevel + 1 foot 2 inches to bottom of a fine to medium grained sandstone. Weathers pinkish. No apparent cross-bedding. Twelve feet ten inches thick.

Location 23. Top of sandstone of location 22. This sandstone appears to be thickest here and decreases in thickness laterally in both directions. Photos 18 and 19 on first role of regular 35 mm camera and 44 and 45 on digital camera.



Photo 45 digital camera. Looking to the south.


Location 24. Three eyelevels + 1 foot 3 inches above location 23. Top of brownish red, cross-bedded, medium to coarse grained sandstone with conglomerate lenses. Nine feet thick. Photos 20-23 in regular camera and photo 47 on digital camera. One dinosaur fossil (small elongate mold with a couple of dinosaur bone fragments – whole thing about six inches long and one inch wide) found in the sandstone.


Photo 46, digital camera – Looking down towards coprolite #1 location from location 24.


Photo 47, digital camera – Looking up towards Buckhorn Conglomerate (cliff near top of picture) from location 24.


Location 25. Two eyelevels above location 24. Near the base of a fine to medium grained, salt and pepper sandstone. About 4 feet thick. Nodular to rubbly weathering.

Location 26. One eyelevel above location 25. Near base of an argillaceous siltstone, light gray. Two feet thick here, but thins in both directions.

Location 27. Three eyelevels + 1 foot 7 inches to the base of a pink, medium to coarse grained, cross-bedded sandstone with conglomeritic lenses. Conglomeritic at base with other zones of conglomeritic sandstone. Very localized. Thins and disappears very rapidly to the north and south. Lateral extent about 100 feet. May be a channel sand or point bar complex. About 4 feet thick at thickest point. Photo 24 on regular camera (first role).

Location 28. Top of the outcrop of Buckhorn Conglomerate. Four eyelevels above location 27. The base of the Buckhorn Conglomerate is 3 feet 7 inches below location 28. Coarse conglomeritic sandstone to conglomerate with in place pieces of petrified wood (the wood has been silicified to chert).



Petrified piece of a log in the Buckhorn Conglomerate.


RESULTING STRATIGRAPHIC SECTION AT COPROLITE LOCALITY

STRATIGRAPHIC SECTION AT THE COPROLITE LOCALITY (the scale is in feet)



After location 28, Jon and I worked our way down off the Buckhorn ridge. On our way back to the coprolite location we found several chunks of dinosaur bone as we came down across the Brushy Basin section. Back at the campsite we had a sandwich.

We all then decided to go to the Stegosaurus plate site. We dug laterally from where Stoney found the plate fragments. Did not find anything. We then hiked up to the sandstone above the plate site to look at dinosaur bones in the sandstone. We walked across the top of the sandstone and found more bone fragments. Also walked over the mudstone above the sandstone and found numerous bone fragments. After about and hour we went back to the plate site (Except for John and Cheri, who continued to look up on top of the sandstone bed). After about another hour, John and Cheri came back and said they had found a big accumulation of dinosaur fragments. We decided we would go there again later, but it was getting late (about 8:00 p.m.), so we went back to the campsite. A campfire was started and Kimber and Cheri made hotdogs and chili for us (It really hit the spot). By then it was dark and we headed back to the motel. Got to the motel about 11:00 p.m. We went right to bed, Stoney and I both were pretty tired. So was Jon Duke. Jason stayed at the coprolite site.
 

SUNDAY AUGUST 8, 1999

Got up about 7:30 and got ready to go. Straightened out the back of Stoney’s truck. It was Sunday, so the Cactus Garden was closed. Went to the Texaco station to get some supplies for Kimber and Peter. Stopped in Castle Dale at a restaurant for breakfast. Got out to the coprolite location about 10:30 a.m.

Jon and I did some eyeleveling of units close to the coprolite.

Location 29. One eyelevel above coprolite #1. Near bottom of a micrite bed.

Location 30. Two feet 1 inch above location 29. Top of micrite bed.

Location 31. Four eyelevels above location 30 to the bottom of a massive bedded, cross-bedded, coarse sandstone and conglomerate. Conglomeritic at base with a lot of pebble conglomerate lenses (perhaps more conglomerate than coarse sandstone). The conglomerate is a sandy pebble conglomerate. Some of the conglomerate lenses are cross-bedded, whereas others are horizontally layered (possibly representing upper flow regime deposits). These deposits are probably braided stream deposits or anastomosing stream deposits. There is no consistent fining upward sequence in these deposits. The cross-beds are in sets from 6 inches to 2 feet thick. The entire unit is 11 feet 10 inches thick.

The pebbles are primarily white quartz pebbles and dark brown to gray chert (mostly the chert).



Conglomerate at location 31.


Conglomerate and coarse sandstone at location 31.


Cross-bedding in coarse sandstone with horizontal bedding in pebble conglomerate unit above.


More cross-bedded sandstone with horizontally bedded pebble conglomerate above.


Another photo of pebble conglomerate and cross-bedding at location 31.


 

Location 32. One eyelevel below coprolite #1 location to the top of an argillaceous micrite. About 2 feet thick.
 

After Jon and I completed the stratigraphic work, we went to help Stoney and John Bishop dig some more of the mudstone away surrounding coprolite #1. We continued to dig until about 5:00 p.m. Stoney, Jon, and I left for the motel. I took a shower and packed my things up, then Stoney and I left for the airport at Salt Lake City. On the way to the airport, Stoney gave me a splendid lecture on the Cretaceous and Tertiary stratigraphy of central Utah. Stoney dropped me off at the airport about 9:00 p.m. I had plenty of time to kill; my flight wasn’t until 11:55 p.m. I had dinner at Burger King then looked around in the gift shops. Bought two Christmas tree ornaments with Utah scenes or symbols on them, one for Jane and one for Melissa. Then waited for the plane to Atlanta. Three hour layover in Atlanta. Arrived in Columbus at 9:54 a.m. Tuesday August 9. Jane was waiting for me when I got off the plane.

GREAT TRIP AND ACCOMPLISHED MUCH!!!