Congratulations to allenearl58 for FTF!
The coordinates for this earthcache bring you to the entrance to
the Arkansas Museum of Natural Resources. This Arkansas State Parks
facility features both indoor and outdoor exhibits chronicling the
discovery of oil in South Arkansas, particularly Smackover, the top
producing field in the era.
The History
Prior to 1921, South Arkansas’ economy was based on cotton
and timber industries which were both dwindling. Populations in the
area’s small towns ranged from less than 100 to just a few
thousand people. Then, in 1921, oil was discovered in El Dorado,
sparking an influx of prospectors from around the country hoping to
find their fortunes in the oil fields of South Arkansas.
The Geology
Southern Arkansas is in the Gulf Coastal Plain, containing nearly
14,000 feet of sediments younger than the basement rocks of the
Paleozoic system.
All of the older and most of the shallower oil fields of the
state were discovered in the early 1920's on structural terraces,
gentle anticlines or domes or along the upthrow side of faults and
produce from sands and sandstones in the Gulf series of sediments.
However, as shallow oil fields became more difficult to find and as
improvements in drilling techniques were made, it was possible to
drill deeper wells. The first productive wells found below the Gulf
series were sandstones in lower Cretacsous beds. In the
1930’s, as deeper tests were drilled, oil and gas production
was developed from Jurassic sandstones and limestone. The most
prolific producing areas consisted of oolitic limestone at the top
of the Smackover formation.
The Smackover Field, as well as other fields in Union County,
are classified as part of the Cotton Valley Beds, or upper
Jurassic.
Cotton Valley sediments are a subsurface sequence of sandstone,
shale and limestone extending from southern Arkansas to northern
Louisiana, northeastern Texas, central Mississippi, and western
Alabama. The beds range in thickness from inches in central Calhoun
County to over 3,400 feet in northern Louisiana, and have been
identified as far north as northern Ouachita County, Arkansas, and
as far south as Bienville Parish in Louisiana. In southern Arkansas
the Cotton Valley group of formations is a series of sandstones
interbedded with shale overlying the Smackover limestone, but in
some areas is separated from the latter by as much as several
hundred feet of red shale and anhydrite.
The Boom
In January 1921, oil was discovered in the Busey #1 Armstrong well
about two miles west of El Dorado in Union County. Based on
the success of this field, later called the El Dorado South Field,
testing for oil began in nearby areas that shared similar
geological characteristics with the El Dorado Field.
In 1922, oil was discovered in the Smackover Field at a depth of
about 2,000 feet. The Smackover Field is located in both Union and
Ouachita counties and was one of the most prolific oil producing
fields in the state. In fact, the large producing rates of this
field led to an increase in the state’s total oil production
each year through 1925.
While drilling for oil, workers often hit natural gas pockets,
causing explosions. In Norphlet, part of the Smackover Field, a
well exploded and blew drilling equipment and a derrick into the
air. Red sand was thrown a mile in all directions with an ignited
gas column. The glow from this explosion could be seen as far away
as Little Rock. The resulting crater swallowed everything nearby,
including a drilling rig, a boiler and a nearby cemetery.
(Visit this crater at N 33° 20.543 W 092° 40.063 and be sure to
look for Cache Hole in the Ground – GCGGWC.)
Today
Though oil production is no longer prevalent in the area, the south
Arkansas oil fields cover a 10-county area and are still producing.
In fact, one of the largest brine reserves in the world is located
under Union and Columbia counties. Bromine is present in abnormally
high concentrations in salt brines in south-central Arkansas. In
fact, chemists report that the concentration of bromine in South
Arkansas is 70 times the concentration of bromine in normal ocean
water. Between 1.5 to 1.8 pounds of bromine are recovered from
every barrel of brine processed. The first commercial recovery of
bromine in Arkansas was from Union County in 1957, and production
has been continuous ever since. Arkansas' industry continues as the
world's leading producer of bromine. Bromine presently is recovered
from brines in Columbia and Union Counties by two major
companies.
Bromine Brine
Elemental bromine is a highly corrosive, reddish-brown, volatile
liquid which, along with fluorine, chlorine, and iodine, forms a
family of elements known as the halogens. Bromine is the only
nonmetallic element that is a liquid at normal temperature and
pressure. As a liquid, bromine is extremely corrosive, yet when
combined with other elements into compounds or chemicals, it
becomes the basis for numerous useful and marketable products.
About 85 percent of the bromine recovered is consumed at the
production site by the bromine producers. Major products include
fire retardants, ingredients in bug and fungus sprays, antiknock
compounds in leaded gasoline, and oil-well completion fluids.
In Arkansas, decomposition of organic debris during the Jurassic
Period released bromine to the forming brines. During the processes
that produced the hydrocarbons composing petroleum and natural gas,
bromine became even more concentrated in the associated salt
brines. In Arkansas, it is thought that brines in the Louann
Formation migrated through the overlying Norphlet Formation into
the Smackover Formation.
The Facility
The Arkansas Museum of Natural Resources, situated in the midst of
the historic 60-mile Smackover Field, offers a 25,000 square foot
exhibit center, a Woodland Walk and an Oilfield Park. Answers to
all the cache requirements can be found at the Museum, in the Oil
Field Park and at the Crater Site in Norphlet.
The Arkansas Museum of Natural Resources is open from 8am until 5
p.m. daily and is only closed on Thanksgiving Day, Christmas Eve,
Christmas Day and New Year’s Day. Admission is free. While
visiting, you can look for One Slick Place (GC18HAX) – a
multi-cache at the museum.
The Cache
You MUST answer the following questions. A photo
requirement is listed below the questions.
1) Just outside of the Earth Globe exhibit, you will enter a
circular corridor, seemingly bored through layers of rock,
representative of the earth's core to the surface. The oversized
drill hole leads through the various geological strata beginning
with the Louann Salt at 8,000 feet in depth and continues to the
earth's surface. What is the diameter of the core
shaft? (You can obtain this information by measuring the
“core shaft actual size” display just outside of the
center of The Earth Globe exhibit.)
2. In 1922, Oil Operator’s Trust Murphy #1, a giant gas well,
blew. The crater caused by this explosion created flames that
burned bright enough for neighbors up to 15 miles away to read the
newspaper on their porches at night. What is the original
diameter and depth of the crater that developed in
Norphlet? (You can obtain this information by visiting the
display just off the “Boom Town Street” display, near
the oral history kiosks.)
3. The Oil Field Park, on the museum grounds, offers examples of
operational equipment from the 1920’s to today. Please
note: The Oil Field Park is open at all times the museum is open
but is not operational on Sundays. One example is the Angle
Iron Derrick and Pump Jack. This 1930’s era differed from
pipe derricks by not collecting water in their structural members.
What did this help prevent and what is the size of the angle iron
derrick (in feet) on display? (You can obtain this information in
the Oil Field Park near the 1930s-40’s Central Power Station
Exhibit)
4. Visit the crater that was formed in Norphlet at
N 33° 20.543 W 092° 40.063 and measure the current
diameter. You can do this by marking one point on either
side of the crater and using the projection feature on your GPSr.
Best estimates will be accepted.
Photo Requirement : You MUST take a picture of you or a member of
your team with the Norphlet crater in the background. DO NOT CROSS
THE FENCE! The crater is located at the end of Crater Road. It's a
large, fenced in hole. If you aren't at a large fenced in hole, you
aren't in the right spot. The museum can also provide you with a
map, if you need one.
E-mail your answers Do not post your answers in your
log. Finds that are posted without the required
picture or email may be deleted.
(Hidden with permission of Arkansas Museum of Natural Resources
State Park, Permit #002)
