The stretch of time from the Bonanza King Formation of the middle Cambrian to the Tin Mountain Limestone of the Early Mississippian is one long glorious straight shot of tropical to subtropical shallow marine deposition. The rocks are represented primarily by limestone and dolomite, with lesser shaly, silty, and sandy intervals. The most notable exception is the Eureka Quartzite of the Late Ordovician, coincidentally enough about the same age as the St. Peter Sandstone.
As is typical for shallow marine rocks of Paleozoic age, these formations include various marine invertebrates. The lengthy and nearly complete sequence provides a rare opportunity to trace the changes in shallow marine assemblages over the Paleozoic. The Cambrian rocks are dominated by brachiopods and trilobites, with microbial structures (i.e. stromatolites, sometimes making accumulations that were essentially reefs), snails and snail-like mollusks, a few quirky early echinoderms, and burrows and trails. Following a transitional stretch, we reach the diversified Middle and Late Ordovician, with corals, bryozoans, bivalves, cephalopods, and stalked echinoderms becoming common. Similar fossils are common in the Silurian. In the Devonian, stromatoporoid sponges become common, and fish diversify.
|This image, from Hunt and Mabey (1966), shows large Upper Ordovician snails (or possibly really snail-like mollusks) (the scale bar is probably the 6 inch ruler seen elsewhere in their photos). The snails are often associated with receptaculitids, a combination seen over a wide part of this region.|
|Devonian stromatoporoids, from Hunt and Mabey (1966). It doesn't help that not only does the name sound like stromatolites, but they look like each other, too.|
Something you may have noticed about the Paleozoic is the relatively high sea levels. In the Late Ordovician, for example, we have great marine invertebrate assemblages of about the same age in California, Utah, Oklahoma, Minnesota, Tennessee, Ohio, and New York. Only two of those states have a marine coast, and even if all of the water trapped in ice today was to melt, you still wouldn't add any of the other states to that list. So what gives? It's not simply a matter of ice caps (and in fact there was an ice age during the Late Ordovician and early Silurian, although North America was at the equator and so didn't join the fun). For one thing, the elevations we see today are not the same as the elevations that existed in the past. The Colorado Plateau, for example, was pretty close to sea level until near the close of the Cretaceous, when it was first uplifted. Another factor has to do not with the height of the land, but with the depth of the marine basin. When tectonic plates are moving relatively rapidly and the mid-ocean ridges are churning out a lot of fresh ocean crust, the ocean basins are naturally shallower: the fresh crust is warmer, more buoyant, and less contracted. If the basin is shallower, and the volume of water stays the same, the water's gotta go somewhere. As the oceanic crust ages and gets farther from the source ridge, it cools, contracts, and sinks, deepening the basin and causing the seas to retreat off of the continents. Shallow basins from accelerated tectonics are thought to be the main culprit in the shallow continental seas of the Cretaceous.
Our Paleozoic paleontological paradise was interrupted in the Late Devonian. To the north and west, a mountain-building event known as the Antler Orogeny was beginning, forming a narrow belt from California and Nevada into Canada. The Death Valley region became a foreland basin on the east of the range. A foreland basin is a feature that appears adjacent to a mountain range due to gravity: the mountain range itself "drags down" the adjoining area. Like most large-scale tectonic events, there is still much to be argued about for the Antler Orogeny, but the long-term upshot was that the passive margin was being converted back into an active margin, which it has remained more or less (the modern margin is kind of weird because of the combination of subduction on the north and south with a transform boundary, the result of continental indigestion suffered after consuming part of the East Pacific Rise). The North American plate began consuming oceanic crust, which eventually led to the growth of the western part of the continent by hostile takeover of bits of crust, the uplift of the Rockies, the creation of Basin and Range topography, the San Andreas Fault, and myriad other consequences. For the moment, though, we're mostly interested in what was going on in a roughly Connecticut-sized area of the margin in the immediate aftermath of the change.
You may notice in the table how the sequence splits up again in the Mississippian. This is a result of DEVA spanning several different areas of deposition. At first, there was a carbonate continental shelf on the southeast and a basin on the northwest, connected by a slope. Then, the slope began to collapse on the southwest, truncating the continental margin over time in an eastward direction. By the Permian, the continental shelf had disappeared from DEVA, replaced by basins separated by a submarine uplift created by the "toe" of a fault block shoved southward. Today, we can recognize distinct sequences of carbonate platform, transitional, and basinal rocks in different parts of the park. The borders between the sequences shifted over time, and the complexities are still being unraveled (the Upland Valley Limestone was named while I was working on the draft). The Mississippian rocks typically divide between shallow marine formations on the south and east, and marine slope formations on the north and west. During the Pennsylvanian, the carbonate platform Bird Spring Formation shed sediment into the Keeler Canyon Formation basin. The Permian formations are slope and basin units, with the exception of the Upland Valley Limestone which appears to have been associated with an island. The shallower formations have much more in the way of macroscopic fossils, which is not surprising because more light would have been available. The slope and basin formations are mostly limited to microfossils and fossils transported from the platform by submarine flows. Forested shoals may have formed during the hiatus between the Santa Rosa Hills Limestone and Indian Springs Formation. The Paleozoic record in DEVA appears to peter out during the middle Permian, although late Permian rocks are present nearby. The end of the Permian is essentially the first epoch-scale hiatus in DEVA since the Proterozoic. We'll pick up again in the Early Triassic, but the Mesozoic and Paleogene are fairly spotty, as we'll see.
Selected references and chart references:
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Burchfiel, B. C. 1969. Geology of the Dry Mountain Quadrangle, Inyo County, California. California Division of Mines and Geology, Sacramento, California. Special Report 99.
Cornwall, H. R., and F. J. Kleinhampl. 1961. Preliminary geologic map and sections of the Bullfrog Quadrangle, Nevada-California. U.S. Geological Survey, Washington, D.C. Miscellaneous Field Studies Map 177. Scale 1:48,000.
Cornwall, H. R., and F. J. Kleinhampl. 1964. Geology of Bullfrog quadrangle and ore deposits related to Bullfrog Hills Caldera, Nye County, Nevada, and Inyo County, California. U.S. Geological Survey, Washington, D.C. Professional Paper 454-J.
Dunne, G. C., R. M. Gulliver, and C. H. Stevens. 1981. Correlation of Mississippian shelf-to-basin strata, eastern California. Geological Society of America Bulletin 92(1):I1–I4, II1–II38.
Elliott, D. K., and R. R. Ilyes. 1996. New Early Devonian pteraspidids (Agnatha, Heterostraci) from Death Valley National Monument, southeastern California. Journal of Paleontology 70(1):152–161.
Elliott, D. K., and M. A. Petriello. 2011. New poraspids (Agnatha, Heterostraci) from the Early Devonian of the western United States. Journal of Vertebrate Paleontology 31(3):518–530.
Gordon, M., Jr. 1964. California Carboniferous cephalopods. U.S. Geological Survey, Washington, D.C. Professional Paper 483-A.
Hall, W. E. 1971. Geology of the Panamint Butte Quadrangle, Inyo County, California. U.S. Geological Survey, Washington, D.C. Bulletin 1299.
Hall, W. E., and E. M. MacKevett. 1958. Economic geology of the Darwin Quadrangle, Inyo County, California. California Division of Mines and Geology, Sacramento, California. Special Report 51.
Hall, W. E., and E. M. MacKevett, Jr. 1962. Geology and ore deposits of the Darwin quadrangle, Inyo County, California. U.S. Geological Survey, Washington, D.C. Professional Paper 368.
Hopper, R. H. 1947. Geologic section from the Sierra Nevada to Death Valley, California. Geological Society of America Bulletin 58(5):393–432.
Hunt, C. B., and D. R. Mabey. 1966. Stratigraphy and structure, Death Valley, California. U.S. Geological Survey, Washington, D.C. Professional Paper 494-A.
Johnson, B. K. 1957. Geology of a part of the Manly Peak Quadrangle, southern Panamint Range, California. University of California Publications in Geological Sciences 30(5):353–423.
Keller, M., J. D. Cooper, and O. Lehnert. 2012. Sauk Megasequence supersequences, southern Great Basin: second-order accommodation events on the southwestern Cordilleran margin platform. Pages 873–896 in J. R. Derby, R. D. Fritz, S. Longacre, W. A. Morgan, and C. A. Sternbach, editors. The great American carbonate bank: the geology and economic resources of the Cambrian-Ordovician Sauk Megasequence of Laurentia. American Association of Petroleum Geologists, Tulsa, Oklahoma. Memoir 98.
Klingman, D. S. 1987. Depositional environments and paleogeographic setting of the Middle Mississippian section in eastern California. Thesis. San Jose State University, San Jose, California.
Langenheim, R. L., Jr., and H. Tischler. 1960. Mississippian and Devonian paleontology and stratigraphy, Quartz Spring area, Inyo County, California. University of California Publications in Geological Sciences 38(2):89–150.
Maldonado, F. 1990. Geologic map of the northwest quarter of the Bullfrog 15-minute Quadrangle, Nye County, Nevada. U.S. Geological Survey, Reston, Virginia. Miscellaneous Investigations Series 1985. Scale 1:24,000.
McAllister, J. F. 1952. Rocks and structure of the Quartz Spring area, northern Panamint Range, California. California Division of Mines and Geology, Sacramento, California. Special Report 25.
McAllister, J. F. 1956. Geologic map of the Ubehebe Peak Quadrangle, California. U.S. Geological Survey, Washington, D.C. Geologic Quadrangle Map 95.
McAllister, J. F. 1974. Silurian, Devonian, and Mississippian formations of the Funeral Mountains in the Ryan Quadrangle, Death Valley region, California. U.S. Geological Survey, Washington, D.C. Bulletin 1386.
Merriam, C. W., and W. E. Hall. 1957. Pennsylvanian and Permian rocks of the southern Inyo Mountains, California. U.S. Geological Survey, Washington, D.C. Bulletin 1061-A.
Nelson, C. A. 1971. Geologic map of the Waucoba Spring Quadrangle, Inyo County, California. U.S. Geological Survey, Washington, D.C. Geologic Quadrangle Map 921. Scale 1:62,500.
Ragan, D. M. 1953. Geology of Butte Valley, Inyo County, California. Thesis. University of Southern California, Los Angeles, California.
Randall, R. G. 1975. Geology of the Salt Springs area, Death Valley, California, and its bearing on early Mesozoic regional tectonics. Thesis. San Jose State University, San Jose, California.
Richards, C. A. 1957. Geology of a part of the Funeral Mountains, Death Valley National Monument, California. Thesis. University of Southern California, Los Angeles, California.
Ross, R. J., Jr. 1964. Middle and Lower Ordovician formations in southernmost Nevada and adjacent California. U.S. Geological Survey, Washington, D.C. Bulletin 1180-C.
Ross, R. J., Jr., and H. Barnes. 1967. Some Middle Ordovician brachiopods and trilobites from the Basin Ranges, western United States. U.S. Geological Survey, Washington, D.C. Professional Paper 523-D.
Stevens, C. H., editor. 1991. Paleozoic shelf-to-basin transition in Owens Valley, California. Society of Economic Geologists and Paleontologists, Pacific Section, Los Angeles, California. Field Trip Guidebook 69.
Stevens, C. H., and P. Stone. 2007. The Pennsylvanian-Early Permian Bird Spring carbonate shelf, southeastern California: fusulinid biostratigraphy, paleogeographic evolution, and tectonic implications. Geological Society of America, Boulder, Colorado. Special Paper 429.
Stevens, C. H., G. C. Dunne, and R. G. Randall. 1979. Carboniferous stratigraphy of part of eastern California. U.S. Geological Survey, Washington, D.C. Professional Paper 1110-CC:CC10–CC21.
Stevens, C. H., D. S. Klingman, C. A. Sandberg, P. Stone, P. Belasky, F. G. Poole, and J. K. Snow. 1996. Mississippian stratigraphic framework of east-central California and southern Nevada with revision of Upper Devonian and Mississippian stratigraphic units in Inyo County, California. U.S. Geological Survey, Reston, Virginia. Bulletin 1988-J.
Stevens, C. H., P. Stone, and S. M. Ritter. 2001. Conodont and fusulinid biostratigraphy and history of the Pennsylvanian to Lower Permian Keeler Basin, east-central California. Geology Studies 46:99–142.
Stevens, C. H., R. T. Magginetti, and P. Stone. 2015. Regional implications of new chronostratigraphic and paleogeographic data from the Early Permian Darwin Basin, east-central California. Stratigraphy 12(2):149–166.
Stevens, C. H., R. T. Magginetti, P. Stone, and S. M. Ritter. 2015. Stratigraphy and paleogeographic significance of Late Pennsylvanian to Early Permian channeled slope sequence in the Darwin Basin, southern Darwin Hills, east-central California. Stratigraphy 12(2):185–196.
Stevens, C. H., R. T. Magginetti, and P. Stone. 2015. Architecture and evolution of an Early Permian carbonate complex on a tectonically active island in east-central California. Stratigraphy 12(2):167–183.
Stone, P., and C. H. Stevens. 1987. Stratigraphy of the Owens Valley Group (Permian), southern Inyo Mountains, California. U.S. Geological Survey, Reston, Virginia. Bulletin 1692.
Stone, P., C. H. Stevens, and R. T. Magginetti. 1987. Pennsylvanian and Permian stratigraphy of the northern Argus Range and Darwin Canyon area, California. U.S. Geological Survey, Reston, Virginia. Bulletin 1691.
Stone, P., G. C. Dunne, C. H. Stevens, and R. M. Gulliver. 1989. Geologic map of Paleozoic and Mesozoic rocks in parts of the Darwin and adjacent quadrangles, Inyo County, California. U.S. Geological Survey, Reston, Virginia. Miscellaneous Investigations Series 1932. Scale 1:31,250.
Stone, P., B. J. Swanson, C. H. Stevens, G. C. Dunne, and S. S. Priest. 2009. Geologic map of the southern Inyo Mountains and vicinity, Inyo County, California. U.S. Geological Survey, Reston, Virginia. Scientific Investigations Map 3094. Scale 1:24,000.
Stone, P., C. H. Stevens, P. Belasky, I. P. Montañez, L. G. Martin, B. R. Wardlaw, C. A. Sandberg, E. Wan, H. A. Olson, and S. S. Priest. 2014. Geologic map and upper Paleozoic stratigraphy of the Marble Canyon area, Cottonwood Canyon quadrangle, Death Valley National Park, Inyo County, California. U.S. Geological Survey, Reston, Virginia. Scientific Investigations Map 3298.
Wrucke, C. T., P. Stone, and C. H. Stevens. 2007. Geologic map of the Warm Spring Canyon area, Death Valley National Park, Inyo County, California. Scientific Investigations Map 2974. Scale 1:24,000.