Texas Almanac, 1992-1993 Page: 617
656 p. : ill. (some col.), maps ; 23 cm.View a full description of this book.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
MINERALS 617
used for a mixture of chemical compounds that is high in
humic acids. In the past, material from these deposits was
sold as soil conditioner. Other uses of leonardite include
modification of viscosity of drill fluids and as sorbants in
water-treatment.
LIGHTWEIGHT AGGREGATE (see Clay, Diatomite, Per-
lite, Vermiculite).
LIGNITE - Lignite, a low-rank coal, is found in belts of
Tertiary Eocene strata that extend across the Texas Gulf
Coastal Plain from the Rio Grande in South Texas to the
Arkansas and Louisiana borders in East Texas. The largest
resources and best grades (approximately 6,500 BTU/
pound) of lignite occur in the Wilcox Group of strata north
of the Colorado River in East and Central Texas.
The near-surface lignite resources, occurring at
depths of less than 200 feet in seams of three feet or thick-
er, are estimated at 23 billion short tons. Recoverable re-
serves of strippable lignite - those that can be
economically mined under current conditions of price and
technology - are estimated to be 9 billion to 11 billion
short tons.
Additional lignite resources of the Texas Gulf Coastal
Plain occur as deep-basin deposits. Deep basin resources,
those that occur at depths of 200 to 2,000 feet in seams of
five feet or thicker, are comparable in magnitude to near-
surface resources. The deep-basin lignites are a potential
energy resource that conceivably could be utilized by in
situ (in place) recovery methods such as underground gas-
ification.
As with bituminous coal, lignite production was signif-
icant prior to the general availability o oil and gas. Rem-
nants of old underground mines are common throughout
the area of lignite occurrence. Large reserves of strippa-
ble lignite have again attracted the attention of energy
suppliers, and Texas is now the nation's 6th leading pro-
ducer of coal, 99 percent of it lignite. Eleven large strip
mines are now producing lignite that is burned for mine-
mouth electric power generation, and additional mines are
planned. One of the currently operating mines is located in
Milam County, where part of the electric power is used for
alumina reduction. Other mines are in Atascosa, Bastrop,
Freestone, Grimes, Harrison, Limestone, Rusk, Panola,
Titus and Hopkins counties, where the electricity gener-
ated supplies municipal, domestic and industrial needs.
Another Harrison County strip mine produces lignite that
is used to make activated carbon.
LIME MATERIAL - Limestones, which are abundant in
some areas of Texas, are heated to produce lime (calcium
oxide) at a number of plants in the state. High magnesium
limestone and dolomite are used to prepare lime at a plant
in Burnet County. Other lime plants are located in Bexar,
Bosque, Comnal, Hill, Johnson and Travis counties. Lime
production captive to the kiln's operator occurs in several
Texas counties. Lime is used in soil stabilization, water pu-
rification, paper and pulp manufacture, metallurgy, sugar
refining, agriculture, construction, removal of sulfur from
stack gases and for many other purposes.
LIMESTONE (see also Building Stone) - Texas is one of
the nation's leading producers of limestone, which is quar-
ried in more than 60 counties. Limestone occurs in nearly
all areas of the state with the exception of most of the Gulf
Coastal Plain and High Plains. Although some of the lime-
stone is quarried for use as dimension stone, most of the
output is crushed for uses such as bulk building materials
(crushed stone, road base, concrete aggregate), chemical
raw materials, fillers or extenders, lime and portland ce-
ment raw materials, agricultural limestone and removal of
sulfur from stack gases.
MAGNESITE - Small deposits of magnesite (natural
magnesium carbonate) have been found in Precambrian
rocks in Lano and Mason counties of Central Texas. There
formerly was small-scale mining of magnesite in the area
- some of the material was used as agricultural stone and
as terrazzo chips. Magnesite also can be calcined to form
magnesia, which is used in metallurgical furnace refrac-
tories and other products.
MAGNESIUM - On the Texas Gulf Coast in Brazoria
County, magnesium chloride is extracted from sea water at
a plant in Freeport and used to produce magnesium com-
pounds and magnesium metal. During World War II, high-
magnesium Ellen burger dolomite rock from Burnet Coun-
ty was used as magnesium ore at a plant near Austin.
MANGANESE - Deposits of manganese minerals, such
as braunite, hollandite and pyrolusite, have been found in
several areas, including Jeff Davis, Llano, Mason, Presid-
io and Val Verde counties. Known deposits are not large.
Small shipments have been made from Jeff Davis, Mason
and Val Verde counties, but no manganese mining has
been reported in Texas since 1954.
MARBLE - Metamorphic and sedimentary marbles
suitable for monument and building stone are found in the
Llano Uplift and nearby areas of Central Texas and the
Trans-Pecos area of West Texas. Gray, white, black,
greenish black, light green, brown and cream-colored
marbles occur in Central Texas in Burnet, Gillespie, Llano
and Mason counties. West Texas metamorphic marbles in-
clude the bluish-white and the black marbles found south-
west of Alpine in Brewster County and the white marble
from Marble Canyon north of Van Horn in Culberson Coun-ty. Marble can be used as dimension stone, terrazzo and
roofing aggregate and for other purposes.
MERCURY (QUICKSILVER) - Mercury minerals, chiefly
cinnabar, occur in the Terlingua district and nearby dis-
tricts of southern Brewster and southeastern Presidio
counties. Mining began there about 1894, and from 1905 to
1935, Texas was one of the nation's leading producers of
quicksilver. Following World War II, a sharp drop in de-
mand and price, along with depletion of developed ore re-
serves, caused abandonment of all the Texas mercury
mines.
With a rise in the price, sporadic mining took place be-
tween 1951-1960. In 1965, when the price of mercury moved
to a record high, renewed interest in the Texas mercury
districts resulted in the reopening of several mines and the
discovery of new ore reserves. By April 1972, however, the
price had declined and the mines have reported no produc-
tion since 1973.
MICA - Large crystals of flexible, transparent mica
minerals in igneous pegmatite rocks and mica flakes in
metamorphic schist rocks are found in the Llano area of
Central Texas and the Van Horn area of West Texas. Most
Central Texas deposits do not meet specifications for sheet
mica, and although several attempts have been made to
produce West Texas sheet mica in Culberson and Hudspeth
counties, sustained production has not been achieved. A
mica quarry operated for a short time in the early 1980s in
the Van Horn Mountains of Culberson and Hudspeth coun-
ties to mine mica schist for use as an additive in rotary
drilling fluids.
MOLYBDENUM - Small occurrences of molybdenite
have been found in Burnet and Llano counties, and wulfe-
nite, another molybdenum mineral, has been noted in
rocks in the Quitman Mountains of Hudspeth County. Mo-
lybdenum minerals also occur at Cave Peak north of Van
Horn in Culberson County, in the Altuda Mountain area of
northwestern Brewster County and in association with
uranium ores of the Gulf Coastal Plain.
PEAT - This spongy organic substance forms in bogs
from plant remains. It has been found in the Gulf Coastal
Plain in several localities including Gonzales, Guadalupe,
Lee, Milam, Polk and San Jacinto counties. There has
been intermittent, small-scale production of some of the
peat for use as a soil conditioner.
PERLITE - Perlite, a glassy igneous rock, expands to a
lightweight, porous mass when heated It can be used as a
lightweight aggregate, filter aid, horticultural aggregate
and for other purposes. Perlite occurs in Presidio County,
where it has been mined in the Pinto Canyon area north of
the Chinati Mountains. No perlite is currently mined in
Texas, but perlite mined outside of Texas s expanded at
plants in Bexar, Dallas, El Paso, Guadalupe, Harris and
Nolan counties.
PHOSPHATE - Rock phosphate is present in Paleozoic
rocks in several areas of Brewster and Presidio counties in
West Texas and in Central Texas, but the known deposits
are not large. In Northeast Texas, sedimentary rock phos-
phate occurs in thin conglom-eratic lenses in Upper Creta-
ceous and Tertiary rock units; possibly some of these low-
grade phosphorites could be processed on a small scale for
local use as a fertilizer. Imported phosphate rock is proc-
essed at a plant in Brownsville.
POTASH - The potassium mineral polyhalite is widely
distributed in the subsurface Permian Basin of West Texas
and has been found in many wells in that area. During
1927-1931, the federal government drilled a series of po-
tash-test wells in Crane, Crockett, Ector, Glasscock, Lov-
ing, Reagan, Upton and Winkler counties. In addition to
poltyhalite, which was found in all of the counties, these
wells revealed th re presence of the potassium minerals car-
nallite and sylvite in Loving County and carnallite in Wink-
ler County. The known Texas potash deposits are not as
rich as those in the New Mexico portion of the Permian Ba-
sin and have not been developed.
PUMICITE (VOLCANIC ASH) - Deposits of volcanic ash
occur in Brazos, Fayette, Gonzales, Karnes, Polk, Starr
and other counties of the Texas Coastal Plain. Deposits
also have been found in the Trans-Pecos area, High Plains
and in several counties east of the High Plains. Volcanic
ash is used to prepare pozzolan cement, cleansing and
scouring compounds and soaps and sweeping compounds;
as a carrier for insecticides, and for other purposes. It has
been mined in Dickens, Lynn, Scurry, Starr and other
counties.
QUICKSILVER (see Mercury).
RARE-EARTH ELEMENTS AND METALS - "Rare-earth
elements" is commonly applied to elements of the lantha-
nide group (atomic numbers 57 through 71) plus yttrium.
Yttrium, atomic number 39 and not a member of the lan-
thanide group, is included as a rare-earth element because
it has similar properties to members of that group and usu-
ally occurs in nature with them. The metals thorium and
scandium are sometimes termed "rare metals" because
their occurence is often associated with the rare-earth
elements.
The marjority of rare-earth elements are consumed as
catalysts in petroleum cracking and other chemical indus-
tries. Rare earths are widely used in the glass industry forMINERALS
617
Upcoming Pages
Here’s what’s next.
Search Inside
This book can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Book.
Kingston, Mike. Texas Almanac, 1992-1993, book, 1991; Dallas, Texas. (https://texashistory.unt.edu/ark:/67531/metapth279642/m1/621/: accessed April 28, 2024), University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu; crediting Texas State Historical Association.