Sunday, September 4, 2016

Death Valley Geology Calling: Part I - Where Is It? What Is It? What Isn't It?

"Death Valley is the Grand Canyon put into a juicer and minced!" 
Geologist, Author and Guide Wayne Ranney, 2016

Over the course of almost two billion years, the Death Valley region has experienced a long and varied series of geologic events with each progressively adding complexity to the former. They include the fragmentation of two supercontinents - Rodinia in the Late Proterozoic and Pangaea in the Mesozoic - at least four episodes of major volcanism, three or more intervals of marine deposition - one in the Late Proterozoic, another during the Paleozoic and a third during the early Mesozoic - at least four prolonged periods of large-scale tectonic deformation and two or more low-latitude, global glaciations in the Late Proterozoic. 

Beginning in the late Mesozoic, tectonic compression led to severe and widespread crustal extension in the late Cenozoic across western North America's Basin and Range province including Death Valley. Extension is thought, in part, to have operated synchronously under the influence of two superimposed stress fields, one tectonically-controlled and the other gravity-induced. 



Iconic and Photogenic Zabriskie Point Badlands Overlooking Death Valley
Beginning ~14 million years ago, before the lowering of adjoining Death Valley, Furnace Creek basin developed in response to right-lateral displacement along the Furnace Creek fault and detachment faulting along the northern part of the Black Mountains. The rhombochasm downdropped during middle Miocene to Pliocene time between the uplifting Funeral Mountains to the north and the Greenwater and Black Mountains to the south. As the northwest-elongated half-graben opened parallel to the Funerals front, the depocenter received Artists Drive, Furnace Creek and Funeral Formations in succession. On display at Zabriskie Point are colorful layered mudstones, siltstones, alluvia and ash of the Furnace Creek Formation that, upon exposure and uplift, have eroded into rills, gullies and extension-tilted badlands. The sentinel peak of Manly Beacon (right) overlooks Death Valley's Badwater Basin (center) and the Panamint Range (background). In the early 20th century, Christian Brevoort Zabriskie was the VP and GM of the Pacific Coast Borax Company. This photo was post-processed with tone mapping. Go there (36°25'12.49"N, 116°48'44.03"N).


Death Valley's landscape lies in contrast to the Grand Canyon in nearby northern Arizona. Their crystalline basements and sedimentary successions formed under closely related orogenic, rift-to-drift and Cordilleran miogeoclinal circumstances, but the Grand Canyon's rocks have remained uplifted, untilted and largely undeformed. If it wasn’t for the fortuitous erosive action of the Colorado River system, they would not have been exposed. 

Death Valley, on the other hand, possesses a diverse, complicated and beguiling terrain with a distribution of rocks that are variably faulted, folded, deformed, mangled, chaotic and nothing less than a challenge to interpret. In addition to being relatively uneroded, unobstructed by vegetation and unmarred by glaciation, extension has provided a landscape that is well exposed and highly accessible.



Tortured South Wall of Titus Canyon in the Grapevine Mountains of Northeastern Death Valley
With the exception of aptly-named Amargosa Chaos of southern Death Valley, perhaps nowhere else in the region better demonstrates the cumulative complexity of geological events experienced by the landscape than on a drive on Titus Canyon Road through east-west trending Titus Canyon in the Grapevines along northern Death Valley’s northeast border. Late Proterozoic through Quaternary strata are exposed in the range with lowermost representing siliciclastic rift strata acquired during the fragmentation of the supercontinent of Rodinia and overlying carbonates, sandstones and shales deposited on the early developing Laurentian passive margin sequence. Factor in compression related to the development of the Cordilleran fold and thrust belt in late Paleozoic and Mesozoic time and Basin and Range extension in late Cenozoic time. The result can be seen in folded shale and limestone beds of the widely-distributed Middle Cambrian Bonanza King Formation that form the south wall of Titus Canyon in the vicinity of the Leadfield Mine. Yet, the wall is even more tortured than it looks. The rocks are completely upside-down, so the oldest rock in the fold is in the core --which makes it an anticline. You can't tell that from the photo, but you can tell it by following the stratigraphy down the canyon. Therefore, it’s a synformal anticline. Think of it as an anticline (where the rock layers get younger away from the axial surface of the fold) that has been inverted, but it has the shape of a synform (with a trough-like shape). Multifolded stratigraphic layers such as this are typical of collisional environments. From the air, the upturned, upfolded (anticlinally), downfolded (synclinally) and recumbant folds (turned back on itself) of Titus Canyon make more sense. Visit Marli Miller (here) for a great perspective. Thanks for the help with the clarification, Marli!


OUR PLAN
In mid-winter 2016, our intrepid party of four, under the guidance of geologist and author Wayne Ranney (here), explored Death Valley from its heights to its depths. Our plan was to investigate the geology, experience the region's otherworldly aura, beat the heat and precede the throngs that arrive to see the colorful wildflowers that typically appear in spring. We succeeded on all accounts and, to our delight, arrived in the midst of a once-in-a-decade spectacular "super-bloom" spawned by El Niño rains in October. 


Helen is Regaled in the Midst of a Wildflower Superbloom
In the shadow of Copper Canyon Turtleback along the Black Mountains front on Death Valley's east side, the gently sloping, spring-fed apron of an alluvial fan provides fertile ground for a new carpet of Desert Gold wildflowers. To withstand the dry blistering heat, they blossom for only a short time and go to seed after just a few weeks. Lying dormant for years, they patiently await the appropriate conditions to germinate. The average annual rainfall in Death Valley is barely two inches, but October 2015 El Niño storms brought a deluge that exceeded that in one day. In February, over 20 species of spectacular wildflowers joyously appeared to celebrate the event. Go there (36°04'45.85"N, 116°45'50.63"W).

This is my first post of three on the geology of Death Valley. It begins with a compilation of some of the region's most vexing questions, many of which remain unanswered and hotly debated. It is followed by a discussion of the region's geographic and physiographic location in western North America. Part II presents a synopsis of Death Valley's geological evolution beginning with the acquisition its basement rocks in the Early Proterozoic. Part III offers a few examples of profound biologic resilience when confronted by Death Valley's environmental extremes and of the diverse human and mining history scattered about the region. Global co-ordinates have been added to each post that, when copied into a mapping program such as Google Earth, will allow you to "Go there."



Our Party of Four (Minus Me) at Ubehebe - Wayne, Helen and Dee
Late afternoon sun casts long shadows into erosion-gullied "big basket in the rock", named by the regional Timbisha Shoshone Native Americans. Ubehebe Crater is one of a dozen or so shallow maars in northern Death Valley volcanic field that erupted phreatomagmatically - a violent explosion of tephra and steam when magma contacts ground or surface water. Uppermost 50 or more beds of unconsolidated ash and fragmented bedrock overlie beds of tilted and faulted, iron oxide-stained, lower Miocene-age alluvium derived from the Grapevine Mountains. Passive volcanism in graben structures such as Death Valley is common and is related to a thinned lithosphere with alkaline magmas sourced from the partial melting of lithospheric mantle. Isotopic analyses of trace elements in the primary magma reveal a Precambrian mantle source in the Mojavia subcontinental lithosphere, suggesting the terrane genesis that formed the Death Valley region (see post Part II). Dating methods indicate a Holocene age of 2,000 to 7,000 years (one recent study found 300 years), recent enough to be considered active and potentially hazardous. It's a reminder that Death Valley's climate was once wetter, when pluvial lakes attained their peak size, and that the calm and motionlessness of the landscape was intensely interrupted in the recent past. Go there (37°00'35.12"N, 117°27'03.14"W).



WELCOME TO DEATH VALLEY
When conversing with individuals unfamiliar with its location - with the exception of geologists, residents of the Southwest and baby-boomers who watched Death Valley Days on television when they were kids - the most common questions are "Where is it?" and "Isn't it a desert?" The uninformed are gratified to learn that it is a desert but are surprised to discover that barely 10% of its surface is covered with sand. But, deserts are defined by lack of rainfall, not surface composition or elevation. And they're not all hot. In fact, the two largest deserts on Earth are located at each of the poles - sandless and frigid. In addition, they are astounded to hear that Death Valley is flanked by spectacular mountain ranges, some snow-capped and some that tower almost two miles above the desert floor, which is below sea level. Lets investigate the geography.




Simply stated, Death Valley is the geological centerpiece of Death Valley National Park in southeastern California along the southwest Nevada state line. The north-south basin of Death Valley is divided into three contiguous subbasins that vary somewhat in structure and timing of formation while sharing a commonality of extensional tectonics, from north to south: Cottonball, Middle and Badwater. They lie between the lofty Panamint Range on the west and the Amargosa Mountain Range on the east. The range-basin-range triad possesses a roughly N-S trend, in keeping with the alternating landforms of the Basin and Range physiographic province in which it resides.

The 110 mile-long Amargosa Range consists of three sub-ranges, from north to south: the Grapevine, Funeral and Black Mountains with the Ibex Hills in the south. Northeast of the Blacks, across Grand View Valley, stretches the smaller Greenwater Range that, along with the Funeral Mountains, defines intervening Furnace Creek Wash, a small basin that preceded the formation of Death Valley proper. State Route 190 follows the wash down into the valley from Death Valley Junction and Las Vegas further east.



Google Earth Image of the Death Valley Domain
Death Valley is bordered by the Panamint and Amargosa Ranges. The relationship of roughly north-south trending mountains and valleys - basins and ranges - that repeat across the landscape is characteristic and namesake of the Basin and Range province, while the endorheic hydrology, with waters that essentially are confined to each basin and never reach the open sea, is a characteristic of the Great Basin subprovince (see my post Part I for detailed explanations). Major roads in and out of the valley are labelled.


On Death Valley's west side are the Last Chance Mountains and the 100 mile-long Panamint Range. The latter consists of two sub-ranges: the Cottonwood and Panamint Mountains. The Owlshead Mountains are to the south. Beyond the Panamint Range to the west is Panamint Valley, and beyond that is Owens Valley - the westernmost valley in the Basin and Range province - and then the Sierra Nevada - the granitic mountainous spine of eastern California. On Death Valley's east side, beyond the Amargosa Range, lies the Amargosa Desert-Valley, and beyond that is Las Vegas Valley beyond the Spring Mountains.



Satellite Image of Death Valley
Flanked by mountain ranges on the east and west that embrace the desert floor, Death Valley extends from north to south for some 140 miles. Computer-enhanced, dark greens are forests of juniper and pine on high peaks that are still ascending, while the valley floor is filled with sediment, blanketed by alluvial fans that splay outward from the mountain fronts, scorchingly hot, dry as a bone and below the level of the sea - and still dropping! Various shades of brown and beige indicate bare ground resulting from varying mineral compositions in the surface. Appearing like limpid pools of water, bright blue-green patches are salt pans that hold little moisture on the surface. Below ground is a massive aquifer related to the region's hydrology and hint at a long-gone lake that once filled the valley in wetter times. Bright green circles off to the east are irrigation systems in Amargosa Valley. The south-flowing river in the lower right is the ephemeral Amargosa. It can be seen heading around the southern Black Mountains and then turning north into Death Valley where it terminates, typical of rivers in the region that never reach the open sea.
From NASA Earth Observatory and Landsat 7


VALLEY OF QUESTIONS
Death Valley's Early Proterozoic crystalline foundation formed during the assembly of the supercontinent of Rodinia on which are deposited Middle and Late Proterozoic shallow-marine, intracratonic basinal carbonate sequences of the Pahrump Group and latest Proterozoic to Early Cambrian sedimentary sequences on the newly-established passive margin of Laurentia. The Precambrian-Cambrian succession was acquired during Rodinia's dissassembly and is one of the best exposed in the world. It was deposited at a time of dramatic change in the biosphere that included putative "snowball earth" glaciations, fluctuating oceanographic and atmospheric chemistries, long-lived mantle convection patterns, and large-scale plate reconfigurations that led to eukaryote diversification prior to the Cambrian Explosion of animals.

•  What is the theorized association between Rodinia's fragmentation, global climate deterioration and biological evolution? 
•  The Pahrump Group contains intervals of carbonate rock directly over suspected glaciogenic deposits. These "cap" carbonates are found globally during the late Proterozoic. The unusual and abrupt facies registers strong negative (depleted) carbon isotopic signatures often associated with extinction events. Most assign them an oceanographic origin with flooding of continental shelves and platforms as low-latitudinal ice sheets melted. Do glaciogenic deposits in Death Valley correlate to similar successions regionally and globally? Do they bear relationships to "snowball earth" glaciations, the Sturtian and Marinoan ice ages in particular?
•  The Late Proterozoic world is also thought to have possessed a number of equatorial Death Valley "Pahrump-type" and Grand Canyon "Chuar-type" intracratonic marine basins. What have we learned from them regarding rifting, paleo-climate and biological evolution? 
•  Distinctive 'fingerprints' such as lithostratographic and geochemical similarities, paleontological correlates and detrital zircon geochronology are used to match rifted margins. What have we learned regarding the configuration of Rodinia? If the rift zone was positioned somewhere between the margins of SW Laurentia and perhaps Australia, Antarctica or Siberia, where was Death Valley in the big picture?



Dante's Spectacular View of Northern Death Valley
Named after the Middle Age Italian poet for his references to hell in the "Divine Comedy", Dante's View lies atop Coffin Ridge on the western front of the Black Mountains, one of three ranges that border Death Valley's east side. Across the valley along the Panamint Mountain front, over a dozen alluvial fans have coalesced into a massive bajada. At its termination on the valley floor, shoreline deposits record the presence of long-gone and enigmatic, oscillating Pleistocene Lake Manly. A mile below our overlook, eerie whitish swirls are precipitated evaporites that coat the salt pan of Badwater Basin among brownish sediments eroded from the ranges. Far to the north are tan sand dunes of Mesquite Flat. The rugated, convex-upward slope in the foreground is Badwater turtleback, one of three controversial features thought to be a region of Proterozoic crust brought to the surface by large-scale extensional faulting. Go there (36°13.582’N, 116°43.545’W).

Crustal thickness in the Basin and Range province averages only 30 km compared to 50 km of the adjacent Colorado Plateau to the east. Yet, before its Cenozoic collapse its crust was actually thicker than the Colorado Plateau, since it was the site of the Sevier Mountains thrust belt acquired during Farallon plate compression. Death Valley's landscape is partially a consequence of widespread gravitational collapse of the Sevier-orogenic, over-thickened Cordilleran crust. It's also the result of the slab's demise beneath the western rim of North America, when an oceanic-oceanic transform plate boundary system "jumped" onto the continent and changed the structural fabric of the Southwest. 

•  How did the development of the Pacific-North American plate boundary effect the structure of Death Valley and the Basin and Range province in which it resides? 
•  Most rifts occur between diverging plates along mid-ocean ridges, such as the East Pacific Rise, while only a few are on land. Continental rifts, whether wide or narrow, form in extensional tectonic settings typified by crustal thinning, sedimentary basins, and thermal activity. Does Death Valley's extensional regime demonstrate these processes?
•  Los Angeles resides on the Pacific plate, along with an "acquired" slice of coastal California and all of Baja California. If continental rifting continues, what is the future of the western continent? Will a new ocean basin form? Will Death Valley also  "depart" from the North American plate or will it "remain" on the plate in the vicinity of a new passive margin, as it did when Rodinia was breaking apart?


Birth of the San Andreas Fault System
Beginning in the latest Jurassic, the Farallon plate began to subduct beneath the westward-migrating (present coordinates) North American plate, driven by the fragmentation of Pangaea and the opening of the Atlantic Ocean. The East Pacific Rise spreading center between the two oceanic plates was likewise drawn toward the Farallon-North American converging boundary. Following the Farallon's demise, the spreading center entered the zone, bringing the Pacific and North American plates into contact along the newly-formed Pacific-North American plate boundary. The event converted the Farallon-North American plate, which was an Andean-style subduction zone (mountain-building and magmatism) into the Pacific-North American transform boundary (horizontal plate motion without the generation of new crust). On land, the boundary is best known as the San Andreas fault system.
Modified from sanandreasfault.org


Death Valley's landscape has undergone dramatic basin and range-style extension, consisting of a downdropped elongate basin flanked by bordering ranges. The ranges formed counterintuitively by crustal stretching rather than crustal compression, which typically drives uplift and continental volcanism. It has to do with strike-slip motion on the ~200 mile-long, north-south trending Death Valley fault system - a complex of zones, fault segments and strands that have been evolving over the past 14 million years. The system is confined to a relatively narrow zone from the northern end of Fish Lake Valley in Nevada, south along the entire eastern margin of Death Valley to the Garlock fault zone in California. The system's subdivisions include, from north to south: the Northern Death Valley, the Black Mountains and the Southern Death fault zones. The Furnace Creek fault system in Furnace Creek Wash branches southeast from the Northern system at the central basin and was a major player in the evolution of Death Valley in the late Miocene and Pliocene but largely inactive in the Quaternary. 

•  If the prevailing tectonic regime for Death Valley is strike-slip, how did the region extensionally "pull apart"? 
•  Furthermore, how did the mountain ranges ascend, if compression is generally required for uplift? 
•  Are the geodynamics ongoing? How do we know? What evidence of extension is there on the landscape that can be readily observed?
•  Why does Death Valley possess such extremes not only in relief but temperature and aridity?
•  For almost 150 years, the fact that topography in the Basin and Range province is controlled by normal faulting is recognized. But, what is the geometric behavior at depth of range-bounded faults as they dip beneath the intervening basins? Are some listric that dip steeply at the surface and abruptly flatten?



Fault Scarps and Tectonic-Induced Liquefaction in Alluvial Fan
Death Valley is bound by a system of relatively youthful, north-south trending active faults. The system extends over 200 miles valley along the mountain fronts on the valley's east side. John McPhee in his Pulitzer Prize-winning Basin and Range describes the system as "Basin. Fault. Range. Basin. Fault. Range. A mile of relief between basin and range." It's responsible for the region's astounding relief, varied landscape and even climate. Geomorphic features that affirm recent tectonic activity are abundant and observable, in spite of the fact that the faults are buried beneath thousands of feet of colluvia and alluvia. Immediately south of Badwater Basin and Badwater Turtleback, an alluvial fan that spills out from Badwater Canyon displays a series of eroded fault scarps (red arrow). Appearing as a series of eroded steps, they mark places where slip along the Black Mountains fault has displaced a portion of the fan. The fan is young geologically, which makes the faults even younger. Near the fan's terminus or toe, seismically-induced liquefaction (white arrow) has occurred in susceptible, unconsolidated and saturated coarse sandy gravel and sand that behaved in an aqueous manner. A series of deep, narrow grabens formed where the fan has extended by sliding downslope. On a large scale, liquefaction can be extremely destructive to population centers, especially in coastal and manmade fill-areas during earthquakes as small as magnitude five.

We frequently focus our attention on rapidly-moving, discrete faults where one or more continental plates interact such as the Pacific-North American plate boundary. Yet, a significant proportion of plate motion is also accommodated on complex, diffuse systems at hundreds to thousands of kilometers from interacting plate boundaries. Such is the case with the San Andreas fault system in coastal California, where of the 48-51 mm/yr of relative motion between the Pacific and North American plates, ~35 mm/yr is accommodated in a zone less than 100 kilometers wide or ~75%. The remainder of residual motion, some 15 mm/yr or ~25%, is distributed in a broad inland boundary of over a thousand kilometers wide in the Walker Lane belt, the Eastern California Shear Zone and the Basin and Range province.

•  How does the migration of strain transfer extensionally to Death Valley?
•  What is the relationship of Basin and Range volcanism to extensional tectonics? Is magmatism a passive response to crustal thinning or is asthenospheric upwelling (which accounts for the Basin and Range province's high thermal gradient, three times normal for continental areas) a trigger for extensional deformation? 
•  Do mantle processes such as a plume play an active role in promoting magmatism? Does a hot, buoyant mantle explain the province's high average elevation of 1,400 meters above sea level? Does that explain the magnitude of intraplate volcanism within the Basin and Range province? Where does Death Valley fit in?
•  Why does the Basin and Range province consist of a broadly-distributed region of strain instead of one or two elongate rifts of typical continental rifts? 
•  Does extension of the Basin and Range's orogenic (Sevier-thickened) lithosphere differ from extension of cratonic lithosphere?      



The Pacific-North American Plate Boundary in Southern California and Northwest Mexico
Jumping onto land, the spreading center converted the convergent plate boundary into a transform zone with dextral strike-slip, which reflects the northwest drift of the Pacific plate relative to the North American plate. The event terminated over 140 million years of continental compression in western North America with the exception of a few small Farallon remnants). , captured a sizable slice of coastal California for the Pacific plate, tore Baja California from mainland Mexico, opened the Gulf of California and initiated ongoing extension across the landscape of western North America including Death Valley. Today, Pacific-North American plate motion is distributed across the western United States primarily along the San Andreas system and the remainder in seismic zones to the east. The transform fault system, rather than linear in strike, warps and bends which produces transpressional and transtensional regions along its path. Death Valley is the type-example where lateral motion has given way to a transtensional pull-apart basin manifested by faulted mountain fronts, tilted and uplifted ranges, extensive saline playa, metamorphic core complexes and spectacular alluvial fans.

Modified from livescience.com, Rymer et al, 2002 and Fuis, 2003.

Death Valley is actually composed of three contiguous sub-basins, from north to south: Cottonball, Middle and Badwater. Their formative and structural histories differ, but they share a commonality of tectonic extension. The northern and southern sub-basins are parallel and trend roughly northwest, while the center sub-basin trends north to south. Faults in the north and south are strike slip, whereas those in the center are largely normal faults with oblique components. 

•  How did they evolve? Did they do so coevally?
•  How can strike-slip and normal faulting co-exist in one fault system? Is there an interplay? What's a pull-apart basin? What's a rhombochasm?
•  What is the relationship of Furnace Creek Basin to the adjoined younger and lower basin of Death Valley?
•  A relatively small Holocene-age volcanic field called Ubehebe lies in northern Death Valley. The field's eruptive style is phreatomagmatic - amagmatic explosions of steam and ash rather than effusive emanations of lava. Whether subterranean or surficial, where did all that water come from? Does the eruption imply a wetter paleo-climate for the region or was the abundance of water related to an underground remnant of paleo-Lake Manly that once filled the entire valley?
•  Mesozoic and Tertiary volcanic and intrusive rocks are found in Death Valley basin and some ranges. What's their genesis in regards to the region's evolutionary history?
•  On a grander scale, the relationship and interplay of tectonics and magmatism in the Basin and Range province has been a topic of long-standing debate. Is there a relationship between extension and magmatism in the Basin and Range province and Death Valley? Does it play an active role in extension or is magmatism merely a passive component of the region's thinned lithosphere? Is it possible that the initial phase of passive rifting could trigger more dynamic asthenospheric ascention? Where does gravitational collapse fit in?


"White Gold" of Death Valley
The story of borax is inseparable with Death Valley's human and geological history. For six years beginning in 1883, wooden wagons with a nine metric ton capacity, drawn by a team of mules led by two horses of the Harmony and Amargosa Borax Works, ferried borax out of Death Valley. The 165-mile, ten-day, whip-cracking, dusty and dangerous, arduous journey crossed the scorching salt pan, climbed over passes in the Panamint Mountains and traversed the arid Mojave Desert to the nearest railroad spur in Mojave, California. Used in detergents, ceramics, cosmetics, enamel glazes, insecticides and fire retardants, white cottonball-shaped crystals of ulexite ore mixed with mud were skimmed from the valley floor. Since 1891, the Pacific Coast Borax Company promoted the "20 Mule Team" trademark on boxes of laundry detergent and "Death Valley Days" radio and TV shows. Death Valley will likely be forever linked with the caravan as well as morbidity, foreboding and lifelessness, much to the consternation of many (especially one geologist I know). It's an unfortunate association, since the valley of death is in reality a "valley of life", perseverance, diversity and adaptation in the face of environmental extremes.


At one time, the Death Valley region was reputed to possess every mineral that put California on the map - gold, silver, copper and lead. But, it was unromantic borax - a whitish salt of boric acid - and everyday talc - a hydrated magnesium silicate - that propelled the region into prominence and led to Death Valley's long-term development. Borax, in particular, put Death Valley on the map, inspired a "white gold" rush and fostered the construction of a narrow gauge railroad, an elegant Spanish-style inn in the desert, a "castle" in a canyon, a radio and television western anthology series, a world famous National Park and a thriving tourist industry.

•  Why were the minerals of borax and talc in such commercial demand? Are they still? 
•  Where are they found? How did they form and when? 
•  What were the unique challenges associated with mining in Death Valley and getting the deposits to market? 
•  From the days of the "single-blanket jackass prospector" and the thousands of shafts and tunnels that probe the subsurface - more in Death Valley National Park than any other - what put an end to the industry that made Death Valley so famous in spite of modern techniques of exploration and mining?


Headframe of the Billie Borate Mine along the Road to Dante's View
Borax was first commercially produced in the U.S. north of San Francisco in 1864. It took almost 20 years before claims reached the arid salt pan of Death Valley in 1881. Encumbered by oppressive heat, lack of water for refining, and transportation difficulties, playa mining on the valley floor ceased when continuing exploration led to the discovery of a richer form of borate called colemanite in a larger and more concentrated lode in Furnace Creek Wash that adjoined Death Valley. Soon after, a narrow-gauge railroad was constructed to bring ore to market. Borates and other salts from the surrounding ranges that became dissolved in volcanically heated water became concentrated within long-gone Furnace Creek Lake and today resides in the lower part of the Furnace Creek Formation (behind and beneath the mine). Death Valley's mining history is punctuated with presidential and congressional closures and reopenings, but ultimately, mining ceased with the establishment of the National Park in 1994, although the underground Billie Mine is the only active operation in the park. Furnace Creek deposits on Ryan Mesa of the Greenwater Range (far left middle distance) are capped by basaltic flows of the Pliocene Funeral Formation of the southern Funeral Mountains. Across Furnace Creek Wash, the northwest-trending Furnace Creek fault zone lies before eastward-tilted sequences of the Funeral Mountains (background). Proterozoic and Paleozoic rocks were thrust-faulted and folded in late Paleozoic and Mesozoic contractional tectonism and then extended in the Cenozoic. That makes the range a transtentional horst block. The summit is Pyramid Mountain at 6,703 feet. Go there (36 20'30.20" N, 116 41'01.83" W).

WHERE IS DEATH VALLEY?
The 140 mile-long, 5 to 20 mile-wide, generally north to south-trending trough is situated mostly in Inyo County in southeast California, astride the border of southwest Nevada. Its central depression reaches 282 feet below sea level and is bordered by mountains as high as 11,049 feet. The dominant orientation is north to south, but many adjacent valleys and mountain ranges trend northwest-southeast. 

In 1933, President Herbert Hoover proclaimed the region a National Monument, along with a connected triangle of land athwart the Nevada state line. In 1984, a small detached unit in Nevada was set aside as a wildlife refuge for the endangered Devil's Hole pupfish. In 1994, the region was redesignated as Death Valley National park with over 3.4 million acres (5,307 square miles). It's the largest park in the contiguous 48 states with over 95% classified as "wilderness" - rugged, unsettled, undeveloped and undivided. Go there (36°27.70 N, 116°52.00 W) to the Death Valley Visitor Center at Furnace Creek Ranch.


Death Valley National Park
Located along the southeastern border of California with southwest Nevada (inset), the park occupies the Great Basin of the Basin and Range province and the Mojave Desert and typifies the morphological, structural, climatic and biological characteristics of each. The park includes two major valleys, Panamint and Death Valley proper, separated by the Panamint Range.
From mappery.com


In 1984, Death Valley became a UNESCO Biosphere Reserve, one of 699 internationally designated that are "reserved to protect biological and cultural diversity while promoting sustainable economic development." In 2013, the region was named an International Dark Sky Park and awarded a "Gold Tier" for the highest level of pristine nocturnal star-viewing away from urban light-pollution. The IDS in association with the National Park Service makes recommendations how dark skies can be protected such as advocating for ideal levels of outdoor light brightness, appropriate sky-shielding and hours of illumination.



Dark Skies over Racetrack Playa and its Mysterious Sailing Stones
Beneath the camera lens-bent arch of the Milky Way, the six-square mile, dry lakebed is nestled between the Cottonwood and Last Chance Ranges in the northwest corner of Death Valley. It's renowned for the locomotive mystery of its trail-leaving, "sailing stones", which has finally been solved. Mountain snowmelt that enters the playa freezes on cold winter nights along with underlying saturated silt and clay. The rocks have a higher thermal conductivity than water, which facilitates their lubrication such that even mild wind shear is able to move the thin ice sheet with its entrained rocks along parallel tracks. Once melted, the rocks are redeposited on the polygonal cracked surface of the playa. Some of the stones are sourced from the Grandstand, a granitic outcrop (center), but most of the dolomitic chunks are from the southeast. Go there (36°39.883’N, 117°33.350’W) to Racetrack Playa.
From Wikimedia Commons, NASA.gov, the NPS and Dan Duriscoe 

BASIN AND RANGE - A GEOMORPHIC PROVINCE
Death Valley lies within the extreme western extent of the ~800,000 sq km Basin and Range physiographic province and within the southern extent of its Great Basin subprovince. Both regions are without counterpart in North America for the extreme extension across the landscape and their average ~1,200 meter-elevation above sea level. In the late Cenozoic, crustal and lithospheric mantle thinning has occurred over an unusually wide area. 

Broad continental extension (as opposed to a narrow zone with a single downward-displaced block of crust) has given rise to the province's surface expression of alternating basins and ranges that extend over a region up to 1,000 km wide. The strain that created the extension is not uniformly distributed over the extended region. As a result, average extensions (and crustal thickness) of 50-100% can vary in areas from 100-400% and less than 10%. It is estimated that the Death Valley region, since the end of Mesozoic compressional thrust faulting, has undergone as much as 160 km of extension.

The province covers most of Nevada, portions of adjoining states and extends south into Arizona, west Texas and northwest Mexico where it engulfs the Sierra Madre Occidental Range. The province lies between the Cascade Ranges and Rockies in the north and the 600-km long granitic spine of the Sierra Nevada and Colorado Plateau in the middle and south. 



Physiographic Provinces of Southwestern North America
Death Valley (red arrow) is in southeastern California along the Nevada border. It's situated within the Mojave Desert in the rain shadow of the Sierra Nevada Range, within the Basin and Range physiographic province (dotted line) and the Great Basin subdivision.
Modified from Wikimedia Commons, image by Kmusser

Each region differs greatly in geology, age, topography, elevation, structure, hydrology, ecology, population density and human history but are related by tectonic processes that created them. Although uncertainty centers on the magnitude, style and timing of the Basin and Range formative event(s), the consensus is that it is the product of widespread, extreme extension, rather than from differential, fluvial erosional processes acting upon folded and faulted rocks in an arid climate or a compressional tectonic episode, as was once thought. It wasn't genetically linked to an extended crust until a faulting-extension connection was made. 

WHAT IS DEATH VALLEY?
The province's name "basin and range" is based on geomorphology, which includes surface and sub-surface rocks, structural elements and evolutionary history. The landscape is typified by abrupt changes in elevation between rugged, longitudinal, asymmetric, tilted and fault-bound, uplifted blocks of crust that form mountain ranges called horsts (German for "heap") and broad, flat, sediment-filled, downdropped blocks of crust that form basins called grabens (German for "grave"). Death Valley typifies the province's corrugated landforms, and is its most famous, most visited and most studied region with the greatest extremes in landscape and climate.


Crustal Extension Creating Horst and Graben Features on the Landscape
From the surface, horsts and grabens appear as a series of ranges and valleys that run perpendicular to the direction of extension. The structures are caused by normal faulting where extension creates failure along a planar fracture plane. This leads to subsidence of a graben's hanging wall between two horstic foot walls. Modified from geoscience.wisc.edu

Two kinds of extensional faults exist in the Basin and Range province: high-angle normal faults (that create the repetitive horsts and grabens and are responsible for the majority of horizontal extension) and low-angle normal detachments faults (with associated metamorphic core complexes). Both types of faults are related to the development of two superimposed stress fields in the province, one related to tectonics and the other to gravitational collapse.


Basin and Range Formation from Crustal Extension
 Normal faults (left) may not always dip in opposite directions. If dipping occurs in similar directions (center), half-grabens form and are accompanied by a domino-like tiling of the fault blocks along listric faults. Normal faults may concave upwards as the dip decreases with depth, where a deep detachment fault (right) follows a curved rather than planar path. Death Valley possesses a combination
Modified from geosci.usyd.edu.

In the late 1880's, geologist Clarence Dutton compared the Basin and Range's alternating topography to "an army of caterpillars crawling northward out of Mexico." The extremes in elevation posed a formidable impediment to westward travel for pioneers, prospectors and settlers in the 1800's and was one of the last regions to be settled in the United States.


Caterpillars Marching Across the Basin and Range from Space
The most striking feature of the Basin and Range province is the parallelism of the mountain ranges. There are hundreds of alternating linear, towering peaks dotted with green pinyon pine and juniper, the loftiest of which are topped with snow, while intervening valleys, the basins, remain low and elongate on the landscape, monotonous, sparsely vegetated, with strangled rivers and ephemeral, salt-rich playa lakes filled with sediment from the bordering ranges. Death Valley (encircled) is in the lower left quadrant, and the elevated Colorado Plateau and Grand Canyon are in the lower right. The NASA image from space is slightly rotated counterclockwise from north.
From geography.about.com



THE GREAT BASIN - A HYDROLOGIC SUBPROVINCE
The ~362,600 sq km Great Basin is the northern subprovince of the Basin and Range, where "The earth is splitting apart there" as well (author John McPhee). Thus, it also possesses the province's distinctive alternating landforms, but the appellation is misleading. Rather than defined by geomorphology, "great basin" is a hydrologic definition. Precipitation is not directed centrally into a massive catchment as implied but into range-flanked, below sea level, endorheic (Greek for "flow within") basins, over 200. 

Each range-basin-range triplet is a closed-system, whose waters, scant and variable as they may be, have no outlet to the sea. Each range  acts as a hydrologic drainage divide that runs down its axis. Water is directed from the ranges' relatively impermeable bedrock to broad basins where over 90% is lost due to evaporation and the rest enters playa or forms aquifers, dictated by regional structure and lithology. Aquifers are the principal source of ground water in over 120 alluvium-filled basins. Draped over this framework are erosionally-created features such as wine-glass canyons, triangular-shaped facets, spur benches, regularly-spaced catchments and omnipresent alluvial fans. Death Valley is representative of the province's geomorphology and the subprovince's hydrology.


Schematic of Types of Hydrologic Areas of Nevada's Great Basin
The Great Basin is a physiographic province based on hydrology, where all combinations of open, closed, undrained, partly drained, and completely drained hydrologic areas are found. Areas underlain and bounded by impermeable bedrock generally are undrained with no subsurface inflow or outflow, the water table beneath the valley floor is near the surface. In a completely drained area, the water table beneath the valley floor may be so deep that all ground-water discharge is by subsurface outflow.
From Maurer et al, 2004.

The Great Basin is a temperate or "cold" desert with hot and dry summers and snowy winters. Aridity is created by the massive rainshadow of the Sierra Nevada Range to the west in addition to local ranges that border each basin. Deserts are defined not by the presence of sand, which to the surprise of first time visitors comprises less than 10% of Death Valley, but by annual precipitation, which is generally less than ten inches. The Great Basin averages nine on the west side and 12 on the east. Before reaching the Great Basin, prevailing westerlies must cross the high Sierra Nevada and local ranges that border the basins such as the Panamints on Death Valley's west side where annual rainfall averages an incredible 2.36 inches!

The Rainshadow Effect
Forced upward against the Sierra Nevada by orographic lift, rising Pacific Ocean moisture-laden air adabiatically cools and generates precipitation on the windward side of the range. Dry air descends producing a vast rainshadow within the desert of the Great Basin on the leeward side. On the west of the range, rivers flow to the sea, while on the leeward side, waters of the Great Basin never reach it. Death Valley is one of the Great Basin's most extreme examples of aridity.
From Wikipedia Creative  Commons

VALLEY OF EXTREMES
As warm, moisture-laden air rises on the windward side of the mountains, it expands and loses heat and moisture in a process called adiabatic cooling. Descending drier air contracts on the leeward side and warms as its humidity plummets. In Death Valley's Badwater Basin, which reaches 282 feet below sea level, high pressure and dry conditions dominate due to the greater weight of the atmosphere above. By the time it reaches Death Valley's sunken floor, the super-heated air is dry as a bone.



Salt Pan of Devil's Golf Course against a Backdrop of Telescope Peak
What a contrast of extremes - snow on the summit of 11,049 foot Telescope Peak and the arid salt pan of Badwater Basin at 282 feet below sea level - separated by over two miles of relief! Devil's Golf Course at Badwater's northern end is a field of jagged pinnacles of silty halite fed by capillary action. Its name was acquired from a 1934 National Park Service guidebook that stated "Only the devil could play golf" there. The mix of hardened mud and halite evaporites is derived from the physical and chemical erosion of the surrounding mountains. Sloping away from the Panamint Mountains is a bajada, formed from coalesced alluvial fans, whose massivity is related to the size of the range and downward slope of the valley floor. Typical of arid sedimentary basins, the fans are signature Quaternary features of Death Valley. Go there (36°17.150’N, 116°49.574’W) to the Devil's Golf Course.

Snowmelt, mountain runoff, springs and water seeps along the fronts and negligible rain within the basins either accumulates in ephemeral, hypersaline playa lakes, infrequently makes its way to adjoining basins, enters the subsurface recharging aquifers or most likely evapotranspirates into the atmosphere in the intense heat. Although scarce, when rain does occur, it can have a catastrophic effect on the landscape by breaking down rock and transporting it down mountain. Alluvial fans, extensive bajadas, debris flows and thousands of feet of sediment basin-fill are commonplace. In Utah, the Great Salt Lake is the Great Basin's largest internal "drain", while Death Valley is arguably its most famous and most studied landform with classic basin and range topography and with an internal hydrologic basin that covers some 8,700 square miles.



Blue-Green Pools and Frozen Rivers of Salt
A serpentine stream has made its way to a short-lived, saltwater-rich, playa lake nestled in a small hollow of Badwater Basin in central Death Valley. The salt pan, one of the planet's largest, is a hot and dry desert of chemical salts (light-colored) and mud (dark-colored) baking in the sun. In addition to springs and mountain runoff, it receives the terminal reach of the intermittent Amargosa River from the south and equally-ephemeral, spring-fed Salt Creek from the north. Eventually, all water succumbs to the heat. Many scattered pools are remnants of heavy rains from late 2015. So heavy was the deluge that dry washes in the north were transformed into floodwaters 100 feet wide with 20-foot waves that left mud, rock debris and damaged roads in Grapevine Canyon. Still reeling from flash floods, Scotty's Castle will be closed for a year or more. Go there (36°11'30.02" N, 116°46'34.57" W) to Badwater Basin.

Death Valley lies within the northern arm of the Mojave Desert, North America's smallest, driest, most unspoiled and undivided North American desert with the greatest range of elevations. The Mojave is a rainshadow desert and serves as a transition zone between the hot Sonoran Desert to the south and cooler Great Basin Desert to the north. The Joshua Tree is considered the region's indicator species and occurs at elevations between 1,300 and 5,900 feet and defines the areal limits of Mojave's ecosystem.



Joshua Tree in the Ghost Town of Rhyolite in the Bullfrog Hills
A Joshua Tree with its dagger-like spines in the Bullfrog Hills of Amargosa Valley stands as a lone sentinel in the ghost town of Rhyolite. The cactus, a member of the Yucca genus and member of the Agave family, reminded Mormon settlers who crossed the desert in the mid-1800's of Biblical Joshua reaching his hands to the sky in prayer. Amargosa is the valley to the east of Death Valley and is separated from it by the Grapevine Mountains of the northern Amargosa Range (far left). Bullfrog acquired its name from the land claims of Frank "Shorty" Harris and Ernest L. Cross, legendary prospectors who discovered gold in 1904. Go there (36°53'59.12" N, 116°49'43.61" W) to Rhyolite.



DEATH VALLEY - A STRUCTURAL PROVINCE
In addition to occupying a locale within the Basin and Range and Great Basin, Death Valley is transitional between three partly overlapping seismic provinces - the Basin and Range, the Walker Lane Belt and the Eastern California Shear Zone. All three are actively deforming regions of extension and shear. Although some combine the latter two into a continuous zone, they are evolving components of the San Andreas fault system along the coast of California. 

The arrival of the East Pacific Rise spreading center at the Farallon-North American plate subduction zone initiated extension about 27 million years ago and 17-18 million years ago at Death Valley. What is the relationship of Death Valley to the San Andreas system, and how did it come to form? Please visit post Part II for an explanation.


Southwest Regional Structure Map of Southeastern California
Shown are the Basin and Range extensional province, the Walker Lane belt and Eastern California seismic zones, the Garlock Fault (a left-lateral strike-slip fault along the north margin of the Mohave Desert), the San Andreas fault system and the Death Valley domain. Death Valley is juxtaposed between a southern extension of the Walker Lane belt on the north and the Garlock fault on the south.
From Ian Norton, 2011.


The Mohave Desert is also a structurally transitional region, in that it contains the Mohave block. The block is a wedge-shaped zone with clockwise rotation between the dextral San Andreas fault on the west and the sinistral strike-slip Garlock fault in the north. The Garlock separates the Mojave region from the Basin and Range province to the north and connects with the dextral Southern Death Valley fault zone. The entire region - the Basin and Range province, the Mojave block and Death Valley region prior to the Oligocene - was a tectonically quiescent, lithospherically unextended, externally-drained plateau. These aspects were reversed when the Farallon-North-American plate subduction zone encountered the Farallon-Pacific spreading ridge. Please visit post Part II for more info.

WHAT ISN'T DEATH VALLEY?
Death Valley acquired its infamous moniker in 1849 when a member of "The Lost '49ers" - a group of pioneers and prospectors who made an ill-fated attempt to find a 500-mile short-cut to the California goldfields - looked back one last time and exclaimed, "Goodbye, Death Valley." The name stuck (to the dismay of at least one geologist I know). But don't be mislead....it's a complete misnomer. Death Valley isn't a valley, and it's far from dead - either biologically or geologically.


"Leaving Death Valley - The Manly Party on the March After Leaving Their Wagons"
Making the arduous journey on foot after butchering their starving oxen for jerky, the Bennett and Arcane families crossed Death Valley's barren desert and lofty Panamint Mountains to the west. Only one of the emigrants died within the valley itself, but the hardships and agony the group encountered were immense and legendary. The ordeal is recounted in William Manly's autobiography. "A man in a starving condition is a savage. He may be as blood-shed and selfish as a wild beast, as docile and gentle as a lamb, or as wild and crazy as a terrified animal, devoid of affection, reason or thought of justice." Manly and partner John Rogers left the destitute group and returned from California to rescue them with provisions. Manly's account did much to popularize Death Valley to the American public. Manly Beacon, Lake Manly and Manly Pass are tributes to his humanitarianism and heroism.
Illustration from Chapter X of William L. Manly's autobiography Death Valley in '49


Geologically speaking, Death Valley is a basin not a valley. Valleys might look similar - regions of low relief and sediment-filled between topographic highs - but their genesis is erosional, produced by the carving action of rivers or gouging of glaciers. Basins - whether bowl-shaped or elongate and often below sea level - sport a tectonic origin. They can be very small (hundreds of meters) or very large (such as ocean basins), but the essential element is the prolonged tectonic creation of relief. 

In Death Valley, extension has bestowed the basin with faults along its flanks, a flat or tilted, down-dropping floor that provides accommodation space for the deposition of thick sediment and parallel mountain ranges along the sides of the basin. The mountain ranges are more steeply sloped on their western flanks in contrast to the eastern flanks, which drops less precipitously to the neighboring basins. The architecture is perhaps visualized best on an elevation profile generated along a 77 km-long SW-NE geologic transect (red line) across the landscape of Death Valley through the ranges and basins that flank it.


Death Valley Transect and Elevation Profile
The SW-NE transect (red line) runs from the basins of Panamint Valley to Amargosa Valley and across Death Valley. The profile illustrates the characteristically steep western slope of the ranges. Subtle listric eastward tilt of the valley floor is disguised by voluminous sediment derived from the ranges but is betrayed by the magnitude of the alluvial complex on the valley's western side. Furnace Creek Wash is an elevated pre-Death Valley basin. Even with a vertical exaggeration of 1X, the dramatic height of Telescope Peak above the floor of Death Valley and the Black Mountains is evident. Note the higher elevation of Furnace Creek Wash, the steepness of Black Mountains' western front and the dimensions of the bajada on the west side of the valley.
Transect and profile generated on Google Earth. Click image for a larger view.

As for the absence of life, Death Valley's Badwater Basin with the Western Hemisphere's lowest elevation, maximum temperatures and near greatest aridity is indeed desolate, salt-infused and lifeless (with the exception of ancient, halo-tolerant prokaryotic Archaea micro-organisms recently discovered). Factor in scorching summers and freezing winters. Everything changes with elevation with increasing water exposure as temperatures become cooler and more life-tolerant. In Death Valley, life is defined and confined by the availability of water.



A Miracle of Germination
Enticed to germinate during the 2016 wildflower "superbloom", this purple, five-lobed, notch-leafed Phacelia (Phacelia crenulata) blossomed on a gravelly, spring-fed slope of an alluvial fan. It's a foul-smelling plant that produces a contact rash similar to that of poison ivy. Desert plants, as do animals, use physical and behavioral mechanisms to adapt to the extremes of heat and aridity. Xerophytes, such as cacti, store and conserve water, often with few or no leaves to reduce transpirational water loss. Phreatophytes adapt by growing long roots to acquire moisture at or near the water table, or shallow roots spread over a large area. Behavioral adaptations include lifestyles in conformance with the seasons of greatest moisture and/or coolest temperatures. Perennials survive by remaining dormant until water is available; whereas, annuals, such as Phacelia, live for a single season when seeds are stimulated to germinate by moisture. Growing, flowering and seeding quickly, they die. As temperatures rose with the approach of summer, flowers retreated to higher and cooler elevations.

HOT AND DRY BUT FAR FROM DEAD
Death Valley's lifeforms are specially adapted to cope with the region's extremes. Life and diversity appear within the Lower Sonoran ecosystem in the first 4,000 feet, where a host of specially evolved lifeforms have adapted to environmental extremes. Cacti, desert holly, scorpions, sidewinders, ravens, roadrunners, kit foxes and kangaroo rats thrive. From 4,000 to 8,500 feet, Upper Sonoran pinyon pine and juniper, and small mammals and reptiles persist. From 4,000 to 8,500 feet within the Transition Zone, sierra juniper, mountain mahogany, mule deer, bobcats, cougars and coyotes exist, and up to 9,000 feet in the Sub-Alpine Zone, where bristlecone pine, limber and bighorn sheep are found. These lifeforms defy our conventional images of Death Valley. Each has evolved creative solutions to the problems of survival.

DEATH VALLEY GEOLOGY CALLING: PART II - HOW DID IT FORM?
Late Cenozoic extensional forces wreaked havoc on the landscape of Death Valley. They uplfited, tilted, deformed, stretched and wrenched crustal blocks of Proterozoic through Cenozoic strata into elongate mountain ranges, while downdropping intervening blocks within basins that variably filled with range-derived colluvium and alluvium, long-gone Pleistocene lakes and saliferous playa. 

The basins contain the deposits that put the region on the map, while the ranges contain the region's oldest rocks and tell the story of Death Valley's ancient past. An excursion would be incomplete without a visit to both. In my next post, I'll present a condensed synopsis of Death Valley's geologic evolution that spans nearly two billion years. Thank you for visiting!

SPECIAL THANKS
Immense gratitude is offered to geologist and author Wayne Ranney for his knowledge, expertise, unlimited enthusiasm, endless wit, exceptional car-camping cuisine, friendship and great companionship. Please visit Wayne here. Great appreciation is also extended to Marli Miller for her personal communications, thoughtful explanations and photographic contributions. A stop at Bennie Troxel's Museum Rock Trail in nearby Shoshone, California is highly recommended. His outdoor chronologic collection of large rocks tells the geologic story of the Death Valley region. And of course, there's Death Valley National Park. Go there!


Thanks, Wayne, for another great trip and for taking me to the next level!

EXTREMELY HELPFUL BOOKS
•  Ancient Landscapes of the Colorado Plateau by Ron Blakey and Wayne Ranney, 2008.
•  A Trip Through Death Valley's Geologic Past by Kenneth E. Lengner, 2009.
•  Death Valley's Titus Canyon and Leadfield Ghost Town by Ken Lengner and Bennie Troxel, Second Edition, 2008.
•  Geology of the American Southwest by W. Scott Baldridge, 2004.
•  Geology of Death Valley National Park by Marli B. Miller and Lauren A. Wright, Third Edition, 2015.
•  Geology of the Great Basin by Bill Fiero, 1986.
•  Geology Underfoot in Death Valley and Owens Valley by Robert P. Sharp and Allen F. Glazner, 2012.
•  Geology Underfoot in Southern California by Robert P. Sharp and Allen F. Glazner, 2014.
•  Hiking Death Valley by Michel Digonnet, 1972.
•  Images of America - Death Valley by Robert P. Palazzo, 2008.
•  Plate Tectonics by Wolfgang Frisch et al, 2011.

ON-LINE MAPS OF DEATH VALLEY
•  Geologic Map of the Death Valley Ground-Water Model Area, Nevada and California by J.B. Workman et al, 2002.
•  Death Valley National Park Map here

NOTABLE DEATH VALLEY FIELD GUIDES BOTH ON-LINE AND IN PRINT
•  A Trip Through Death Valley's Geologic Past by Kenneth E. Lengner, 2009.
•  Cal Poly Geology Club, Death Valley Field Trip – 2004 (On-line)
•  Death Valley National Park Visitor Guide - Winter/Spring 2016 
•  Death Valley's Titus Canyon and Leadfield Ghost Town by Ken Lengner and Bennie Troxel, Second Edition, 2008.
•  Field Trip Guide to Death Valley National Park, Geology of the National Parks, San Francisco State University, March 22-26, 2002 (On-line)
•  Geology of Death Valley National Park by Marli B. Miller and Lauren A. Wright, Third Edition, 2015
•  Hiking Death Valley by Michel Digonnet, 1972.
•  Hofstra University, Field Trip Guidebook, Geology 143D - Geology of California/Nevada, Spring Semester April 11, 2009 (On-line)
•  Proceedings of Conference on Status of Geologic Research and Mapping in Death Valley National Park, Las Vegas, Nevada, USGS, Open File Report 99-153, 1999 (On-Line)
•  Quaternary and Late Pliocene Geology of the Death Valley Region: Recent Observations on Tectonics, Stratigraphy, and Lake Cycles, Guidebook for the 2001 Pacific Cell—Friends of the Pleistocene Fieldtrip (Online)
•  Stanford Project on Deep-Water Depositional Systems, 23rd Annual Meeting and Field Workshop, Death Valley California, Field Guide: Upper Paleozoic Deep-Water Passive Margin Sequences of the Death Valley Region (On-line)
•  Virtual Field Guide of the Death Valley Region, Geology Program, Department of Earth Sciences, Palomar College (On-line)

VERY INFORMATIVE PROFESSIONAL PAPERS
•  Analogue Modelling of Continental Extension: A Review Focused on the Relations Between the Patterns of Deformation and the Presence of Magma by Giacomo Corti et al, Earth-Science Reviews 63, 2003.
•  An Imbricate Midcrustal Suture Zone: The Mojave-Yavapai Province Boundary in Grand Canyon, Arizona by Mark E. Holland et al, GSA Bulletin, September/October 2015.
•  A Positive Test of East Antarctica–Laurentia Juxtaposition Within the Rodinia Supercontinent by J. W. Goodge et al, Science, 2008. 
Assembly, Configuration, and Break-up History of Rodinia: A Synthesis by Z.X. Li et al, Precambrian Research, 2008.
•  A USGS Study of Talc Deposits and Associated Amphibole Asbestos Within Mined Deposits of the Southern Death Valley Region, California by Bradley S. Van Gosen et al, USGS, 2004. 
•  Basin and Range Volcanism as a Passive Response to Extensional Tectonics by Keith Putirka and Bryant Platt, Geosphere, 2012.
•  Cenozoic Extension and Magmatism in the North American Cordillera: The Role of Gravitational Collapse by Mian Liu, Tectonophysics 342, 2001.
•  Detrital Zircon Provence, Geochronology and Revised Stratigraphy of the Mesoproterozoic and Neoproterozoic Pahrump (Super) Group, Death Valley Region, California by Robert Clyde Mahon, Thesis, Idaho State University, 2012.
•  Evolution of Mountainous Topography in the Basin and Range Province by Michael A. Ellis et al, Basin Research, 1999. 
•  Extensional Tectonics in the Basin and Range Province and the Geology of the Grapevine Mountains, Death Valley Region, California and Nevada, Thesis by Nathan A. Niemi, CIT, 2002.
•  Geochronologic and Stratigraphic Constraints on the Mesoproterozoic and Neoproterozoic Pahrump Group, Death Valley, California: A Record of the Assembly, Stability, and Breakup of Rodinia by Robert C. Mahon et al, GSA Bulletin, 2014.
•  Geologic map of the Death Valley Ground-Water Model Area, Nevada and California by J.B. Workman et al, USGS 2381-A, 2002.
•  Geomorphic Evidence for Late-Wisconsin and Holocene Tectonic Deformation, Death Valley, California by Roger L. Hooke, GSA Bulletin, 1972.
•  Glacigenic and Related Strata of the Neoproterozoic Kingston Peak Formation in the Panamint Range, Death Valley Region, California, etc. by Ryan Peterson, Thesis, CIT, 2009. 
•  Gravitational collapse of the continental crust: definition, regimes and modes by P. Reya et al, Tectonophysics 342, 2001.
•  Groundwater Geology and Hydrology of Death Valley National Park, California and Nevada by M.S. Bedinger and J.R.Harrill, Technical Report NPS/NRSS/WRD/NRTR—2012/652, 2012.
•  Hydrogeology and Hydrologic Landscape Regions of Nevada by Douglas K. Maurer et al, USGS Report 2004-5131, 2004. 
•  Late Cenozoic Crustal Extension and Magmatism, Southern Death Valley Region, California by J.P. Calzia and O.T. Ramo, GSA Field Guide 2, 2000.
•  Late Quaternary Tectonic Activity on the Death Valley and Furnace Creek Faults, Death Valley, California by Ralph E. Klinger and Lucille A. Piety, USGA, 2001.
•  Nd Isotopic Composition of Cratonic Rocks in the Southern Death Valley Region: Evidence for a Substantial Archean Source Component in Mojavia by O.T. Remo and J.P. Calzia, Geology 26, 1998. 
•  Neoproterozoic Uinta Mountain Group of Northeastern Utah: Pre-Sturtian Geographic, Tectonic and Biologic Evolution by Carol M. Dehler et al, GSA Field Guide 6, 2005.
• Sliding Stones of Racetrack Playa, Death Valley, USA: The Roles of Rock Thermal Conductivity and Fluctuating Water Levels by Gunther Kletetschka et al, Geomorphology, 2013.
Supercontinent Tectonics and Biogeochemical Cycle: A Matter of ‘Life and Death’ by M. Santosh, Geoscience Frontiers, 2010. 
• Tectonic influences on the spatial and temporal evolution of the Walker Lane by James E. Faulds and Christopher D. Henry, Arizona Geological Society, Digest 22, 2008.
Tectonic Model for the Proterozoic Growth of North America by Steven J. Whitmeyer and Karl E. Karlstrom, Geosphere, 2007. 
•  Tectonostratigraphic Evolution of the ~780–730 Ma Beck Spring Dolomite: Basin Formation in the Core of Rodinia by Emily F. Smith et al, Geological Society of London, 2015. 
•  Terrestrial Cosmogenic-Nuclide Dating of Alluvial Fans in Death Valley, California by Michael N. Machette et al, USGS, Professional Paper 1755, 2008. 
•  The Laurentian Record of Neoproterozoic Glaciation, Tectonism, and Eukaryotic Evolution in Death Valley, California by Francis A. Macdonald et al, GSA Bulletin, 2013.
•  The Making and Unmaking of a Supercontinent: Rodinia Revisited Joseph G. Meert and Trond H. Torsvik, Tectonophysics, 375, 2003. 
•  The Relationship between the Neoproterozoic Noonday Dolomite and the Ibex Formation: New Observations and Their Bearing on "Snowball Earth" by Frank A. Corsetti and Alan J. Kaufman, Earth Science Reviews, 2005. 
•  Toward a Neoproterozoic Composite Carbon-isotope Record by Galven P. Halverson et al, GSA Bulletin, 2005.
•  Two Diamictites, Two Cap Carbonates, Two Carbon 13 Excursions, Two Rifts: The Neoproterozoic Kingston Peak Formation, Death Valley, California by A.R. Prave, Geology, 1999.
•  Two-stage Formation of Death Valley by Ian Norton, GSA Geosphere, 2011.
•  U-Pb Geochronology of 1.1 Ga Diabase in the Southwestern United States: Testing Models for the Origin of a Post-Grenville Large Igneous Province by Ryan M. Bright et al, Lithosphere online, 2014.
•  Variations Across and Along a Major Continental Rift: an Interdisciplinary Study of the Basin and Range Province, Western USA by Craig H. Jones et al, Tectonophysics 213, 1992.