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The Uzbek Tian Shan is a prominent metal-rich belt, hosting world-class orogenic Au deposits such as Muruntau. However, its post-collisional history in relation to fluid alteration and mineralisation remains elusive. We present apatite U–Pb dates and rare earth element geochemistry for 44 granitoids, revealing a prolonged history of low-grade metamorphism and associated fluid alteration between ~285 and ~240 Ma. A resulting apatite U–Pb age interpolation map reveals two young anomalies that are interpreted as post-orogenic fluid circulation cells. In addition, the extent of Meso-Cenozoic denudation is presented using apatite fission track (FT) age data. In areas of good data coverage, the combined Apatite U–Pb and FT anomalies reveal a correlation with the locations of orogenic Au mineralisation. Although more data is required to further evaluate such correlation, our study illustrates that integrated multi-method apatite thermochronology and geochemistry may have the potential to become a novel viable tool for mineral exploration. Unlabelled Image • Integrated apatite U–Pb and trace element geochemistry date fluid alteration • Young apatite U–Pb anomalies revealed, interpreted as fluid circulation cells • Apatite fission track results reveal the extent of superimposed denudation. • In areas of good data coverage, anomalies correlate with mineral deposits. [ABSTRACT FROM AUTHOR]

The Central African Mesoproterozoic Kibara belt in Katanga (DRCongo) forms a metallogenic province that hosts a variety of granite-related mineralization, rich in cassiterite, columbite–tantalite, wolframite/ferberite, spodumene and beryl. This mineralization is mainly present in pegmatites and quartz veins that are thought to be associated with the youngest granite generation in the Kibara belt (i.e., so-called “E-group” granite generation). Manono-Kitotolo is one of the world's largest Sn, Nb–Ta and Li mineralized pegmatites, with a large resource of spodumene, columbite–tantalite and cassiterite still remaining. Mineralized pegmatites have intruded along the foliation in the Mesoproterozoic metasedimentary rocks and dolerites of the Manono-Kitotolo area. The pegmatites have been emplaced very late during the climax of the Kibaran orogeny, probably during the transition from orogenic collapse to extensional tectonics, based on their structural position. The emplacement of the pegmatites resulted in an intense alteration of the doleritic and metasedimentary host-rocks, resulting in muscovitization, tourmalinization and silicification. A mineralogical and geochemical zonation typical for granitic pegmatites has been identified that was affected by metasomatic/hydrothermal alteration, mainly albitization and greisenization. The latter alteration is associated with the main phase of cassiterite mineralization. A first stage with Nb–Ta, Li and minor Sn, however, already formed pre-alteration, directly associated with pegmatite crystallization. 40 Ar– 39 Ar muscovite dating of unaltered pegmatites resulted in ages of 938.8 ± 5.1 Ma and 934.0 ± 5.9 Ma. These ages are overlapping with the U–Pb age of the Nb–Ta mineralization (940 ± 5.1 Ma), also giving new temporal constraints on the fertile E-group granite generation in the KIB. The 40 Ar– 39 Ar muscovite age of a mineralized greisen is 923.3 ± 8.3 Ma, which is younger but still partly within error of the 40 Ar– 39 Ar ages of the unaltered pegmatites. Based on the partial overlap in age, but also on field and paragenetic relationships and the stable isotope composition of the fluids, this greisenization and associated cassiterite mineralization can still be linked to the pegmatite crystallization. [ABSTRACT FROM AUTHOR]

Abstract: A multiphase origin of the Cu–Co ores in the western part of the Lufilian fold-and-thrust belt in Central Africa is proposed based on literature, satellite image interpretations and petrographic and fluid inclusion analyses on samples from the stratiform mineralization of Kamoto and Musonoi (DR Congo). The various mineral occurrences in the Katanga Copperbelt can be classified in distinct categories: stratiform, supergene enrichment and vein-type. The stratiform mineralization form the largest group and can be found mainly in Lower Roan (R-2) rocks, which can be identified as ridges on satellite imagery. Ore deposits outside the R-2 occur along lineaments and result often from supergene enrichment. The main phase of the stratiform mineralization in the Katanga Copperbelt occurred during diagenesis preceding the Lufilian orogeny. Petrographic observation identified various mineralizing phases, which played a role in the formation of these stratiform mineralization. Mineralization started during early diagenesis, but mainly occurred during further burial. After the formation of early diagenetic pyrite, the circulation of diagenetic Cu–Co-rich fluids resulted in the formation of the main mineralization. Preliminary microthermometric investigation of primary inclusions in authigenic quartz, associated with the main stage of stratiform mineralization, indicates that an H2O–NaCl fluid with a minimum temperature between 80 and 195°C and a salinity between 8.4 and 18.4 eq. wt% NaCl circulated during the main phase of mineralization. Numerous faults and fractures formed during the Lufilian orogeny cut the stratiform mineralization. They are, however, at Kamoto and Musonoi only associated with minor sulphides. Supergene alteration along faults and fractures resulted in an enrichment of the mineralization, with the formation of secondary Cu-oxides, -carbonates and -silicates. The importance of the interaction of various processes for the formation of economic Cu–Co ore deposits is confirmed by the straightforward relationship on satellite imagery between the location of economic mineral occurrences and faults, which acted as pathway for descending waters that caused the supergene enrichment and upgrading of the primary mineralization. [Copyright &y& Elsevier]

In the Lower Palaeozoic Anglo–Brabant fold belt in Belgium, a detailed study of the geochemistry of different generations of pyrite has been carried out by electron microprobe analysis. The occurrence of pyrite is related to different episodes in the evolution of this fold belt. Pyrite occurs either as a pre- or as a syn-deformation phase in the metamorphosed sedimentary and igneous rocks. Pre-cleavage pyrite in greenschist metamorphosed sedimentary rocks has a relative higher Ni-content. As illustrated in the Kupferschiefer, this could be due to the release of Ni from organic matter during diagenesis. Pre-cleavage pyrite in the igneous rocks has higher Cu, Pb, Cd and Zn contents, which could be caused by the incorporation of these elements in the sulphide phase during the final stage of the crystallisation of the magma. Syn-deformation pyrite along cleavage planes and in quartz/carbonate veins is characterised by higher As, Sb, Se and Au contents, typical for hydrothermal mineralisation in a greenschist facies fold belt. [ABSTRACT FROM AUTHOR]

Mineralised vein systems have been investigated at nine localities at the southern margin of the Anglo-Brabant fold belt in Belgium. During the late Silurian to early Middle Devonian Caledonian orogeny, shear zones formed, inferred to be associated with granitoid basement blocks in the subsurface. The circulation of a metamorphic fluid, possibly originating in the Cambrian core of the fold belt, along these shear zones resulted in the formation of mesozonal orogenic mineralisation at the southern margin of the Anglo-Brabant fold belt. The fluid had a composition dominated by H2O–CO2–X–NaCl–KCl. The shear zones form part of a greater fault zone, the Nieuwpoort–Asquempont fault zone, which is characterised by normal faulting that started before the Givetian and by the reactivation of the shear zones. Two fluid generations are associated with this normal faulting. First, a low salinity H2O–NaCl(–KCl) fluid migrated through the Palaeozoic rocks after the Silurian. Based on the isotopic composition, this fluid could be a late-metamorphic Caledonian fluid or a younger fluid that originated from the Rhenohercynian basin and interacted with Lower Devonian rocks along its migration path. Second, a high salinity H2O–NaCl–CaCl2 fluid was identified in the fault systems. Similar fluids have been found in southern and eastern Belgium, where they produced Mississippi Valley-type Zn–Pb deposits. These fluids are interpreted as evaporative brines that infiltrated the Lower Palaeozoic basement, from where they were expelled during extensional tectonism in the Mesozoic. [ABSTRACT FROM AUTHOR]

Reports on the identification of a Lower Palaeozoic mesothermal gold mineralization formed during the Caledonian orogeny in Wales, Scotland and Ireland. Application of [sup 40]Ar/[sup 39]Ar technique in the dating of mineralizing events; Brittle-ductile origin of the shear zone in the Marcq area.

The origin of giant, sedimentary rock-hosted copper-cobalt (Cu-Co) provinces remains contentious, in part due to the lack of precise and reliable ages for mineralisation. As such, no consensus has been reached on the genetic model for ore formation, and the relationships between tectonism, palaeo-fluid circulation and mineralisation. Here, we link the timing of Cu-Co mineralisation in the Central African Copperbelt to compressional tectonics during the Lufilian Orogeny by using new ca. 609-473 Ma ages given by rhenium-osmium (Re-Os) isotope data for individual Cu-Co sulphides (carrolite and bornite) from the Cu-Co Kamoto deposit. The initial Os isotope composition of carrolite is compatible with the leaching of Os and Cu(-Co) from Mesoproterozoic Cu sulphide deposits hosted in fertile basement. In contrast, the ca. 473 Ma Cu-Au mineralisation stage, which is coeval with late- to post-compressional deformation, may be a distal expression of fluid flow and heat transfer caused by magmatic intrusions in the core of the collisional orogen. The Re-Os ages support a model for mineralisation driven by evaporite dissolution and percolation of large volumes of dense brines in the Katangan Basin during the Lufilian Orogeny. [ABSTRACT FROM AUTHOR]

Abstract Background There is a demand for serum markers for the routine assessment of the progression of liver cancer. We previously found that serum N-linked sugar chains are altered in hepatocellular carcinoma (HCC). Here, we studied glycomic alterations during development of HCC in a rat model. Results Rat HCC was induced by the hepatocarcinogen, diethylnitrosamine (DENA). N-glycans were profiled using the DSA-FACE technique developed in our laboratory. In comparison with control rats, DENA rats showed a gradual but significant increase in two glycans (R5a and R5b) in serum total N-glycans during progression of liver cirrhosis and cancer, and a decrease in a biantennary glycan (P5). The log of the ratio of R5a to P1 (NGA2F) and R5b to P1 [log(R5a/P1) and log(R5b/P1)] were significantly (p < 0.0001) elevated in HCC rats, but not in rats with cirrhosis or fibrosis or in control rats. We thus propose a GlycoTest model using the above-mentioned serum glycan markers to monitor the progression of cirrhosis and HCC in the DENA-treated rat model. When DENA-treated rats were subsequently treated with farnesylthiosalicyclic acid, an anticancer drug, progression to HCC was prevented and GlycoTest markers (P5, R5a and R5b) reverted towards non-DENA levels, and the HCC-specific markers, log(R5a/P1) and log(R5b/P1), normalized completely. Conclusions: We found an increase in core-α-1,6-fucosylated glycoproteins in serum and liver of rats with HCC, which demonstrates that fucosylation is altered during progression of HCC. Our GlycoTest model can be used to monitor progression of HCC and to follow up treatment of liver tumors in the DENA rat. This GlycoTest model is particularly important because a rapid non-invasive diagnostic procedure for tumour progression in this rat model would greatly facilitate the search for anticancer drugs.