This presentation is a brief overview of some of the areas in Texas where mining has taken place and some of the mitigation work completed by the AML program.
We will focus on mining sites from the 1880s to 1950 where there have been adverse effects from mining. Extraction of mineral resources has taken place in Texas for more than 300 years – not including the earlier use of different minerals by Native Americans. The first documented mining was for silver near El Paso, in the 1680s. Much of the mining for industrial minerals ceased by the 1940s and early 1950s – with the exception of coal, lignite, mercury, and several other industrial minerals.
This presentation will provide a very brief overview of the Texas Abandoned Mine Land Program (or AML), a review of some of the completed projects and future work, and a tour of some of the historical mining areas in Texas, with specific examples of AML program mitigation for each area.
Reclamation of abandoned coal mining problems was outlined in SMCRA, in 1977, and included in Title IV of the law. Funding for the program comes from a fee on mined coal in Texas.These funds are deposited in the Abandoned Mine Land Reclamation Trust Fund. The Texas AML program submits grant requests to the Office of Surface Mining for prioritized reclamation projects. The first Texas AML project was completed in northeast Texas in 1980.
As part of the TX AML Program’s efforts to find, catalog, and prioritize mine sites that needed reclamation, a series of statewide mine inventories were initiated in the late 1980s. A prior, coal-related inventory had been done in the late 1970s – those locations will be shown in a later slide. The state was divided into 3 sections - the first inventory, for south Texas, was completed as an Inter-agency contract between the Commission and the Bureau of Economic Geology – a research unit of the University of Texas in Austin. Mine sites were prioritized according to their size and proximity to residences and/or public roadways. The majority of the sites were related to caliche pits, for road-base materials.
The second inventory, for east Texas, was also completed as an Inter-agency contract between the Commission and the Bureau of Economic. The majority of the sites were related to sand and gravel mining. Clay and iron ore were other extracted commodities.
The third, and final, mine inventory covered 122 counties in west Texas. Almost 14,000 mine sites were identified. Only the 5,654 locations greater than 2 acres were included in the inventory. The Commission utilized agency personnel to conduct this survey. Much of the site reconnaissance was conducted by airplane. The majority of these sites were also related to the extraction of construction materials (caliche, limestone, and sand & gravel). However, the bulk of Texas’ hardrock mines are also located within this region.
This shows the result of all the mine inventories we’ve conducted. The coal sites, shown in black, also include a localized, coal mining inventory for north-central that was completed earlier by the B.E.G. in 1979.
In addition to the 316 coal-related sites, there are approximately 340 other non-construction-related mine sites in Texas. Uranium sites (both surface and in-situ operations) are found in the Tertiary formations that parallel the Gulf Coast. The most common non-coal sites in east Texas were iron ore operations. The majority of the metals and industrial minerals extracted in Texas are found in the Trans-Pecos area. The most important mineral resources extracted in west Texas were mercury, silver, and tin.
There are 6 levels of prioritization concerning the affects from past mining activities. Our program receives funding for only Priority I and II sites. The only difference between the two priority levels is that extreme danger is involved in the first priority. Priority III sites involve restoration of land and water resources and the environment previously degraded by adverse effects of past mining practices.
There are 17 Priority I and II problem types in the national AML Inventory System. We’ve only encountered six of those problems in Texas. The most common coal-related priority I and II problems are Dangerous Piles and Embankments, Hazardous Water Bodies, and Subsidence. The most common non-coal problems are dangerous highwalls, portals, and vertical openings. The last 3 problems are exclusively related to underground mining.
The only highwalls associated with historical coal mining (pre-1950s) are now underwater – they were flooded when the Cedar Creek Reservoir was completed in 1965. These spoil ridges and highwalls resulted from the first surface mining in Texas, by McAlester Fuels – later the Malakoff Fuel Co. Most of the highwalls in Texas resulted from pre-act uranium surface mines that were active from 1959 to 1976.
Waste piles and banks that pose a danger from unstable, steep slopes, and/or wind-blown dust and grit.
Water bodies that are considered an attractive nuisance – the hazard results from steep or unstable banks, hidden underwater ledges, or rocks or debris on the bottom.
Surface entrances to a drift, tunnel, adit, or entry which is not sealed or barricaded.
Surface expression of underground mine subsidence which damages property and poses a danger. There must be evidence of subsidence activity and/or continued damage within the last five years.
If an isolated pothole or vertical opening is created – it’s classified as a vertical opening.
Vertical or steeply-inclined shafts or openings that are not sealed or barricaded.
There have been 75 separate work contracts covering 35 mining sites. There are two ongoing contracts – one for coal and another for a uranium mine. Statewide reclamation quantities (for all mine sites) include 2,500 acres of spoil, over 10 miles of dangerous highwalls, 350 vertical openings, and 70 portals. Approximately $31 million of construction costs were associated with this work.
There are mitigation projects currently being designed for dangerous vertical openings in the Terlingua area and Franklin Mountains State Park. We still have 9 uranium mines with dangerous highwalls and dangerous piles and embankments. There are several coal-related sites where landowner permission is pending. The other coal-related sites are locations where future subsidence problems are very likely.
This map shows where existing mine shafts and existing and ongoing subsidence problems may affect the surrounding population. Most importantly, expanding housing construction in areas near large urban centers is resulting in the increased potential for residences being situated over and adjacent to undermined areas.
These maps are found on the Railroad Commission’s web page – the information is can be downloaded as a PDF or polygon shapefiles that can be utilized with GIS software.
There are at least 27 historical markers along roads and state highways that are related to some aspect of mining. The highest concentration of markers is around the former coal mining town, Thurber. Around half of the mining-related state historical markers are associated with coal.
The remainder of the presentation will cover historical mining in six areas where we have completed AML projects. The exception is Thurber, where no AML mitigation has been needed, but it’s great historical importance merits a brief visit.
The No. 10 Mine had the second largest extent of workings, around 235-feet deep. It opened in 1889 and was shut down in 1933.
Longwall mining was used at these mines – where the entire face of the coal seam was undercut and the coal was broken up with a pick and/or explosives. This diagram shows how this was done – the roof props were meant to be temporary.
The mine workings were georeferenced so you can appreciate the scale of the operations. Around 3,000 tons of coal were produced daily.
Shaft collars and shale and/or gob piles are all that remain of the mines. The shafts were sealed off and the refuse piles can be a problem if they erode and clog up streams. We have had no AML projects around Thurber – in part because of the geology, the mining method, and depth of the workings.
Thurber was truly a company town, so when the coal mining and brick plant closed down, nearly all of the structures were torn down around 1935 – all that remains is this smokestack. At one time 8 to 10,000 people lived here.
If you’re driving between Forth Worth and Abiline, it’s well worth making time to visit the Gordon Center’s museum.
AML problems have occurred in several of the mining areas – most notably the Liberty Coal and the W.C. Dodd Mine.
W.C. Dodd discovered a lignite seam on a hillside while squirrel hunting. It was a slope mine – several of the portals were still accessible in 1994. Room-and-pillar mining employing around 25 miners.
The average depth of cover at this mine was 25 feet, which meant subsidence has been occurring sporadically since the mine was closed. The photo on the left was taken from inside the collapsing workings. The reclamation in 1995 involved daylighting the workings and backfilling the voids.
We got a call from the new landowner in 2001-2002, concerned that one of his horses would fall into 11 recently opened subsidence features.
Daylighting and backfilling was again used to mitigate this site.
Strip mining was also used at Rockdale – this method was first attempted in 1918.
The mine spurs along the International-Great Northern line east of Rockdale were named after the coal mines they serviced: Witcher, Vogel, and Big Lump. Lignite here was extracted with picks and loaded into cars – each holding around 1,500 pounds. Mules were used to draw the carts.
Some of the mines used the lignite to run boilers, which in turn powered electric generators – allowing them to use electric locomotives for underground transportation.
The shallow cover over some of the lateral entries and rooms have collapsed over the years. This aerial photograph shows some of the subsided, flooded workings. We have not had any AML projects related to underground mining in Milam County.
Subsidence is very common over some of the mines.
You can clearly see the strike of the lignite seams north of Bastrop. We’ve had four AML projects here – both sites experienced repeated subsidence.
The water in the stock tank overlying the the Consumer’s Coal Co. mine disappeared into the workings after the roof was breached. The hole was backfilled once in 1989, then a second time in 1996. This shows the work that took place the second time.
Several holes opened up around a new residence in 2005 and 2007 – daylighting and backfilling were used to mitigate the problem.
There were five coal mine sites along Briggs Rd. Several of the located near the old rail spur.
Drilling and grouting was done in 1985 to stabilize Briggs Rd. where mine voids were detected. Backfilling of subsidence was done in 1985 and 1994. Again, the shallow cover over the workings is conducive to subsidence problems.
Subsidence features are again developing near Briggs Rd.
We’ll now switch over to some of ourhardrock AML sites in west Texas.
We’ve had 8 project areas in the Big Bend region. The most extensive closures were done around Terlingua and Lone Star - Mariposa. The monument the RCT installed at the No. 6 shaft gives some background information about the closures to visitors.
The following slides will demonstrate the most common methods of fixing the problems we encounter in west Texas: vertical openings,portals, and subsidence. We try very hard to maintain any structures if possible.
In the early 1990s we started implementing bat-friendly closures.
The corrugated metal pipe has an angle iron closure at the bottom end to allow passage by bats and exclude people.
The cable nets are used when there is loose rock – concrete pods anchor the net to the ground. Recessed grates are used to minimize materials needed for the closure (when there’s competent rock) and to allow people to view the workings.
Pre-cast and cast-in-place concrete caps were used in the 1980s. Many of the closure sites were in spectacular locations.
There are so many AML sites in the Big Bend Region that we’ll only cover 3 sites in two of the mercury mining districts. One is part of the Mariscal District and two are in the Terlingua District.
These photos show work in progress and the final closure. The shaft here was around 300 feet deep. You can see what the shaft looked like from the 90-foot deep level of the mine.
Most of the rock work around the mines in the National Park was safeguarded when possible and closures were built around or over the structures.
Now we’ll go northwest 30 miles or so to the Terlingua District. We’ll only look at two of the mining areas of the 29 in the District. We have excellent records of these mining operations because of extensive surveys completed during World War II, as mercury was a strategic material used in weapons.
Once mining ceased by the end of WWII, the village was abandoned. Over the years, people have drifted into town and Terlingua has become a full-fledged tourist destination.
The only modern-day fatality that has been reported occurred in 1982, when a 14-year-old playing with a friend fell down one of the shafts. It’s likely the No. 16 shaft is where he fell around 240 feet.
This shows the extensive mining around Terlingua. Over 23 miles of underground workings were accessed through 3 shafts. 64 of the closures involved backfilling – the remaining closures were 7 grates and 5 concrete slabs.
Evidence of this work can still be seen in the mine waste piles that border the village to the south and west. Not much has changed in the 70-80 years since the earlier picture was taken. Strong winds around 18 months ago knocked down the Rainbow Mine headframe.
Not much remained of the structures after 1945 – the number 8 shaft was closed in a way that you can still see some of the workings.
This is how many of the mine openings appeared in the early 1980s, before we began our closure work.
A couple more examples of the grate closures installed at Terlingua.
We’ll travel around 5 miles west to California Hill. The road to this mining area goes through the grounds of the annual Terlingua International Chili Championship site. California Hill was named by Californians coming from the mercury mines out west – this was the beginning of mercury mining in Texas. The 1902 topographic map shows this as the original Terlingua.
We’ve called this the Lone Star-Mariposa area, even though it’s comprised of a dozen separate mining operations. The 175 closures here cost over $500,000. 131 mine shafts were closed – 65 backfilled, 12 cable nets, and 54 steel grates. 30 adits and 14 trenches were also closed.
These photographs show the Swiss-cheese nature of the workings here. Mining began around the 1890s and pretty much ended in the 1930s. Many of the trenches resulted from prospecting done after 1943.
These are some of the grate and cupola closures.
Some of the cable nets were large enough to require cranes for installation.
The last area we’ll visit is Franklin Mountains State Park, near El Paso. The primary commodity mined was tin.
There were 4 large trenches and several vertical openings that required closure.
These are some of the finished closures.
This last group of photos shows the extent of preservation we’ve been able to achieve at Big Bend Ranch State Park, at the Fresno Mine. The integrity of the structure remains after a grate and bat cupola were installed.
Historical Mining in Texas and the Abandoned Mine Land Program
Jon E. Brandt, P.G. TX AML Program
Resources – extracted for over Mineral 300 years in Texas Most of the mining since 1950 has involved coal, lignite, uranium, mercury, and other industrial minerals (talc, sulfur, sand & gravel, etc.)
Brief overview of the Texas AML Program Abandoned Mine Land Projects • Summary of completed projects • Future work Virtual Tour of Historical Mining in Texas
Surface Mining Control and Reclamation Act of 1977 (SMCRA) Title IV – Abandoned Mine Land Recl. Code of Federal Regulations (CFR), Title 30 (Mineral Resources), Part 943: approval of TX AML Program in June 1980.
South TexasInventory Completed by Bureau of Economic Geology in 1989
East TexasInventory Completed by Bureau of Economic Geology in 1990
West TexasInventory Completed by Texas AML Staff in 1991
Over 12,200mine sitesThe majority of thelocations areconstruction-related
I – concerns the protection of Priority public health, safety, general welfare, and property from EXTREME DANGER of adverse affects of mining practices. II – the same, without extreme Priority danger present
Dangerous Highwalls (DH) Hazardous Water Body (HWB) Dangerous Piles & Embankments (DPE) Portals (P) Vertical Opening (VO) Subsidence (S)
Lignite discovered here in 1911 1991920s or earlier? 4Photo reprinted in MalakoffNews, Dec. 16, 2006
Milam County 1890 to 1930s (underground) Lignite (Eocene) Around 12 mining companies International-Great Northern Railroad
Lignite was found: • 1 seam • 5 to 14-feet thick • 33 to 180-feet deep (avg. closer to 50-60 ft)Slope Mine, 1890 Slope mines and vertical shafts Approx. 40 mines Photos courtesy of Willie, Vogel’s first shaft Gus, and Louise Lorenz mine, 1890
Vogel and Lorenz Coal & Manufacturing Co., 1913Milam County Map – 1920s Photo courtesy of Willie, Gus, and Louise Lorenz
Big Lump Company, aroundBlack Diamond Coal Co., 1903 1910, electric haulage Photo courtesy of Willie, Gus, and Photo from Phillips & Worrell, Louise Lorenz 1913
N.A.I.P. aerial photograph, 2010Inset: example of undergroundworkings - Texas Coal Co., c. 1913, Near Rockdale:from Phillips and Worrell Potential Subsidence