|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Geological Survey of Japan, Mineral and Fuel Resources Department, Tsukuba, Japan
There are many examples of spatially associated porphyry and epithermal ore deposits; a genetic connection has been suggested for some and argued against for others. Nowhere is this spatial association better demonstrated than in the Mankayan district of northern Luzon, Philippines, where the Lepanto high-sulfidation epithermal Cu-Au deposit is superadjacent to the Far Southeast porphyry Cu-Au orebody; together they contain >3.8 million tons (Mt) Cu and >550 t Au.Quartz diorite porphyry dikes intruded Miocene basement rocks of metavolcanic and volcaniclastic rocks to a 300-m elevation. These intrusions postdate the Pliocene volcanic breccia and dacite porphyry that host much of the epithermal ore. K silicate alteration, consisting of biotite-magnetite and minor K feldspar, is centered on the quartz diorite porphyry. K-Ar ages of the biotite are 1.41 + or - 0.05 Ma (n = 6). Vitreous, anhedral quartz veins are associated with this early alteration and contain vapor-rich and hypersaline liquid inclusions with maximum homogenization temperatures of 450 degrees to 550 degrees C (and 50-55 wt % NaCl equiv salinities). Lithostatic pressure estimates indicate a paleosurface at a > or = 1,500-m elevation. Advanced argillic alteration formed over the top of the porphyry and consists of quartz-alunite, dated at 1.42 + or - 0.08 Ma (n = 5), synchronous with K silicate alteration. The lower limit of extensive quartz-alunite alteration is at a [asymp] 600-m elevation. Similar alteration and a core of leached, silicic alteration extend northwestward >4 km along the basement dacite contact, localized by the Lepanto fault. Chemical and S isotope zoning of alunite along strike indicates progressively lower temperatures away from the porphyry, from 350 degrees to 200 degrees C. K silicate alteration is overprinted by alteration consisting of chlorite plus hematite and/or sericite-illite, with a marginal zone containing pyrophyllite and an outer zone of propylitic alteration. The chlorite-sericite alteration is cut by veins of euhedral quartz that locally fill reopened anhedral quartz veins. The euhedral quartz veins contain anhydrite-white mica-pyrite + or - chalcopyrite + or - bornite and have halos of sericite; illite separated from these halos has ages of 1.30 + or - 0.07 Ma (n = 10). Fluid inclusions provide evidence for boiling on inception of this fracturing event (T h = 350 degrees C, 5 wt % NaCl equiv) and indicate a depth of 1,500 to 2,000 m below the paleowater table. This brittle-fracture event was followed by cooling and dilution of the hydrothermal fluid.The elevation of the enargite Au epithermal ore and its host of silicic alteration increases as the unconformity between the basement and dacite breccia rises from a 700- to 1,200-m elevation with increasing distance from the porphyry. Published data on enargite-hosted fluid inclusions (T h = 295 degrees -200 degrees C, 4-2 wt % NaCl equiv) indicate that the temperature and salinity both decrease with increasing distance from the porphyry. Epithermal ore consists of stage 1 euhedral pyrite-enargite-luzonite, and subsequent stage 2 Au is accompanied by tetrahedrite-chalcopyrite-sphalerite plus telluride and selenide minerals. Anhydrite and barite gangue minerals are followed by late vug-fulling quartz and kandite minerals. The quartz-alunite alteration halo passes outward to "kandite" (kaolinite-nacrite-diclcite) alteration, then to chlorite or montmorillonite, depending on the host rock (basement or dacite, respectively).The dated minerals were also analyzed for their delta 18 O and delta D compositions, and their associated hydrothermal water values were calculated. Water in isotopic equilibrium with biotite averaged +6.3 and -45 per mil, respectively, typical of hypersaline liquid exsolved from felsic magma. The acidic water that deposited the alunite formed when magmatic vapor (+7ppm delta 18 O and -25ppm delta D) was absorbed by local meteoric water (-10ppm delta 18 O and -70ppm delta D) in a proportion of [asymp] 9:1 magmatic to meteoric. Lateral flow to the northwest and progressive mixing with ground water diluted the magmatic component to 1:1 at a distance of 4 km from the porphyry. At the depth of the porphyry, deposit, the later water isotopically stable with sericite was dominantly magmatic (+5.7ppm delta 18 O and -43ppm delta D) in the core. The marginal sericitie alteration (+1.5ppm delta 18 O and -51ppm delta D water values) indicates a maximum 20 to 30 percent component of local meteoric water. Pyrophyllite in both the porphyry and epithermal deposits formed from water with an isotopic composition similar to that which formed the sericitic alteration. The late euhedral quartz veining and sericitic alteration appear to have been associated with the majority of Cu and Au deposition. In addition, mineralogic, paragenetic, isotopic, and fluid inclusion evidence suggests that this water precipitated the enargite and Au within the epithermal deposit.Our results reinforce guidelines for exploration of such deposits. Advanced argillic (quartz-alunite) and K silicate alteration at Lepanto-Far Southeast are coupled in origin and result from vapor and hypersaline liquid separation. Thus, exploration programs for buried porphyry deposits should document carefully the geologic, morphologic, and temporal characteristics of exposed areas of advanced argillic alteration and its origin. Sericitic alteration at Far Southeast is associated with porphyry Cu and Au ore and appears to represent the roots of the main-stage Cu-Au mineralization in the epithermal deposit, hosted by silicic and quartz-alunite alteration that has a lower limit near the top of porphyry Cu-Au ore. In some cases, the sericitic overprint of a porphyry system, particularly where it is related to Cu and Au enrichment, may indicate a potential for nearby epithermal mineralization. Similarly, sericite and/or pyrophyllite underlying or overprinting a zone of hypogene advanced argillic (quartz-alunite) alteration indicates that mineralizing fluid may have ascended to epithermal depths. Epithermal ore at Lepanto-Far Southeast reflects a paleohydrologic regime dominated by lateral fluid flow, with a marked control by intersection of the Lepanto fault and a lithologic unconformity. Recognizing evidence for lateral flow is critical, as paleohydrology controlled the distribution of alteration and mineralization in many high-sulfidation epithermal deposits.
This record provided courtesy of AGI/GeoRef.
This article has been cited by other articles:
|
|
 |
|
  C. Pudack, W. E. Halter, C. A. Heinrich, and T. Pettke Evolution of Magmatic Vapor to Gold-Rich Epithermal Liquid: The Porphyry to Epithermal Transition at Nevados de Famatina, Northwest Argentina Economic Geology, July 1, 2009; 104(4): 449 - 477. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H.-Y. Liang, W. Sun, W.-C. Su, and R. E. Zartman PORPHYRY COPPER-GOLD MINERALIZATION AT YULONG, CHINA, PROMOTED BY DECREASING REDOX POTENTIAL DURING MAGNETITE ALTERATION Economic Geology, July 1, 2009; 104(4): 587 - 596. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. P. Braxton, D. R. Cooke, A. M. Ignacio, R. O. Rye, and P. J. Waters Ultra-Deep Oxidation and Exotic Copper Formation at the Late Pliocene Boyongan and Bayugo Porphyry Copper-Gold Deposits, Surigao, Philippines: Geology, Mineralogy, Paleoaltimetry, and their Implications for Geologic, Physiographic, and Tectonic Controls Economic Geology, May 1, 2009; 104(3): 333 - 349. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Audetat, T. Pettke, C. A. Heinrich, and R. J. Bodnar Special Paper: The Composition of Magmatic-Hydrothermal Fluids in Barren and Mineralized Intrusions Economic Geology, August 1, 2008; 103(5): 877 - 908. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. A. Valencia, C. Eastoe, J. Ruiz, L. Ochoa-Landin, G. Gehrels, C. Gonzalez-Leon, F. Barra, and E. Espinoza Hydrothermal Evolution of the Porphyry Copper Deposit at La Caridad, Sonora, Mexico, and the Relationship with a Neighboring High-Sulfidation Epithermal Deposit Economic Geology, May 1, 2008; 103(3): 473 - 491. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Baumgartner, L. Fontbote, and T. Vennemann Mineral Zoning and Geochemistry of Epithermal Polymetallic Zn-Pb-Ag-Cu-Bi Mineralization at Cerro de Pasco, Peru Economic Geology, May 1, 2008; 103(3): 493 - 537. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. M. Bongiolo, P. Patrier-Mas, A. S. Mexias, D. Beaufort, and M. L. L. Formoso SPATIAL AND TEMPORAL EVOLUTION OF HYDROTHERMAL ALTERATION AT LAVRAS DO SUL, BRAZIL: EVIDENCE FROM DIOCTAHEDRAL CLAY MINERALS Clays and Clay Minerals, April 1, 2008; 56(2): 222 - 243. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. G. Rusk, M. H. Reed, and J. H. Dilles Fluid Inclusion Evidence for Magmatic-Hydrothermal Fluid Evolution in the Porphyry Copper-Molybdenum Deposit at Butte, Montana Economic Geology, March 1, 2008; 103(2): 307 - 334. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. J. Nutt and A. H. Hofstra Bald Mountain Gold Mining District, Nevada: A Jurassic Reduced Intrusion-Related Gold System Economic Geology, September 1, 2007; 102(6): 1129 - 1155. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. A. Heinrich Fluid-Fluid Interactions in Magmatic-Hydrothermal Ore Formation Reviews in Mineralogy and Geochemistry, July 1, 2007; 65(1): 363 - 387. [Full Text] [PDF]
|
|
|
|
 |
|
 A. Camprubi and T. Albinson Epithermal deposits in Mexico--Update of current knowledge, and an empirical reclassification Geological Society of America Special Papers, January 1, 2007; 422(0): 377 - 415. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Valencia-Moreno, L. Ochoa-Landin, B. Noguez-Alcantara, J. Ruiz, and E. Perez-Segura Geological and metallogenetic characteristics of the porphyry copper deposits of Mexico and their situation in the world context Geological Society of America Special Papers, January 1, 2007; 422(0): 433 - 458. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Wallier, R. Rey, K. Kouzmanov, T. Pettke, C. A. Heinrich, S. Leary, G. O'Connor, C. G. Tamas, T. Vennemann, and T. Ullrich Magmatic Fluids in the Breccia-Hosted Epithermal Au-Ag Deposit of Rosia Montana, Romania Economic Geology, August 1, 2006; 101(5): 923 - 954. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. F. Ducart, A. P. Crosta, C. R. S. Filho, and J. Coniglio Alteration Mineralogy at the Cerro La Mina Epithermal Prospect, Patagonia, Argentina: Field Mapping, Short-Wave Infrared Spectroscopy, and ASTER Images Economic Geology, August 1, 2006; 101(5): 981 - 996. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B.-E. Khashgerel, R. O. Rye, J. W. Hedenquist, and I. Kavalieris Geology and Reconnaissance Stable Isotope Study of the Oyu Tolgoi Porphyry Cu-Au System, South Gobi, Mongolia Economic Geology, May 1, 2006; 101(3): 503 - 522. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Moura, N. F. Botelho, G. R. Olivo, and T. K. Kyser Granite-Related Paleoproterozoic, Serrinha Gold Deposit, Southern Amazonia, Brazil: Hydrothermal Alteration, Fluid Inclusion and Stable Isotope Constraints on Genesis and Evolution Economic Geology, May 1, 2006; 101(3): 585 - 605. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. R. Seal II Sulfur Isotope Geochemistry of Sulfide Minerals Reviews in Mineralogy and Geochemistry, January 1, 2006; 61(1): 633 - 677. [Full Text] [PDF]
|
|
|
|
|
|
F. Bouzari and A. H. Clark Prograde Evolution and Geothermal Affinities of a Major Porphyry Copper Deposit: The Cerro Colorado Hypogene Protore, I Region, Northern Chile Economic Geology, January 1, 2006; 101(1): 95 - 134. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. L. Scherbarth and P. G. Spry Mineralogical, Petrological, Stable Isotope, and Fluid Inclusion Characteristics of the Tuvatu Gold-Silver Telluride Deposit, Fiji: Comparisons with the Emperor Deposit Economic Geology, January 1, 2006; 101(1): 135 - 158. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. E. Williams-Jones and C. A. Heinrich 100th Anniversary Special Paper: Vapor Transport of Metals and the Formation of Magmatic-Hydrothermal Ore Deposits Economic Geology, October 1, 2005; 100(7): 1287 - 1312. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Cooke, P. Hollings, and J. L. Walshe Giant Porphyry Deposits: Characteristics, Distribution, and Tectonic Controls Economic Geology, August 1, 2005; 100(5): 801 - 818. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Chouinard, A. E. Williams-Jones, R. W. Leonardson, C. J. Hodgson, P. Silva, C. Tellez, J. Vega, and F. Rojas Geology and Genesis of the Multistage High-Sulfidation Epithermal Pascua Au-Ag-Cu Deposit, Chile and Argentina Economic Geology, May 1, 2005; 100(3): 463 - 490. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. E. Kesler Ore-Forming Fluids Elements, January 1, 2005; 1(1): 13 - 18. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Leahy, A. C. Barnicoat, R. P. Foster, S. R. Lawrence, and R. W. Napier Geodynamic processes that control the global distribution of giant gold deposits Geological Society, London, Special Publications, January 1, 2005; 248(1): 119 - 132. [Abstract] [PDF]
|
|
|
|
|
|
C. L. Deyell, R. Leonardson, R. O. Rye, J. F. H. Thompson, T. Bissig, and D. R. Cooke Alunite in the Pascua-Lama High-Sulfidation Deposit: Constraints on Alteration and Ore Deposition Using Stable Isotope Geochemistry Economic Geology, January 1, 2005; 100(1): 131 - 148. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Kodera, J. Lexa, A. H. Rankin, and A. E. Fallick Fluid Evolution in a Subvolcanic Granodiorite Pluton Related to Fe and Pb-Zn Mineralization, Banska Stiavnica Ore District, Slovakia Economic Geology, December 1, 2004; 99(8): 1745 - 1770. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. P. Mernagh, C. A. Heinrich, and E. J. Mikucki TEMPERATURE GRADIENTS RECORDED BY FLUID INCLUSIONS AND HYDROTHERMAL ALTERATION AT THE MOUNT CHARLOTTE GOLD DEPOSIT, KALGOORLIE, AUSTRALIA Can Mineral, October 1, 2004; 42(5): 1383 - 1404. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Kouzmanov, C. Ramboz, L. Bailly, and K. Bogdanov GENESIS OF HIGH-SULFIDATION VINCIENNITE-BEARING Cu As Sn ( Can Mineral, October 1, 2004; 42(5): 1501 - 1521. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. A. Heinrich, T. Driesner, A. Stefansson, and T. M. Seward Magmatic vapor contraction and the transport of gold from the porphyry environment to epithermal ore deposits Geology, September 1, 2004; 32(9): 761 - 764. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P.B. Redmond, M.T. Einaudi, E.E. Inan, M.R. Landtwing, and C.A. Heinrich Copper deposition by fluid cooling in intrusion-centered systems: New insights from the Bingham porphyry ore deposit, Utah Geology, March 1, 2004; 32(3): 217 - 220. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Baker, E. Van Achterberg, C. G. Ryan, and J. R. Lang Composition and evolution of ore fluids in a magmatic-hydrothermal skarn deposit Geology, February 1, 2004; 32(2): 117 - 120. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Seedorff and M. T. Einaudi Henderson Porphyry Molybdenum System, Colorado: I. Sequence and Abundance of Hydrothermal Mineral Assemblages, Flow Paths of Evolving Fluids, and Evolutionary Style Economic Geology, January 1, 2004; 99(1): 3 - 37. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Seedorff and M. T. Einaudi Henderson Porphyry Molybdenum System, Colorado: II. Decoupling of Introduction and Deposition of Metals during Geochemical Evolution of Hydrothermal Fluids Economic Geology, January 1, 2004; 99(1): 39 - 72. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Nemcok, J. N. Moore, R. Allis, and J. McCulloch Fracture development within a stratovolcano: the Karaha-Telaga Bodas geothermal field, Java volcanic arc Geological Society, London, Special Publications, January 1, 2004; 231(1): 223 - 242. [Abstract] [PDF]
|
|
|
|
|
|
J. P. Richards and J. P. Richards Tectono-Magmatic Precursors for Porphyry Cu-(Mo-Au) Deposit Formation Economic Geology, December 1, 2003; 98(8): 1515 - 1533. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. C. Simon, A. C. Simon, T. Pettke, P. A. Candela, P. M. Piccoli, and C. A. Heinrich Experimental determination of Au solubility in rhyolite melt and magnetite: Constraints on magmatic Au budgets American Mineralogist, November 1, 2003; 88(11-12): 1644 - 1651. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. A. Gilg, H. A. GILG, B. WEBER, J. KASBOHM, and R. FREI Isotope geochemistry and origin of illite-smectite and kaolinite from the Seilitz and Kemmlitz kaolin deposits, Saxony, Germany Clay Minerals, March 1, 2003; 38(1): 95 - 112. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
null Hou Zengqian, H. Zengqian, M. Hongwen, K. Zaw, Z. Yuquan, W. Mingjie, W. Zeng, P. Guitang, and T. Renli The Himalayan Yulong Porphyry Copper Belt: Product of Large-Scale Strike-Slip Faulting in Eastern Tibet Economic Geology, January 1, 2003; 98(1): 125 - 145. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. D. Meinert, L. D. Meinert, J. W. Hedenquist, H. Satoh, and Y. Matsuhisa Formation of Anhydrous and Hydrous Skarn in Cu-Au Ore Deposits by Magmatic Fluids Economic Geology, January 1, 2003; 98(1): 147 - 156. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Petersen, S. Petersen, P. M. Herzig, M. D. Hannington, I. R. Jonasson, and A. Arribas Jr. Submarine Gold Mineralization Near Lihir Island, New Ireland Fore-Arc, Papua New Guinea Economic Geology, December 1, 2002; 97(8): 1795 - 1813. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Ulrich and C. A. Heinrich Geology and Alteration Geochemistry of the Porphyry Cu-Au Deposit at Bajo de la Alumbrera, Argentina Economic Geology, December 1, 2002; 97(8): 1865 - 1888. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Ulrich, D. Gunther, and C. A. Heinrich The Evolution of a Porphyry Cu-Au Deposit, Based on LA-ICP-MS Analysis of Fluid Inclusions: Bajo de la Alumbrera, Argentina Economic Geology, December 1, 2002; 97(8): 1889 - 1920. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Mavrogenes, A. J. Berry, M. Newville, and S. R. Sutton Copper speciation in vapor-phase fluid inclusions from the Mole Granite, Australia American Mineralogist, October 1, 2002; 87(10): 1360 - 1364. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Landtwig, M. R. Landtwing, E. D. Dillenbeck, M. H. Leake, and C. A. Heinrich Evolution of the Breccia-Hosted Porphyry Cu-Mo-Au Deposit at Agua Rica, Argentina: Progressive Unroofing of a Magmatic Hydrothermal System Economic Geology, September 1, 2002; 97(6): 1273 - 1292. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Bissig, T. Bissig, A. H. Clark, J. K.W. Lee, and C. J. Hodgson Miocene Landscape Evolution and Geomorphologic Controls on Epithermal Processes in the El Indio-Pascua Au-Ag-Cu Belt, Chile and Argentina Economic Geology, August 1, 2002; 97(5): 971 - 996. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Baker and T. Baker EMPLACEMENT DEPTH AND CARBON DIOXIDE-RICH FLUID INCLUSIONS IN INTRUSION-RELATED GOLD DEPOSITS Economic Geology, August 1, 2002; 97(5): 1111 - 1117. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Manske, S. L. Manske, and A. H. Paul Geology of a Major New Porphyry Copper Center in the Superior (Pioneer) District, Arizona Economic Geology, March 1, 2002; 97(2): 197 - 220. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. C. R. Willan, R. C. R. WILLAN, and D. C. ARMSTRONG Successive geothermal, volcanic-hydrothermal and contact-metasomatic events in Cenozoic volcanic-arc basalts, South Shetland Islands, Antarctica Geological Magazine, March 1, 2002; 139(2): 209 - 231. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Marchev and B. Singer 40Ar/39Ar geochronology of magmatism and hydrothermal activity of the Madjarovo base-precious metal ore district, eastern Rhodopes, Bulgaria Geological Society, London, Special Publications, January 1, 2002; 204(1): 137 - 150. [Abstract] [PDF]
|
|
|
|
|
|
T. Ulrich, T. Ulrich, and C. A. Heinrich Geology and Alteration Geochemistry of the Porphyry Cu-Au Deposit at Bajo de la Alumbrera, Argentina Economic Geology, December 1, 2001; 96(8): 1719 - 1742. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Ulrich, T. Ulrich, D. Gunther, and C. A. Heinrich The Evolution of a Porphyry Cu-Au Deposit, Based on LA-ICP-MS Analysis of Fluid Inclusions: Bajo de la Alumbrera, Argentina Economic Geology, December 1, 2001; 96(8): 1743 - 1774. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Watanabe, Y. Watanabe, and J. W. Hedenquist Mineralogic and Stable Isotope Zonation at the Surface over the El Salvador Porphyry Copper Deposit, Chile Economic Geology, December 1, 2001; 96(8): 1775 - 1797. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. John and D. A. John Miocene and Early Pliocene Epithermal Gold-Silver Deposits in the Northern Great Basin, Western United States: Characteristics, Distribution, and Relationship to Magmatism Economic Geology, December 1, 2001; 96(8): 1827 - 1853. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Perello, J. Perello, D. Cox, D. Garamjav, S. Sanjdorj, S. Diakov, D. Schissel, T.-O. Munkhbat, and G. Oyun Oyu Tolgoi, Mongolia: Siluro-Devonian Porphyry Cu-Au-(Mo) and High-Sulfidation Cu Mineralization with a Cretaceous Chalcocite Blanket Economic Geology, September 1, 2001; 96(6): 1407 - 1428. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Muntean, J. L. Muntean, and M. T. Einaudi Porphyry-Epithermal Transition: Maricunga Belt, Northern Chile Economic Geology, July 1, 2001; 96(4): 743 - 772. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Parnell, J. Parnell, G. Earls, J. J. Wilkinson, D. H. W. Hutton, A. J. Boyce, A. E. Fallick, R. M. Ellam, S. A. Gleeson, N. R. Moles, et al. Regional Fluid Flow and Gold Mineralization in the Dalradian of the Sperrin Mountains, Northern Ireland Economic Geology, November 1, 2000; 95(7): 1389 - 1416. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. B. Franchini, M. B. Franchini, L. D. Meinert, and T. F. Montenegro Skarns Related to Porphyry-Style Mineralization at Caicayen Hill, Neuquen, Argentina: Composition and Evolution of Hydrothermal Fluids Economic Geology, September 1, 2000; 95(6): 1197 - 1213. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Singer, B. Singer, and P. Marchev TEMPORAL EVOLUTION OF ARC MAGMATISM AND HYDROTHERMAL ACTIVITY, INCLUDING EPITHERMAL GOLD VEINS, BOROVITSA CALDERA, SOUTHERN BULGARIA Economic Geology, August 1, 2000; 95(5): 1155 - 1164. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Simon, G. Simon, S. E. Kesler, E. J. Essene, and S. L. Chryssoulis Gold in Porphyry Copper Deposits: Experimental Determination of the Distribution of Gold in the Cu-Fe-S System at 400{degrees} to 700{degrees}C Economic Geology, March 1, 2000; 95(2): 259 - 270. [Abstract] [Full Text] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
