Posted on 04/02/2004 2:00:07 PM PST by DannyTN
Link has pictures.
More than one thousand large fossil bones stand out in bold relief upon the rock wall at the Quarry Visitor Center in Utahs Dinosaur National Monument. The first-time visitor is stunned by the magnitude of the exhibit. The quarry face (known best as The Wall) is surely the finest onlocation dinosaur display in the world. This tangled knot of dinosaur bones represents a classic mass burial deposit, a trademark of what geologists call the Morrison Formation. Extending from New Mexico to Canada, the Morrison Formation covers about 700 thousand square miles and has been assigned to the Jurassic System. How did such a burial take place? We seek to find the real significance of the deposit at Dinosaur National Monument (DNM) and to dispel myths that our culture has delivered to us.
History of The Wall
On the heels of the American dinosaur rush, Earl Douglass in 1909 discovered eight articulated brontosaur tail vertebrae, standing out in relief from a sandstone ridge in eastern Utah. As digging began, he was shocked at how the skeletons turned up, literally one on top of another, and how the smaller stegosaurs got in the way of the prized sauropods.1 The sedimentary rock package containing the bones can be called the Quarry andstone, a lensshaped pebbly sandstone up to 50 feet in thickness that is exposed for 3,000 feet along the ridge outcrop.
The Quarry sandstone is composed chiefly of ii chert and tuff grains.2 Volcanoes certainly supplied the tuff grains, and perhaps the chert pebbles as well. It is part of the overall 470-foot-thick Brushy Basin Member of the Morrison Formation that is dominantly mudstone. No less than a dozen well-articulated sauropods were excavated over a 15-year period ending in 1924. Probably none was more famous than the original Brontosaurus excavated by Douglass, that remains the most complete ever found, and that has stood in Pittsburghs Carnegie Museum since 1915.
The Quarry Visitor Center was opened officially to the public in 1958. Popular caricatures about dinosaurs can now be compared with the stark reality of the deposit itself, in an exhibit that is without parallel in the world.
The Jurassic Park caricature
Of all the popular images of dinosaurs, perhaps none has been so compelling as the one featured on the front cover of Life Magazine over 50 years ago.3 The magazine displayed Brontosaurus, the snub-nosed sauropod, half-floating in the waters of a swamp and lazily munching on its lush vegetation. The artwork was derived from the Yale Peabody Museums mural painted by artist Rudolf Zallinger after sixmonths of consultation with the worlds top geologists.4 It had been considered fact, not speculation, that the mural and magazine cover accurately represented the world in which Brontosaurus lived 150 million years ago. Because the purpose was to depict The Age of Reptiles, mammals do not appear. The image became an icon so compelling that even a U.S. postage stamp bore its likeness. The image was derived, in a major way, from the deposit visible at the Quarry Visitor Center Today, this Jurassic Park caricature can be regarded as twentieth-century folklore. Brontosaurus, the icon that stood for at least two generations, underwent an extreme makeover in the 1970s, to correct two mistakes made much earlier. The result was a new name, Apatosaurus, and a radically different head with a The classic dinosaur massed accumulation deposit at the DNM Quarry. Photo: Steve Austin iii The artwork on this 1970 U.S. postage stamp was an icon for over three decades. long-snouted and delicate look.5
Almost all geologists familiar with the Morrison Formation question the swamp image, and some call it heresy.6 The contention that waters were somehow needed to buoy the giant herbivores is also discounted. The image that these were slothful, stupid, and lumbering beasts was revised with new evidence leading some to suggest warm-bloodedness.
Sedimentary evidence indicating bone transport means that we see the dinosaur burial site today, not the park in which they lived. Mammals are not depicted in The Age of Reptiles icon, but mammal fossils are well represented in the Morrison Formation at DNM.7
Finally, the age for the deposit has been adjusted so many times over the last 80 years that there is little reason for confidence that the currently accepted age is the correct one.8 Thus, the image that had been so widely embraced by the public involved a largely fictional animal in the fictional waters of a fictional swamp during a fictional age. This was the original Jurassic Park, concocted not by Hollywood, nor by creationists, but by the very scientific leaders, museum curators, and government administrators who were most familiar with the DNM deposit.
Six facts regarding the Dinosaur National Monument deposit We need to get the real story for the Quarry Visitor Center deposit. Recognizing the facts is important because they help us get beyond the cultural baggage and icons to develop a deeper understanding.
Montmorillonite, the kind of clay formed by alteration of volcanic ash, alone accounts for over 50% of the 470-foot-thick Brushy Basin Member at DNM.15 A staggering quantity of volcanic materials, estimated at more than 4,000 cubic miles,16 occurs within the thin but widespread Brushy Basin Member in Wyoming, Utah, Colorado, New Mexico, and Arizona. No volcano is known within the boundary of the Morrison deposit, no local lava flows are known within the Morrison boundary, and geologists place the nearest explosive volcanic source vents in southern California or Nevada.17 How these coarse volcanic materials in such colossal quantities were distributed on so wide a scale remains a mystery.
Imagine an exploding volcano in southern California that rained half-inchdiameter pumice and lapilli fragments on Utah and Colorado. That would be a most extraordinary eruption.
The majority of dinosaur skeletal items were buried while articulated or closely associated with a parent carcass, including some nearly complete carcasses that came to rest in stiff rigor mortis positions.18 The dismembered carcasses certainly contained tissue adhering to bone at the time of burial. Quarry invertebrates include not only the unionid clams, but also two genera of gill-breathing snails from the prosobranch family.19 Modern snails from this family, that are nearly identical to these fossil forms, require in their life-cycle waters that are (1) perennial, (2) well-oxygenated, and (3) low in turbidity. Such conditions could hardly have been met during deposition of the Quarry sandstone bed, much less the overall Brushy Basin Member. This enigma has been called the Morrison gastropod problem.20 The snails must also be regarded as part of the death assemblage. The fact that all of these fossil types were selectively sorted during transport from an unknown distance before burial makes very difficult the job of reconstructing an ancient ecosystem.
Conclusion
It is difficult to escape the conclusion that something extraordinary took place at Dinosaur National Monument. The deposit indicates enormous volcanoes, a suspension means of transport, multiple kinds of death assemblages, and a host of paleoenvironmental problems. Yet, DNM is only one of many dinosaur-massed assemblages. The above six points are hardly debatable, but are very much understated. Why does the public not receive frequent reminders of the facts so obvious within The Wall at DNM? Why does a coherent dinosaur environment seem so elusive? Jurassic Park is too peaceful a picture here. Clams, snails, and dismembered dinosaurs within the same deposit demonstrate a watery catastrophe. Jurassic Jumble is more appropriate.
Endnotes
1. Chure, D., and West, L., 1994, Dinosaur: the Dinosaur National Monument Quarry: Vernal, Utah, Dinosaur Nature Association, 40 pp.
2. Turner, C., and Peterson, F., 1992, Sedimentology and Stratigraphy of the Morrison Formation in Dinosaur National Monument, Utah and Colorado: Annual Report of the National Park Service (unpublished), contract #CA-1463-5-0001, in cooperation with the U.S. Geological Survey, 80 pp.
3. Life Magazine, September 1953.
4. Zallingers famous mural was painted under the supervision of Yale geologist and museum director Carl O. Dunbar with Harvard and Yale scientists tutoring him for six months prior to commencing the mural. The mural is known to have inspired a new generation of paleontologists.
5. Douglass identified the correct diplodocus-like skull for his sauropod, but was overruled by his supervisors at Carnegie Museum who deferred to an earlier, incorrect, precedent. Thus, the size, shape, and features of the Apatosaurus head were disputed for over a century (Encyclopaedia Britannica, 1986).
6. Bakker, R., 1986, The Dinosaur Heresies: New Theories Unlocking the Mystery of the Dinosaurs and their Extinction: New York, William Morrow, 482 pp.
7. Engelmann, G., and Callison, G., 1998, Mammalian faunas of the Morrison Formation: Modern Geology, vol. 23, pp. 343380.
8. A claystone very near the top of the Quarry sandstone at DNM that yielded a 135.2 ± 5.5 Ma K-Ar date in 1986, gave a 152.9 ± 1.2 Ma Ar-Ar date in 1991 (Kowallis, B., et al., 1991, Age of the Brushy Basin Member of the Morrison Formation, Colorado Plateau, Western USA, Cretaceous Research, vol. 12, pp. 483493). The age of the Morrison Formation has been the chief point of dispute for over 70 years as of 1944 (Stokes, W., 1944, Morrison Formation and related deposits in and adjacent to the Colorado Plateau: Geological Society of America The massed accumulations of the Morrison Formation remain a geologic mystery. Photo Courtesy: National Park Service viii
© 2004 by ICR All Rights Reserved Single copies 10¢ Order from: INSTITUTE FOR CREATION RESEARCH P.O. Box 2667, El Cajon, CA 92021 Available for Bulletin, vol. 55, pp. 951992). As of 1998, one of the significant unresolved problems related to the Morrison Formation is its age, both chronostratigraphically and biostratigraphically (Kowallis, B., et. al., 1998, The isotopic age of the Morrison Formation in the western interior; final report: in, C. Turner and F. Peterson, eds., Final Report: The Morrison Formation Extinct Ecosystems Project: unpublished report, in cooperation of the National Park Service and the U.S. Geological Survey, pp. 167200).
9. Chure and West, op. cit.
10. Cummins, R., 1994, Taphonomic processes in modern freshwater molluscan death assemblages: implications for the freshwater fossil record: Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 108, pp. 5573.
11. Good, S., 1998, Bivalves as tools for paleoenvironmental analysisUpper Jurassic Morrison Formation of the Western Interior: final report: in, C. Turner and F. Peterson, eds., Final Report: The Morrison Formation Extinct Ecosystems Project, op. cit., pp. 121158.
12. Evanoff, E., Good, S., and Hanley, J., 1998, An overview of the freshwater mollusks from the Morrison Formation (Upper Jurassic, Western Interior, USA): Modern Geology, vol. 22, pp. 423450.
13. Turner, C. and Fishman, N., 1991, Jurassic Lake Toodichi: a large alkaline, saline lake, Morrison Formation, eastern Colorado Plateau: Geological Society of America Bulletin, vol. 103, pp. 538558.
14. Wahlstrom, E., 1966, Geochemistry and petrology of the Morrison Formation, Dillon, Colorado: Geological Society of America Bulletin, vol. 77, pp. 727740.
15. Bilbey, S., 1992, Stratigraphy and sedimentary petrology of the Upper Jurassic-Lower Cretaceous rocks at Cleveland-Lloyd Dinosaur Quarry with a comparison to the Dinosaur National Monument Quarry, Utah: Ph.D. dissertation, University of Utah, 280 pp.
16. Area of Brushy Basin volcanics exceeds 120,000 square miles in eastern Utah, northeastern Arizona, northern New Mexico, western Colorado, and southern Wyoming. Thickness of volcanics averages about 200 feet through this area. Therefore, volume of volcanics is at least 4,300 cubic miles.
17. Christiansen, E., Kowallis, B., and Barton, M., 1994, Temporal and spatial distribution of volcanic ash in Mesozoic sedimentary rocks of the western interior: an alternative record of Mesozoic magmatism, in, M. Caputo, F. Peterson, and K. Franczyk, eds., Mesozoic Systems of the Rocky Mountain Region, USA: Denver, Rocky Mountain Section SEPM (Society for Sedimentary Geology), pp. 7394.
18. Lawton, R., 1977, Taphonomy of the Dinosaur Quarry, Dinosaur National Monument: Contributions to Geology, University of Wyoming, vol. 15, no. 2, pp. 119126.
19. Evanoff, E., et. al., 1998, op. cit., and Yen, T., 1952, Molluscan fauna of the Morrison Formation, United States Geological Survey Professional Paper 233-B, pp. 2155.
20. Evanoff, E., 1998, Paleoenvironmental implications of freshwater gastropod faunas in the Upper Jurassic Morrison Formation of the Western Interioran enigma between geologic and biologic evidence; final report: in, C. Turner, and F. Peterson, eds., Final Report: The Morrison Formation Extinct Ecosystem Project, op. cit., pp. 103104.
21. Turner and Peterson, 1992, op. cit.
22. Pierson, T., and Scott, K., 1985, Downstream dilution of a lahar: transition from debris flow to hyperconcentrated streamflow: Water Resources Research, vol. 21, pp. 15111524.
23. White, T. E., 1964, The dinosaur quarry, in, E. Sabatka, ed., Guidebook to the Geology and Mineral Resources of the Uinta Basin: Salt Lake City, Intermountain Association of Geologists, pp. 2526.
24. Dodson, P., Behrensmeyer, A., Bakker, R., and McIntosh, J., 1980, Taphonomy and paleoecology of the dinosaur beds of the Jurassic Morrison Formation: Paleobiology, vol. 6, no. 2, pp. 208232.
25. Dodson et. al., op. cit.
26. Dodson et. al., op. cit.
You might find this article interesting, note that they rule out a river accumulation.
"Creationists might want to do some original research."
Try this article.
??? You think clams are mammals???
And what did you think of the time frame of the catastrophe?
Now, what was your point?
No, there was clams and mammal fossils there. " Sedimentary evidence indicating bone transport means that we see the dinosaur burial site today, not the park in which they lived. Mammals are not depicted in The Age of Reptiles icon, but mammal fossils are well represented in the Morrison Formation at DNM.7 "
"And what did you think of the time frame of the catastrophe?"
I didn't see where it concluded a time frame, I was dissappointed that the article did not provide specific evidence for a short time frame. It did say this though. "Finally, the age for the deposit has been adjusted so many times over the last 80 years that there is little reason for confidence that the currently accepted age is the correct one.8 "
Now, what was your point?
That a global flood fits better with the evidence than localized river flooding. And that the so-called scientific community are often grossly wrong in their assumptions and conclusions because their world view / religion influences their science.
Strange about all that emphasis on clams, eh?
And, mammals, eh? Funny how they didn't point any out. Would these "mammal fossils" be full grown elephants, modern gorillas, or some already known shrew-like proto-mammals from 65-million+ years ago?
I didn't see where it concluded a time frame,
Ditto, except for the well defined term Jurassic.
And the adjustment of the estimated age? Was that adjusting from 79 to 80 million years ago or 65 million to 6 thousand? Not the 6,000, eh? Didn't think so.
That a global flood fits better with the evidence than localized river flooding.
BWAAAAAAAAAAAAAAAAAAAHAHAHAHA!!! Oh, you make me laugh so much.
At least the authors weren't foolish enough to stick their necks out and mention a "flood", global or otherwise.
Second, jutst because how this assemblage came togther is not fully understood, in no way does that indicats that it resulted from a massive and catrastrophic flood. For example, Ashfall fossil beds in Nebraska show a similar but much more recent assemblage of animals; it resulted from a massive distant volcanic eruption.
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