Epithermal Gold Mineralization in the Trenggalek District,East Java,Indonesia     

Ryohei Takahashi  Yuki Shingo  Akira Imai  Koichiro Watanabe  Agung Harijoko  I Wayan Warmada  Arifudin Idrus  Lucas Donny Setijadji  Phouvang Phoumephone  Anders Scherstén  Laurence Page 《Resource Geology》2014,64(2):149-166

Gold‐mineralized quartz veins at the Trenggalek district of the Southern Mountains Range in East Java, Indonesia, are hosted by Oligo‐Miocene volcaniclastic and volcanic rocks, and are distributed close to andesitic plugs in the northern prospects (Dalangturu, Suruh, Jati, Gregah, Jombok, Salak, and Kojan) and the southern prospects (Sentul and Buluroto). The plugs are subalkaline tholeiitic basaltic‐andesite to calc‐alkaline andesite in composition. ⁴⁰Ar–³⁹Ar dating of a quartz‐adularia vein at the Dalangturu prospect yielded an age of 16.29 ± 0.56 Ma (2σ), and a crystal tuff of a limestone‐pyroclastic rock sequence at the southwest of the Dalangturu prospect was determined as 15.6 ± 0.5 Ma (2σ). Statistic overlap of ages suggests that the gold mineralization in the northern prospects took place in a shallow marine to subaerial transitional environment. Hydrothermal alteration of the host rocks is characterized by the replacement of quartz, illite and adularia. Quartz veins in surface outcrops are up to 50 cm wide in the northern prospects and up to 3 m wide in the southern prospects, showing a banded or brecciated texture, and are composed of quartz, adularia, carbonates with pyrite, electrum, sphalerite, galena, and polybasite. Gold contents of quartz veins are positively correlated with Ag, Zn, Pb, and Cu contents in both the northern and southern prospects. The quartz veins at the Jati, Gregah, and Sentul prospects have relatively lower gold‐silver ratios (Ag/Au = 23.2) compared to those at the Kojan, Dalangturu, Salak, and Suruh prospects (Ag/Au = 66.8). The quartz veins at the Dalangturu prospect are relatively rich in base metal sulfides. Ag/(Au+Ag) ratios of electrum in the Dalangturu prospect range from 45.2 to 65.0 at%, and FeS contents of sphalerite range from 1.2 to 6.4 mol%. Fluid inclusion microthermometry indicates ore‐forming temperatures of 190–200°C and 220–230°C at the Sentul and Kojan prospects, respectively. Widely variable vapor/liquid ratio of fluid inclusions indicates that fluid boiling took place within the hydrothermal system at the Sentul prospect. Salinities of ore‐fluids range from 0 to 0.7 wt% (av. 0.4 wt% NaCl equiv.) and from 0.5 to 1.4 wt% (av. 0.9 wt%) for the Sentul and Kojan prospects, respectively. The boiling of hydrothermal fluid was one of the gold deposition mechanisms in the Sentul prospect.  相似文献   

Can radiative forcing be limited to 2.6 Wm−2 without negative emissions from bioenergy AND CO2 capture and storage?     

James Edmonds  Patrick Luckow  Katherine Calvin  Marshall Wise  Jim Dooley  Page Kyle  Son H. Kim  Pralit Patel  Leon Clarke 《Climatic change》2013,118(1):29-43

Combining bioenergy and carbon dioxide (CO₂) capture and storage (CCS) technologies (BECCS) has the potential to remove CO₂ from the atmosphere while producing useful energy. BECCS has played a central role in scenarios that reduce climate forcing to low levels such as 2.6 Wm^?2. In this paper we consider whether BECCS is essential to limiting radiative forcing (RF) to 2.6 Wm^?2 by 2100 using the Global Change Assessment Model, a closely coupled model of biogeophysical and human Earth systems. We show that BECCS can potentially reduce the cost of limiting RF to 2.6 Wm^?2 by 2100 but that a variety of technology combinations that do not include BECCS can also achieve this goal, under appropriate emissions mitigation policies. We note that with appropriate supporting land-use policies terrestrial sequestration could deliver carbon storage ranging from 200 to 700 PgCO₂-equiavalent over the 21st century. We explore substantial delays in participation by some geopolitical regions. We find that the value of BECCS is substantially higher under delay and that delay results in higher transient RF and climate change. However, when major regions postponed mitigation indefinitely, it was impossible to return RF to 2.6 Wm^?2 by 2100. Neither finite land resources nor finite potential geologic storage capacity represented a meaningful technical limit on the ability of BECCS to contribute to emissions mitigation in the numerical experiments reported in this paper.  相似文献   

The origin of the Fe K features in Markarian 205 and Markarian 509     

M. J. Page  S. W. Davis  N. J. Salvi 《Monthly notices of the Royal Astronomical Society》2003,343(4):1241-1247

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Serendipitous active galactic nuclei in the XMM–Newton fields of Markarian 205 and QSO 0130−403     

K. L. Page  M. J. L. Turner  J. N. Reeves  P. T. O'Brien  S. Sembay 《Monthly notices of the Royal Astronomical Society》2003,338(4):1004-1012

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An XMM–Newton observation of Mkn 3 – a Seyfert galaxy just over the edge     

K. A. Pounds  K. L. Page 《Monthly notices of the Royal Astronomical Society》2005,360(3):1123-1131

A 100-ks XMM–Newton observation of the nearby Seyfert 2 galaxy Mkn 3 offers a unique opportunity to explore the complexity of its X-ray spectrum. We find the  ∼3–8 keV  continuum to be dominated by reflection from cold matter, with fluorescent K-shell lines detected from Ni, Fe, Ca, Ar, S, Si and Mg. At higher energies an intrinsic power-law continuum, with canonical Seyfert 1 photon index, is seen through a near-Compton-thick cold absorber. A soft excess below ∼3 keV is found to be dominated by line emission from an outflow of 'warm' gas, photoionized and photoexcited by the intrinsically strong X-ray continuum. Measured blueshifts in the strong Fe Kα and O  vii and O  viii emission lines are discussed in terms of the properties of the putative molecular torus and ionized outflow.  相似文献   

Submillimetre photometry of X-ray absorbed quasi-stellar objects: their formation and evolutionary status     

J. A. Stevens  M. J. Page  R. J. Ivison  F. J. Carrera  J. P. D. Mittaz  Ian Smail  I. M. MHardy 《Monthly notices of the Royal Astronomical Society》2005,360(2):610-618

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A medium-deep Chandra and Subaru survey of the 13-h XMM/ROSAT deep survey area     

I. M. MHardy  K. F. Gunn  A. M. Newsam  K. O. Mason  M. J. Page  T. Takata  K. Sekiguchi  T. Sasseen  F. Cordova  L. R. Jones  N. Loaring 《Monthly notices of the Royal Astronomical Society》2003,342(3):802-822

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The nature of X-ray selected extremely red objects     

J. A. Stevens  M. J. Page  R. J. Ivison  Ian Smail  I. Lehmann  G. Hasinger  G. Szokoly 《Monthly notices of the Royal Astronomical Society》2003,342(1):249-258

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Impacts of rising air temperatures and emissions mitigation on electricity demand and supply in the United States: a multi-model comparison   总被引：2，自引：2，他引：0  

James McFarland  Yuyu Zhou  Leon Clarke  Patrick Sullivan  Jesse Colman  Wendy S. Jaglom  Michelle Colley  Pralit Patel  Jiyon Eom  Son H. Kim  G. Page Kyle  Peter Schultz  Boddu Venkatesh  Juanita Haydel  Charlotte Mack  Jared Creason 《Climatic change》2015,132(1):111-125

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GRB 050505: a high-redshift burst discovered by Swift     

C. P. Hurkett  J. P. Osborne  K. L. Page  E. Rol  M. R. Goad  P. T. O'Brien  A. Beardmore  O. Godet  D. N. Burrows  N. R. Tanvir  A. Levan  B. Zhang  D. Malesani  J. E. Hill  J. A. Kennea  R. Chapman  V. La Parola  M. Perri  P. Romano  R. Smith  N. Gehrels 《Monthly notices of the Royal Astronomical Society》2006,368(3):1101-1109

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