scholarly journals Magma Emplacement Rates and Porphyry Copper Deposits: Thermal Modeling of the Yerington Batholith, Nevada

2017 ◽  
Vol 112 (7) ◽  
pp. 1653-1672 ◽  
Author(s):  
Anne Schöpa ◽  
Catherine Annen ◽  
John H. Dilles ◽  
R. Stephen J. Sparks ◽  
Jon D. Blundy
Keyword(s):  
Porphyry Copper ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
Testable Hypothesis ◽  
Porphyry Copper Deposits ◽  
Magma Chambers ◽  
Deposit Formation ◽  
Slow Cooling ◽  
Copper Deposits ◽  
Magma Emplacement

Abstract Many porphyry copper deposits are associated with granitoid plutons. Porphyry copper deposit genesis is commonly attributed to degassing of pluton-forming intermediate to silicic magma chambers during slow cooling and crystallization. We use numerical simulations of thermal evolution during pluton growth to investigate the links between pluton construction, magma accumulation and solidification, volatile release, and porphyry copper deposit formation. The Jurassic Yerington batholith, Nevada, serves as a case study because of its exceptional exposure, revealing the geometry of three main intrusions. The last intrusion, the Luhr Hill granite, is associated with economic porphyry copper deposits localized over cupolas where dikes and fluid flow were focused. Our simulations for the conceptual model linking porphyry copper deposits with the presence of large, highly molten magma chambers show that the Luhr Hill granite must have been emplaced at a vertical thickening rate of several cm/yr or more. This magma emplacement rate is much higher than the time-averaged formation rates of other batholiths reported in the literature. Such low rates, although common, do not lead to magma accumulation and might be one of the reasons why many granitoid plutons are barren. Based on our results, we formulate the new testable hypothesis of a link between porphyry copper deposit formation and the emplacement time scale of the associated magma intrusion.

scholarly journals Application of Dirichlet Process and Support Vector Machine Techniques for Mapping Alteration Zones Associated with Porphyry Copper Deposit Using ASTER Remote Sensing Imagery

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1235
Author(s):  
Mastoureh Yousefi ◽  
Seyed Hasan Tabatabaei ◽  
Reyhaneh Rikhtehgaran ◽  
Amin Beiranvand Pour ◽  
Biswajeet Pradhan
Keyword(s):  
Hydrothermal Alteration ◽  
Porphyry Copper ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
Training Data ◽  
Support Vector ◽  
Porphyry Copper Deposits ◽  
Copper Deposits ◽  
Alteration Zones ◽  
Hydrothermal Alteration Zones

The application of machine learning (ML) algorithms for processing remote sensing data is momentous, particularly for mapping hydrothermal alteration zones associated with porphyry copper deposits. The unsupervised Dirichlet Process (DP) and the supervised Support Vector Machine (SVM) techniques can be executed for mapping hydrothermal alteration zones associated with porphyry copper deposits. The main objective of this investigation is to practice an algorithm that can accurately model the best training data as input for supervised methods such as SVM. For this purpose, the Zefreh porphyry copper deposit located in the Urumieh-Dokhtar Magmatic Arc (UDMA) of central Iran was selected and used as training data. Initially, using ASTER data, different alteration zones of the Zefreh porphyry copper deposit were detected by Band Ratio, Relative Band Depth (RBD), Linear Spectral Unmixing (LSU), Spectral Feature Fitting (SFF), and Orthogonal Subspace Projection (OSP) techniques. Then, using the DP method, the exact extent of each alteration was determined. Finally, the detected alterations were used as training data to identify similar alteration zones in full scene of ASTER using SVM and Spectral Angle Mapper (SAM) methods. Several high potential zones were identified in the study area. Field surveys and laboratory analysis were used to validate the image processing results. This investigation demonstrates that the application of the SVM algorithm for mapping hydrothermal alteration zones associated with porphyry copper deposits is broadly applicable to ASTER data and can be used for prospectivity mapping in many metallogenic provinces around the world.

Porphyry copper deposit formation by sub-volcanic sulphur dioxide flux and chemisorption

2015 ◽  
Vol 8 (3) ◽  
pp. 210-215 ◽  
Author(s):  
Richard W. Henley ◽  
Penelope L. King ◽  
Jeremy L. Wykes ◽  
Christian J. Renggli ◽  
Frank J. Brink ◽  
...  
Keyword(s):  
Sulphur Dioxide ◽  
Porphyry Copper ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
Deposit Formation

scholarly journals Supplemental Material: A new model for the optimal structural context for giant porphyry copper deposit formation

2021 ◽  
Author(s):  
Jose Piquer ◽  
et al.
Keyword(s):  
Porphyry Copper ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
Mineral Deposits ◽  
Deposit Formation ◽  
New Model ◽  
Structural Context

Tables S1 and S2, a summary of all the relevant data from mineral deposits and active volcanic systems compiled for testing the model presented in this work.<br>

Integrated study of supergene copper deposits from Atacama Desert, Northern Chile: coupled petro-geochemical approach and U-Pb LA-ICP-MS in situ dating

2020 ◽  
Author(s):  
Zia Steven Kahou ◽  
Stéphanie Brichau ◽  
Stéphanie Duchêne ◽  
Marc Poujol ◽  
Eduardo Campos ◽  
...  
Keyword(s):  
Porphyry Copper ◽  
Atacama Desert ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
Northern Chile ◽  
Copper Deposits ◽  
Common Lead ◽  
Copper Mineralization ◽  
Icp Ms

&lt;p&gt;Supergene copper mineralization (SCM) are nowadays the economic viability of many porphyry copper deposits worldwide. These mineralization are derived from supergene processes, defined by Ransome (1912) as sulfide oxidation and leaching of ore deposits in the weathering environment, and any attendant secondary sulfide enrichment. For supergene copper mineralization to form, favorable tectonics, climate and geomorphologic conditions are required. Tectonics control the uplift needed to induce groundwater lowering and leaching of sulphides from a porphyry copper deposit. Climate controls copper leaching in the supergene environment and groundwater circulation towards the locus where supergene copper-bearing minerals precipitate. Two types of SCM have been recognized: 1) in-situ SCM, which are products of descending aqueous solutions and 2) exotic SCM,&amp;#160; which are the products of lateral migration of supergene copper solutions from a parental porphyry copper deposit (Sillitoe, 2005).&lt;/p&gt;&lt;p&gt;In the Atacama Desert, such deposits seem to take place during specific Tertiary climatic periods and relief formation. But many uncertainties remain regarding the genesis and the exact timing for their formation. In this study, a coupled approach combining a petro-geochemical study and LA-ICP-MS U-Pb dating were applied to four mining copper deposits (e.g. Mina Sur, Damiana, El Cobre, Zaldivar) from hyperarid Atacama Desert of Northern Chile. Textural features are the same in all the deposits with chrysocolla as the abundant mineral, followed by black chrysocolla, pseudomalachite and minor atacamite and copper wad. Their geochemical compositions (i.e. major, traces and rare Earth elements) also show homogeneous results suggesting similar process in their genesis. U-Pb dating were performed on black chrysocolla, chrysocolla and pseudomalachite from all the deposits. Apart from Mina Sur deposit, all the mines mentioned above showed high common lead content. To try to extract in these deposit an U-Pb age, complementary analyses to quantify accurately common lead concentration are ongoing, using MC-ICPMS. At Mina Sur, U-Pb dating performed on pseudomalachite bands yields a crystallisation age of 18.4 &amp;#177; 1.0 Ma. For the black chrysocolla clasts, the &lt;sup&gt;206&lt;/sup&gt;Pb/&lt;sup&gt;238&lt;/sup&gt;U apparent ages are ranging from 19.7 &amp;#177; 5.0 Ma down to 6.1 &amp;#177; 0.3 Ma, a spreading that we interpret as the result of uranium and lead mobility linked to fluid circulation following crystallization. Isotopic analyses, i.e. Cu and O isotopes, are in progress to better constrain the source and nature of these fluids. This study demonstrates, for the first time, that supergene copper mineralization presents a chronological potential and can be dated, at least in some case, by the U-Th-Pb method. Furthermore, the age obtained on pseudomalachite indicates that Mina Sur deposition took place as early as 19 Ma, a result that is in agreement with geological constraints in the mining district and the supergene ages already known in the Atacama Desert. These promising results represent a new tool to understand the physico-chemical, climatic and geological conditions that prevailed during the formation of supergene copper deposits and a proxy for their prospection around the world and maybe date climatic variation.&lt;/p&gt;

Exhumation and Preservation of Paleozoic Porphyry Cu Deposits: Insights from the Yandong Deposit, Southern Central Asian Orogenic Belt

2021 ◽  
Author(s):  
Lin Gong ◽  
Barry P. Kohn ◽  
Zhiyong Zhang ◽  
Bing Xiao ◽  
Lin Wu ◽  
...  
Keyword(s):  
Middle Jurassic ◽  
Mineral Exploration ◽  
Porphyry Copper ◽  
Copper Deposit ◽  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Porphyry Copper Deposits ◽  
Copper Deposits ◽  
Central Asian ◽  
Chinese Tianshan

Abstract Paleozoic porphyry copper deposits are generally much less common than their Mesozoic or Cenozoic counterparts, as they can be completely eroded in rapidly uplifting arcs. There are, however, some large Paleozoic porphyry copper deposits preserved worldwide, especially in the Central Asian orogenic belt, although the processes by which these ancient porphyry deposits were preserved are poorly constrained. The Carboniferous Yandong porphyry copper deposit was selected as a case study to resolve this issue using a combination of thermal history models derived from low-temperature thermochronology data and regional geologic records. Our results show that Yandong preserves a record of at least two episodes of cooling separated by a phase of mild Middle Jurassic reheating. These two cooling events included one major event, linked to the Qiangtang collision or northward motion of Tarim plate during the late Permian to Triassic, and one minor event, possibly related to the Lhasa collision or closure of Mongol-Okhotsk Ocean from the Middle Jurassic to Early Cretaceous, respectively. Tectonic quiescence and limited exhumation prevailed from the Late Cretaceous to Cenozoic in the Yandong area. Combining our results with regional geologic records, we propose that extensional tectonic subsidence, postmineralization burial, dry paleoclimatic conditions, and Cenozoic tectonic quiescence were key factors for the preservation of Yandong. This study demonstrates that anomalously old apatite fission track ages, integrated with age-elevation relationships, can have implications for mineral exploration strategies in the Chinese Tianshan orogens.

scholarly journals Zircon and titanite petrochronology link plutonism, volcanism and porphyry copper deposit formation in the Yerington batholith, Nevada, USA

2021 ◽  
Author(s):  
Maria Paula Castellanos-Melendez ◽  
Cyril Chelle-Michou ◽  
Jörn-Frederik Wotzlaw ◽  
John Dilles
Keyword(s):  
Porphyry Copper ◽  
Copper Deposit ◽  
Porphyry Copper Deposit ◽  
Deposit Formation
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