scholarly journals Multiple Porphyry Cu-Mo Events in the Eastern Pontides Metallogenic Belt, Turkey: From Early Cretaceous Subduction to Eocene Postcollision Evolution

2019 ◽  
Vol 114 (7) ◽  
pp. 1285-1300 ◽  
Author(s):  
Okan Delibaş ◽  
Robert Moritz ◽  
David Selby ◽  
Deniz Göç ◽  
Mustafa Kemal Revan
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Inductively Coupled Plasma ◽  
Calc Alkaline ◽  
Eastern Pontides ◽  
Inductively Coupled ◽  
Porphyry Cu ◽  
Icp Ms ◽  
Lesser Caucasus ◽  
Cretaceous Subduction

Abstract Four porphyry Cu-Mo systems were investigated by Re-Os molybdenite geochronology to constrain their timing with respect to the geodynamic and magmatic evolution of the eastern Pontides, Turkey. Molybdenite from the Ispir-Ulutaş deposit yielded an Re-Os age of 131.0 ± 0.7 Ma, which is consistent with Early Cretaceous U-Pb laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) zircon ages of local calc-alkaline intrusions. It demonstrates that porphyry deposits were already formed during Early Cretaceous subduction of the Neotethys along the eastern Pontides, and that they can be correlated with porphyry Cu events in the adjacent Lesser Caucasus. Molybdenite Re-Os ages of 76.0 ± 0.4 and 75.7 ± 0.4 Ma at the Elbeyli prospect and 77.2 ± 1.0 Ma at the Emeksen prospect overlap with U-Pb LA-ICP-MS zircon ages of shoshonitic to high-K calc-alkaline intrusions in the region, which were emplaced during Late Cretaceous Neotethys subduction. A 50.7 ± 0.3 Ma molybdenite Re-Os age at the Güzelyayla deposit confirms porphyry Cu-Mo emplacement coeval with Eocene postcollisional, calc-alkaline adakitic magmatism of the eastern Pontides. An electron microprobe study of molybdenite samples, supplemented by data obtained during Re-Os dating, shows that the Eocene Güzelyayla deposit and the Late Cretaceous Emeksen prospect have the highest Re enrichment. Postcollisional melting of a thickened mafic lower continental crust and melting of a metasomatized lithospheric mantle with little to no interaction with upper crustal rocks may explain the Re enrichment at Güzelyayla and Emeksen, respectively.

scholarly journals Rare and Critical Metals in Pyrite, Chalcopyrite, Magnetite, and Titanite from the Vathi Porphyry Cu-Au±Mo Deposit, Northern Greece

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 630
Author(s):  
Christos L. Stergiou ◽  
Vasilios Melfos ◽  
Panagiotis Voudouris ◽  
Lambrini Papadopoulou ◽  
Paul G. Spry ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Mineral Chemistry ◽  
Critical Metals ◽  
Northern Greece ◽  
Inductively Coupled ◽  
Porphyry Cu ◽  
Icp Ms ◽  
Quartz Monzonite ◽  
Ore Minerals ◽  
Plasma Mass Spectrometry

The Vathi porphyry Cu-Au±Mo deposit is located in the Kilkis ore district, northern Greece. Hydrothermally altered and mineralized samples of latite and quartz monzonite are enriched with numerous rare and critical metals. The present study focuses on the bulk geochemistry and the mineral chemistry of pyrite, chalcopyrite, magnetite, and titanite. Pyrite and chalcopyrite are the most abundant ore minerals at Vathi and are related to potassic, propylitic, and sericitic hydrothermal alterations (A- and D-veins), as well as to the late-stage epithermal overprint (E-veins). Magnetite and titanite are found mainly in M-type veins and as disseminations in the potassic-calcic alteration of quartz monzonite. Disseminated magnetite is also present in the potassic alteration in latite, which is overprinted by sericitic alteration. Scanning electron microscopy and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of pyrite and chalcopyrite reveal the presence of pyrrhotite, galena, and Bi-telluride inclusions in pyrite and enrichments of Ag, Co, Sb, Se, and Ti. Chalcopyrite hosts bornite, sphalerite, galena, and Bi-sulfosalt inclusions and is enriched with Ag, In, and Ti. Inclusions of wittichenite, tetradymite, and cuprobismutite reflect enrichments of Te and Bi in the mineralizing fluids. Native gold is related to A- and D-type veins and is found as nano-inclusions in pyrite. Titanite inclusions characterize magnetite, whereas titanite is a major host of Ce, Gd, La, Nd, Sm, Th, and W.

The Giant Chalukou Porphyry Mo Deposit, Northeast China: The Product of a Short-Lived, High Flux Mineralizing Event

2021 ◽  
Author(s):  
Qingqing Zhao ◽  
Degao Zhai ◽  
Ryan Mathur ◽  
Jiajun Liu ◽  
David Selby ◽  
...  
Keyword(s):  
High Precision ◽  
Inductively Coupled Plasma ◽  
Hydrothermal Activity ◽  
Ore Deposits ◽  
Ionization Mass ◽  
Inductively Coupled ◽  
Fine Grained ◽  
Porphyry Cu ◽  
Icp Ms ◽  
Porphyry Mo Deposit

Abstract Whether giant porphyry ore deposits are the products of single, short-lived magmatic-hydrothermal events or multiple events over a prolonged interval is a topic of considerable debate. Previous studies, however, have all been devoted to porphyry Cu and Cu-Mo deposits. In this paper, we report high-precision isotope dilution-negative-thermal ionization mass spectrometric (ID-N-TIMS) molybdenite Re-Os ages for the newly discovered, world-class Chalukou porphyry Mo deposit (reserves of 2.46 Mt @ 0.087 wt % Mo) in NE China. Samples were selected based on a careful evaluation of the relative timing of the different vein types (i.e., A, B, and D veins), thereby ensuring that the suite of samples analyzed could be used to reliably determine the age and duration of mineralization. The molybdenite Re-Os geochronology reveals that hydrothermal activity at Chalukou involved two magmatic-hydrothermal events spanning an interval of 6.92 ± 0.16 m.y. The first event (153.96 ± 0.08/0.63/0.79 Ma, molybdenite ID-N-TIMS Re-Os age) was associated with the emplacement of a granite porphyry dated at 152.1 ± 2.2 Ma (zircon laser ablation-inductively coupled plasma-microscopic [LA-ICP-MS] U-Pb ages), and led to only minor Mo mineralization, accounting for <10% of the overall Mo budget. The bulk of the Mo (>90%) was deposited in less than 650 kyr, between 147.67 ± 0.10/0.60/0.76 and 147.04 ± 0.12/0.72/0.86 Ma (molybdenite ID-N-TIMS Re-Os ages), coincident with the emplacement of a fine-grained porphyry at 148.1 ± 2.6 Ma (zircon LA-ICP-MS U-Pb ages). The high-precision Re-Os age determinations presented here show, contrary to the finding of a number of studies of porphyry Cu and Cu-Mo systems, that the giant Chalukou porphyry Mo deposit primarily formed in a single, short-lived (<650 kyr) hydrothermal event, suggesting that this may also have been the case for other giant porphyry Mo deposits.

Using Mineral Chemistry to Aid Exploration: A Case Study from the Resolution Porphyry Cu-Mo Deposit, Arizona

2020 ◽  
Vol 115 (4) ◽  
pp. 813-840 ◽  
Author(s):  
David R. Cooke ◽  
Jamie J. Wilkinson ◽  
Mike Baker ◽  
Paul Agnew ◽  
Josh Phillips ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Mineral Chemistry ◽  
Three Dimensions ◽  
Temperature Sensitive ◽  
Blind Test ◽  
Inductively Coupled ◽  
Porphyry Cu ◽  
The North ◽  
Icp Ms ◽  
Volcaniclastic Rocks

Abstract The giant, high-grade Resolution porphyry Cu-Mo deposit in the Superior district of Arizona is hosted in Proterozoic and Paleozoic basement and in an overlying Cretaceous volcaniclastic breccia and sandstone package. Resolution has a central domain of potassic alteration that extends more than 1 km outboard of the ore zone, overlapping with a propylitic halo characterized by epidote, chlorite, and pyrite that is particularly well developed in the Laramide volcaniclastic rocks and Proterozoic dolerite sills. The potassic and propylitic assemblages were overprinted in the upper parts of the deposit by intense phyllic and advanced argillic alteration. The district was disrupted by Tertiary Basin and Range extension, and the fault block containing Resolution and its Cretaceous host succession was buried under thick mid-Miocene dacitic volcanic cover, obscuring the geologic, geophysical, and geochemical footprint of the deposit. To test the potential of propylitic mineral chemistry analyses to aid in the detection of concealed porphyry deposits, a blind test was conducted using a suite of epidote-chlorite ± pyrite-altered Laramide volcaniclastic rocks and Proterozoic dolerites collected from the propylitic halo, with samples taken from two domains located to the north and south and above the Resolution ore zone. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data of epidote provided indications of deposit fertility and proximity. Competition for chalcophile elements (As, Sb, Pb) between coexisting pyrite and epidote grains led to a subdued As-Sb fertility response in epidote, consistent with epidote collected between 0.7 and 1.5 km from the center of a large porphyry deposit. Temperature-sensitive trace elements in chlorite provided coherent spatial zonation patterns, implying a heat source centered at depth between the two sample clusters, and application of chlorite proximitor calculations based on LA-ICP-MS analyses provided a precisely defined drill target in this location in three dimensions. Drilling of this target would have resulted in the discovery of Resolution, confirming that epidote and chlorite mineral chemistry can potentially add value to porphyry exploration under cover.

Late Jurassic to Early Cretaceous magmatism in the Xiong’ershan gold district, central China: implications for gold mineralization and geodynamics

2019 ◽  
Vol 157 (3) ◽  
pp. 435-457
Author(s):  
Zhenshan Pang ◽  
Fuping Gao ◽  
Yangsong Du ◽  
Yilun Du ◽  
Zhaojian Zong ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Inductively Coupled Plasma ◽  
Late Jurassic ◽  
Gold Mineralization ◽  
Central China ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Metamorphic Basement ◽  
Plasma Mass Spectrometry ◽  
Cretaceous Magmatism

AbstractThe Xiong’ershan area is the third largest gold-producing district in China. The Late Jurassic to Early Cretaceous magmatism in the Xiong’ershan area can be divided into two episodes: early (165–150 Ma) and late (138–113 Ma). Laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) zircon U–Pb dating yields ages of 160.7 ± 0.6 Ma and 127.2 ± 1.0 Ma for the Wuzhangshan and Huashan monzogranites in the Xiong’ershan area, respectively, representing the two magmatic episodes. The Wuzhangshan monzogranites exhibit adakite-like geochemical features (e.g. high Sr/Y ratios, low Yb and Y contents). Their Sr–Nd–Hf isotopic compositions are consistent with those of the amphibolites of the Taihua Group, indicating that the Wuzhangshan monzogranites were formed from partial melting of the Taihua Group metamorphic rocks. Compared to the Wuzhangshan rocks, the Huashan monzogranites have higher MgO, Cr, Co and Ni contents, but lower Sr/Y and Fe3+/Fe2+. All the samples from the Huashan monzogranites plot in the area between the Taihua Group amphibolite rocks and the mantle rocks in the (87Sr/86Sr)t vs εNd(t) and age vs εHf(t) diagrams, suggesting that the Huashan monzogranites were probably generated by mixing of mantle-derived magmas and the Taihua Group metamorphic basement melts. The gold mineralization (136–110 Ma) is coeval with the emplacement of the late-episode magmas, implying that crustal–mantle mixed magma might be a better target for gold mineralization compared to the ancient metamorphic basement melt. The data presented in this study further indicate that the transformation of the lithosphere from thickening to thinning in the Xiong’ershan area probably occurred between ~160 Ma and ~127 Ma, and that the gold mineralization in this area was probably related to lithospheric thinning.

Discovery of a Neoproterozoic granite in the Northern Alxa region, NW China: its age, petrogenesis and tectonic significance

2015 ◽  
Vol 153 (3) ◽  
pp. 512-523 ◽  
Author(s):  
WEN ZHANG ◽  
VICTORIA PEASE ◽  
QINGPENG MENG ◽  
RONGGUO ZHENG ◽  
TONNY B. THOMSEN ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Calc Alkaline ◽  
Alkaline Pluton ◽  
Crustal Rocks ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Tectonic Significance ◽  
Southern Central ◽  
Plasma Mass Spectrometry ◽  
Very High

AbstractA Neoproterozoic granite (Western Huhetaoergai granite) from the Northern Alxa region, southern Central Asia Orogenic Belt (CAOB) is first recognized by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb zircon dating (889±8 Ma). It is a highly fractionated potassium-rich calc-alkaline pluton with lowεNd(t) (−2.6 to −1.1) and high (87Sr/86Sr)t(0.727305–0.735626), and is probably derived from a mantle source and assimilated crustal rocks with very high87Sr/86Sr. Regional geology implies that it may reflect the existence of a microcontinent, and the formation of the Western Huhetaoergai granite is related to the assembly of Rodinia.

Geochronological constraints on magmatism and polyphase deformation and metamorphism in the southern Omineca Belt, British Columbia

2017 ◽  
Vol 54 (5) ◽  
pp. 529-549 ◽  
Author(s):  
Ewan Russell Webster ◽  
David Pattison ◽  
S. Andrew DuFrane
Keyword(s):  
British Columbia ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Middle Jurassic ◽  
Inductively Coupled Plasma ◽  
Contact Aureole ◽  
Inductively Coupled ◽  
The North ◽  
Three Samples ◽  
Geochronological Constraints

The Omineca Belt between Nelson and Creston in southeastern British Columbia was affected by overlapping pulses of Mesozoic magmatism, metamorphism, and deformation. U–Pb geochronological data from zircon and monazite were collected by laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS) to constrain the timing of these events. The Porcupine Creek stock (162.3 ± 1.3 Ma) intruded across folds and fabrics associated with the earliest phase of regional deformation and metamorphism (D1M1), restricting it to the Early–Middle Jurassic. The Jurassic structures are overprinted northwards by Early Cretaceous deformation and metamorphism (D2M2). The Baldy pluton (117.8 ± 1.2 Ma) crosscuts the regional 144–134 Ma M2 isograds, yet was pervasively affected by the D2 deformation, indicating that D2 deformation outlasted M2 metamorphism but had ceased by 111 Ma, the age of an undeformed pluton. Monazite dates from a kyanite-bearing rock in the contact aureole of the Middle Jurassic Wall stock overlap with the age of the intrusion (167 Ma), indicating a contact rather than regional origin for the kyanite. In the southeast part of the study area, three samples from the regional sillimanite zone contain monazite intergrown with sillimanite that yield dates between 80 and 69 Ma, indicating an episode of Late Cretaceous (M3) Barrovian metamorphism and deformation (D3). To the north of this domain, in an area characterized by the older D2M2 deformation, a sillimanite zone schist contains two main monazite age populations, suggestive of overlapping effects of Early Cretaceous and Late Cretaceous metamorphic episodes.

scholarly journals Geochemical Characteristics of the Late Cretaceous Lower Zhoutian Formation in the Jitai Basin, Southeast China: Implications for palaeoenvironment and provenance

2021 ◽  
Author(s):  
Kai Yan ◽  
Chun-Lian Wang ◽  
Steffen Mischke ◽  
Jiu-Yi Wang ◽  
Li-Jian Shen ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Brackish Water ◽  
Inductively Coupled Plasma ◽  
Salt Water ◽  
Upper Crust ◽  
Element Geochemistry ◽  
Southeast China ◽  
Inductively Coupled ◽  
Icp Ms

Abstract Major, trace and rare earth element geochemistry of the late Cretaceous lower Zhoutian Formation from the Jitai Basin of Southeast China were measured by inductively coupled plasma mass spectromentry (ICP-MS) analysis. The paleoclimate, paleo-environment and provenance of lower Zhoutian Formation in the Jitai Basin are analyzed in detail with these data.According to the research, the range of Sr/Cu values is wide, which indicates the changeable palaeoclimate, the curves of FeO/MnO and Al2O3/MgO are negatively correlated with the Sr/Cu curves. These changes indicate that the palaeoclimate of the late Cretaceous lower Zhoutian Formation in the Jitai Basin was divided into two parts. The lower part experienced two cooling events; the upper part was dominated by warm humid climate.The changes of B/Ga and Sr/Ba curves are similar to Sr/Cu curves. According to these values, the salinity of the late Cretaceous lower Zhoutian Formation in the Jitai Basin was consistent with palaeoclimate. The salinity of lower part changed from salt water to fresh/brackish water. The upper part was mainly fresh/brackish water, and there were many changes from fresh/brackish water to salt water. The values of Ni/Co, V/Cr, V/(V + Ni) and Ce/Ce* are relatively stable, indicating a long-term oxidation environment. The diagrams of La-Th-Sc, Th-Sc-Zr/10, La/Th-Hf and sandstone-siltstone background function show that the provenance in lower Zhoutian Formation mainly is a mixture of upper crust felsic sediments and old components.

Single Particle Inductively Coupled Plasma Mass Spectrometry: Investigating Nonlinear Response Observed in Pulse Counting Mode and Extending the Linear Dynamic Range by Compensating for Dead Time Related Count Losses on a Microsecond Timescale

2019 ◽  
Author(s):  
Ingo Strenge ◽  
Carsten Engelhard
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
Nonlinear Response ◽  
Dynamic Range ◽  
Dead Time ◽  
Inorganic Nanoparticles ◽  
Linear Dynamic Range ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

<p>The article demonstrates the importance of using a suitable approach to compensate for dead time relate count losses (a certain measurement artefact) whenever short, but potentially strong transient signals are to be analysed using inductively coupled plasma mass spectrometry (ICP-MS). Findings strongly support the theory that inadequate time resolution, and therefore insufficient compensation for these count losses, is one of the main reasons for size underestimation observed when analysing inorganic nanoparticles using ICP-MS, a topic still controversially discussed.</p>

Sign in / Sign up

Export Citation Format

Share Document