Coal and Peat Fires: a Global Perspective Edited by Glenn B

CHAPTER 23 ◆ ◆ The “Volcanoes” of Midwestern Venezuela CHAPTER CONTENTS

23.1 The “Volcanoes” of Midwestern Venezuela Introduction Geologic Setting The “Volcanoes” Discussion and Conclusions Acknowledgments References

The main gas vent of “Volcán de Las Monas”, where the ammonium sulfates tschermigite, godovikovite, and mascagnite were identified by the authors. In 1994, the vent was 1.6 m wide and 0.25 m high at its widest point, and a thermocouple temperature of 225 °C was measured 40 cm inside. This coal-fire is located in a hillside in a remote region of northwest- ern Venezuela, with no coal-mining activity. According to local inhabitants, the coal-fire started in the 1950s, with the maximum activity in the late 1980s and early 1990s, when intermittent columns of smoke were visible up to a few kilometers away. In 1990, the vents were completely lined with sulfates. In 2012, the maximum temperature measured had decreased to 52 °C and there were no sulfate mineral deposits. Photo by Franco Urbani, 1990. Coal and Peat Fires: A Global Perspective Edited by Glenn B. Stracher, Anupma Prakash and Ellina V. Sokol 610 Copyright © 2015 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/B978-0-444-59509-6.00023-5

23.1 The “Volcanoes” of Midwestern Venezuela Manuel David Soto Franco Urbani

Coal-fire and ammonium sulfates at “Volcán de Las Monas”, Venezuela. Vent details are mentioned in the previous photo. Photo by Franco Urbani, 1990.

Introduction

Several sites with underground coal-fires, known locally as “volcán” (volcano), “volcancito” (little volcano) or “fumarola” (fumarole), have been reported in western Venezuela (Briceño-Méndez, 1876). During the last third of the sixteenth century, the Spanish Royal authorities distributed a questionnaire known as the “Geographical Rela- tions” to their colonies, with the goal of compiling a general description of all Spanish territories. On January 21, 1579, the principals of the city of El Tocuyo wrote “We declare that at eight leagues from this city (El Tocuyo), in the mountains located in the direction of the sunrise, there is a large volcano (Fumarola de Sanare) that has three mouths. It is always smoking and emits a sulfurous smell… When the weather changes its roars can be heard in this city, and sometimes after those roars, large earthquakes occur that alarm the Spaniards as well as the natives. Fur- thermore, at seven leagues in the same direction from this volcano, above the valley of Quíbor, and at seven leagues from this town, there was another smaller volcano (Volcancito de San Miguel) that used to smoke and blow ash, but it is now extinct because in the past four years it no longer smokes as it used to do for many years” (Ponce de León et al., 1579 and Urbani 1996). This was the first description of coal-fires in the Americas, although for this locality it took 410 years (Urbani et al., 1987) to be recognized as the result of coal-fire.

Coal-fires are known in several regions of Venezuela such as the Perijá Cordillera near the border with Colombia, the southern part of the Mérida Andes, and also in eastern Venezuela; all are related to tertiary coal-bearing geological units that sporadically have been exploited commercially.

In this chapter, we studied five coal-fires located in the northern half of Lara State (Figure 23.1.1), surrounding the towns of Quíbor and Quebrada Arriba. This study includes a description of the geology of the area of combustion, and identification and analysis of thermally altered rocks and minerals deposited in and around gas vents and ground fissures.

Geologic Setting

The study area is included in the Lara Nappes geological province (Stephan et al., 1985) that originated due to a southeast vergent nappe-piling event that occurred during the late Eocene—early Oligocene. The event was caused by the oblique convergence of the Caribbean plate on the northern portion of the South American plate, producing a complex tectonic imbrication of igneous and sedimentary units of Cretaceous age with Paleogene turbidites. Later, during mid-Tertiary times an extensional period with crustal thinning created a basin that was filled transgressively by several Miocene formations deposited unconformably over the previous units. The “Volcanoes” of Midwestern Venezuela 611

Figure 23.1.1. Location map of coal-fires in midwestern Venezuela. The black dots mark the locations of current or burnt-out coal-fires with their local names. Polygons identify further detailed maps. Map coordinates are in kilometers, UTM zone P19, datum PSA56. Modified fromSoto (1997).

The five coal-fires in the state of LaraFigure ( 23.1.1) occur in three different geological formations:

1. The area south of Quíbor (Figure 23.1.2) is crossed by the Boconó Fault (the major seismogenic fault of western Venezuela) and one of its branches, the Río Turbio Fault. Three coal-fire sites occur south of the Boconó fault in the Villanueva Formation (Figure 23.1.2): Volcancito de San Miguel (VSM), the Fumarola de Sanare (FS), both known since 1579, and the Volcán de Gusama (VG), which started in 1990 after a large landslide. The Vil- lanueva Formation is a Late Cretaceous unit composed of black shale with minor amounts of sandstone, limestone, and chert that have been affected by a very low-grade (subgreen schist facies) metamorphism (Von der Osten and Zozaya, 1957). This is an allocthonous unit emplaced during the mid-Tertiary nappe-piling event of the Caribbean realm. No coal-bed outcrops are described in the literature and none were found during our fieldwork.

2. Outcrops south of Quíbor, but in the north side of the Boconó Fault, are composed of unconsolidated beds of sand and clay with minor lignite inliers of the Pliocene Pegón Formation (Jefferson, 1964). The coal-fire in the “Mina de Yay” (MY, Figure 23.1.2) started in 1985 when a lignite seam, 70 cm thick, ignited spontaneously after it was exposed by mining white clays used in the ceramic industry.

3. The Volcán de Las Monas (Figure 23.1.1), located north of the town of Quebrada Arriba, is a smoldering coal bed in the Miocene Cerro Pelado Formation. This formation unconformably overlies the pre-Neogene nappes. The unit is composed of thick packages of sandstone, intercalated with shale and scattered lignite beds (Liddle, 1928). 612 Soto and Urbani

Figure 23.1.2. Location map of coal-fire sites south of Quíbor, Lara State, Venezuela. Abbreviations of coal-fire sites: VSM, Volcancito de San Miguel; VG, Volcán de Gusama; FS, Fumarola de Sanare; and MY, Mina de Yay. Rectangles around the sites locate more detailed maps. Geological units: K, Villanueva Formation, Late Creta- ceous. Tp, Morán Formation, Paleogene. Tn, Pegón Formation, Neogene. Map coordinates are in kilometers, UTM zone P19, datum PSA56. Modified from Soto (1997).

The “Volcanoes”

A summary of location, geological context, temperature, and probable origin of the five coal-fires sites is presented in Table 23.1.1. Samples richest in carbon were collected and analyzed in each locality (Table 23.1.2). All of the mineral samples collected were identified by X-ray diffraction (XRD) and with an electron microprobe-scanning electron microscope (EMP-SEM). The sample data are summarized in Table 23.1.3.

At Volcancito de San Miguel, Fumarola de Sanare, and Volcán de Gusama (all within the Villanueva Formation) only dark (carbon-rich) slates were available for sampling. No coal beds have been found at either of these localities, neither by previous regional–geological surveys nor in our own work. Therefore, the source of combustion is open to further research. On the contrary, at Mina de Yay and Volcán de Las Monas, lignite was sampled.

Volcancito de San Miguel

At this site (Figure 23.1.3) there are several vents that emanate hot humid gas with an acrid and pungent smell, at the top of a landslide with many ground fissures opened in the weathered slates of the Villanueva Formation ( Figures 23.1.4 and 23.1.5). The highest temperature measured in 1990 was 95 °C, about 60 cm inside the main vent at that time. However, the temperature recorded in 2012 was only 45 °C. The elders of nearby towns say that they have never seen emissions of smoke or vapor.

The secondary minerals deposited in and around the gas vents are Ca, Fe, and Mg sulfates. Gypsum (CaSO4·2H2O) is dominant and can be found covering and agglutinating the ground surface up to a few square meters around the vents. In places exposed to rainfall gypsum shows groove dissolution while in niches protected from the rain 3+ appears with magnesiocopiapite (MgFe 4(SO4)6(OH)2·20(H2O)) which forms pale green and yellowish efflorescence (Figure 23.1.6). In addition, anhydrite (CaSO4) is present along the foliation planes of thermally altered slates and found inside and around hot gas vents (Figure 23.1.7). The “Volcanoes” of Midwestern Venezuela 613

Table 23.1.1 General data for five coal-fires in Midwestern Venezuela.

Site Location Geological Unit, Lithology Origin Observations Volcancito de 5.9 km S of San Villanueva Formation Coal bed or dark Known since 1579 San Miguel Miguel 1425 m of (Late Cretaceous). carbonaceous slates, 1986: 83 °C elevation above sea Dark carbonaceous exposed by landslides 1990: 95 °C at 60 cm level (easl) slates, probably with in steep mountain below the surface 69°30′25″W coal or carbon-rich side 1994: 85 °C 9°49′52″N inliers. Very low grade 2012: 45 °C metasediments Volcán de 4.3 km SE of Ditto. Ditto. Started in 1990 Gusama Cubiro 1991: 281 °C at 70 cm 1520 m easl inside the vent 69°32′56″W 1994: 27 °C inactive 9°45′54″N Volcán de 4.2 km NEE of Ditto. Ditto. Known since 1579 Sanare Sanare 1931: 115 °C 1900 m easl 1994: 100 °C 69°36′13″W 2011: “warm” 9 45′51″N Mina de Yay 3.9 km NWW of Pegón Formation Lignite exposed by Started in 1985 Sanare (Late Miocene—Pliocene) exploitation of a 1986: >500 °C 1100 m easl Kaolinite shale with lignite clay mine 1990: 104 °C 69°40′55″W seams 1994: 50 °C 9°46′6″N 2012: Inactive Volcán de Las 13.8 km NNE of Cerro Pelado Formation Lignite bed exposed Known since 1950s Monas Quebrada Arriba (Early Miocene) in steep slope 1990: >110 °C 710 m easl Sandstone and shale with 1994: 225 °C at 40 cm 70°30′19″W scattered lignite seams inside the vent 10°21′22″N 2012: 52 °C

Table 23.1.2 Analyses (% by weight) of samples from five coal-fires in Midwestern Venezuela.

Site Moisture Ash Volatile Fixed C Lithology Volcán de Sanare 1.3 67.5 8.3 23.2 Black slate Volcancito de San Miguel 0.5 62.0 10.8 26.7 Black slate Volcán de Gusama 0.8 87.3 9.9 1.9 Black slate Volcán de Las Monas 9.1 21.9 53.8 15.2 Lignite Mina de Yay 18.0 16.8 55.6 15.2 Lignite The low moisture of the black slates is due to the nearness of the samples to the underground combustion. Analysis by the authors and Professor Angelica Delgado, Coal and Oil Waste Laboratory, Universidad Simon Bolivar, Venezuela, 1994.

A distinct feature of this locality is the presence of a resinous substance that agglutinates the lose soil and thermally altered rock fragments in and around the gas vents (Figure 23.1.8). After careful separation, the substance was identified by XRD and EMP-SEM as the iron sulfate ferrohexahydrite (FeSO4·6(H2O)), probably with minor amounts of lausenite (Fe2(SO4)3·6(H2O)). 614 Soto and Urbani

Table 23.1.3 Minerals associated with the combustion of five coal-fires in Midwestern Venezuela.

Site Minerals Identified Mineral Properties Formula

Volcancito de San Ferrohexahydrite and Brown resinous agglutinative FeSO4·6(H2O) Miguel lausenite? material Fe2(SO4)3·6(H2O) 3+ Magnesiocopiapite Pale green efflorescence MgFe 4(SO4)6(OH)2·20(H2O) Anhydrite Between slate foliation planes CaSO4 Gypsum Crusts on the ground surface CaSO4·2H2O Volcán de Gusama Unidentified Resinous agglutinant – Anhydrite Between foliation planes CaSO4 Gypsum Crusts at the surface CaSO4·2H2O 3+ Jarosite Efflorescences KFe 3(SO4)2(OH)6 Fumarola de Sanare Calcite Crusts, stalactitic, dogtooth and CaCO3 Anhydrite helictite shapes in vents CaSO4 Gypsum Between foliation planes CaSO4·2H2O 3+ Fibroferrite Crusts at surface Fe (SO4)(OH)·5(H2O) Greenish-yellow efflorescence Mina de Yay Anhydrite All collected in 1994, around the CaSO4 Gypsum hottest (50 °C) locations of clay CaSO4·2H2O 3+ Jarosite KFe 3(SO4)2(OH)6 2+ Halotrichite Fe Al2(SO4)4·22(H2O) Volcán de Las Tschermigite Crusts stalactitic and botryoidal (NH4)Al(SO4)2·12(H2O) 3+ Monas* Godovikovite In small vent, 27 °C (NH4)(Al,Fe )(SO4)2 Mascagnite In small vent, 43 °C (NH4)2SO4 Lecontite In shale bedrock (NH4,K)Na(SO4)·2(H2O) Alunogen On clinker surface Al2(SO4)3·17(H2O) Alunite On clinker surface KAl3(SO4)2(OH)6 Hematite Fe2O3 2+ 3+ Magnetite Fe Fe 2O4 *Composition of water condensed from the vapor emanating at the main vent. Analysis by ion chromatography (in milligram per liter) done +2 + +2 + + by Dr Armando Ramírez, Universidad Central de Venezuela, 1994: Ca : 11, Na : 5.5, Mg : 3.7, NH4 : 3.6, K : 0.4.

Figure 23.1.3. Location and geological map of Volcancito de San Miguel, Venezuela. The black dot marks the coal-fire site. The hachured lines indicate steep scarps at the tops of active and old landslides. Dash line: road or walking path. Thin line: creeks. Thick line: high-angle right lateral Río Turbio fault. Geological unit: K, Villanueva Formation, Late Cretaceous. The black spot located the coal-fire locality. Map coordinates are in kilometers, UTM zone P19, datum PSA56. Modified from Soto (1997). The “Volcanoes” of Midwestern Venezuela 615

Figure 23.1.4. View to the west of the Río Turbio valley, Venezuela. The mountain near the middle of the photo is Cerro Negro, and the arrow points to Volcancito de San Miguel. The planar slope on the right side of the mountain is about 200 m in height. Photo by Franco Urbani, 2012.

Figure 23.1.5. Volcancito de San Miguel, Venezuela. The main gas-emitting fissure shown here is located at the top of the landslide. Photo by Franco Urbani, 1990. 616 Soto and Urbani

(a)

(b)

Figure 23.1.6. Volcancito de San Miguel, Venezuela. (a) Outcrop of the Villanueva Formation, at 5 m from the main gas vent. The foliation planes (1) of the dark gray slate cover and protect the underneath mineral deposits. The rain has produced the vertical groove morphology in gypsum (2). Below there are deposits of botryoidal yellowish magnesiocopiapite (3). Soil and rocks around the vents area have similar gypsum deposits. The horizontal field of view is 60 cm. (b) SEM image of gypsum crystals. Photo by Franco Urbani, 2012; SEM image by Manuel David Soto, 1994.

Figure 23.1.7. Volcancito de San Miguel, Venezuela. Thermally altered slate from the Villanueva Formation, with white crystals of anhydrite. Sample collected 20 cm inside a gas vent. The diameter of the coins is 23 mm. Photo by Manuel David Soto, 1994. The “Volcanoes” of Midwestern Venezuela 617

(a)

(b)

(c)

Figure 23.1.8. Volcancito de San Miguel, Venezuela. (a) Gas vent with lose fragments of slate and deposits of magnesiocopiapite (yellowish) and gypsum (gray and white). The darker areas at the left and bottom-left of the vent consist of small fragments of thermally altered rock amalgamated by a resinous material in which ferrohexahydrite and lausenite were identified. The presence of these sulfates minerals always around the gas vents suggests that they have nucleated in association with the coal-fire gases. (b) Resinous stalactite of ferrohexahydrite collected 20 cm inside a gas vent. (c) SEM image of resinous material from the sample in Figure 23.1.8(b). Photos and SEM image by Manuel David Soto, 1994. 618 Soto and Urbani

Volcán de Gusama

In this location (Figure 23.1.9), the coal-fire started in mid-1990 after a period of heavy rains that triggered landslides inside an area affected previously by larger landslides (Figure 23.1.10). Local residents stated that smoke emissions started roughly a week after the second landslide occurred, causing alarm in the neighborhood, as many believed that a real volcano could erupt.

Figure 23.1.9. Location and geological map of Volcán de Gusama, Venezuela. Symbols as in Figure 23.1.3. Note the presence of numerous landslides. The black dot locates the coal-fire. Geological unit: K, Villanueva Formation, Late Cretaceous. Map coordinates are in kilometers, UTM zone P19, datum PSA56. Modified fromSoto (1997).

Figure 23.1.10. Volcán de Gusama, Venezuela. View of one of several large landslides that appear at the southern side of the Río Turbio Fault. The arrow shows the location of the coal-fire which was first reported in 1990 after a reactivation of the large landslide. The top of the landslide is approximately 325 m wide. Photo by Franco Urbani, 1991. The “Volcanoes” of Midwestern Venezuela 619

Figure 23.1.11. Volcán de Gusama, Venezuela. A wooden stick inserted 60 cm inside the gas vent caught fire. The red-colored rocks are thermally altered slates of the Villanueva Formation. A maximum temperature of 281 °C was measured 70 cm inside the vent in 1991. Photo by Franco Urbani, 1991.

In 1991 the authors visited the site and the maximum temperature of 281 °C was measured with a thermocouple 70 cm inside the largest vent. The vents emitted moist hot air with a mild sulfurous odor. A wooden stick introduced 3+ into the fissure caught fire (Figure 23.1.11). Some patches of jarosite (KFe 3(SO4)2(OH)6) coat few small gas vents. As at the previous site, anhydrite was present along still hot foliation planes of thermally altered slate fragments, and a resinous material agglutinating rock fragment was found near some vents. However, not enough resinous material could be collected for analysis. Sometime between 1991 and 1994 the coal-fire died spontaneously. In 1994 only gypsum was found near the inactive vents.

Fumarola de Sanare

This feature (Figures 23.1.12 and 23.1.13), also known as Volcán de Sanare, is clearly visible from the town of Sanare and has alarmed Sanare’s residents since 1579. As a result, it has been the coal-fire locality most cited in Venezuelan books and newspapers. According to available records, it seems to have 60- to 80-year-long cycles of reactivation producing emissions of water vapor and smoke that can be easily seen from Sanare (likely because of the backdrop provided by the very steep mountain side of Cerro La Neblina). Vapor and smoke can be explained as caused by rainwater entering ground fissures and boiling as it reaches deep coal-fires, because the activity usually happens at the beginning of the rainy season.

The highest temperature ever measured at this site was 115 °C (by naturalist Brother Nectario María in 1931). The highest temperature measured during our study in 1994 was 100 °C, 30 cm inside one of the vents (Figure 3+ 23.1.14). Three sulfate minerals were found in and around the vents. Fibroferrite (Fe (SO4)(OH)·5(H2O)) appears as yellowish efflorescences in places protected from direct rainfall. Anhydrite appears as crystals embedded in still hot thermally altered slate, and gypsum appears as crusts covering thermally altered rocks. Calcite (CaCO3) crystals usually cover the inner walls of vents with stalactitic, dogtooth, and helictite morphologies.

The landslide that originates the current fire is about 150 m in height and has an inverted V shape with its base at 1800 m above sea level. Above the landslide, thick cloud-forest-type vegetation grows continuously. Our 1994 620 Soto and Urbani

Figure 23.1.12. Location and geological map of Fumarola de Sanare, Venezuela. Dash-dotted lines indicate creeks, other symbols as in Figure 23.1.3. The black dot locates the coal-fire. Geological unit: K, Villanueva Formation, Late Cretaceous. Map coordinates are in kilometers, UTM zone P19, datum PSA56. Modified fromSoto (1997).

Figure 23.1.13. Fumarola de Sanare, Venezuela. View of La Neblina mountain, where a coal-fire is located at the top of a landslide (white arrow). The tops of the coronas of other landslides (yellow arrows), partially overgrown by cloud-forest-type vegetation, are visible. There are also other scarps probably formed by landslides. It is not known when the other landslides occurred or if they generated coal-fires. Photo by Franco Urbani, 1994. The “Volcanoes” of Midwestern Venezuela 621

(a)

(b)

(c)

Figure 23.1.14. Fumarola de Sanare, Venezuela. (a) Gas vent in thermally altered slates of the Villanueva Forma- tion. The thermometer reads 95 °C and has a diameter of 4 cm. (b) Sample of thermally altered slate with embedded anhydrite crystals, collected inside the vent of Figure 23.1.14(a). The diameter of the coins is 23 mm. (c) SEM image of two anhydrite crystals, showing morphology inherited from gypsum. Photos and SEM image by Manuel David Soto, 1994. 622 Soto and Urbani observations were made at the top of this landslide, where vegetation was already colonizing the area (Figure 23.1.13). In 2010 Mr José Escalona, the chronicler of Sanare, who in 1994 guided us to the site, stated that the current place of activity in the landslide has been the same since at least the 1960s even though in very rainy years the landslide reactivates and exposes bare rocks that are subsequently overgrown by vegetation within a couple of years.

Mina de Yay

About 3 km northwest of Sanare (Figure 23.1.2) in 1985, a 0.7 m thick lignite layer was exposed by heavy machinery in a kaolin mine (Figure 23.1.15). A couple of weeks later, spontaneous combustion started. The mine operators tried to extinguish the coal-fire by covering it with clay without success. During our first visit, in 1986, large flames erupted instantly when we uncovered the lignite bed (Figures 23.1.16 and 23.1.17) and the adjacent altered clay was red hot. We were able to replicate the red hot color in the laboratory with temperatures above 500 °C. Temperatures at the site decreased to 104 °C in 1990, to 50 °C in 1994, and to the

Figure 23.1.15. Mina de Yay, Venezuela. View of the open pit mine. In the past two decades kaolinite has been intermittently exploited for the ceramic industry. The 190-m-long lagoon was dug to collect acid runoff from a coal-fire area and prevent entering into nearby drainage. The arrow points to the location of the 1986 coal-fire. Photo by Franco Urbani, 1986.

Figure 23.1.16. Mina de Yay, Venezuela. General view of the coal-fire. An arrow points to an observer in the right side of the photo. Photo by Franco Urbani, 1986. The “Volcanoes” of Midwestern Venezuela 623

Figure 23.1.17. Mina de Yay, Venezuela. Flames erupted when clay covering the smoking area (Figure 23.1.16) was removed. Photo by Franco Urbani, 1986.

ambient temperature in 2012. In 1994, the sulfate minerals anhydrite, gypsum, jarosite, and halotrichite 2+ (Fe Al2(SO4)4·22(H2O)) in addition to highly thermally altered clays (clinker) were collected at the warmest places of the coal-fire site.

Volcán de Las Monas

Smoke emissions at this locality (Figures 23.1.18–23.1.20) have been sporadic events with about decadal cycles that have been documented by local residents since the area was populated in the mid-1950s. Its maximum activity was in the late 1980s and early 1990s.

The site was visited in 1990, 1994, and 2012. Mineralogically and petrologically it is the most colorful and complex coal-fire locality known in the Lara State, although the variety of minerals precipitated in the main vent (as well as the temperature) have shown a diminishing trend since 1990. During our first visit in 1990 a smoke column was visible 1 km away from the access road and the main vent was entirely lined with delicate crusts, stalactitic and 3+ globular shapes of the ammonium sulfates tschermigite ((NH4)Al(SO4)2·12(H2O)), godovikovite ((NH4)(Al,Fe ) (SO4)2), and mascagnite ((NH4)2SO4) (Figure 23.1.21). In 1990, the maximum temperature reading possible (110 °C) for the available thermometer was surpassed. In 1994 the maximum temperature recorded with a thermocouple at 40 cm inside the main vent was 225 °C, and tschermigite was the only mineral present (Figures 23.1.22 and 23.1.23). 624 Soto and Urbani

Figure 23.1.18. Geological map of the Las Monas region, north of Quebrada Arriba, Venezuela. The Volcán de Las Monas is located in the small rectangle area (as seen in Figure 23.1.19). The geological units: Tma, Agua Clara Formation; Tmc, Cerro Pelado Formation; and Tmct, Castillo Formation. Map coordinates are in kilometers, UTM zone P19, datum PSA56. Modified from Soto (1997).

Figure 23.1.19. Topographic details of Volcán de Las Monas, Venezuela. Its location appears in the rectangular area of Figure 23.1.18. Tmc is the Cerro Pelado Formation. The white area within the dash-dotted line delineates the vegetation-free thermal and acid sulfate alteration zone. The starred line shows the inferred trace of the subsurface coal bed. Main gas vents are indicated by the irregular black shapes, and the black circles are where magnetic data were collected. Contour lines are in meters above sea level. Map coordinates are in kilometers, UTM zone P19, datum PSA56. Modified from Soto (1997). The “Volcanoes” of Midwestern Venezuela 625

Figure 23.1.20. Volcán de Las Monas, Venezuela. Parallel hills along the Las Monas creek. The arrow indicates the location of the coal-fire. Photo by Manuel David Soto, 1994.

(a) (b)

Figure 23.1.21. Volcán de Las Monas, Venezuela. (a) In 1990 much of the main vent shown in this photo was lined with ammonium sulfates nucleated in association with coal-fire gas. The reddish colors of the rocks and soil are due to the thermal and acid sulfate alteration of shale, siltstone, and sandstone of the Cerro Pelado Formation. During the study period of 1990–1994 the gas vent shown here was approximately 1.6 m long and 0.25 m high at its widest point. Below the lower right side of the vent, a 35-cm-long geologic hammer as scale. (b) Detail of mineral deposits at the lower right side vent shown in Figure 23.1.21(a). Photo height is 20 cm. (c) Deepest part of the gas vent, at the center of the vent shown in Figure 23.1.21(a), fully coated here with the ammonium sulfates tschermigite, godovikovite, and yellowish globular mascagnite at the center. Photo height is 15 cm. (d) SEM image of surface of the globular mascagnite with desiccation cracks. Photos by Franco Urbani, 1990; SEM image by Manuel David Soto, 1994. 626 Soto and Urbani

Figure 23.1.22. Volcán de Las Monas, Venezuela. Vegetation-free thermal and acid sulfate alteration zone in 1994. Observers stare at longitudinal cracks where coal-fire gas and vapor escaped into the atmosphere and where minerals are nucleated. Maximum temperature measured in the cracks was 67 °C; ambient temperature in alteration zone was 29 °C. The red colors of rocks and soil are due to the thermal and acid sulfate alteration of shale, siltstone, and sandstone of the Cerro Pelado Formation. Photo by Manuel David Soto, 1994.

In 2012, thermal activity at this site decreased and the main gas vent had collapsed, no ammonium sulfates were found (Figure 23.1.24) and the temperature was 52 °C, an indication that the smoldering of the underground coal- seam was cooling off.

This coal-fire is produced by an almost vertical, 4-m-thick lignite layer that was observed at the nearby Las Monas creek. During our 1994 visit a deformed zone of thermally altered rocks was observed and sampled above the unburned coal. It is likely that such deformation was due to the collapse of the overlaying shale once part of the coal was burned.

One meter stratigraphically over the lignite layer at Las Monas creek the shales looks unaltered, whereas in the deformed zone and uphill the shale fragments display thermal alteration easily recognized by the changes in color, from dark brown to beige and orange or reddish tones (Figure 23.1.25). A series of samples with different degrees of thermal alteration were analyzed by Mossbauer spectroscopy (D’Onofrio et al., 1996) (Table 23.1.4), finding that the clinker samples with higher thermal alterationFigure ( 23.1.25(c)) contain magnetite 2+ 3+ (Fe Fe 2O4) which explains the anomalously high values of total magnetic field associated with this locality and is discussed below. The “Volcanoes” of Midwestern Venezuela 627

(a)

(b)

(c)

Figure 23.1.23. Volcán de Las Monas, Venezuela. (a) Main gas vent as seen in 1994, note that most of the ammonium sulfates seen in 1990 (Figure 23.1.21(a)) were gone, probably due to the heavy rains of 1993. A maximum temperature of 225 °C was measured 40 cm inside this vent. Below the lower right side of the vent, a 35-cm-long geologic hammer as scale. (b) Deepest part (0.5 m) of the gas vent in 1994, at the center of the vent shown in Figure 23.1.23(a), partially coated only with the ammonium sulfate tschermigite. (c) Tschermigite stalactite collected 40 cm inside a gas vent. Photos by Manuel David Soto, 1994. 628 Soto and Urbani

Figure 23.1.24. Volcán de Las Monas, Venezuela. Collapsed gas vent in 2012. This is the same location as Figure 23.1.21(a) (1990) and Figure 23.1.23(a) (1994). The ammonium sulfates previously seen are now absent, in con- cordance with the diminished temperature of 52 °C. Only red-colored rocks and soil due to the thermal and acid sulfate alteration remain. For scale, a 7-cm Brunton compass at center. Photo by Alí Gómez, 2012.

This coal-fire is very different from the previous localities because thermal and acid sulfate alteration has created a vegetation-free area of about 60 m × 20 m (Figures 23.1.19 and 23.1.22), with exposed reddish rocks due to thermal alteration.

A handheld proton precession magnetometer (1 gamma sensitivity) was used to carry out a survey of the total magnetic field on this vegetation-free area. Anomalously high values of total magnetic field were recorded around the main vent and other minor vents (maximum of 36,295 gammas), mainly toward the south of the vegetation-free area (Figure 23.1.26). No obvious pattern emerges from mapping the total magnetic field (Figure 23.1.26(a)). How- ever, by applying the reduction to the pole process to the raw magnetic data (Figure 23.1.26(b)), the temporal and spatial drift caused by the variations of the earth’s magnetic field is eliminated and therefore the anomalies are restored to their original locations (Antonio Orlaiz, personal communication, July 20, 2013). By mapping the reduced to pole total magnetic field the match between the closures (magnetic highs) and the position of the vents and longitudinal cracks is clear. The closures or highs of the magnetic field also closely match the trend of the inferred subsurface coal bed, which crops out in the nearby Las Monas creek, where its strike and dip is N16°W 63°S. This match, and the presence of magnetite (Figure 23.1.25(c)) derived from iron oxides already present in the rocks previous to the coal-fire, is consistent with magnetic anomalies above areas of coal-fires that have been reported elsewhere (Hooper, 1987). For this reason, regional aeromagnetic surveys are used to delineate areas affected by active and old underground coal-fires. The “Volcanoes” of Midwestern Venezuela 629

(a)

(b)

(c)

Figure 23.1.25. Volcán de Las Monas, Venezuela. Shale and clinkers from the Cerro Pelado Formation, collected above the outcropping coal, about 50 m from the main vent. (a) Relatively fresh dark brown sample collected 1 m stratigraphically over the coal. (b) Medium thermally altered beige clinker collected in a deformed zone over the coal. The red patina over the sample is hematite. (c) High thermally altered orange sample of clinker collected in a deformed zone over the coal. The dark material that welds the clinker fragments at the surface of the sample is rich in magnetite. The diameter of all the coins is 23 mm. Photos by Manuel David Soto, 1994. 630 Soto and Urbani

Figure 23.1.26. Volcán de Las Monas, Venezuela. (a) Map of the total magnetic field. (b) Map of reduced pole total magnetic field. Symbols of the base map are as inFigure 23.1.19. Survey by Manuel David Soto in 1995. Gridding and reduction to the pole by Antonio Orlaiz in 2013. Map coordinates are in kilometers, UTM zone P19, datum PSA56. Modified from Soto (1997). The “Volcanoes” of Midwestern Venezuela 631

Table 23.1.4 Fe oxidation state and composition by Mossbauer spectroscopy of the Fe-bearing mineral fraction in samples with different degrees of thermal alteration. Volcán de Las Monas.

Fe Oxidation State and Mineral Sample Sample Location Composition (in %) Unaltered shale One meter stratigraphically Fe3+ in limonite or clay (60) over the lignite layer Fe2+ in clay (40) Clinker with intermediate In the vegetation-free thermal Hematite (33) degree of thermal alteration and acid sulfate alteration zone, Paramagnetic Fe3+ (18) close to the main vent Distorsionate Fe3+ (41) Clinker with intermediate In the deformation zone Hematite (56) degree of thermal alteration over lignite layer Paramagnetic Fe3+ (34) Distorsionate Fe3+ (10) Clinker with higher degree In the deformation zone Hematite (17) of thermal alteration over lignite layer Magnetite (30) Fe3+ in clay skeletons (24) Fe2+ in clay skeletons (29) Modified fromD’Onofrio et al. (1996).

Discussion and Conclusions

The gas vents and ground fissures of Volcancito de San Miguel, Volcán de Gusama, and Fumarola de Sanare share the common feature of being located at the top of landslides in very steep mountainous terrains (Figure 23.1.27). The rock fractures generated by the landslides may be the triggering factor allowing air to enter into contact with underground coal seams or carbon-rich slates so that subsequent oxidation proceeds and the rocks begins to smol- der. This ignition mechanism has been widely reported in the literature, in many different geomorphological, tectonic, and lithological settings (Kuenzer and Stracher, 2011).

The San Miguel and Sanare sites have been known for more than four centuries. Activity over such a long period is probably not due to a single landslide, but rather as the result of decadal/century long cycles of activity that con- tinue until total extinction, then recommence when a new nearby landslide in the same general area starts a new fire. Around the Fumarola de Sanare several vegetation-covered scars of old landslides are visible (Figure 23.1.13) but currently only one shows recurrent mass movement activity as well as underground smoldering. The same occurs in the arid area of Volcancito de San Miguel, where several kilometer long scars and the tops of landslides were mapped (Figure 23.1.3).

The locality of Volcán de Gusama was active for only 3 years and started after a landslide occurred within an area affected by a previous larger landslide (Figures 23.1.9 and 23.1.10).

The Late Cretaceous Villanueva Formation in which these coal-fire sites are found consists mainly of black slates that were affected by a very low-grade metamorphism (pre-green schist facies) from a protolith of organic matter- rich shale. It is not known what type of material is smoldering underground, but due to the overall metamorphism of the formation, it seems probable that black slates or seams of anthracite or bituminous coal could be the source of the fires. However, no coals have been reported in the literature or found during our fieldwork.

The coal-fire at Mina de Yay had an anthropogenic origin due to mining of clay (kaolinite) that exposed a lignite seam. The temperature of the altered clay (clinker) outcrops has diminished from more than 500 °C (red-hot clay) in 1985 to today’s ambient temperature.

The Volcán de Las Monas is due to the smoldering of a 4-m-thick lignite layer that cropped out in a nearby creek. It is the most colorful and complex coal-fire locality known in the Lara State. After six decades of activity it will probably burn out within the next decade due to the consumption of the coal bed. 632 Soto and Urbani

Figure 23.1.27. Schematic cross-section of the Volcancito de San Miguel, north is to the right. Thick dark line represents probable coal beds in the Villanueva Formation (K), with a coal-fire exhaling smoke at the surface. Yel- low area represents Quaternary colluvial materials from landslide debris. Modified fromSoto (1997).

Acknowledgments

We thank Juan José Salazar, Director of the Anthropological Museum of Quíbor, and Mauro Álvarez, co-owner of San Jacinto Ranch in Quebrada Arriba, for their hospitality and logistical support in the field. We are also grateful to Mr José Escalona (chronicler of Sanare) for guiding us around Sanare; Marina Peña (Venezuelan Foundation for Seismological Research—FUNVISIS, Caracas) for redrawing the original line drawings; Antonio Orlaiz (Repsol, Houston) for his assistance with magnetic data processing; Ian Gath (Repsol, Madrid); María Carlota Marcano (University of Michigan, USA); Pedro Jugo (Laurentian University, Canada); Robert B. Finkelman (University of Texas at Dallas); and Glenn B. Stracher (East Georgia State College) for their review of this chapter.

References

Briceño-Méndez, W., 1876. Informe presentado al Poder Ejecutivo del Estado sobre la exploración de la region carbonífera de Tulé y de los depósitos de petróleo, betunes, asfaltos y carbon que contiene el estado: Report of 1876. In: Martínez, A.R. (Ed.), 1976, El carbón del. Zulia, Corpozulia, Caracas, pp. 25–52. D’Onofrio, L., Gonz·lez-JimÈnez, F., Orihuela, N., Soto, M., 1996. Mineralogical and magnetic study of an area affected by the spontaneous combustion of coal. In: Fifth Latin American Conference on Application of the Mösssbauer effect. Memoir. Perú. Hooper, R.L., 1987. Factors affecting the magnetic susceptibility of baked rocks above a burned coal seam. Inter- national Journal of Coal Geology 9, 157–169. Jefferson, C., 1964. Post-Eoceno entre Quíbor y Sanare, Estado Lara: Boletín Informativo Asociación Venezolana de Geología. Minas y Petróleo 7 (7), 218–223. Kuenzer, C., Stracher, G., 2011. Geomorphology of coal seam fires. Geomorphology 38, 209–222. Liddle, R.A., 1928. The Geology of Venezuela and Trinidad. J. P. Mac Gowan, Fort Worth, Texas. 552 p. Ponce de León, R., de Porras, J.R., Martínez, P., Pacheco, F., de Santa Cruz, M., Alemán, J., de Castro, J., Cataño, J., Suárez, F., Gutiérrez, P., 1579. Descripción de la ciudad de Tocuyo, año de 1578: manuscript signed in Maracaibo, January 21, 1578. In: Centeno Gräu, M. (Ed.), 1969, Estudios Sismológicos, Ed. Academia Cien- cias Físicas, Matemáticas y Naturales, Caracas, p. 81, 116. Soto, M.D., 1997. “Fumarolas” del estado Lara: Estudio geológico de los procesos de combustion espontánea de rocas carbonosas: Universidad Central de Venezuela, Escuela de Geología. (Bachelor thesis). Reproduced in Geos, Caracas, issue 36, p. 81 + 230 p. and supplementary data, 2004. Stephan, J.F., 1985. Andes et chaîne Caraïbe sur la transversale de Barquisimeto (Vénézuéla). Evolution géodin- amique. Symposium Géodynamique des Caraïbes, Paris. Éditions Technip, Paris, pp. 505–529. Urbani, F., 1996. Notas históricas sobre los “Volcanes” del estado Lara. Boletín de Historia de Las Geociencias en Venezuela 57, 1–17. Urbani, F., Hevia, A., Jáuregui, J., Káncev, I., Colina, B., 1987. Los “volcanes” de la zona de Sanare, Edo. Lara: XXXVI Convención Nacional de Asociación Venezolana para el Avance de la Ciencia, Maracaibo, Resúmenes, p. 78. Von der Osten, E., Zozaya, D., 1957. Geología de la parte suroeste del estado Lara, región De Quíbor. Boletín Geol. Caracas 4 (9), 3–52.

Coal and Peat Fires: A Global Perspective Volume 3: Case Studies – Coal Fires

Edited by Glenn B. Stracher Division of Science and Mathematics, University System of Georgia, 131 College Circle, Swainsboro, Georgia 30401 USA

Anupma Prakash Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, Alaska 99775 USA

Ellina V. Sokol Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Koptyuga, 3, Novosibirsk 630090 Russia

Amsterdam – Boston – Heidelberg – London – New York – Oxford – Paris San Diego – San Francisco – Singapore – Sydney – Tokyo Contents

Volume 1: Coal – Geology and Combustion Volume 2: Photographs and Multimedia Tours Volume 3: Case Studies – Coal Fires Volume 4: Peat – Geology, Combustion, and Case Studies On Line: Interactive World Map of Coal and Peat Fires by Rudiger Gens Captions for Front Cover Photos ii Dedication v Preface to Volume 1 vii Preface to Volume 2 ix Preface to Volume 3 xi Acknowledgments xiii List of Contributors xxv Chapters 1. Spontaneous Combustion in Open-Cut Coal Mines: Australian Experience and Research 1 Stuart Day, Norman Bainbridge (late), John Carras, William Lilley, Clive Roberts, Abouna Saghafi, David Williams 1.1 Causes and Controlling Factors of Self-Heating 2 Introduction 2 Self-Heating and Spontaneous Combustion 4 1.2 Mine Spoil Piles 10 Structure 10 Self-Heating in Spoil 12 1.3 Atmospheric Emissions 16 Greenhouse Gas Emissions 16 Toxic Gas Emissions 23 1.4 Control and Prevention of Self-Heating in Spoil 25 Prediction of Heating 25 Material Placement 27 Cover Layers 28 Grouting 31 1.5 Précis 33 Additional Research 33 Conclusions 33 Acknowledgments 33 Important Terms 34 References 34 WWW Addresses: Additional Reading 36 2. Nanominerals and Ultrafine Particles from Brazilian Coal Fires 37 Luis F.O. Silva, Marcos L.S. Oliveira 2.1 Nanominerals and Ultrafine Particles 38 Introduction 38

xv xvi Contents

Sampling and Study Area 40 Analytical Procedures 43 Discussion 45 Conclusions 51 Acknowledgments 52 Important Terms 52 References 52 WWW Addresses: Additional Reading 55 3. Remote and In situ Mapping of Coal Fires: Case Studies from China and India 57 Claudia Kuenzer 3.1 Remote Sensing of Coal Fires 58 Introduction 58 Thermal Detection and Monitoring 61 Risk Area Delineation 65 Quantification 68 Additional Techniques 70 3.2 In situ Mapping of Coal Fires in Wuda, Inner Mongolia 72 Introduction 72 Coal Fire Indicators and Mapping Techniques 74 Coal Fire Dynamics Analyses 76 Discussion 80 3.3 Coal Fire Green House Gas Emission 83 Introduction 83 Quantification Challenges 84 Acknowledgments 88 Important Terms 88 References 89 4. Coal Combustion and Mineralization in the Helan Shan Mountains of Northern China 95 Glenn B. Stracher, Paul A. Schroeder, Yelena White, Claudia Kuenzer 4.1 Coal Combustion and Mineralization in the Helan Shan Mountains 96 Introduction 96 Geologic Setting and Coal Fires 96 Thermochemical Mineralization Processes 99 Analytical Methods 100 Analytical Results and Mineralogical Data 101 Discussion 104 Acknowledgments 104 Important Terms 104 References 105 WWW Addresses: Additional Reading 107 5. Mineralogy of Burning-Coal Waste Piles in Collieries of the Czech Republic 109 Vladimír Žáček, Roman Skála

5.1 Mineralogy of Burning-Coal Waste Piles 110 Introduction 110 Burning Dump and Mineral Localities 110 Analytical Methods and Mineralogy 120 Unnamed and Poorly Determined Phases 149 Environmental Aspects 153 Discussion 153 Acknowledgments 155 References 155 6. Combustion Metamorphism in the Most Basin, Czech Republic 161 Vladimír Žáček, Roman Skála, Zdeněk Dvořák 6.1 Combustion Metamorphism in the Most Basin 162 Introduction 162 Contents xvii

Mining History 163 Geology and Mineralogy 163 Analytical Methods 167 CM Rocks 167 Age of Combustion Metamorphism 179 Mineralogy 179 Unnamed Phases 196 Summary 197 Acknowledgments 199 References 199 7. Mineralogy of the Burning Anna I Coal Mine Dump, Alsdorf, Germany 203 Thomas Witzke, Frank de Wit, Uwe Kolitsch, Günter Blaß 7.1 Mineralogy of the Burning Anna I Coal Mine Dump 204 Introduction 204 Geology and Self-Ignition of the Anna I Dump 204 Sources of Elements for Mineral Formation 205 Mineral Formation Processes 206 Vent Types and Mineral Zones 212 Minerals and Their Associations 215 Analogy with Fossa Crater, Vulcano Island, Italy 235 Discussion 236 A Personal Note 236 Acknowledgments 237 Important Terms 237 References 237 8. Geothermal Utilization of Smoldering Mining Dumps 241 Sylvia Kürten, Martin Feinendegen, Yves Noel 8.1 Smoldering Mining Dumps 242 Introduction 242 Research Program 242 Dump Under Investigation 243 Test Pits 243 Drilling Operations 245 Laboratory Tests 246 Stability Analyses 248 8.2 Pilot Plant 250 Conventional Geothermal Energy 250 Plant Concept 251 BHEs and TG 252 8.3 Geothermal Utilization 254 Thermal Response Tests 254 Thermal Behavior of the BHEs 256 Long-Term Behavior of the BHEs 258 Discussion and Outlook 259 Acknowledgments 260 Important Terms 260 References 260 WWW Addresses: Additional Reading 261 9. Impact of Mining Activities on Land Use Land Cover in the Jharia Coalfield, India 263 Hina Pande, Rahul D. Garg, Amit K. Sen, Anupma Prakash 9.1 The Jharia Coalfield 264 Location and Geology 264 Mining History 264 Land Use Land Cover Classes 265 9.2 Changes in Land Use Land Cover 269 Role of Remote Sensing 269 xviii Contents

Long Term Change: A Qualitative Analysis 269 Fifteen Years of Change: A Quantitative Analysis 271 Discussion 276 Conclusions 276 Important Terms 276 References 277 WWW Addresses: Additional Reading 279

10. Stone-Tool Workshops of the Hatrurim Basin, Israel: Mineralogy, Geochemistry, and Rock Mechanics of Lithic Industrial Materials 281 Yevgeny Vapnik, Irina Galuskina, Vyacheslav Palchik, Ellina V. Sokol, Evgeny Galuskin, Nancy Lindsley-Griffin, Glenn B. Stracher

10.1 Stone-Tool Workshops of the Hatrurim Basin, Israel 282 Introduction 282 Stone-Tool Workshops 283 Samples 287 Analytical Methods 287 Mineralogy and Mineral Chemistry 291 Physical and Mechanical Properties of Stone Tools 302 Major and Trace Elements and Stone-Tools Protolith 306 Thermal Regime of Rock Formation 312 Conclusions 312 Acknowledgments 313 Important Terms 313 References 313 11. Geophysical Studies of Pyrometamorphic and Hydrothermal Rocks of the Nabi Musa Mottled Zone, Vicinity of the Dead Sea Transform, Israel 317 Yevgeny Vapnik, Boris Khesin (late), Sonia Itkis

11.1 Geophysical Studies of the Nabi Musa Mottled Zone, Israel 318 Introduction 318 Geologic Setting 319 Geophysical Investigations 321 Results 323 Discussion 328 Conclusions 333 Acknowledgments 333 Important Terms 334 References 334

12. Preliminary Assessment of the Coal Fires of Malawi 339 Zuze Dulanya, Hendrix Kaonga 12.1 Coal Fires of Malawi 340 Introduction 340 Malawi and the Study Area 340 The Potential for Coal Fires in Malawi 342 Remote Sensing 345 Conclusions 346 References 347

13. e Fir Prevention in Coal Waste Dumps: Exemplified by the Rymer Cones, Upper Silesian Coal Basin, Poland 349 Magdalena Misz-Kennan, Mariusz Gardocki, Adam Tabor 13.1 Coal Waste Dump Fires 350 Introduction 350 Fire Prevention 351 13.2 Technology for Fire Prevention and Reclamation 352 Introduction 352 Rymer Cones Dump 352 Contents xix

13.3 Monitoring Rymer Cones and Implementing Fire Mitigation 356 Introduction 356 Monitoring and Mitigation 362 Conclusions 384 Important Terms 385 References 385 14. Thermal Transformations of Waste Rock at the Starzykowiec Coal Waste Dump, Poland 387 Magdalena Misz-Kennan, Monika Fabiańska, Justyna Ciesielczuk

14.1 The Starzykowiec Coal Waste Dump 388 Introduction 388 14.2 Research Procedures 390 Sample Collecting 390 Laboratory Methods 390 14.3 Analytical Results 392 Introduction 392 Proximate and Ultimate Analyses 392 Petrographic Analyses of Organic Matter 393 Mineral Analyses 400 Geochemical Analyses 407 Borders Between Two Groups of Waste Rock 426 Conclusions 426 Acknowledgments 427 Important Terms 427 References 428 15. The Thermal History of Select Coal-Waste Dumps in the Upper Silesian Coal Basin, Poland 431 Magdalena Misz-Kennan, Adam Tabor 15.1 Coal-Waste Dumps 432 Self-heating 432 15.2 Characteristics of Waste Dumps in Poland 435 Introduction 435 Rymer Cones 435 The Chwałowice Coal Dump, Starzykowiec 437 The Marcel Coal Mine Dump 437 15.3 Monitoring Self-heating Processes 440 15.4 Results of Waste Dump Monitoring 442 Rymer Cones 442 The Chwałowice Coal Dump, Starzykowiec 450 The Marcel Coal Mine Dump 450 15.5 Self-heating and Fire Prevention 459 Discussion 459 Summary 459 Important Terms 461 References 461

16. Coal Mining and Combustion in the Coal Waste Dumps of Poland 463 Justyna Ciesielczuk 16.1 Coal Mining and Waste Dumps in Poland 464 Introduction 464 Waste Management and Coal Dumping 466 Examples of Self-ignition in Waste Dumps 469 Summary 472 Acknowledgments 472 Important Terms 472 References 472 xx Contents

17. Mineral Transformations and Actinide Transport: Combustion Metamorphism in the Wojkowice Coal-Waste Dump, Upper Silesian Coal Basin, Poland 475 Justyna Ciesielczuk, Grażyna Bzowska, Mariusz Paszkowski 17.1 Mineral Transformations and Actinide Transport in the Wojkowice Coal Dump, Poland 476 Introduction 476 Analytical Methodology 477 Mineralogy 477 Radioactivity 478 Discussion 486 Conclusions 490 Acknowledgments 491 Important Terms 491 References 491 18. Mineralogy and Magnetic Parameters of Materials Resulting from the Mining and Consumption of Coal from the Douro Coalfield, Northwest Portugal 493 Joana Ribeiro, Helena Sant’Ovaia, Celeste Gomes, Colin Ward, Deolinda Flores 18.1 Mineralogy and Magnetic Parameters of Materials from the Douro Coalfield, Northwest Portugal 494 Introduction 494 Douro Coalfield: Study Objectives 495 Environmental Magnetic Studies 496 Sampling and Analytical Methods 497 Results and Discussion 498 Conclusions 505 Acknowledgments 506 Important Terms 506 References 507 19. Ancient Coal Fires on the Southwestern Periphery of the Kuznetsk Basin, West Siberia, Russia: Geology and Geochronology 509 Sophia A. Novikova, Ellina V. Sokol, Igor S. Novikov, Alexey V. Travin 19.1 Coal Fires in the Kuznetsk Basin, Russia 510 Introduction 510 Geological Background 510 Tectonic Position and Geomorphic Framework of the Kuznetsk Basin 512 Tectonic History of the Kuznetsk Basin 513 Geology and Geomorphology of the Kuznetsk Basin: Southwestern Periphery 517 CM Complexes 519 Analytical Methods 527 Mineralogy and Petrography of High-Temperature CM Rocks 527 40Ar/39Ar Analytical Results 534 Discussion 537 Acknowledgments 538 Important Terms 538 References 538 20. Ellestadite-Group Minerals in Combustion Metamorphic Rocks 543 Svetlana N. Kokh, Ellina V. Sokol, Victor V. Sharygin 20.1 Ellestadite-Group Minerals in Combustion Metamorphic Rocks 544 Introduction 544 Burnt Coal Spoil-Heaps 544 Sample Collection and Analyses 545 Ellestadite Mineral Assemblages 548 Discussion 559 Acknowledgments 560 Important Terms 560 References 561 21. Fayalite from Paralavas Associated with Natural Coal Fires: Combustion Metamorphic Complexes in the Kuznetsk Coal Basin, Russia 563 Sophia A. Novikova, Ellina V. Sokol, Vyacheslav F. Pavlov Contents xxi

21.1 Fayalite, Paralavas, and Combustion Metamorphic Complexes in the Kuznetsk Basin, Russia 564 Introduction 564 CM Fe-Rich Olivine 564 Analytical Methods 566 Fayalite from Kuznetsk Paralavas 566 Discussion and Conclusions 575 Acknowledgments 578 Important Terms 578 References 578 22. Mineralogy and Origin of Fayalite–Sekaninaite Paralava: Ravat Coal Fire, Central Tajikistan 581 Victor V. Sharygin, Ellina V. Sokol, Dmitriy I. Belakovsky 22.1 Mineralogy and Origin of Fayalite–Sekaninaite Paralava: Ravat Coal Fire, Central Tajikistan 582 Introduction 582 Regional Geology and Origin of the Ravat Coal Fire 582 Analytical Techniques 585 Paralava from the Ravat Coal Fire 585 Mineral Chemistry of the Ravat Paralava 588 Discussion and Conclusions 603 Acknowledgments 604 Important Terms 605 References 605 23. The “Volcanoes” of Midwestern Venezuela 609 Manuel David Soto, Franco Urbani 23.1 The “Volcanoes” of Midwestern Venezuela 610 Introduction 610 Geologic Setting 610 The “Volcanoes” 612 Discussion and Conclusions 631 Acknowledgments 632 References 632 24. Coal-Fire Hazard Mapping in High-Latitude Coal Basins: A Case Study from Interior Alaska 633 Christine F. Waigl, Anupma Prakash, Akida Ferguson, Martin Stuefer 24.1 High-Latitude Coal Fires 634 Introduction 634 Alaskan Context 635 24.2 Case Study from Interior Alaska 638 Introduction 638 Study Area 638 Data 639 Data Processing 641 Results 643 Discussion 645 Conclusions 646 Acknowledgments 647 Important Terms 647 References 647 WWW Addresses: Additional Reading 649 25. Anthracite Coal-Mine Fires of Northeastern Pennsylvania 651 Melissa A. Nolter, Harold W. Aurand Jr., Daniel H. Vice 25.1 Anthracite Coal Fires of Northeastern Pennsylvania 652 Introduction 652 History of Coal Mining 656 Origin of Coal Fires 657 The Anthracite Fires 657 Mine Fires: ∼1820–1900 657 xxii Contents

Mine Fires: ∼1900–2000 658 Mine Fires: ∼2000 to Present 661 Discussion 662 Acknowledgments 663 Important Terms 663 References 663 26. Historic Record of Coal Fires in the Richmond Basin, Virginia 667 James C. Hower 26.1 Historic Record of Coal Fires in the Richmond Basin, Virginia 668 Introduction 668 Historical Record of Coal Fires 668 Acknowledgments 670 References 670 27. Coal Fires of the Pacific Northwest, USA 671 Daniel H. Vice, Glenn B. Stracher, Aaron Eckert 27.1 Coal Fires of the Pacific Northwest, USA 672 Introduction 672 Regional Coal Geology 672 Coal Fires 675 Conclusions 679 Acknowledgments 679 References 679 28. Combustion Mineralogy and Petrology of Oil-Shale Slags in Lapanouse, Sévérac-le-Château, Aveyron, France: Analogies with Hydrocarbon Fires 681 Pierre Gatel, Vladimír Žáček, Łukasz Kruszewski, Bertrand Devouard, Vincent Thiéry, Christiane Eytier, Jean-Robert Eytier, Georges Favreau, Jonathan Vigier, Glenn B. Stracher

28.1 Combustion Mineralogy of Oil-Shale Slags 682 Introduction 682 Geologic Setting 683 Oil Shale Exploitation and Processing 684 Composition of Unprocessed Oil Shale and Limestone 685 Fossil Organic Material in Oil Shale 688 Slags and Microminerals 690 Bulk Mineralogy of Slags 692 Mineral Distribution in the Slag Dumps 697 Microminerals Described Since Early 2000 698 The Origin of Combustion Minerals in Oil-Shale Slag 716 Natural versus Anthropogenic 720 Microminerals Photo Annex 722 Acknowledgments 739 Important Terms 739 References 739 WWW Addresses: Additional Reading 742 29. A Review of Coal-Fire Sampling Methods 743 Trent M. Garrison, James C. Hower, Glenn B. Stracher, Kevin R. Henke, Jennifer M.K. O’Keefe 29.1 A Review of Coal-Fire Sampling Methods 744 Introduction 744 Sampling Locations 744 Short-term Sampling Techniques 745 Long-term Sampling Techniques 750 Other Sampling Techniques 751 Summary 752 Acknowledgments 754 Important Terms 755 References 755