Geology and Mining

The Very Low Frequency Electromagnetic (VLF-EM) method, which enables surveying without contact with the ground, is suitable for ground surveys in a wide area and has been used in mapping geology and in mineral exploration for decades. The technique makes use of signal radiation from military navigation radio transmitters operating in the frequency range of 15-30 kHz. When the electromagnetic wave impinges on the surface it is both reflected back into the air and refracted into the earth. By measuring the shifted reflected magnetic field relative to the primary field, subsurface structures can be constrained. Freely and readily available primary signals anywhere around the earth make the VLF method very convenient and efficient for field data collection. Further, VLF data processing using digital linear filtering is quite accurate and very efficient in depicting the qualitative information about subsurface conductors, even though quantitative interpretation of VLF data is as complex as other EM data interpretation. In this study, various aspect of VLF-EM method such as basic theory, worldwide VLF transmitters, and quantities measured and a case study review of the integrated geophysical exploration for sulphide minerals In the Wadi Sa'al area, south Sinai in Egypt (only the VLF-EM method used in this study were review).

The study were to assess on the impacts of mining activities on land degradation, land stability, atmosphere, water resource, biodiversity and on local residents as well on local uses of mineral resources in Kape area.Data's employed were gathered through field observation, group discussion, and asking local peoples aboutimpact of gold mining, their consequences and their activities in the study area. Theoperations that practiced in the study area characterized by shallow diggings some meters depthunderground and on the surface, which follow the reefs. This activities meansriverbed gold panning creates a number of serious environmental impacts such as landdegradation, land stability, soil erosion, deforestation and impacts on both surface andsubsurface water. Because the local people gets income daily from this activities and have highdemand for gold leads to increase in mining activities which results in land use changes. Therefore,the government and its partners should make efforts to harmonize forestry and mininglaws to avoid conflicts of interest which lead to sustainable management of bothforest and mineral resources.

A B S T R A C T Determining the provenance of non-ferrous metals is a major issue in archaeology and history. The classical method using Pb isotopes shows several limitations, and new isotopic tracers need to be developed in archae-ometallurgy. Recently, Fe isotopes were found to be promising for iron metal tracing. In this context, we evaluated the pertinence of Fe isotopes as a new tool for provenance studies of non-ferrous metals. We collected slag and furnace lining samples from the Imiter silver mine in Morocco (Anti-Atlas), where many archaeological remains attest ancient lead-silver production. Their mineralogical composition was investigated by optical microscopic observations, SEM-EDS and EPMA. Besides, we measured both Pb and Fe isotope compositions of these samples by high resolution MC-ICP-MS after wet sample decomposition and purification chemistry. The occurrence of Ag, Pb, Cu and Ag/Pb metallic beads in the slag samples and their high Fe content suggests that these metallurgical materials result from the exploitation of Ag-rich polymetallic ores associated with gossan formations. Isotopic analyses of these slags highlighted their heterogeneous Pb isotope compositions and homogeneous Fe isotope composition. This points to the exploitation of two distinct ore sources with different Pb but similar Fe isotope compositions, despite the Fe isotope variability often encountered in metallic ores worldwide. Hence, Fe isotopes provide a complementary approach to trace lead-silver products from Imiter. Overall, the combination of Pb and Fe isotope analyses constitutes a promising method for further provenance investigations of non-ferrous metals.

""Abstract : Khalashpir coal field is the 3rd largest coal field in Bangladesh, where coal occurs at depths of
257m to 483m below the surface. Considering the Geological, Geo-environment and other related geoengineering
information, underground mining have been selected there to extract the deposit. In this paper, our
concern is about shaft sinking method for underground mining. Depths of the coal seams reveal the necessity of
a vertical shaft underground which again needs deep excavation. The problem arises with the excavation
because of nearly 138m thick Dupitila Sandstone Formation just 6m below the surface in the area. It is loose,
water bearing, containing dominantly porous and permeable sandstone and experiences massive water flow. So,
the major concern is that any excavation through this will readily collapse and suffer massive water inrush. This
will totally disturb the whole mining work progression and cause economic loss as well. By analyzing the
ground condition of the Khalashpir cola field, artificial ground freezing has been identified most appropriate as
shaft sinking method to control the ground water and to stabilize the loose soil during excavation. Lawfulness of
the method and reason of neglecting other two common shaft sinking methods has been pointed out in this
paper.""

The study were to assess on the impacts of mining activities on land degradation, land stability, atmosphere, water resource, biodiversity and on local residents as well on local uses of mineral resources in Kape area.Data’s employed were gathered through field observation, group discussion, and asking local peoples aboutimpact of gold mining, their consequences and their activities in the study area. Theoperations that practiced in the study area characterized by shallow diggings some meters depthunderground and on the surface, which follow the reefs. This activities meansriverbed gold panning creates a number of serious environmental impacts such as landdegradation, land stability, soil erosion, deforestation and impacts on both surface andsubsurface water. Because the local people gets income daily from this activities and have highdemand for gold leads to increase in mining activities which results in land use changes. Therefore,the government and its partners should make effort...

This paper presents a political economic appraisal of the de-peasantisation of indigenous communities through an ethnographic exploration of artisanal mining and trade of coloured gemstones in the Kalahandi district of western Odisha (formerly Orissa) in eastern India. It shows that the Khonds, one of the poorest indigenous groups living in this part of India have taken up mining of semi-precious gemstones since the 1990s. This period coincides with the opening of the Indian market of gemstones to the world, alluring this community to often replace their traditional subsistence agriculture with artisanal mining. In addition, a number of other factors have contributed to push more peasants out of agriculture to the informal mining sector for livelihood as it provides them with higher return and quick money. A series of droughts accompanied with deepening agrarian crisis and exploitative caste and class relations have particularly affected the Khond and other tribes of the Kalahandi region. At the same time, the increase in global demands have led to an intensification of informal gemstone mining by the Khonds. However, the indigenous people have not significantly benefitted; although the rate of out-migration has slackened, many are now without land and working in mines as daily wage labourers. This is because the proliferation of mining has also attracted the entry of opportunistic outsiders who collude with the local state, local politicians, caste-leaders and class-elites, police, and bureaucracy to sweep up the profits. This paper shows that the indigenous people continue to remain impoverished as the informal nature of the mining business further pushes them into living precarious lives.

"""Khalashpir coal field, the 3rd largest coal field of Bangladesh where proved reserve of about 143 million tons and probable reserve of about 685 million tons is estimated, has been decided for underground mining and artificial ground freezing (AGF) technique has been proposed as shaft sinking method after feasibility study. This method has been used in mining industry over the past 125 years for support of shaft sinking, tunneling and foundation excavation. To run the process brine solution is chilled between -25oC and -35oC in large refrigerant plant. The brine is then circulated through freezing tubes in required pattern to remove hit from the ground and thus freeze the soil to achieve soil strength and decrease the mobility of liquid water. This process results in a frozen earth barrier which gives strength to loose soil and bars water from inrushing excavation work for sinking a shaft. In this paper structural design of frozen ground works has been proposed to achieve a vertical cylindrical ice-wall for shaft sinking in Khalashpir coal field.
""""

This report describes the structural measurements of veins on oriented drill core that were critical in defining the locations of gold-bearing veins. The last drill hole in the program targeted three veins, based on the previous measurements and historical data (extrapolated and hand drawn onto cross sections under field conditions), to prove that the structural interpretation of the multiple vein deposit was correct.

This research assesses the distribution of Pb, Zn, Cu, Cd, Co and Ni in soils in Ishiagu. Mining has become prominent in this area because of existence of Pb – Zn lodes, veins and veinlets. It has thus become necessary to assess these because these metals are associated with Pb-Zn mineralization and are also significant in environmental health consideration, since they constitute priority pollutants. The concentration of Pb varies from 0.5 to 13671 mg/kg; Zn from 7.5 to 1460.5 mg/kg; Cu from 4 to 36.5 mg/kg; Cd from 0.5 to 10 mg/kg; Ni from 2 to 40 mg/kg and Co from, 0.5 to 146.5 mg/kg. Pb, Zn, Cd and Co attains toxic limit of 100, 300, 5 and 40 mg/kg respectively in the samples from Ugwu-Ajirija, Eziator, Amagu, Amaeze and Amokwe. The close proximity between the polluted areas and areas with history of mining is established. The source of these metals in soil is the mineralized vein, the mine dumps, the Asu River Shales and the minor basic intrusive. Mining of the Pb-Zn ores is res...

Resum L'anàlisi preliminar de les mesures escintil·lomètriques del total de xocs (TC) i de les desintegracions derivades dels elements radioactius K, U i Th han permès elaborar els primers mapes d'isolínies de radiació gamma natural per a la zona meridional de la Conca de Barberà compresa per les Muntanyes de Prades. Aquests mapes de contorns s'han superposat i comparat amb el mapa geològic de la zona i s'ha revelat una extraordinària correlació entre ambdós. La bona correspondència existent fa possible establir uns fons de radiació regionals amb uns valors característics de TC, K, U i Th per a les diferents litologies que caracteritzen el substrat geològic de les Muntanyes de Prades. Dins del sòcol paleozoic es discriminen els terrenys metasedimentaris amb mineralitzacions, caracteritzats pels valors de radiació molt alts (TC:335,07; K:4,31; U:2,62; Th:0,46) i els terrenys metasedimentaris sense mineralitzacions, amb valors lleugerament més baixos (TC:156,74; K:2,70; U:1,07; Th:0,41). Tant mateix, es pot delimitar amb una bona precisió l'àrea corresponent a l'aflorament del batòlit granític, definida per valors de radiació elevats i compresos en un rang restringits (TC:191,27; K:2,86; U:1,72; Th:0,55) L'eixam de dics de pòrfir associats al cos granític mostra una major disparitat radiomètrica, amb valors més elevats que el granit i propers als valors radiomètrics obtinguts pels metasediments amb mineralitzacions (TC:188,34; K:2,55; U:1,76; Th:0,30). A la cobertora, els materials detrítics i carbonatats del Mesozoic i Cenozoic queden perfectament diferenciats, presentant valors baixos compresos entre TC:162,35; K:2,70; U:0,78; Th:0,23 per les calcàries amb fucoides de la base del Muschelkalk inferior i valors de TC:50,06; K: 0,66; U: 0,42; Th 0,04 per les calcàries palustres cenozoiques. A més dels intervals i valors mitjans característics per a cadascuna de les litologies, s'ha pogut constatar l'existència de valors anòmals en les pissarres negres ampelítiques del Silurià i Devonià i en alguns dics de pòrfir. En les primeres degut a la presència d'importants indicis de mineralitzacions de tipus sedimentari exhalatiu, enriquides en sulfurs metàl·lics, òxids i fosfats. En el cas dels pòrfirs, per processos d'assimilació o contaminació geoquímica en emplaçar-se. Les dades obtingudes constitueixen una eina valuosa per a caracteritzar el paisatge geoquímic de la Conca de Barberà i permeten generar un registre regional dels fons de radioactivitat gamma natural. Conegudes, a la seva vegada, les anomalies degudes a processos geològics de dispersió o concentració, l'objectiu últim és proveir d'un indicador útil per a l'avaluació i control de l'estat del territori i els efectes que pugui tenir qualsevol activitat humana present o futura.

The Mesozoic bauxitic-limonitic deposits of the Comino Valley- Sora area have been exploited since proto-historic times, but this area became crucial for the “iron rush” in the Bourbon era. The Kingdom of Naples decided to finance scientific researches in the area between Pescosolido and Picinisco (southeastern Lazio), in order to strengthen military defenses and to combat invasive or rebellious pressures. This led to the realization, in the period between 1770 and 1860, of the Royal Mines of Canneto, San Donato Val di Comino and Campoli Appennino, and of the Royal Forges of Canneto and Rosanisco. Fundamental was the supervision of technicians, including the engineer and geologist Gaetano Tenore. Following the Bourbon crisis of 1860, the industrial activity of the area was abandoned with, in many cases, its definitive loss of evidence (e.g. many of the mines of Campoli and San Donato Val di Comino, as well as the Canneto forge). The geological relevance of the mineralogical and stratigraphic studies performed in this area (with their socio-cultural and economic implication), coupled with the fact that most of this geological heritage is disappearing, allowed to identify several “sites of geological memory” in this area.

The Mesozoic bauxitic-limonitic deposits of the Comino Valley- Sora area have been exploited since proto-historic times, but this area became crucial for the “iron rush” in the Bourbon era. The Kingdom of Naples decided to finance scientific researches in the area between Pescosolido and Picinisco (southeastern Lazio), in order to strengthen military defenses and to combat invasive or rebellious pressures. This led to the realization, in the period between 1770 and 1860, of the Royal Mines of Canneto, San Donato Val di Comino and Campoli Appennino, and of the Royal Forges of Canneto and Rosanisco. Fundamental was the supervision of technicians, including the engineer and geologist Gaetano Tenore. Following the Bourbon crisis of 1860, the industrial activity of the area was abandoned with, in many cases, its definitive loss of evidence (e.g. many of the mines of Campoli and San Donato Val di Comino, as well as the Canneto forge). The geological relevance of the mineralogical and stra...