scholarly journals Lead-Zinc Ore Deposits of the Tsushima Islands, Nagasaki Prefecture, with Special Reference to Shigekuma-type Mineralization

1977 ◽  
Vol 23 (3) ◽  
pp. 417-480
Author(s):  
Nobutaka Shimada
Keyword(s):  
Special Reference ◽  
Ore Deposits ◽  
Lead Zinc ◽  
Nagasaki Prefecture

Pétrographie et altération de la matière organiquedu gisement de plomb–zinc–cuivre de tourist–Bou Beker,Maroc nord oriental

1996 ◽  
Vol 33 (10) ◽  
pp. 1363-1374 ◽  
Author(s):  
M. Bouadellah ◽  
A. C. Brown ◽  
Y. Héroux
Keyword(s):  
Organic Matter ◽  
Ore Deposits ◽  
Mississippi Valley ◽  
Sulfide Mineralization ◽  
Mineralization Process ◽  
Associated Gas ◽  
Regional Flow ◽  
Lead Zinc ◽  
Reflectance Measurements ◽  
Ore Deposition

Reflectance measurements and organic petrography were used to study altered organic matter in the dolomitic Middle Jurassic Beddiane sequence hosting the Beddiane lead–zinc deposit. Organic matter occurs in the lower dolostone units of the formation where zinc sulfide mineralization prevails. The upper units, where lead sulfide mineralization is dominant, contain lesser amounts of organic matter. The organic matter in the Beddiane sequence consists of macerals, amorphous kerogen, and solid bitumen, inertinite and vitrinite are ubiquitous. The amount of exinite increases toward mineralized areas but the ratio exinite/kerogen remains constant. Two types of vitrinite are considered on the basis of their reflectance: Vt1 with low reflectance values (0.3–0.5%) and Vt2 with higher values (0.7–1.25%). The ratio Vt1/Vt2 increases and the reflectance values for Vt1 decrease toward the zinc-prevailing units, Organic matter associated with the mineralization exhibits features such as oxidation halos and desiccation cracks, together with a low-fluorescent exinite. The association of the kerogen content, the trend in reflectance values, and the alteration features of the Mississippi Valley-type Beddiane deposit support the hypothesis that the regional flow of hot brines associated with the mineralization process was the cause of anomalous heating, that the occurrence of exinite maceral and its associated gas played a role in the ore deposition, and that the new chemical equilibrium reached by the zinc-dominant host rock after ore deposition is responsible for the suppressed reflectance values within and near the ore deposits.

Symposium: Role of organisms and organic matter in ore deposition/Le rôle des organismes et de la matière organique dans la formation des gisements métallifères

1985 ◽  
Vol 22 (12) ◽  
pp. 1890-1892 ◽  
Author(s):  
R. W. Macqueen
Keyword(s):  
Organic Matter ◽  
Ore Deposits ◽  
Sulphate Reduction ◽  
Sulphide Mineral ◽  
Special Session ◽  
Geochemical Cycle ◽  
Lead Zinc ◽  
Pine Point ◽  
Earth’S System ◽  
Ore Deposition

The following seven papers were presented on May 16, 1984, at the Geological Association of Canada and Mineralogical Association of Canada joint annual meeting. The special session, organized by R. W. Macqueen and J. A. Coope, contained 10 papers and was sponsored by the Mineral Deposits Division of the Geological Association of Canada.Our objective in organizing the special session was to examine organically based processes and relationships that may be of major importance to the origin of ore deposits. As noted by Fyfe (1984), the concept of the geochemical cycle focuses attention on pathways of chemical elements and isotopes of the Earth's system during geologic history. It is clear from the chemistry of carbon-rich materials that a wide range of elements is concentrated directly or indirectly by biological processes operating as part of the geochemical cycle. Two of the papers of the special session examine some of these concentration processes, although definitive links to actual ore deposits cannot be made yet. Beveridge and Fyfe document the remarkable ability of the anionic cell walls of certain bacteria to concentrate metals and to provide sites for nucleation and growth of minerals. In a related paper, Mann and Fyfe show that several species of simple freshwater green algae readily concentrate large amounts of uranium under both experimental and natural conditions (Elliot Lake and Thames River, Ontario).Two papers deal with aspects of sulphate reduction. Birnbaum and Wireman describe controlled experiments that suggest that sulphate-reducing bacteria may be involved in the selective replacement of sulphate-evaporite minerals by silica and in the precipitation of silica in association with sulphide mineral phases in banded iron formations. Their work focuses directly on the effect that bacterial sulphate reduction has on silica solubility. Trudinger et al. examine the question of mechanisms of sulphate reduction at temperatures less than 200 °C and the bearing this has on origin of sulphide for low-temperature sulphide ore deposits. Although there is empirical evidence favouring abiological sulphate reduction at temperatures in the vicinity of 100 °C, Trudinger et al. have not been able to demonstrate abiological reduction of sulphate under controlled laboratory conditions and at temperatures under about 200 °C. Perhaps catalysts, as yet undiscovered, are involved in this process in nature.Impressive progress has been made in understanding the diagenetic evolution of organic matter in response to heat and pressure in geological environments: excellent reviews are found in Barnes et al. (1984) and Bustin et al. (1985). Simoneit's paper examines and reviews the genesis of petroleum in a most unusual setting, that of the active ocean ridge spreading centre of Guaymas Basin, Gulf of California. There, in the vicinity of black smokers and associated metallic sulphide deposits, petroleum originates instantaneously geologically as a result of hydrothermal activity. The question of genetic involvement of organic matter in the origin of the metallic sulphides (e.g., reduction of sulphate to H2S) cannot be answered yet for this setting with the available data.The final two special session papers included here are concerned with organic matter associated with mineralization in Canadian Shield Precambrian settings. Willingham et al. demonstrate that Elliot Lake – Blind River Early Proterozoic uranium deposits with minor amounts of associated gold also contain kerogen-like organic matter. Some of this organic matter has anomalously rich amounts of gold and uranium and appears to have originated as mats of cyanobacteria, possibly with the ability to concentrate these metals. For a number of settings in the Archean-aged Abitibi greenstone belt of Ontario and Quebec, Springer demonstrates that carbon, at least partly of organic origin, is closely associated with some gold deposits. Her interpretation is that carbon activated by shear-zone-associated hydrothermal fluids has provided sites for fixing some of the gold.Three of the papers given at the special session are not included here. H. T. Shacklette reviewed metal uptake by young conifer trees, demonstrating that nursery-grown seedlings of several species readily concentrated a variety of metals, including lead, zinc, tin, and gold, over a 7 year period. This work is of interest to those involved in geochemical prospecting and is now published elsewhere (King et al. 1984). R. W. Macqueen presented quantitative data on the genesis of sulphide by abiological bitumen–sulphate reactions at the Pine Point lead–zinc property, Northwest Territories, Canada (Macqueen and Powell 1983; Powell and Macqueen 1984). Although Trudinger et al. have not been able to demonstrate abiological reduction of sulphate at temperatures approximating those of Pine Point [Formula: see text], the data presented by Macqueen (Powell and Macqueen 1984) are consistent with the amounts, alteration, and composition of bitumens at Pine Point, as well as with the presence of native sulphur and the sulphur isotope compositions of the various Pine Point sulphur species. This work is continuing, and a more extensive account is in preparation. J. R. Watterson examined relationships between freezing climates and the local chemical behaviour of gold in the weathering cycle, concluding that ice-induced accumulation of organic acids, bacteria, and other organic matter at mineral surfaces may increase rates of chemical attack, leading to dissolution of normally insoluble metals such as gold (Watterson 1986).Interest in organic aspects of the geochemical cycle, including ore deposition, is growing dramatically (e.g., Fyfe 1984). Although the following papers address a limited range of topics within the field, they do indicate some of the diversity and variety of active processes and associations between metallic elements and organic components. Perhaps, in the not too distant future, we will be able to identify or even discover whole classes of ore deposits that owe their origin directly to organic influences operating within the geochemical cycle.

scholarly journals Iranian regional l ament zones and the location of Cu, Pb, Zn and Fe deposits

2020 ◽  
Vol 63 (2) ◽  
pp. 8-20
Author(s):  
A. Sohrabi ◽  
S. Beygi ◽  
I. V. Talovina ◽  
A. A. Kruglova ◽  
N. S. Krikun
Keyword(s):  
Large Scale ◽  
Ore Deposits ◽  
Mineral Deposits ◽  
Geological Structures ◽  
Structural Mapping ◽  
Geological Maps ◽  
Lead Zinc ◽  
Zagros Orogenic Belt ◽  
The Relationship ◽  
Copper Lead

Background. Large-scale geological structures, such as lineaments, are of great research interest due to their potential to mark the presence of ore fields.Aim. To determine the relationship between ore deposits, lineaments and large-scale faults in Iran using satellite imagery, digital relief modelling and structural mapping.Materials and methods. In this study, we compiled a map of lineaments in the Iran, which were determined both automatically and manually. A database of the distribution of ore deposits and lineaments was compiled from available maps, publications and reports on ore deposits in Iran. These maps were overlaid to study the relationship between the locations of the lineaments, faults and ore deposits.Results. An analysis of the lineaments revealed on geological maps indicates the presence of four dominant strike directions of large and small lineaments. The developed lineament map shows the main northwest trending longitudinal faults, which are parallel to the main strike of the Zagros orogenic belt; sublatitudinal and submeridional trending oblique faults; northeast trending transverse faults. A “Combined map of lineaments and deposits of copper, lead, zinc and iron in Iran” was compiled by the ArcGis software using maps of lineaments and mineral deposits. The ore deposits identified were analysed to determine the distribution of the distances between each deposit using the counting and cumulative methods the ArcGis software.Conclusions. About 90% and 50% of ore deposits are located at a distance of less than 15 km and 5 km, respectively, from the centre line of the associated lineament. A direct relationship between the density of lineaments and the presence of deposits was observed. The obtained results demonstrate the potential of this method for assessing the prospects of ore fields in hard-to-reach and poorly studied regions.

Geological structure and localization of mineralization at the Moryanikho-Merkurikhinskoye ore field

2022 ◽  
pp. 75-84
Author(s):  
Maria Zaitseva
Keyword(s):  
Mineral Composition ◽  
Practical Interest ◽  
Field Work ◽  
Geological Structure ◽  
Ore Deposits ◽  
Yenisei Ridge ◽  
Shelf Zone ◽  
Structural Factors ◽  
Lead And Zinc ◽  
Lead Zinc

The paper discusses the lithological and facial features of the terrigenous-carbonate (biohermic) ore-bearing geological formation of the Moryanikho-Merkurikhinskoye ore field (Yenisei Ridge), which hosts stratiform lead-zinc deposits in carbonate strata. Ore-hosting lithofacies and their paleostructural position are characterized. Based on the previous studies, as well as the author’s own materials obtained as a result of field work, the main favorable lithological, facial and structural factors for hosting Moryanikhinsky-type stratiform lead-zinc mineralization are defined: the presence of paleodepressions within the shelf zone; development of carbonate rocks – dolomites, stromatolite dolomites and limestones, which are biohermic structures on the slopes of paleo-uplifts; the presence of an admixture of tuffaceous material in terrigenous rock varieties. The influence of tectonic faults on the formation of ore deposits and the morphology of ore bodies is indicated. The main types of ores of the Moryanikho- Merkurikhinsky ore field, as well as their mineral composition are described. The paper discusses the main ore types, as well as their mineral composition typical of the Moryanikho-Merkurikhinskoye ore field. The largest and well-studied lead and zinc stratiform Moryanikhinskoye deposit and Merkurikhinskoye ore occurrence located within the ore field are briefly characterized. The Moryanikhinskoye deposit is a typical example for searching for stratiform deposits of lead and zinc in the carbonate strata of the Angara-Bolshepitskaya mineragenic zone, which is of practical interest in developing predictive prospecting models of deposits and improving the efficiency of prospecting.

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