Particles carried by ascending gas flow at the Tongchanghe copper mine, Guizhou Province, China

Abstract

We collected and analyzed, using transmission electron microscopy, the particles carried by ascending gas flow in soil above the concealed orebody of the Tongchanghe copper mine, Guizhou Province. Particles of native copper, native copper-iron alloy, and native chromium-iron-copper alloy particles in the ascending gas flow were first discovered. Commonly, they were aggregations of relatively small particles. Individual particles within aggregations were subcircular, elliptical, regularly polygonal, or elongate and from 5 to 40 nm in size. The aggregations were subcircular or elliptical and 20-150 nm in size. Chloride, oxide, sulfate, and hydroxide particles containing ore-forming metals in the ascending gas flow were also discovered. The elements of the particles were commonly in a high valence state, suggesting that they were formed in a near-surface oxidizing environment. Discovery of the particles extracted from the ascending gas flow above the Tongchanghe copper mine provided a powerful tool for exploration for deep concealed orebodies. Our study also showed that native copper, native copper-iron alloys, native chromium-iron-copper alloys, as well as chloride, oxide, sulfate, and hydroxide compounds containing ore-forming metals can be transported in particle form by ascending gas flow below the Earth's surface.

Sulfur-containing particles emitted by concealed sulfide ore deposits: an unknown source of sulfur-containing particles in the atmosphere

“…Moreover, sulfate aerosols can directly affect the climate (Graf et al, 1998). In our previous work, particles carried by an ascending geogas flow in the soil (Holub et al, 1999(Holub et al, , 2001Cao et al, 2009Cao et al, , 2010bCao et al, , 2011Liu et al, 2011;Wei et al, 2013;Hu et al, 2015) were studied and found to contain sulfur. Further research showed that sulfur-containing particles carried by ascending geogas flows can be transported through the soil layers and into the atmosphere.…”

Prospecting Application of Nanoparticles and Nearly Nanoscale Particles Within Plant Tissues

“…Previous studies have also proved that soil overlying ore deposits can present anomalous concentrations of corresponding ore‐forming elements (Levitan et al, ; Sadeghi et al, ). It was also demonstrated that metal‐bearing particles can transfer upwards through ascending gas flow and ground water (Cao et al, , ; Cao, ; Hu et al, ; Li et al, ). Luo et al () has demonstrated that there were many metal‐bearing particles preserved in the soil above the orebodies.…”

TEM observations of particles based on sampling in gas and soil at the Dongshengmiao polymetallic pyrite deposit, Inner Mongolia, Northern China

“…The origins and migration forms of the particles carried by the ascending gas flow are one of the important problems to solve in geogas prospecting, and they play an extremely important role in the application of deposit prospecting (Cao, 2011;Cao et al, 2009Cao et al, , 2010aEtiope and Lombardi, 1996;Malmqvist, 1980, 1982;Zhou et al, 2003). In our studies, the particles carried by the ascending gas flow and the corresponding soil samples were collected and analyzed by TEM technique.…”

“…A comparison of the particles carried by the ascending gas flows from four different deposits (Cao et al, , 2010aWei et al, 2013).…”

“…The basic principles of geogas prospecting are that geogas is widely present as an ascending gas flow in the earth (Gold and Soter, 1980;Chiodini et al, 1995;Xie, 1995;Wang et al, 1997;Tong and Li, 1999;Wang et al, 1999;Morner and Etiope, 2002;Etiope and Martinelli, 2002;Annunziatellis et al, 2003;Wang, 2003;Cameron et al, 2004;Wang et al, 2007) and when the ascending gas flows through the ore body, it can carry solid substances from the concealed ore bodies or other geological bodies and transport them to the earth's surface; these solid substances primarily take the form of nano-scale particles (Cao, 2011;Cao et al, 2010a;Etiope, 1998;Etiope and Lombardi, 1996;Tong and Li, 1999;Tong et al, 1998;Wang et al, 2007). These ascending gas flow-carried substances can be captured by a collector, and a wealth of mineralization information about the concealed ore bodies can be obtained by using modern testing technologies (Cao et al, 2005(Cao et al, , 2010bMa et al, 1998;Malmqvist et al, 1999;Tong and Li, 1999;Tong et al, 1998;Wang et al, 1997Wang et al, , 1999Wang et al, , 2007Xie et al, 1999).…”