47 research outputs found
GOLD-BISMUTH-TELLURIDE-SULFIDE ASSEMBLAGES AT THE STANOS SHEAR ZONE-RELATED PROSPECT, CHALKIDIKI, NORTHERN GREECE
No full textCu-Au mineralization in the Stanos area occurs in regional NE-SW trending shear zones within the crystalline Servomacedonian Massif on the Chalkidiki Peninsula, northern Greece. Orebodies are generally located along the contact between orthogneisses of
Silurian age of the Vertiskos terrane and marbles and garnet-graphite schists of the Svoula series. These lithologies were intruded by the Triassic Arnea granitoid, which occurs about 3 km southwest of the sulfide mineralization. In this study we report new mineralogical data from three sites along the major mineralized shear zones that include the ancient Cu-Au mines of Paliomylos,
Chalkoma, and Karambogia.
The Stanos copper-gold mineralization is structurally-controlled and restricted to high-strain shear zones within gneisses that developed late during regional ductile shearing. This deformation event was related to southwestward overthrusting of the Vertiskos
unit onto the Svoula lithologies at upper-greenschist to lower-amphibolite facies conditions. The mineralized shear zones are
either planar or lensoid, with abrupt transitions to unaltered gneiss, and have a thickness of tens of centimeters across the few
meters of lateral exposure. Their internal structure is heterogeneous with moderate- to high-strain bands where the foliation shows
a sigmoidal trajectory appearing as S-C′ structures or discontinuity planes. Within the shear zones, the alteration assemblages
typically include biotite and muscovite, quartz, ±chlorite, ±siderite and rarely apatite, monazite, xenotime, and zircon. Detailed
textural studies of the ore assemblages revealed two stages of hydrothermal mineralization during shearing. Iron-bearing sulfides
(pyrite, arsenopyrite and pyrrhotite) were introduced and followed by a copper-bearing association that included chalcopyrite
with minor galena, sphalerite, molybdenite and Bi-Au-Te minerals. Ore minerals form disseminated to massive aggregates along
foliation planes, asymmetric crenulation cleavages and S-C′ fabrics. In places, they surround or form the strain shadows of
s-shaped quartz porphyroblasts indicating synkinematic deposition.
The Au-Bi-Te association consists mainly of Bi sulfosalts (bismuthinite derivatives, lillianite homologues, matildite, ikunolite), native
elements (bismuth, gold-silver alloy), and bismuth sulfotellurides (joseite-A, joseite-B and telluronevskite). Most of these minerals
exist in two-, three-and more rarely four-component blebs or patches often with curvilinear boundaries, mostly disseminated
within chalcopyrite. Phase relations in the system Au-Bi-Te suggest the following paragenetic sequence: bismuthinite derivatives +
ikunolite → lillianite homologues + matildite + gold-silver alloy + bismuth sulfotellurides → native bismuth + galena → molybdenite
+ chalcopyrite. The bismuthinite derivatives are mainly bismuthinite (including cuprian members), gladite-krupkaite, hammarite
and aikinite (Fig. 1a). Ikunolite is Se-free corresponding to the formula Bi4S3 and is reported here for the first time in Greece.
Gold-silver alloy (up to 38.1 wt. % Ag) appears either as 100-micron grains disseminated in chalcopyrite or as rounded droplets coexisting with blebs of Bi-minerals. Matildite with almost ideal composition, lillianite homologues representing members of the
lillianite-gustavite solid solutions series, higher order homologues (N=6, N=7), as well as vikingite are the major Ag carrier in the
ores (Fig. 1b). The bismuth sulfotellurides joseite-A, joseite-B and telluronevskite (grains up to 10μm) of the joseite- and tsumoite
isoseries, respectively, according to the definition of Cook et al. (2007), are closely associated with lillianite homologues (Fig. 2).
Native bismuth in symplectitic intergrowths with galena (probably decomposition products of galenobismuthite), rims bismuthinite
derivatives and lillianite homologues and probably represents the last Bi-bearing hydrothermal pulse of the system. Molybdenite
is Re-free and typical of metamorphic molybdenites. The observed association suggests an evolution of the system towards more
reducing conditions and that precious metals may have been scavenged by composite Bi-Te-Pb-S melts in a manner proposed by
Ciobanu et al. (2005). The Stanos shear zone-related system shares many characteristics in common with orogenic gold systems; however its accurate classification is a subject of further investigation
Validity testing of patient objections to acceptance of tamper-resistant opioid formulations
No full textCharles E Argoff,1 Steven P Stanos,2 Matthew S Wieman31Department of Neurology, Albany Medical College Neurology Group, Albany, NY, USA; 2Rehabilitation Institute of Chicago, Center for Pain Management, Northwestern University Medical School, Feinberg School of Medicine, Chicago, IL, USA; 3Department of Medical Sciences, Endo Pharmaceuticals Inc, Chadds Ford, PA, USABackground: Tamper-resistant formulations (TRFs) of oral opioid drugs are intended to prevent certain types of abuse (eg, intranasal, intravenous). Patients raising objections to receiving a TRF may have valid concerns or may be seeking a formulation that can be more easily misused.Methods: US clinicians experienced in pain management met in October 2011 to discuss common patient objections to being switched from a non-TRF opioid to a TRF of the same opioid. Retail pharmacy, health insurance, and scientific data were used to assess the potential validity of these patient objections.Results: Clinical experience switching patients from a non-TRF to a TRF opioid was limited to oxycodone controlled release (CR), as it was the only TRF available at that time; knowledge of other TRFs was limited to the scientific literature. Common objections from patients included “costs more,” “not covered by insurance,” “can't feel it working,” and “causes adverse events.” Objective retail pharmacy and insurance coverage information for oxycodone CR was accessible and indicated that patient objections were based on cost and coverage varied by insurer. Unpublished trial results (ClinicalTrials.gov) revealed that TRF oxycodone CR has a slower initial release than the non-TRF formulation, which may reduce positive subjective effects. The complaint “I can't feel it working” may reflect lessened positive subjective effects rather than reduced analgesic efficacy. Most tolerability complaints lacked objective support.Conclusion: The general process used to assess the validity of patient objections to TRF oxycodone CR may be applied to other TRFs once they become available. Publication of clinical data on TRFs would help clinicians to appropriately weigh patient concerns.Keywords: opioid analgesics, chronic pain, substance abuse, tamper-resistant formulation
BISMUTHINITE DERIVATIVES, LILLIANITE HOMOLOGUES, AND BISMUTH SULFOTELLURIDES AS INDICATORS OF GOLD MINERALIZATION IN THE STANOS SHEAR-ZONE RELATED DEPOSIT, CHALKIDIKI, NORTHERN GREECE
No full textUSAAbstractArsenic-copper-gold-bismuth mineralization in the Stanos area is hosted by a km-long, NW-SE trending ductile to brittle shear zone within Silurian orthogneisses of the Vertiskos terrane of the Servomacedonian Massif, Chalkidiki Peninsula, northern Greece. Shearing was accompanied by iron-potassic alteration of the gneisses including biotite, muscovite, chlorite, apatite, zircon, quartz, and minor rare-earth element phosphates. Metallic minerals form disseminated to massive aggregates along foliation planes, asymmetric crenulation cleavages, and S-C' fabrics. Detailed textural investigation of the ore assemblages revealed two stages of hydrothermal mineralization during shearing. An initial introduction of iron sulfides (pyrite, arsenopyrite, and pyrrhotite) was followed by a copper-bearing stage that is associated with the formation of chalcopyrite, minor sulfides (galena, sphalerite, and molybdenite), and Bi-Cu-Pb-Au-Ag-Te minerals. The stage II metallic mineral association consists mainly of Bi sulfosalts (bismuthinite derivatives, lillianite homologues, matildite), native elements (bismuth, electrum), and bismuth chalcogenides (joséite-A, joséite-B, ikunolite, and unnamed Bi-Pb-bearing sulfotellurides). The bismuthinite derivatives are mainly bismuthinite (including cuprian varieties), gladite-krupkaite, paarite, salzburgite, and an unnamed CuPbBi7S12 phase. The ikunolite is Se-free, corresponding to the formula Bi4S3, and is the first known occurrence in Greece. Most stage II minerals exist in two-, three-, and, more rarely, four-component blebs or patches generally with curvilinear boundaries, suggesting the possibility that they were precipitated in a molten form. Phase relationships among minerals in the system Au-Bi-Te-Pb-Ag-Cu indicate that they formed by successive hydrothermal pulses from fluids that penetrated the shear zone at different times contemporaneous with ductile deformation. These pulses deposited the following assemblages in paragenetic order: molybdenite + cosalite + native bismuth + galenobismutite → gustavite/lillianite + native gold + native bismuth + bismuth sulfotellurides → bismuthinite-aikinite solid solution series→ matildite + native bismuth + galena → chalcopyrite + bornite. The observed association suggests that the system evolved under fluctuating f(S2) and f(O2) conditions and precious metals may have been scavenged by composite Bi-Te-Pb-S melts at temperatures well above 350 oC. The enrichment of Bi, Mo, Pb likely indicates a magmatic contribution to the ore-forming fluid
Bismuthinite derivatives, lillianite homologues, and bismuth sulfotellurides as indicators of gold mineralization in the stanos shear-zone related deposit, Chalkidiki, Northern Greece
No full textArsenic-copper-gold-bismuth mineralization in the Stanos area is hosted by a km-long, NW-SE trending ductile to brittle shear zone within Silurian orthogneisses of the Vertiskos terrane of the Servomacedonian Massif, Chalkidiki Peninsula, northern Greece. Shearing was accompanied by iron-potassic alteration of the gneisses including biotite, muscovite, chlorite, apatite, zircon, quartz, and minor rare-earth element phosphates. Metallic minerals form disseminated to massive aggregates along foliation planes, asymmetric crenulation cleavages, and S-C' fabrics. Detailed textural investigation of the ore assemblages revealed two stages of hydrothermal mineralization during shearing. An initial introduction of iron sulfides (pyrite, arsenopyrite, and pyrrhotite) was followed by a copper-bearing stage that is associated with the formation of chalcopyrite, minor sulfides (galena, sphalerite, and molybdenite), and Bi-Cu-Pb-Au-Ag-Te minerals. The stage II metallic mineral association consists mainly of Bi sulfosalts (bismuthinite derivatives, lillianite homologues, matildite), native elements (bismuth, electrum), and bismuth chalcogenides (joséite-A, joséite-B, ikunolite, and unnamed Bi-Pb-bearing sulfotellurides). The bismuthinite derivatives are mainly bismuthinite (including cuprian varieties), gladite-krupkaite, paarite, salzburgite, and an unnamed CuPbBi7S12 phase. The ikunolite is Se-free, corresponding to the formula Bi4S3, and is the first known occurrence in Greece. Most stage II minerals exist in two-, three-, and, more rarely, four-component blebs or patches generally with curvilinear boundaries, suggesting the possibility that they were precipitated in a molten form. Phase relationships among minerals in the system Au-Bi-Te-Pb-Ag-Cu indicate that they formed by successive hydrothermal pulses from fluids that penetrated the shear zone at different times contemporaneous with ductile deformation. These pulses deposited the following assemblages in paragenetic order: molybdenite + cosalite + native bismuth + galenobismutite → gustavite/lillianite + native gold + native bismuth + bismuth sulfotellurides → bismuthinite-aikinite solid solution series→ matildite + native bismuth + galena → chalcopyrite + bornite. The observed association suggests that the system evolved under fluctuating f(S2) and f(O2) conditions and precious metals may have been scavenged by composite Bi-Te-Pb-S melts at temperatures well above 350 °C. The enrichment of Bi, Mo, Pb likely indicates a magmatic contribution to the ore-forming fluid
Validity testing of patient objections to acceptance of tamper-resistant opioid formulations
No full textImpact of self-efficacy in biofeedback and relaxation training within an interdisciplinary pain management program
No full text(539) The art of initial Biofeedback and Relaxation Training session within an Interdisciplinary Pain Management Program
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