9 research outputs found

    The formation of gold-rich seafloor sulfide deposits: Evidence from the Beebe Hydrothermal Vent Field, Cayman Trough

    Get PDF
    The Beebe vent field (BVF) in the Cayman Trough has built an auriferous massive sulfide deposit on the ultra-slow spreading mid-Cayman spreading centre. The genesis of auriferous sulfide deposits at mid-ocean ridges is not fully understood, although there is a growing recognition that slow and ultra-slow spreading centres are conducive to gold mineralization. Analysis of hydrothermal precipitates from the BVF indicates that the highest gold contents are present within “beehive diffusers”, which have developed a highly porous pyrrhotite framework. The beehive structure allows vent fluids to effuse slowly, while allowing ingress of seawater to cool the fluid. The prevalence of pyrrhotite in the beehive samples, lack of sulfates, association between pyrrhotite and gold grains, and results of thermodynamic modelling, suggests gold precipitation occurred under highly reduced conditions even during mixing with seawater. In contrast, high temperature chimneys, with a single orifice, maintain high temperatures to the primary vent orifice and much of the gold is lost to seawater. Despite this, both chimney types are relatively gold enriched, which points to a further underlying cause for high gold at the BVF such as interaction of hydrothermal fluids with ultramafic lithologies in the basement. The final gold composition of the deposit is partially controlled by loss of gold during mass-wasting of the material, with gold depletion most prevalent in blocks formed at beehive-type chimneys. The BVF demonstrates that the overall gold content of a massive sulfide deposit is the sum of basement, precipitation, and surface processes

    Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13  TeV with the ATLAS Detector

    No full text
    International audienceThis Letter reports the observation of WWWWWW production and a measurement of its cross section using 139 fb1^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWWWWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWWWWW production cross section is measured to be 820±100(stat)±80(syst)820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)} fb, approximately 2.6 standard deviations from the predicted cross section of 511±18511 \pm 18 fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

    Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13  TeV with the ATLAS Detector

    No full text
    International audienceThis Letter reports the observation of WWWWWW production and a measurement of its cross section using 139 fb1^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWWWWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWWWWW production cross section is measured to be 820±100(stat)±80(syst)820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)} fb, approximately 2.6 standard deviations from the predicted cross section of 511±18511 \pm 18 fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

    Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13  TeV with the ATLAS Detector

    No full text
    International audienceThis Letter reports the observation of WWWWWW production and a measurement of its cross section using 139 fb1^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWWWWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWWWWW production cross section is measured to be 820±100(stat)±80(syst)820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)} fb, approximately 2.6 standard deviations from the predicted cross section of 511±18511 \pm 18 fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

    Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13  TeV with the ATLAS Detector

    No full text
    International audienceThis Letter reports the observation of WWWWWW production and a measurement of its cross section using 139 fb1^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWWWWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWWWWW production cross section is measured to be 820±100(stat)±80(syst)820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)} fb, approximately 2.6 standard deviations from the predicted cross section of 511±18511 \pm 18 fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

    Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13  TeV with the ATLAS Detector

    No full text
    International audienceThis Letter reports the observation of WWWWWW production and a measurement of its cross section using 139 fb1^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWWWWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWWWWW production cross section is measured to be 820±100(stat)±80(syst)820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)} fb, approximately 2.6 standard deviations from the predicted cross section of 511±18511 \pm 18 fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

    Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13  TeV with the ATLAS Detector

    No full text
    International audienceThis Letter reports the observation of WWWWWW production and a measurement of its cross section using 139 fb1^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWWWWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWWWWW production cross section is measured to be 820±100(stat)±80(syst)820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)} fb, approximately 2.6 standard deviations from the predicted cross section of 511±18511 \pm 18 fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

    Observation of WWW Production in pp Collisions at p=13 TeV with the ATLAS Detector ffi s

    No full text
    This Letter reports the observation of WWW production and a measurement of its cross section using 139  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWW production cross section is measured to be 820±100 (stat)±80 (syst)  fb, approximately 2.6 standard deviations from the predicted cross section of 511±18  fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

    Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13  TeV with the ATLAS Detector

    No full text
    International audienceThis Letter reports the observation of WWWWWW production and a measurement of its cross section using 139 fb1^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWWWWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWWWWW production cross section is measured to be 820±100(stat)±80(syst)820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)} fb, approximately 2.6 standard deviations from the predicted cross section of 511±18511 \pm 18 fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy
    corecore