Geochemical Features of the Distribution of Ore Elements in the Polymetal Ores of Mehmanian Deposit (Azerbaijan Part of the Lesser Caucasus)

By using the results of geochemical research methods, the geochemical features of distribution of basic ore elements in Mehmanian polimetal deposit ores have been considered in the article. The definition features of main ore elements were given, close positive and negative relations between elements pairs were defined by correlation analysis according to the selected elements. On the basis of analysis of current analytical information results complexity has been studied, geochemical condition of localization of productive sulphide mineralization in the generation stage of ore formation has been analyzed. Behaviour features of elements have been investigated, the interaction between them has been clarified and based on their statistical analysis of geochemical features of the deposit has been made. The dependence features of one ore element from the other were determined in various types of ores of the deposit.

Mineral Prospectivity Modeling using AVIRIS-NG VNIR-SWIR data and Gravity data for Gold-Sulphide mineralization in parts of GADAG schist belt, Karnataka, India

<p>Gadag schist belt, India is known for sulphide-gold mineralization. In the study area mineralization is controlled structurally and lithologically. In this context, Airborne Visible-Infrared Imaging Spectrometer - Next Generation (AVIRIS-NG) Visible Near InfraRed (VNIR) - Shortwave Infrared (SWIR) bands were utilized to derive alteration zones and structures present in the study area. Lithological boundaries have also been updated using AVIRIS-NG VNIR-SWIR bands derived images enhancement products i.e. Minimum Noise Fraction (MNF) and False Colour Composite (FCC). Further, image spectra of alteration zones (Hydrous mineral etc.) derived from AVIRIS-NG calibrated VNIR-SWIR bands were compared with the standard corresponding reference library spectra (USGS, JPL spectral library). These image spectra have been utilized to demarcate the alteration zones using the Matched Filtering spectral mapping method. Structures were demarcated using high pass (HP) filtered image and FCC images. Low pass (LP) filter image and along with MNF & FCC image composite were utilized to update the lithological boundaries in the study area.</p><p>Ground gravity data has also been processed to derive the subsurface evidences relevant to the deposit in the present study area. Subsurface structures which are responsible for the transportation of mineral rich fluid in the near subsurface are delineated using the gravity data derived products. Apart from this, basement depths are also derived from the gravity data which are being utilized for the validation as well as to further precise the locations of mineral deposits.  These subsurface structures (gravity data), lithology, lineament density and alteration zones are very important evidential layers which have been integrated using fuzzy logic integration techniques to identify potential zones of gold-sulphide mineralization in the present study area. The prospective zones are validated using the secondary data and basement depth derived from the gravity data.</p><p>For similar kind of gold-sulphide mineralization, AVIRIS-NG data and Gravity data can be used to derive the important evidential layers in any part of the world. There are only few studies where such integration approach has been utilized to explore new potential zones of gold sulphide mineralization. </p><p>Keywords: AVIRIS-NG, VNIR-SWIR, alteration, MNF, FCC, Gravity, Basement Depth</p>

Geology of the recently discovered massive and stockwork sulphide mineralization at Semblana, Rosa Magra and Monte Branco, Neves–Corvo mine region, Iberian Pyrite Belt, Portugal

The recently discovered massive and stockwork sulphide mineralization of Semblana-Rosa Magra and Monte Branco, situated ESE of the Neves–Corvo volcanogenic massive sulphide (VMS) deposit in the Iberian Pyrite Belt (IPB) is presented. Geological setting and tectonic model is discussed based on proxies such as palynostratigraphy and U–Pb zircon geochronology. The mineralization is found within the IPB Volcano-Sedimentary Complex (VSC) Lower sequence, which includes felsic volcanic rocks (rhyolites) with U–Pb ages in zircons of 359.6 ± 1.6 Ma, and black shales of the Neves Formation of late Strunian age. Massive sulphides are enveloped by these shales, implying that felsic volcanism, mineralization and shale sedimentation are essentially coeval. This circumstance is considered highly prospective, as it represents an important exploration vector to target VMS mineralization across the IPB, in areas where the Lower VSC sequence is present. The Upper VSC sequence, with siliciclastic and volcanogenic sedimentary rocks of middle–late Visean age, shows no massive mineralization but a late Tournaisian (350.9 ± 2.3 Ma) volcanism with disseminated sulphides was also identified. Nevertheless, stratigraphic palynological gaps were found within the Strunian and in the Tournaisian sediments, between the Lower and Upper VSC sequences, reflecting probable erosion and uplift mechanisms linked with extensional tectonics. The Semblana and Monte Branco deposits and the Rosa Magra stockwork are enclosed by tectonic sheets that dismembered the VSC sequence in a fold-and-thrust tectonic complex, characteristic of the NE Neves–Corvo region. The methodologies used allow a geological comparison between Neves–Corvo and other IPB mine regions such as Lousal–Caveira, Herrerias, Tharsis and Aznalcollar.

Stream Sediment Geochemical Survey on Metamorphic Rock, Kolaka, Southeast Sulawesi, Indonesia.

The aim of this research is to conduct surface geological mapping to determine the lithologies that underlies the linear geochemical characteristics of Ag, As, Cd, Co,Cu, Fe, Mn, Ni, Pb, Zn by using stream sediment data. Furthermore, to know the distribution of these elements lithologically in the area. This study uses 10 sediment stream samples of 80 mesh up to 100 mesh which then chemical elements are analyzed with AAS. Alteration mineralization occcurs in quartz chlorite geneiss: quartz, epidote, chlorite, muscovite, sericite, calcite, monmorillonite, pyrite, sphalerite, bornite and chalcopyrite. Based on linearity analysis elements are grouped into three according to the significant value of 0.3 to 0.9, which are significant elements Ni, Pb=Cu=Zn and As, abundant elements in lateralization and sulphide mineralization. The geochemical characteristics of the Ni element reflect the associated distribution of ultramafic weathering which results are transported regionally and together with other elements as stream sediments. While Pb, Cu, Zn are related to quartz veins in metamorphic or intrusive rocks.

Geological and geochemical signs and criteria of potential mineralization in the Tangaralakh intrusion

The scope of the discussion embraces the problems connected with development and improvement of geological information processing methods and systems, as well as modeling of primary mineral deposits in exploration of side rock mass and deep horizons of the deposits under mining and in new areas with intent to discover potential copper-nickel sulphide mineralization. The target of the research is the geological and geochemical preconditions and signs of sulphide mineralization in the potentially ore-bearing Tangaralakh field adjacent to the deposits of the Talnakh ore-magmatic system. The integrated research is based on the conventional different-rank geological, geochemical, magmatic, structural, tectonic, lithological and stratigraphical preconditions and signs of sulphide copper-nickel platinum-bearing ore in the Norilsk Region. The geochemical search of ore objects in the Norilsk Region provided the best results in case of the geological and structural analysis of spatial interactions between geochemical abnormalities as the geochemical zonality is yet the chief factor in the mineralization prediction. This method of improvement of geological-geochemical information processing and modeling of mineral deposits was tested in geological-geochemical modeling of the Talnakh ore province bodies. From the research findings, the structural and tectonic conditions of localization of the potentially ore-bearing Tangaralakh intrusion were determined. The structural modeling of geochemical field of the mineralization revealed the types of geochemical associations marking different compositions of sulphide mineralization in disseminated ore in different sections of the Tangaralakh intrusion. It is found that the geochemical zonality coincides with the mineral zonality of the disseminated ore horizon formed at different stages of orogenesis. The similarity elements are found in the geological-geochemical models of the Tangaralakh potentially ore-bearing ore field and Talnakh ore field (ore-magmatic system).