Journey to the northwestern sector of Death Valley National Park to visit one of the great Early Cambrian fossil localities in North America.
Please note: Fossil collecting is prohibited within the boundaries of Death Valley National Park, except by special permit from the National Park Service--a special use permit given only to qualified, trained scientists with a degree from an accredited university who seek to undertake research that can be fully verified and corroborated by the National Park Service. No fossil must be removed from the world-famous Waucoba Spring geologic section in Death Valley National Park without such a permit--under penalty of the law. Rest assured that unauthorized individuals caught removing fossils from the Waucoba Spring Section will be prosecuted to the fullest extent of the law. And understand that the Waucoba Spring Section is frequently patrolled by park rangers, because they recognize that the wonderful early Cambrian fossils preserved there are a great temptation for unauthorized folks to remove illegally from the national park.
And now for the obligatory words of caution. Endemic to the Mojave Desert of California, including the Las Vegas, Nevada, region by the way, is Valley Fever. This is a potentially serious illness called, scientifically, Coccidioidomycosis, or "coccy" for short; it's caused by the inhalation of an infectious airborne fungus whose spores lie dormant in the uncultivated, harsh alkaline soils of the Mojave Desert. According to the page "Valley Fever Maps And History," Death Valley National Park just happens to lie within a northern sector of the Mojave where Valley Fever spores have been detected. When an unsuspecting and susceptible individual breaths the spores into his or her lungs, the fungus springs to life, as it prefers the moist, dark recesses of the human lungs (cats, dogs, rodents and even snakes, among other vertebrates, are also susceptible to "coccy") to multiply and be happy. Most cases of active Valley Fever resemble a minor touch of the flu, though the majority of those exposed show absolutely no symptoms of any kind of illness; it is important to note, of course, that in rather rare instances Valley Fever can progress to a severe and serious infection, causing high fever, chills, unending fatigue, rapid weight loss, inflammation of the joints, meningitis, pneumonia and even death. Every fossil enthusiast who chooses to visit the Mojave Desert must be fully aware of the risks involved.
|A visitor to the Waucoba district looks eastward to the classic Early Cambrian Waucoba Spring section in northwestern Death Valley National Park. The slope at upper left is composed of the Lower Cambrian Montenegro Member of the Campito Formation (near the base, or oldest layers, of the section), which yields some of the oldest Olenellid trilobites in North America, in addition to many annelid burrows and arthropod tracks and trails. Prior to December 1994, when the Desert Protection act became law and created Death Valley National Park, the world-famous Waucoba Spring geologic section could be found outside of Death Valley National Monument. Today, the Waucoba Spring district lies within Death Valley National Park. Removing fossils from a national park without prior formal, written approval from the National Park Service is verboten.|
Relatively few localities on Earth record the important Precambrian-Early Cambrian transition period--a fascinating and truly mysterious interval some 545 to 500 million years ago, when abundant animal life with shells or a hard external covering first appear in the geologic record.
One of the best places to study this crucial boundary between two major geological Eras (Precambrian and Paleozoic) is the Waucoba district, some 35 miles southeast of Big Pine, California, on the eastern slopes of the Inyo Mountains, a locality that now lies within the northwestern border of Death Valley National Park (as of 1994, when the Desert Protection Act became law). Here can be found the classic Waucoba Spring section, first measured and described by Charles Doolittle Walcott in the 1890s.
Walcott is most famous for his discovery of the Middle Cambrian Burgess Shale fauna of Canada, an assemblage of soft-bodied organisms whose representatives have been recovered elsewhere only at a specific Early Cambrian site in China. But Walcott was vitally interested in all aspects of the Cambrian Period, and his detailed analysis of the Waucoba Spring geologic section elevated the site to the status of type reference section for the Waucoban Series of the lowermost Cambrian. This means that all age-equivalent strata in the world are correlated with the Waucoba Spring rocks.
Not only is the important Precambrian-Cambrian boundary well exposed near Waucoba Spring, but the sequence is amazingly fossiliferous for strata of such profound antiquity. Among the diverse fossil types that can be observed in situ at Waucoba are archeocyathids, an extinct, primitive invertebrate animal that secreted a conical to cup-shaped shell typically one-quarter to two inches long--the first reef-forming animal on Earth, it was likely an early calcareous sponge, although many archeocyathid purists still prefer to call it a unique organism with no known modern analogs, deserving of its own scientific Phylum. There are also worm trails, miscellaneous invertebrate tracks and trails (probably from trilobites and other kinds of ancient arthropods), salterella (an early experiment, now an extinct member of the Phylum called Agmata, with a small tusk-shaped shell roughly a quarter inch long), algal bodies, brachiopods and trilobites. Most of the fossil material is surprisingly well-preserved, and there is even one specific site where perfect, intact trilobite carapaces can be observed. Please note, of course, that the Waucoba Spring geologic section presently resides within the borders of Death Valley National Park. One must not remove fossil specimens within the park's boundaries without formal, written approval from the National Park Service personnel at Furnace Creek in Death Valley.
To reach the Waucoba district, first travel to the intersection of Highway 395 and State Route 168 in Big Pine, California. Turn east on route 168 and proceed 2.4 miles to Death Valley Road (to Saline Valley, Eureka Valley and Scotty's Castle). Turn right here.
At the 2.3 mile mark from the SR 168, look to the north of the road (left) and you will begin to see the impressive badlands carved the Pleistocene sedimentary rocks deposited in ancient Lake Waucoba. These calcareous silts and sands, so prominently exposed, accumulated during the Sherwin Glacial Stage of the Pleistocene Epoch, approximately 760,000 years ago.
The Waucoba Lake Beds (their formal geologic formation name) are in fact correlated with the Sherwin Till, a deposit of rocky rubble left behind in the neighboring Sierra Nevada during one of the four major glacier meltings recognized by geologists. Thus, Pleistocene Lake Waucoba was formed by direct runoff from glacier meltings in the Sierra Nevada to the immediate west. It is not known how long the lake existed as such, but the presently exposed strata exceed 100 feet in several places, an indication that sedimentary deposition occurred over many thousands of years.
In the 1890s, C.D. Walcott, on his way to the Early Cambrian rocks exposed farther southeast, discovered an abundance of freshwater snail fossils from several beds in the Pleistocene section. For those interested in researching the original reference to the molluscan assemblage, Walcott's paper appears in the Journal of Geology, volume 5, 1897.
During the next mile and half the Waucoba Lake Beds are easily accessible to the north of Death Valley Road. Several beckoning dirt trails lead off into the rugged badlands and, indeed, this might be a valuable area in which to conduct original paleontological investigations. I have run across very few references to the fossil mollusks and in fact know of no scientific paper dedicated exclusively to their geologic occurrence.
When you have driven 13.5 miles from the SR 168, turn right on Waucoba-Saline Road. This path can be followed all the way through Saline Valley, just inside the westernmost boundary of Death Valley National Park. It is for the most part a well-graded dirt road, although the Whippoorwill Canyon area a few miles up ahead tends to be rocky and rutted--a condition one would expect to encounter on a dirt route through such a defile in the mountains.
At the 8.1 mile point from Death Valley Road, Waucoba-Saline Road begins to cut through one of the oldest recognizable sedimentary rock formations in North America: the Wyman Formation. The dark-brown to gray-brown exposures along either side of the path consist of heat and pressure-altered sandstones and siltstones. Some portions of the formation have been changed to quartzite through the eons of tortuous metamorphism. From a distance, these Wyman rocks have a suspicious volcanic aspect: a blocky, basalt-like tone and style of outcropping. Closer examination, though, reveals the obvious sedimentary nature of the material; the strata reveal the characteristic layered bedding and fine-grained composition of altered sandstones and siltstones.
No animal remains have been recovered from the Wyman Formation. At this point in the local stratigraphic section you are standing thousands of feet below the first occurrence of Olenellid trilobites, which in a traditional sense used to define the beginning of the Cambrian Period and the Paleozoic Era. Not any longer, though. The Precambrian-Cambrian boundary is now defined as either (1) the appearance of a trace fossil called Treptichnus pedum, or (2) a distinctive negative carbon isotope excursion in the sediments at the boundary. Rarely do the two defining occurrences--biological and geochemical--occur together, but there's one place in Death Valley where such a unique combination of defining events can be studied. It's in Boundary Canyon near Daylight Pass, along the road to Beatty, Nevada, in the lower member of the Wood Canyon Formation.
Unicellular organisms, in addition to species of algae, most certainly lived here during Wyman time--nearly a billion or so years ago--but due to intense metamorphism any trace of their former existence has long since been obliterated.Still, a relatively few pure limestone pods have been reported in the Wyman. If such rocks could be located in the predominantly detrital terrigenous terrain, there would naturally be a greater opportunity to discover some of the oldest identifiable animal fossils on Earth.
At a point 13.8 miles from Death Valley Road, the path starts to slice through scenic Whippoorwill Canyon. Rocks exposed here belong to the upper Precambrian Reed Dolomite and Deep Spring Formation, roughly 700 to 600 million years old. In contrast to the predominantly detrital Wyman Formation, these two rock units contain relatively high percentages of carbonates, rocks composed of calcium carbonate and magnesium carbonate (dolomite), precipitated on the floors of vast, warm, shallow seas.
Near the very top of the Reed Dolomite, in strata transitional with the younger Deep Spring Formation, scientists have found the earliest evidence of a widespread variety of animals with shells. Most of the described specimens are minute, measured in millimeters (about one-twenty-fourth of an inch). But they represent such identifiable forms as worm tubes and primitive mollusks. I have personally scoured the Whippoorwill Canyon area for fossils but have yet to find any there. (The worm-tube/primitive mollusk horizon occurs in the same formations at Mount Dunfey in neighboring Esmeralda County, Nevada. It also shows up in the Westgard Pass region several miles east of Big Pine.) Even so, this is an excellent place for paleontological explorations. It is one of the most significant geologic regions in all the world. Because most of the sedimentary material exposed here is miraculously unaltered, there is great potential for the discovery of the oldest identifiable animal with a shell.
For two miles the Waucoba-Saline Road carves through the Precambrian strata of Whippoorwill Canyon. All along this route you move gradually upsection--that is, as you proceed south the rocks become progressively younger in geologic age. The base, or the section bearing the oldest layers of the classic Waucoban section, as defined by pioneering paleontologist Walcott, occurs in transitional Upper Precambrian to Lower Cambrian rocks of the Campito Formation. This world-famous change from the Precambrian to the Paleozoic Era lies directly to the east of the Waucoba-Saline Road, 16 miles from the Death Valley Road junction. To the left of the road you will note typically blocky weathering black to brownish quartzites and shales of the Andrews Mountain member of the Campito Formation, within which the oldest Olenellid trilobites have been recovered. The fossils are by no means common here--they are, indeed, frustratingly rare (one lone occurrence discovered by a very lucky paleontologist; unfortunately, there is reason to believe that that specimen could have come from much younger strata--the trilobite was recovered from a wash and could have been transported to the site of discovery), although exposures of the Andrews Mountain member in neighboring Esmeralda County have yielded a few identifiable trilobite specimens.
After examining the exposures of the Campito Formation here, proceed one additional mile to the turnoff to Waucoba Spring, where you will be within a short hiking distance of fossiliferous Early Cambrian strata in the Waucoba section. Waucoba Spring lies approximately one-half mile west of Waucoba-Saline Road, 17 miles south of the intersection with Death Valley Road.
The spring is an old and famous watering hole for the local fauna, including feral burros whose presence in the Death Valley region has generated much controversy. Some investigators claim the burros foul critical watering holes and scare off more sensitive creatures such as bighorn sheep. Others exonerate the asses, pointing out that they have just as much right to exist in the wild as any indigenous creature and charges that they are solely to blame for the ruination of the ecology are absurd.
During my first visit to the Waucoba a number of years ago, I recall having observed quite a few burros. They'd halt right in front of a moving vehicle, staring inscrutably ahead. Subsequent trips to the Waucoban wilds in recent years have revealed a dramatic drop in the visible burro population. I do not know whether natural selection has been weeding out the weak or artificial measures have been employed--such as periodic thinning of the paces/herds by gunfire.
The classic Early Cambrian Waucoba Spring section described by Walcott lies to the east of Waucoba-Saline Valley Road. To reach the fossil-bearing exposures it is necessary to hike approximately a quarter of a mile to the nearest hillslope, directly east of the turnoff to Waucoba Spring. This slope is composed of the greenish shales and quartzites of the Montenegro Member of the Campito Formation, within whose detrital rocks can be seen worm trails, invertebrate tracks (many made by trilobites, but also several varieties that have not been positively identified as yet) and infrequent trilobite head shields, or cephalons. A much better region in which to hunt for the oldest reasonably common trilobites in the geologic record is over in neighboring Esmeralda County, Nevada, where geologist J. S. Hollingworth has had several Montenegro Member sections under study for over ten years now. One specific section has yielded many complete Fallotaspis trilobites, along with several other early Olenellid trilobite varieties. Click Here to take a look at a mostly complete Fallotaspis trilobite I collected from the Montenegro Member of the Lower Cambrian Campito Formation of Esmeralda County, Nevada.
|Here is the southernmost area of a portion of a geologic map showing a good portion of the classic Waucoba Spring geologic reference section that lies north and east of the turnoff to Waucoba Spring. All of this area now lies with the boundaries of Death Valley National Park--absolutely no collecting of any kind is allowed without a formal permit issued by the National Park Service. The black arrow at lower center of image points to the intersection with the dirt trail that leads west to Waucoba Spring--a junction that lies 17 miles from Death Valley Road. The contour interval is 80 feet; scale is one mile equals two and one-fifth inches. For those unfamiliar with reading such geologic maps, one thing to remember is that the universal symbol for all Cambrian-age formations is a distinctive capital C with an elongated dash (-) through the center of the letter. Geologic formations detailed in the image include, from oldest to youngest: rh, Hines Tongue member of the Precambrian Reed Dolomite; ru, upper member of the Reed Dolomite; dl, dm, du--lower, middle and upper members, respectively, of the Precambrian Deep Spring Formation; Cc (all capital "C's" here refer to the Cambrian symbol, as discussed above), Precambrian-Early Cambrian Campito Formation undivided; Cca, Precambrian and Early Cambrian Andrews Mountain Member of the Campito Formation; Ccm, Lower Cambrian Montenegro Member of the Campito Formation; Cpl, lower archeocyathid-bearing limestone member of the Lower Cambrian Poleta Formation; Cp, middle and upper members of the Poleta Formation combined; Ch, Lower Cambrian Harkless Formation; Csl, lower member of the Lower Cambrian Saline Valley Formation; Mpl, lower member of the Upper Mississippian Perdido Formation; Kd, Cretaceous-age diorite volcanics; black arrow obscures the symbol Qf, which refers to Quaternary alluvial fan gravel.|
As you continue to hike in a generally southeasterly direction along the hillside, the greenish shales and quartzites give way to geologically younger gray-blue to buff-brown archaeocyathid-bearing limestones of the Poleta Formation. Most specimens range from a half-inch to two inches in length, and quite a number of archeocyathid fragments have weathered out of the rocks. A few of the more densely packed clusters of archeocyathids observed in the limestones are likely the preserved remains of primitive, localized reefs.
All of the trilobites within the Poleta Formation occur in the younger, gray-green shales which lie directly on top of the archeocyathid-bearing limestone. In addition to the trilobites, which are apparently rare in the extensive deposits of shale, abundant worm trails and invertebrate tracks can also be seen. These fossiliferous shales are in striking stratigraphic contact with the older archeocyathid limestone, and the lithologic contrast is so distinctive that this contact can be traced with assurance throughout the Waucoba district, and the western Great Basin, as well (northern Inyo County and western Esmeralda County, Nevada).
Additional fossil material can be observed in place from the next-youngest geologic rock unit in the Waucoban section, the Harkless Formation. An overabundance of worm trails and invertebrate tracks, plus salterella and a few species of archeocyathids are characteristic of the formation, which outcrops roughly three-quarters of a mile to one mile directly east of the Waucoba Spring turnoff. The Harkless is chiefly a terrigenous unit of gray shale and siltstone, interbedded with brownish quartzites. Minor lenticular blue-gray limestones in the youngest phases of deposition often yield large archeocyathids, some up to nine inches in length.
Extended periods of hiking are obviously required to examine all of the fossil material present in these geologic rock formations. The trilobites in particular are seldom even common at any one locality. They are usually confined to the greenish shales of the Poleta Formation, several feet above the archeocyathid-rich limestones.
A better place in which to observe in situ trilobites lies farther south, in much younger exposures of the Early Cambrian Waucoba section at Algae Ridge, where the Lower Cambrian Mule Spring Limestone contains abundant fossil remains of a species of blue-green algae called Girvanella.
The Mule Spring limestone contains the highest concentration of fossil algae of any Cambrian formation in the Great Basin. It is estimated that in some horizons Girvanella fossils constitute fully 40 percent of the limestones by volume. At Algae Ridge these fossil remains are certainly locally prolific, appearing as oval to circular black blobs roughly one-quarter to three-quarters of an inch in diameter, embedded in the blue-gray rocks.
The Mule Spring Limestone marks the very top, or youngest part of the Waucoba Spring geologic reference section. Above it lies the Middle Cambrian Monola Formation whose prominent exposures can be seen about a mile and a half to the south, near where the dramatic expanse of Saline Valley commences.
The prime trilobite locality (prior to December 1994 this site was open to hobby fossil collecting; please note that it now lies within the borders of Death Valley National Park. Look and touch, but don't keep anything you find there--unless it's a photograph of a fossil specimen, of course) lies on Algae Ridge in the Saline Valley Formation.
At the fossil site one can examine abundant trilobite head shields, plus occasional perfect, intact specimens. During my last visit to the site before it was assimilated by the national park system, I was fortunate to find three complete, whole trilobites--a powerfully exhilarating and rewarding experience, to be certain. Perfect specimens are far from common, of course, but the fact that there are any at all helps set this specific Early Cambrian fossil site apart from most others.
A superior supplemental publication to consult is USGS Professional Paper 620, Upper Precambrian and Lower Cambrian Strata in the Southern Great Basin, California and Nevada, by John H. Stewart, 1970. Stewart describes in marvelous detail all of the Early Cambrian geologic formation of Inyo County, California, and Esmeralda County, Nevada--a genuine gem of geologic literature.
The Waucoba district is a wild, rugged, pristine land. It is also out in the middle of nowhere, miles from civilization. This means that adventurers traveling to the region must make certain that their vehicles are in perfect working condition and must also carry in extra food, plenty of water, spare fan belts (and know how to change one!) and protective clothing. In short, take all necessary precautions to ensure a safe experience.
Most of my Waucoban trips have been during the early Spring, mainly in early to mid April. I'm not presuming to suggest that this is the most comfortable time of the year there, but, by way personal experience, I recall one August spell that turned into pure vapor lock of the brain--soaring daytime temperatures even up in Whippoorwill Canyon--and a brief stay in December practically froze my toes off.
The Waucoba district certainly contains one of the greatest Early Cambrian stratigraphic sections in all the world: the classic Waucoba Spring section first described by C.D. Walcott in the late 1800s. Except for the improvement of Waucoba-Saline Road and the addition of a few minor off-road-vehicle trails, the region likely appears much the same as it did over a hundred years ago. The Precambrian-Early Cambrian transition exposed here records the fossilized remains of plants and animals that lived in this part of what is now the Great Basin some 600 to 515 million years ago--a time so distant, so primordial that it echoes back to a moment when the Spirit moved over the face of the waters and said, "Let there be light."
In addition to my many Web pages pertaining to matters paleontological and geological, I also have 5 sites up and running that feature my solo, acoustic, instrumental 6 and 12-string guitar playing--in addition to songs I have recorded with my parents over the years (family music) And it's all free music--for listening and for downloads of the mp3 files.
Jump on over to The Acoustic Guitar Solitaire Of Inyo--A Cyber-CD for 30 covers of some of my favorite songs--all played on a 1976 Martin D-35 6-string guitar.
For 32 mp3 selections of original compositions and covers of some of my favorite songs--all played on a 1970 Stella 12-string guitar, a 1976 Martin D-35 guitar and a Sigma DMISTCE guitar, head on over to Beyond The Timberline--A Cyber-CD .
At The Distant Path--A Cyber CD listen to me play 32 covers and original compositions on a 1976 Martin D-35, a Sigma DMISTCE 6-string guitar and a 1970 Stella 12-string guitar.
Over at Inyo And Folks--A Musical History I've created a page that features 35 songs I recorded with my parents--all played on acoustic 6 and 12-string guitars, banjo, kazoo and tambourine.
Go to Acoustic Stratigraphy to listen to me play 34 covers of some of my favorite songs on 6 and 12-string guitars.
For a streaming m3u playlist of all 163 of my songs placed on the internet, go to All Inyo All The Time. Simply click on the link and all 163 musical selections will play in order of their appearance on the web--from my first Cyber-CD (The Acoustic Guitar Solitaire Of Inyo) to the last, "Inyo And Folks--A Musical History."