A sulphur isotopic study of the Bleikvassli Zn-Pb-Cu deposit, Nordland, northern Norway

The Bleikvassli Zn-Pb-Cu deposit occurs in the Uppermost Allochthon in the Caledonides of northern Norway. The orebody is enclosed in amphibolite-facies schists and gneisses, underlain by amphibolites, and it has been classified as a sediment-hosted massive sulphide (SEDEX) deposit. The stratiform ore is dominantly pyritic, with a basal layer of pyrrhotitic ore. Sulphide veins occur in the footwall. The orebody generally has a limited range of δ34S, from 0.3 to 4.5% (x = 2.4 ± 1.2‰, 1 σ, n = 26). The lowest δ34S values (0.3–2.3‰) were found in sulphide veins in the footwall and vent proximal stratiform ore. More distal pyritic Zn-Pb ore has heavier average δ34S values (up to 4.5‰). The ore sulphides were deposited from a hydrothermal solution with δ34S about 2‰ perhaps with the incorporation of a minor portion of sulphide from the ambient seawater. The hydrothermal solution probably acquired most of its sulphide from the underlying mixed lithology; notably basaltic rocks. Sulphide produced by thermochemical reduction of seawater in the deep conduit system may also have been incorporated. Bacteriogenic sulphide is not likely as a major source of ore sulphur in the massive ore. Sulphide incorporated in distal pyrite, which have δ34S from -12 to-10‰, could have formed either by oxidation of the hydrothermal sulphide, or by bacterial reduction of seawater sulphate in the depositional environment. Exchange of sulphur isotopes probably took place only on a localized scale during Caledonian metamorphism, the bulk sulphur isotopic composition of the ore being preserved in a hand specimen scale

Military applications of hyperspectral imagery

Optical imaging, including infrared imaging, generally has many important applications, both civilian and military. In recent years, technological advances have made multi- and hyperspectral imaging a viable technology in many demanding military application areas. The aim of the CEPA JP 8.10 program has been to evaluate the potential benefit of spectral imaging techniques in tactical military applications. This unclassified executive summary describes the activities in the program and outlines some of the results. More specific results are given in classified reports and presentations. The JP 8.10 program started in March 2002 and ended in February 2005. The participating nations were France, Germany, Italy, Netherlands, Norway, Sweden and United-Kingdom, each with a contribution of 2 man-years per year. Essential objectives of the program were to: 1) analyze the available spectral information in the optronic landscape from visible to infrared; 2) analyze the operational utility of multi- and hyperspectral imaging for detection, recognition and identification of targets, including low-signature targets; 3) identify applications where spectral imaging can provide a strong gain in performance; 4) propose technical recommendations of future spectral imaging systems and critical components. Finally, a stated objective of the JP 8.10 program is to "ensure the proper link with the image processing community". The presentation is organized as follows. In a first step, the two trials (Pirrene and Kvarn) are presented including a summary of the acquired optical properties of the different landscape materials and of the spectral images. Then, a phenomenology study is conducted analyzing the spectral behavior of the optical properties, understanding the signal at the sensor and, by processing spectroradiometric measurements evaluating the potential to discriminate spectral signatures. Cameo-Sim simulation software is presented including first validation results and the generation of spectral synthetic images. Results obtained on measured and synthetic images are shown and discussed with reference to two main classes of image processing tasks: anomaly detection and signature based target detection. Furthermore, preliminary works on band selection are also presented which aim to optimize the spectral configuration of an image sensor. Finally, the main conclusions of the WEAG program CEPA JP8.10 are give