Geology Of The Death Valley Area

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Geology Of The Death Valley Area Powered By Docstoc
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                Crustal thinning and rifting
<br><br>Late Precambrian Noonday Formation scoured in Mosaic Canyon by
episodic flow. (USGS photo)
<br><br>At the same time the Earth was apparently in a severe glaciation
(see above), a rift started to open and a sea flooded the subsiding
region. The rifting zone was part of a system of zones responsible for
breaking apart the supercontinent Rodinia and creating the Pacific Ocean.
One of the three arms of the local rifting zone, the Amargosa Rift,
failed to split the continent. A shoreline similar to the present
Atlantic Ocean margin of the United States (with coastal lowlands and a
wide, shallow shelf but no volcanoes) lay to the east near where Las
Vegas, Nevada, now resides.
<br><br>The first formation to be deposited was the Noonday Dolomite. It
was formed from an algal mat-covered carbonate bank. Today it is up to
1000 feet (300 m) thick and is a pale yellowish-gray cliff-former. The
area subsided as the continental crust thinned and the Pacific widened;
the carbonate bank soon became covered by thin beds of silt and layers of
limy ooze. These sediments in time hardened to become the siltstone and
limestone of the Ibex Formation. A good outcrop of both the Noonday and
overlying Ibex formations can be seen just east of the Ashford Mill Site.
<br><br>An angular unconformity truncates progressively older (lower)
parts of the underlying Pahrump Group starting in the southern part of
the area and moving north. At its northernmost extent, the unconformity
in fact removed all of the Pahrump, and the Noonday rests directly on the
Proterozoic Complex. An ancient period of erosion removed that part of
the Pahrump due to its being higher (and thus more exposed) than the rest
of the formation.
<br><br> Passive margin formed
<br><br>As the incipient Pacific widened in the Late Proterozoic and
Early Paleozoic, it broke the continental crust in two and a true ocean
basin developed to the west. All the earlier formations were thus
dissected along a steep front on the two halves of the previous
continent. A wedge of clastic sediment then started to accumulate at the
base of the two underwater precipices, starting the formation of opposing
continental shelves.
<br><br>Three formations developed from sediment that accumulated on the
wedge. They are, from oldest to youngest:
<br><br>Johnnie Formation (varicolored shaly),
<br><br>Stirling Quartzite,
<br><br>Wood Canyon Formation, and the
<br><br>Zabriskie Quartzite.
<br><br>Together the Stirling, Wood Canyon, and Zabriskie units are about
6000 feet (1800 m) thick and are made of well-cemented sandstones and
conglomerates. They also contain the region's first known fossils of
complex life: Ediacara fauna, trilobites, archaeocyathas, primitive
echinoderm burrows and tracks have been found in the Wood Canyon
Formation. The very earliest animals are exceedingly rare, occurring well
west of Death Valley in limy offshore muds contemporary to the Stirling
Quartzite. The developmental pace increased in Wood Canyon times, for
this sandy formation preserves a host of worm tubes and enigmatic trails.
Ultimately, in late Wood Canyon sediments the first animals with durable
shells emerge to open the earliest copiously fossiliferous period, the
Cambrian (see Cambrian Explosion). Good outcrops of these three
formations are exposed on the north face of Tucki Mountain in the
northern Panamint Mountains.
<br><br>The side road to Aguereberry Point successively traverses the
shaly Johnnie Formation, the white Stirling Quartzite, and dark
quartzites of the Wood Canyon Formation; at the Point itself is the great
light-colored band of Zabriskie Quartzite dipping away toward Death
Valley. Parts of this sequence are also prominent between Death Valley
Buttes and Daylight Pass, in upper Echo Canyon, and just west of Mare
Spring in Titus Canyon. Before tilting to their present orientation,
these four formations were a continuous pile of mud and sand three miles
(5 km) deep that accumulated slowly on the nearshore ocean bottom.
<br><br> A carbonate shelf forms
<br><br>Striped Butte in Butte Valley. Steeply tilted limestone beds of
the Permian Anvil Spring Formation. A major fault behind the butte
separates it from Precambrian Noonday and Johnnie Formation rocks, about
billion years older. (USGS photo)
<br><br>The sandy mudflats gave way about 550 Ma to a carbonate platform
which lasted for the next 300 million years of Paleozoic time. Sediment
accumulated on the new but slowly subsiding continental shelf for an
extremely long time; all through the remaining Paleozoic and into the
Early Mesozoic. Erosion had so subdued nearby parts of the continent that
rivers ran clear, no longer supplying abundant sand and silt to the
continental shelf. At the time, the Death Valley area's position was then
within ten or twenty degrees of the Paleozoic equator. So the combination
of a warm sunlit climate and clear mud-free waters promoted prolific
production of biotic (from life) carbonates. Thick beds of carbonate-rich
sediments were periodically interrupted by periods of emergence, creating
the (in order of deposition);
<br><br>Carrara Formation,
<br><br>Bonanza King Formation,
<br><br>Nopah Formation, and the
<br><br>Pogonip Group.
<br><br>These sediments were lithified into limestone and dolomite after
they were buried and compacted by yet more sediment. Thickest of these
units is the dolomitic Bonanza King Formation, which forms the dark and
light banded lower slopes of Pyramid Peak and the gorges of Titus and
Grotto Canyons.
<br><br>An intervening period occurred in the Mid Ordovician (about 450
Ma) when a sheet of quartz-rich sand blanketed a large part of the
continent after the above-mentioned units were laid down. The sand later
hardened into sandstone and later still metamorphosed into the 400 foot
(120 m) thick Eureka Quartzite. This great white band of Ordovician rock
stands out on the summit of Pyramid Peak, near the Racetrack, and high on
the east shoulder of Tucki Mountain. No American source is known for the
Eureka sand, which once blanketed a 150000 square mile (390000 km) belt
from California to Alberta. It may have been swept southward by longshore
currents from an eroding sandstone terrain in Canada.
<br><br>Deposition of carbonate sediments resumed and continued into the
Triassic. Four formations were deposited during this time (from oldest to
<br><br>Ely Springs Dolomite,
<br><br>Hidden Valley Dolomite,
<br><br>Lost Burro Formation, and the
<br><br>Tin Mountain Limestone.
<br><br>The other period of interruption occurred between 350 and 250 Ma
when sporadic pulses of mud swept southward into the Death Valley region
during the erosion of highlands in north-central Nevada.
<br><br>Although details of geography varied during this immense interval
of time, a north-northeasterly trending coastline generally ran from
Arizona up through Utah. A marine carbonate platform only tens of feet
deep but more than 100 miles (160 km) wide stretched westward to a
fringing rim of offshore reefs. Limy mud and sand eroded by storm waves
from the reefs and the platform collected on the quieter ocean floor at
depths of 100 feet (30 m) or so. The Death Valley area's carbonates
appear to represent all three environments (down-slope basin, reef, and
back-reef platform) owing to movement through time of the reef-line
<br><br>All told these eight formations and one group are 20000 feet
(6100 m) thick and are buried below much of Cottonwood, Funeral,
Grapevine, and Panamint ranges. Good outcrops can be seen in the southern
Funeral Mountains outside the park and in Butte Valley within park
borders. The Eureka Quartzite appears as a relatively thin, nearly white
band with the grayish Pogonip Group below and the almost black Ely
Springs Dolomite above. All strata are often vertically displaced by
normal faulting.
<br><br> Change to active margin and uplift
<br><br>The western edge of the North American continent was later pushed
against the oceanic plate under the Pacific Ocean. An area of great
compression called a subduction zone was thus formed in the early to mid
Mesozoic, which replaced the quiet, sea-covered continental margin with
erupting volcanoes and uplifting mountains. A chain of volcanoes pushed
through the continental crust parallel to the deep trench, fed by magma
rising from the subducting oceanic plate as it entered the Earth's hot
interior. Thousands of feet (hundreds of meters) of lavas erupted,
pushing the ocean over 200 miles (300 km) to the west.
<br><br>Compressive forces built up along the entire length of the broad
continental shelf. The Sierran Arc, also called the Cordilleran Mesozoic
magmatic arc, started to form from heat and pressure generated from the
subduction. Compressive forces caused thrust faults to develop and
granitic blobs of magma called plutons to rise in the Death Valley region
and beyond, most notably creating the Sierra Nevada Batholith to the
west. Thrust faulting was so severe that the continental shelf was
shortened and some parts of older formations were moved on top of younger
rock units, creating a confusing mess for geologists to sort out.
<br><br>Skidoo townsite in 1906.
<br><br>The plutons in the park are Jurassic and Cretaceous aged and are
located toward the park's western margin where they can be seen from
unimproved roads. One of these relatively small granitic plutons was
emplaced 6787 Ma and spawned one of the more profitable precious metal
deposits in the Death Valley area, giving rise to the town and mines of
Skidoo (although these gold deposits were quite small compared to the
larger California goldfields west of the Sierra Nevada Mountains). In the
Death Valley area these solidified blobs of magma are located under much
of the Owlshead Mountains and are found in the western end of the
Panamint Mountains. Thrusted areas can be seen at Schwaub Peak in the
southern part of the Funeral Mountains.
<br><br>A long period of uplift and erosion was concurrent with and
followed the above events, creating a major unconformity. Sediments worn
off the Death Valley region were shed both east and west and carried by
wind and water; the eastern sediments ended up in Colorado and are now
famous for their dinosaur fossils. No Jurassic to Eocene sedimentary
formations exist in the area except for some possibly Jurassic-age
volcanic rock around Butte Valley. Large parts of previously deposited
formations were removed; probably by streams that washed the sediment
into the Cretaceous Seaway that longitudinally divided North America to
the east.
<br><br> Development of a flood plain
<br><br>After 150 million years of volcanism, plutonism, metamorphism,
and thrust faulting had run their course, the early part of the Cenozoic
era (early Tertiary, 6530 Ma) was a time of repose. Neither igneous nor
sedimentary rocks of this age are known here. A relatively featureless
plain was created from erosion over many millions of years. Deposition
resumed some 35 Ma in the Oligocene epoch on a flood plain that developed
in the area. Sluggish streams migrated laterally over the surface, laying
down cobbles, sand, and mud. Outcrops of the resulting conglomerates,
sandstone, and mudstone of the Titus Canyon Formation can be observed in
road cuts at Daylight Pass on Daylight Pass Road, which becomes State
Route 374 a short distance from the pass. Several other similar
formations were also laid down.
<br><br> Extension creates the Basin and Range
<br><br>Full extent of the Basin and Range. (NPS image)
<br><br>Starting around 16 Ma in Miocene time and continuing into the
present, a large part of the North American Plate in the region has been
under extension by literally being pulled apart. Debate still surrounds
the cause of this crustal stretching, but an increasingly popular idea
among geologists called the slab gap hypothesis states that the spreading
zone of the subducted Farallon Plate is pushing the continent apart.
Whatever the cause, the result has been the creation of a large and
still-growing region of relatively thin crust.
<br><br>While rock at depth can plastically thin like stretched silly
putty, rock closer to the surface responds by breaking along normal
faults into downfallen basins called grabens and small mountain ranges
known as horsts that run parallel to each other on either side of the
graben. Geologists therefore call this region the Basin and Range.
Normally the number of horsts and grabens is limited, but in the Basin
and Range region there are dozens of horst/graben structures; each
roughly north-south trending. A succession of these extend from
immediately east of the Sierra Nevada, through almost all of Nevada, and
into western Utah and southern Idaho.

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<br>The rocks that would become the Panamint Range were stacked on top of
the rocks that would become the Black Mountains and the Cottonwood
Mountains. In the next several million years, the Black Mountains began
to rise, and the Panamint/Cottonwood Mountains slid westward off the
Black Mountains along low-angle normal faults. Starting about 6 Ma, the
Cottonwood Mountains slid northwest off the top of the Panamint Range.
There is also some evidence that the Grapevine Mountains may have slid
off the Funeral Mountains. Some geologists are not satisfied that we have
enough evidence to believe that the mountains were stacked on top of each
other, but were rather stacked adjacent to each other.
<br><br>The deep Death Valley basin is filled with sediment (light
yellow) eroded from the surrounding mountains. Black lines show some of
the major faults that created the valley. (USGS image)
<br><br>The expanding Basin and Range started to pull apart the Death
Valley area 3 Ma in the Pleistocene, and by about 2 Ma Death Valley,
Panamint Valley and their associated ranges were formed. Complicating
this is right-lateral movement along strike-slip faults (faults that rub
past each other so that a theoretical observer standing on one side who
is facing the other sees it move right). These fault systems run parallel
to and at the base of the ranges. Very often the same faults move
laterally and vertically, simultaneously making them strike-slip and
normal (i.e. oblique-slip). Torsional forces, probably associated with
north-westerly movement of the Pacific Plate along the San Andreas Fault
west of the region, is responsible for the lateral movement. Most of the
vertical movement on normal faults in the valleys of the Death Valley
area has manifested itself by the downward movement of their grabens.
<br><br>Much of the extra local stretching in Death Valley that is
responsible for its lower depth and wider valley floor is caused by left
lateral strike-slip movement along the Garlock Fault south of the park
(the Garlock Fault separates the Sierra Nevada range from the Mojave
Desert). This particular fault is pulling the Panamint Range westward,
causing the Death Valley graben to slip downward along the Furnace Creek
Fault system at the foot of the Black Mountains, creating the lowest dry
point in the Western Hemisphere at Badwater.
<br><br> Volcanism and valley-fill sedimentation
<br><br>The less than 300000 year old Split Cinder Cone was created by
magma that followed a fault line. That same fault has since moved right
laterally, tearing the small volcano in half. (Tom Bean, NPS image)
<br><br>Artist's Palette got its colors from volcanic deposits
<br><br>Igneous activity associated with the extension occurred from 12
to 4 Ma. Both intrusive (plutonic/solidified underground) and extrusive
(volcanic/solidified above ground) igneous rocks were created. Basaltic
magma followed fault lines to the surface and erupted as cinder cones
(such as Split Cinder Cone) and lava flows. Other times, heat from magma
migrating close to the surface would superheat overlaying groundwater
until it exploded not unlike an exploding pressure-cooker, creating
blowout craters and tuff rings such as the roughly 2000 year old Ubehebe
Crater complex (photo) in the northern part of the park.
<br><br>Some lakes formed before the area was pulled apart by Basin and
Range extension. Most notable among them was a large lake geologists call
Furnace Creek Lake, which existed from 9 Ma to 5 Ma in a dry climate (but
not as dry as today's). The resulting Furnace Creek Formation is made of
lakebed sediments that consist of saline muds, gravels from nearby
mountains and ash from the then active Black Mountain volcanic field.
Today it can be seen exposed in the badlands at Zabriskie Point (see that
article for further details).
<br><br>Sedimentation after the creation of the Death and Panamint
grabens (basins) wasnd still isoncentrated in their resulting valleys
from material eroded from adjacent horsts (ranges). The amount of
sediment deposited has roughly kept up with this subsidence, resulting in
retention of more or less the same valley floor elevation over time.
<br><br>About 23 Ma, in the Pleistocene, continental ice sheets expanded
from the polar regions of the globe to cover lower latitudes far north of
the region, starting a series of ice ages. Alpine glaciers formed on the
nearby Sierra Nevada, but even though no glaciers touched the Death
Valley area, the cooler and wetter climate meant that rivers flowed into
the valleys of the region year round. Since the valleys in the Basin and
Range region formed by faulting, not by river erosion, many of the basins
have no outlets, meaning they will fill up with water like a bathtub
until they overflow into the next valley. So during the cooler and wetter
pluvial climates of the ice ages, much of eastern California, all of
Nevada, and western Utah were covered by large lakes separated by linear
islands (the present day ranges).
<br><br>The Lake Manly lake system as it might have looked during its
last maximum extent 22000 years ago. Arrows indicate river water flow,
gray lines are current highways, and red dots are towns. (USGS image)
<br><br>Lake Manly, the lake that filled Death Valley as late as 10500
years ago, was the last of a chain of lakes fed by the Amargosa and
Mojave Rivers, and possibly also the Owens River. It was also the lowest
point in the Great Basin drainage system. At its height during the Great
Ice Age some 22000 years ago, water filled Lake Manly to form a body of
water that may have been 585 feet (187 m) deep, about 8 to 10 miles (15
to 16 km) wide, and 90 miles (145 km) long. But the saltpans seen on the
valley floor are from the 30-foot-deep (10-m-deep) Holocene lake, which
dried up only a few thousand years ago. The Devils Golf Course forms a
small part of this salt pan; Badwater Basin forms another. Panamint
Valley had a lake of its own, which geologists call Lake Panamint.
Ancient weak shorelines called strandlines from Lake Manly can easily be
seen on a former island in the lake appropriately called Shoreline Butte.
<br><br>Stream gradients increased on flanking mountain ranges as they
were uplifted. These swifter moving streams are dry most of the year but
have nevertheless cut true river valleys, canyons, and gorges that face
Death and Panamint valleys. In this arid environment, alluvial fans form
at the mouth of these streams. Very large alluvial fans merged to form
continuous alluvial slopes called bajadas along the Panamint Range. The
faster uplift along the Black Mountains formed much smaller alluvial fans
due to the fact that older fans are buried under playa sediments before
they can grow too large. Slot canyons are often found at the mouths of
the streams that feed the fans, and the slot canyons in turn are topped
by V-shaped gorges. This forms what looks like a wineglass shape to some
people, thus giving them their names, "wineglass canyons".
<br><br> Table of formations
<br><br>This table of formations exposed in the Death Valley area lists
and describes the exposed formations of the Death Valley National Park
and the surrounding area.
<br><br>Lithology and thickness
<br><br>Characteristic fossils
<br><br>Fan gravel; silt and salt on floor of playa, less than 100 feet
(30 m) thick.
<br><br>Fan gravel; silt and salt buried under floor of playa; perhaps
2000 feet thick (600 m).
<br><br>Funeral fanglomerate
<br><br>Cemented fan gravel with interbedded basaltic lavas, gravels cut
by veins of calcite (Mexican onyx); perhaps 1000 feet (300 m) thick.
<br><br>Diatoms, pollen.
<br><br>Furnace Creek Formation
<br><br>Cemented gravel, silty and saliferous playa deposits; various
salts, especially borates, more than 5000 feet (1500 m) thick.
<br><br>Artist Drive Formation
<br><br>Cemented gravel; playa deposits, much volcanic debris, perhaps
5000 feet (1500 m) thick.
<br><br>Titus Canyon Formation
<br><br>Cemented gravel; mostly stream deposits; 3000 feet (900 m) thick.
<br><br>Vertebrates, titanotheres, etc.
<br><br>Eocene and Paleocene
<br><br>Granitic intrusions and volcanics, not known to be represented by
sedimentary deposits.
<br><br>Cretaceous and Jurassic
<br><br>Not represented, area was being eroded.
<br><br>Butte Valley Formation of Johnson (1957)
<br><br>Exposed in Butte Valley 1 mile south of this area; 8000 feet
(2500 m) of metasediments and volcanics.
<br><br>Ammonites, smooth-shelled brachiopods, belemnites, and
<br><br>Pennsylvanian and Permian
<br><br>Formations at east foot of Tucki Mountain
<br><br>Conglomerate, limestone, and some shale. Conglomerate contains
cobbles of limestone of Mississippian, Pennsylvanian, and Permian age.
Limestone and shale contain spherical chert nodules. Abundant fusulinids.
Thickness uncertain on account of faulting; estimate 3000 feet + (900 m
+), top eroded.
<br><br>Beds with fusulinids, especially Fusulinella
<br><br>Mississippian and Pennsylvanian
<br><br>Rest Spring Shale
<br><br>Mostly shale, some limestone, abundant spherical chert nodules.
Thickness uncertain because of faulting; estimate 750 feet (230 m).
<br><br>Tin Mountain Limestone and younger limestone
<br><br>Mapped as 1 unit. Tin Mountain Limestone 1000 feet (300 m) thick,
is black with thin-bedded lower member and thick-bedded upper member.
Unnamed limestone formation, 725 feet (221 m) thick, consists of
interbedded chert and limestone in thin beds and in about equal
<br><br>Mixed brachiopods, corals, and crinoid stems. Syringopora (open-
spaced colonies) Caninia cf. C. cornicula.
<br><br>Middle and Upper Devonian
<br><br>Lost Burro Formation
<br><br>Limestone in light and dark beds 110 feet (0.33 m) thick give
striped effect on mountainsides. Two quartzite beds, each about 3 feet (1
m) thick, near base, numerous sandstone beds 8001000 feet (240300 m)
above base. Top 200 feet (60 m) is well-bedded limestone and quartzite.
Total thickness uncertain because of faulting; estimated 2000 feet (600
<br><br>Brachiopods abundant, especially Spirifer, Cyrtospirifer,
Productilla, Carmarotoechia, Atrypa. Stromatoporoids. Syringopora
(closely spaced colonies).
<br><br>Silurian and Devonian
<br><br>Silurian and Lower Devonian
<br><br>Hidden Valley Dolomite
<br><br>Thick-bedded, fine-grained, and even-grained dolomite, mostly
light color. Thickness 3001,400 feet (90430 m).
<br><br>Crinoid stems abundant, Including large types. Favosites.
<br><br>Upper Ordovician
<br><br>Ely Springs Dolomite
<br><br>Massive black dolomite, 400800 feet (120240 m) thick.
<br><br>Streptelasmatid corals: Grewingkia, Bighornia. Brachiopods.
<br><br>Middle and Upper (?) Ordovician
<br><br>Eureka Quartzite
<br><br>Massive quartzite, with thin-bedded quartzite at base and top,
350 feet (105 m) thick.
<br><br>Lower and Middle Ordovician
<br><br>Pogonip Group
<br><br>Dolomite, with some limestone, at base, shale unit in middle,
massive dolomite at top. Thickness, 1,500 feet (460 m).
<br><br>Abundant large gastropods in massive dolomite at top: Palliseria
and Maclurites, associated with Receptaculites. In lower beds:
Protopliomerops, Kirkella, Orthid brachiopods.
<br><br>Upper Cambrian
<br><br>Nopah Formation
<br><br>Highly fossiliferous shale member 100 feet thick at base, upper 1
200 feet is dolomite in thick alternating black and light hands about 100
feet thick. Total thickness of formation 1,2001,500 feet.
<br><br>In upper part, gastropods. In basal 100 feet (30 m), trilobite
trash beds containing Elburgis, Pseudagnostus, Horriagnostris, Elvinia,
<br><br>Middle and Upper Cambrian
<br><br>Bonanza King Formation
<br><br>Mostly thick-bedded arid massive dark-colored dolomite, thin-
bedded limestone member 500 feet (150 m) thick 1000 feet (300 m) below
top of formation, 2 brown-weathering shaIy units, upper one
fossiliferous, about 200 arid 500 feet (150 m), respectively, below thin-
bedded member. Total thickness Uncertain because of faulting; estimated
about 3000 feet (900 m) in Panamint Range, 2000 feet (600 m) in Funeral
<br><br>The only fossiliferous bed is shale below limestone member neat
middle of formation. This shale contains linguloid brachiopods and
trilobite trash beds with fragments of "Ehmaniella."
<br><br>Lower and Middle Cambrian
<br><br>Carrara Formation
<br><br>An alternation of shaly and silty members with limestone members
transitional between underlying clastic formations and overlying
carbonate ones. Thickness about 1000 feet (300 m) but variable because of
<br><br>Numerous trilobite trash beds in lower part yield fragments of
olenellid trilobites.
<br><br>Lower Cambrian
<br><br>Zabriskie Quartzite
<br><br>Quartzite, mostly massive arid granulated due to shearing,
locally it) beds 6 inches (15 cm) to 2 feet (60 cm) thick ' trot much
cross bedded. Thickness more than 150 feet (45 m), variable because of
<br><br>No fossils.
<br><br>Lower Cambrian and Lower Cambrian (?)
<br><br>Wood Canyon Formation
<br><br>Basal unit is well-bedded quartzite above 1,650 feet (500 m)
thick ' shaly Unit above this 520 feet (75 m) thick contains lowest
olenellids in section; top unit of dolomite and quartzite 400 feet (120
m) thick.
<br><br>A few scattered olenellid trilobites and archaeocyathids in upper
part of formation. Scolithus? tubes.
<br><br>Stirling Quartzite
<br><br>Well-bedded quartzite in beds 15 feet (30150 cm) thick comprising
thick members of quartzite 700800 feet (210240 m) thick separated by 500
feet (150 m) of purple shale, crossbedding conspicuous in quartzite.
Maximum thickness about 2000 feet (600 m).
<br><br>Johnnie Formation
<br><br>Mostly shale, in part olive brown, in part purple. Basal member
400 feet (120 m) thick is interbedded dolomite arid quartzite with pebble
conglomerate. Locally, fair dolomite near middle arid at top. Thickness
more than 4000 feet (1200 m).
<br><br>Noonday Dolomite
<br><br>In southern Panamint Range, dolomite in Indistinct beds; lower
part cream colored, upper part gray. Thickness 800 feet (240 m). Farther
north, where mapped as Noonday(?) Dolomite, contains much limestone, tan
and white, and some limestone conglomerate. Thickness about 1000 feet
(300 m).
<br><br>Scolithus? tubes.
<br><br>Kingston Peak(?) Formation
<br><br>Mostly conglomerate, quartzite, and shale; some limestone arid
dolomite near middle. At least 3000 feet (900 m) thick. Although
tentatively assigned to Kingston Peak Formation, similar rocks along west
side of Panamint Range have been identified as Kingston Peak.
<br><br>Beck Spring Dolomite
<br><br>Not mapped; outcrops are to the west. Blue-gray cherry dolomite,
thickness estimated about 500 feet Identification uncertain.
<br><br>Pahrump Series
<br><br>Crystal Spring Formation
<br><br>Recognized only in Galena Canyon and south. Total thickness about
2000 feet (600 m). Consists of basal conglomerate overlain by quartzite
that grades upward into purple shale arid thinly bedded dolomite, upper
part, thick bedded dolomite, diabase, and chert. Talc deposits where
diabase intrudes dolomite.
<br><br>Rocks of the crystalline basement
<br><br>Metasedimentary rocks with granitic intrusions.
<br><br> Table of salts
<br><br>This False-color radar image shows central Death Valley and the
different surface types in the area. Radar is sensitive to surface
roughness with rough areas showing up brighter than smooth areas, which
appear dark. This is seen in the contrast between the bright mountains
that surround the dark, smooth basins and valleys of Death Valley. The
image shows Furnace Creek alluvial fan (green crescent feature) at the
far right, and the sand dunes near Stove Pipe Wells at the center. (NASA
<br><br>Known or probable occurrence
<br><br>Principal constituent of chloride zone and of salt-impregnated
sulfate and carbonate deposits.
<br><br>With halite.
<br><br>Carbonate zone of Cottonball Basin, especially in marshes.
<br><br>Questionably present on floodplain in Badwater Basin, would be
expected in marshes of carbonate zone in Cottonball Basin.
<br><br>Carbonate zone and floodplain in Badwater Basin.
<br><br>Occurs as clastic grains in sediments underlying salt pan and as
sharply terminated crystals in clay fraction of carbonate zone and in
sediments underlying sulfate zone.
<br><br>Obtained in artificially evaporated brines from Death Valley; not
yet identified in salt pan; may be expected in carbonate zone of
Cottonball Basin.
<br><br>identified only as a detrital mineral; may be expected in
carbonate zone.
<br><br>Northupite and/or tychite
<br><br>Na3MgCl(CO3) and/or Na6Mg2(SO4)(CO3)4
<br><br>An isotropic mineral, having index of refraction in the range of
Northupite and Tychite, has been observed in saline facies of sulfate
zone in Cottonball Basin.
<br><br>Sulfate zone in Cottonball Basin.
<br><br>Common in all zones in Cottonball Basin and in sulfate marshes in
Middle and Badwater basins.
<br><br>Occurs on floodplains in Cottonball Basin immediately following
winter storms.
<br><br>Common on floodplains except in central part of Badwater Basin;
sulfate zone in Cottonball Basin.
<br><br>As layer capping massive gypsum 1 mile (2 km) north of Badwater.
Possibly also as dry-period efflorescence on floodplains.
<br><br>As layer capping massive gypsum along west side of Badwater Basin
and as dry-period efflorescence in floodplains.
<br><br>In sulfate caliche, layer in carbonate zone, particularly in
Middle and Badwater basins, in sulfate marshes and as massive deposits in
sulfate zone.
<br><br>Questionably present in efflorescence on floodplain in chloride
<br><br>Questionably present on floodplain in chloride zone.
<br><br>Found with massive gypsum.
<br><br>Possibly present in Middle Basin in surface layer of layered
sulfate and chloride salts.
<br><br>Probably occurs as dehydration product of borax.
<br><br>Floodplains and marshes in Cottonball Basin.
<br><br>Questionably present (X-ray determination but unsatisfactory) in
floodplain in Badwater Basin.
<br><br>Found in all zones in Badwater Basin and in rough silty rock salt
in Cottonball Basin
<br><br>Questionably present (X-ray determination but unsatisfactory) in
floodplain in Badwater Basin.
<br><br>Common in floodplain in Cottonball Basin; known as "cottonball"
<br><br>A fibrous borate with index of refraction higher than ulexite
occurs on dry areas in Cottonball Basin following hot dry spells and in
surface layer of smooth silty rock salt.
<br><br>Soda niter
<br><br>Weak, but positive chemical tests obtained locally.
<br><br> See also
<br><br>Death Valley National Park
<br><br>Places of interest in the Death Valley area
<br><br> Notes
<br><br>^ Harris et al., Geology of National Parks, 632. section 3,
paragraph 1
<br><br>^ "A Mudflat to Remember". Death Valley National Park through
time. USGS.
Retrieved 2005-07-06. , paragraph 1
<br><br>^ Harris et al., Geology of National Parks, 632, section 3,
paragraph 2
<br><br>^ Harris et al., Geology of National Parks, 632, section 3,
paragraph 3
<br><br>^ Harris et al., 634, section 4, paragraph 1
<br><br>^ "The Earliest Animal". Death Valley National Park through time.
USGS. Retrieved
2005-07-06. , paragraph 1
<br><br>^ "A Mudflat to Remember". , paragraph 3
<br><br>^ "Death Valley- Caribbean-style". Death Valley National Park
through time. USGS.
Retrieved 2005-07-06. , paragraph 1
<br><br>^ "Death Valley- Caribbean-style". , paragraph 4
<br><br>^ "Death Valley- Caribbean-style". , paragraph 2
<br><br>^ Harris et al., Geology of National Parks, 634, section 5,
paragraph 2
<br><br>^ "The Earth Shook, The Sea Withdrew". Death Valley National Park
through time. USGS.
Retrieved 2005-07-06. , paragraph 2
<br><br>^ Harris et al., Geology of National Parks, 634635, section 6,
paragraph 1
<br><br>^ "Granite". Death Valley National Park through time. USGS. Retrieved 2005-07-
06. , paragraph 1
<br><br>^ "Granite". , paragraph 2
<br><br>^ Harris et al., Geology of National Parks, 635, section 6,
paragraph 1
<br><br>^ "Quiet to Chaos". Death Valley National Park through time.
USGS. Retrieved
2005-07-06. , paragraph 1
<br><br>^ Harris et al., Geology of National Parks, page 635, section 8,
paragraph 1
<br><br>^ Harris et al., Geology of National Parks, page 611, paragraph 1
<br><br>^ "Forces Driving Mountain Building in Death Valley". Death
Valley National Park through time. USGS. Retrieved 2005-07-
06. , paragraph 3
<br><br>^ "Recent Geologic Changes". Death Valley National Park through
time. USGS.
Retrieved 2005-07-06. , paragraph 1
<br><br>^ Kiver, Eugene P.; David V. Harris (1999). Geology of U.S.
Parklands (5th ed.). New York: John Wiley &amp; Sons. pp. 278279. ISBN
0-471-33218-6. , "General Geology", paragraph 3
<br><br>^ Harris et al., Geology of National Parks, 616, paragraph 2
<br><br>^ Sharp, Robert P.; Allen F. Glazner (1997). Geology Underfoot in
Death Valley and Owens Valley. Missoula, MT: Mountain Press Publishing.
pp. 4153. ISBN 0-87842-362-1.Â
<br><br>^ Hunt, C.B., and Mabey, D.R., 1966, General geology of Death
Valley, California, U.S. Geological Survey Professional Paper 494.
(adapted public domain table)
<br><br> References
<br><br>USGS: Death Valley National Park through time (some adapted
public domain text), , , , , , , , (viewed November 5, 2004, last
modified 01/13/04)
<br><br>USGS Death Valley geology field trip , (viewed November 5, 2004,
last modified 01/13/04)
<br><br>USGS/NPS: Rock Formations exposed in the Death Valley area
(adapted public domain table)
<br><br> External links
<br><br>Proceedings on Conference on Status of Geologic Research and
Mapping, Death Valley National Park
<br><br>Tertiary Extensional Features, Death Valley, Eastern California
<br><br> Categories: Geology of California | Death Valley | Regional
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