scholarly journals Copper Mineralization Potential of Late Triassic Granitoids in Northern Yidun Arc, SW China

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 337 ◽  
Author(s):  
Xing-Yuan Li ◽  
Jing-Ru Zhang ◽  
Hao Song ◽  
Chun-Kit Lai
Keyword(s):  
Age Dating ◽  
Late Triassic ◽  
Clear Correlation ◽  
Sw China ◽  
Copper Mineralization ◽  
Icp Ms ◽  
High Concentrations ◽  
T Values ◽  
Yidun Arc

Yidun arc is an important constituent of the Sanjiang Tethyan Domain in SW China. The Changdagou pluton, located in the northern part of the Yidun Arc, mainly consists of granodiorite. In this study, we conducted in-situ LA-ICP-MS zircon U-Pb dating, and trace element and Hf isotope analyses on the Changdagou granites. Age dating results yielded a weighted mean U-Pb age of 214.97 ± 0.98 Ma (MSWD = 1.2, 2σ), broadly coeval with extensive late Triassic magmatism across the Yidun Arc. All zircon grains analyzed showed high concentrations of Th, U, and HREE, with positive Ce and negative Eu anomalies. Logfo2 and CeN/CeN* values vary from FMQ −3.14 to FMQ +7.44 (average FMQ +3.98), and 14 to 172 (avg. 98), respectively. The zircon EuN/EuN* (avg. 0.22) ratios have no clear correlation with the CeN/CeN* ratios, suggesting that the former were mainly affected by the magma water content. In addition, zircon εHf(t) values vary in a narrow range (–2.9 to −4.9, avg. −3.4) that clusters around zero, indicating a greater component of mantle-derived magma. Hence, we propose that the Changdagou granodiorite was derived from a highly oxidized, “wet”, Cu-rich source, of the type likely to generate porphyry Cu mineralization. However, these parameters (logfO2, EuN/EuN*, (Ce/Nd)/Y, and εHf(t)) are all lower than those of intrusions associated with Cu ores at Pulang and Lannitang, which may explain why the Cu deposit discovered at Changdagou is small by comparison. Furthermore, on the basis of the decreasing trends of εHf, logfO2, and H2O content from south to north along the Yiduan arc, we infer that the northern segment of the Yidun arc (including Changdagou) was located further away from the subduction front.

Effects of stimulation on steroid output and perfusion medium flow rate in the isolated perfused rat adrenal gland in situ

1986 ◽  
Vol 109 (2) ◽  
pp. 279-285 ◽  
Author(s):  
J. P. Hinson ◽  
G. P. Vinson ◽  
B. J. Whitehouse ◽  
G. M. Price
Keyword(s):  
Flow Rate ◽  
Zona Glomerulosa ◽  
Clear Correlation ◽  
Perfusion Medium ◽  
Flow Rates ◽  
Vascular Elements ◽  
Medium Flow ◽  
High Concentrations ◽  
Adrenal Vasculature

ABSTRACT Using the in-situ, isolated, perfused rat adrenal system, the actions of adrenal stimulants on steroidogenesis and perfusion medium flow rates (under constant perfusion pump conditions) have been studied. In a series of 100 experiments, initial rates of corticosterone output and flow rates were found to be positively correlated, although there was no such relationship between initial rates of aldosterone output and flow rates. Furthermore, in stable perfusion conditions, bolus injections of ACTH increased both flow rate and steroid output in a dose-related manner. In individual experiments there was a clear correlation between corticosterone and flow, but the association between aldosterone secretion rate and flow was less evident. It is possible that this discrepancy arises because of temporal differences in the responses of these two steroids. Flow was also stimulated by dibutyryl cyclic AMP (dbcAMP), with correlations with steroid output similar to ACTH, but the specific zona glomerulosa stimulants angiotensin II amide and potassium ions had, if anything, inhibitory effects on flow, but only at high concentrations. The data suggest that ACTH and dbcAMP evoke specific responses in the adrenal vasculature, resulting in relatively decreased intraglandular vascular resistance. They furthermore suggest that the secretory functions of the inner adrenocortical zones are subject to the additional control of vascular elements in the intact gland. J. Endocr. (1986) 109, 279–285

Gabbro in Wanning, Hainan Island: LA-ICP-MS Chronometry and its Geological Significance

2011 ◽  
Vol 137 ◽  
pp. 307-311
Author(s):  
Li Mei Tang
Keyword(s):  
Tectonic Setting ◽  
Research Work ◽  
Hainan Island ◽  
Major And Trace Elements ◽  
Ocean Basin ◽  
Age Dating ◽  
Icp Ms ◽  
Tethys Ocean ◽  
T Values ◽  
Made In

Gabbro is mostly the result of partly melting from mantle rock, and its formation is usually related with extension tectonic, the research work on Triassic gabbro from Hainan island has important instruction significance to its tectonic background. System chronometry and geochemistry research on hornblende gabbro in Wanning area was made in this paper, and its tectonic significance is to be discussed. The LA-ICP-MS zircon U-Pb age dating result shows that the gabbro in Wanning area was formed in 241±1.7Ma. The major and trace elements characteristic shows that the rocks belong to alkaline series, enrichment in light REE (LREE/HREE＝7.22-8.5) and LILE Rb, Th, and Sr, Ba while depleted in HFSE Nb, Ta and Zr, Hf. The Wanning gabbro exhibits a narrow range of εNd(t) values (1.59-1.76), and a broad rang 87Sr/86Sr initial ratios(0.70633-0.70964). The tectonic background of Wanning gabbro is intracontinental extensional setting, and its geochemistry characteristic declare that there was an ancient ocean basin existed, and maybe one branch of the ancient eastern Tethys ocean. The formation age and tectonic setting declare that the ancient ocean basin was disappeared at least before 241Ma.

Genesis of the Gaosong Sn–Cu deposit, Gejiu district, SW China: Constraints from in situ LA-ICP-MS cassiterite U–Pb dating and trace element fingerprinting

2018 ◽  
Vol 92 ◽  
pp. 627-642 ◽  
Author(s):  
Jia Guo ◽  
Rongqing Zhang ◽  
Congying Li ◽  
Weidong Sun ◽  
Yongbin Hu ◽  
...  
Keyword(s):  
Trace Element ◽  
Sw China ◽  
Icp Ms

Petrogenesis of the Late Triassic volcanic rocks in the Southern Yidun arc, SW China: Constraints from the geochronology, geochemistry, and Sr–Nd–Pb–Hf isotopes

Lithos ◽  
2014 ◽  
Vol 190-191 ◽  
pp. 363-382 ◽  
Author(s):  
Cheng-Biao Leng ◽  
Qiu-Yue Huang ◽  
Xing-Chun Zhang ◽  
Shou-Xu Wang ◽  
Hong Zhong ◽  
...  
Keyword(s):  
Volcanic Rocks ◽  
Late Triassic ◽  
Hf Isotopes ◽  
Sw China ◽  
Yidun Arc

First U-Pb LA-ICP-MS in situ dating of supergene copper mineralization: case study in the Chuquicamata mining district, Atacama Desert, Chile

2020 ◽  
Author(s):  
Zia Steven Kahou ◽  
Stéphanie Brichau ◽  
Marc Poujol ◽  
Stéphanie Duchêne ◽  
Eduardo Campos ◽  
...  
Keyword(s):  
Atacama Desert ◽  
Mining District ◽  
Copper Mineralization ◽  
Icp Ms

scholarly journals Advanced in situ geochronological and trace element microanalysis by laser ablation techniques

2006 ◽  
Vol 10 ◽  
pp. 25-28 ◽  
Author(s):  
Dirk Frei ◽  
Julie A. Hollis ◽  
Axel Gerdes ◽  
Dan Harlov ◽  
Christine Karlsson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Trace Element ◽  
Inductively Coupled Plasma ◽  
Age Dating ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Wide Range ◽  
Plasma Mass Spectrometry

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was developed in 1985 and the first commercial laser ablation systems were introduced in the mid 1990s. Since then, LA-ICP-MS has become an important analytical tool in the earth sciences. Initially, the main interest for geologists was in its ability to quantitatively determine the contents of a wide range of elements in many minerals at very low concentrations (a few ppm and below) with relatively high spatial resolution (spot diameters of typically 30–100 μm). The potential of LA-ICP-MS for rapid in situ U–Th–Pb geochronology was already realised in the early to mid 1990s. However, the full potential of LA-ICP-MS as the low-cost alternative to ion-microprobe techniques for highly precise and accurate in situ U–Th–Pb age dating was not realised until the relatively recent advances in laser technologies and the introduction of magnetic sectorfield ICP-MS (SF-ICPMS) instruments. In March 2005, the Geological Survey of Denmark and Greenland (GEUS) commissioned a new laser ablation magnetic sectorfield inductively coupled plasma mass spectrometry (LA-SF-ICP-MS) facility employing a ThermoFinnigan Element2 high resolution magnetic sectorfield ICP-MS and a Merchantek New Wave 213 nm UV laser ablation system. The new GEUS LA-SF-ICP-MS facility is widely used on Survey research projects in Denmark and Greenland, as well as in collaborative research and contract projects conducted with partners from academia and industry worldwide. Here, we present examples from some of the these ongoing studies that highlight the application of the new facility for advanced geochronological and trace element in situ microanalysis of geomaterials. The application of LASF-ICP-MS based in situ zircon geochronology to regional studies addressing the Archaean geology of southern West Greenland is presented by Hollis et al. (2006, this volume).

scholarly journals Recognition of Late Triassic Cu-Mo Mineralization in the Northern Yidun Arc (S.E. Tibetan Plateau): Implications for Regional Exploration

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 765 ◽  
Author(s):  
Zhen-Dong Tian ◽  
Cheng-Biao Leng ◽  
Xing-Chun Zhang ◽  
Li-Min Zhou ◽  
Yan-Wen Tang
Keyword(s):  
Tibetan Plateau ◽  
Late Triassic ◽  
Geodynamic Setting ◽  
Type I ◽  
Type Ii ◽  
Host Granite ◽  
Icp Ms ◽  
Tethys Ocean ◽  
Metallogenic Age ◽  
Yidun Arc

The Yidun arc, located in the southeastern Tibetan Plateau, was formed by the westward subduction of the Ganze-Litang Paleo-Tethys ocean in Late Triassic. It is well-known for the formation of numerous Mesozoic porphyry-skarn Cu-Mo-(Au) deposits in the arc. To date, more than 20 Cu-Mo-(Au) deposits (>10 million tonnes Cu resources) have been discovered in the southern Eastern Yidun arc. However, few Cu-Mo deposits have been discovered in the northern Eastern Yidun arc. In recent years, some Cu-Mo deposits or occurrence are successively discovered in the northern Eastern Yidun arc, but their ore-forming ages are not well constrained. It remains unclear whether such Cu-Mo mineralization formed by similar metallogenic event and geodynamic setting as the Cu-Mo-(Au) mineralization in the south. In order to determine the metallogenic age and shed light on potential links between Cu-Mo mineralization and regional magmatic events, we present molybdenite Re-Os and zircon U-Pb ages to constrain the timing of two types of Cu-Mo mineralization in the northern Eastern Yidun arc (type I and type II). Molybdenite ICP-MS Re-Os dating results show that type I mineralization was formed at 217.7 ± 3.6 Ma, which is highly consistent with the formation ages of the host granite (218.1 ± 1.5 Ma, 2σ, n = 15, MSWD = 0.92) and aplite dyke (217.3 ± 1.3 Ma, 2σ, n = 16, MSWD = 0.50) within error. While the type II mineralization has a relatively younger formation age of 211.8 ± 4.7 Ma than the host granite (217.1 ± 1.5 Ma, 2σ, n = 14, MSWD = 0.96) and type I Cu-Mo mineralization. These data indicate that the Cu-Mo mineralization in the northern Eastern Yidun arc was temporally and spatially related to the Late Triassic magmatism in the region. Rhenium (Re) concentrations in the molybdenite from type I mineralization, ranging from 12.77 to 111.1 ppm (typically > 100 ppm), indicate that the ore-forming metals were derived mainly from a mantle source. However, Re contents in molybdenite from the type II mineralization, ranging from 7.983 to 10.40 ppm, indicate that the ore-forming metals were derived from a mixed mantle and crustal source with a predominantly crustal component. This study confirms that the northern Eastern Yidun arc exists Late Triassic Cu-Mo metallogenesis, and thus much attention should be paid on this region to find more Late Triassic Cu-Mo resources.

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

<p>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,  which are the products of lateral migration of supergene copper solutions from a parental porphyry copper deposit (Sillitoe, 2005).</p><p>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 ± 1.0 Ma. For the black chrysocolla clasts, the <sup>206</sup>Pb/<sup>238</sup>U apparent ages are ranging from 19.7 ± 5.0 Ma down to 6.1 ± 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.</p>

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