scholarly journals LA-ICP-MS U–Pb Dating of Cenozoic Rutile Inclusions in the Yuanjiang Marble-Hosted Ruby Deposit, Ailao Shan Complex, Southwest China

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 433
Author(s):  
Tianjian Yang ◽  
Xiaoming Sun ◽  
Guiyong Shi ◽  
Ying Liu
Keyword(s):  
Southwest China ◽  
Mineral Deposits ◽  
Cooling History ◽  
Host Matrix ◽  
Icp Ms ◽  
Lateral Shearing ◽  
The World ◽  
History Of ◽  
Tectonic Belt

Among the marble-hosted ruby deposits in the Himalayan tectonic belt, which yields the highest-quality rubies in the world, the Yuanjiang deposit is the only economically viable one located in China. More attempts are necessary to put constraints on the ore-forming age of these marble-hosted ruby deposits. Here, we dated rutile inclusions in the Yuanjiang rubies using the LA-ICP-MS U–Pb method, which yielded a lower intercept 206Pb/238U age of 20.2 ± 1.2 Ma on the Tera-Wasserburg plot, close to the 22.5–22.2 Ma 40Ar/39Ar ages of phlogopite from the ruby host matrix assemblage. Our U–Pb rutile age put a constraint on the cooling history of the Yuanjiang rubies deposit. The new rutile age is consistent with our previous model that shows the ca. 28–22 Ma left lateral shearing plays an important role in transporting the ruby deposit toward the surface. This study provides the first example of in-situ U–Pb dating of rutile in the Himalayan tectonic belt, demonstrating the great potential of U–Pb rutile geochronology for Cenozoic mineral deposits.

Coupling thermodynamic modeling and high-resolution in situ LA-ICP-MS monazite geochronology: evidence for Barrovian metamorphism late in the Grenvillian history of southeastern Ontario

2014 ◽  
Vol 108 (6) ◽  
pp. 741-758 ◽  
Author(s):  
Travis McCarron ◽  
Fred Gaidies ◽  
Christopher R. M. McFarlane ◽  
R. Michael Easton ◽  
Peter Jones
Keyword(s):  
High Resolution ◽  
Thermodynamic Modeling ◽  
Icp Ms ◽  
History Of

First in-situ Rb-Sr dating of metasedimentary rocks from the Pontiac subprovince, Superior Craton, Canada. Implications towards the regional metamorphic evolution of the sequence.

2020 ◽  
Author(s):  
Nicholas Leventis ◽  
Thomas Zack ◽  
Iain Pitcairn ◽  
Johan Högmalm
Keyword(s):  
Accretionary Prism ◽  
Metasedimentary Rocks ◽  
Metamorphic History ◽  
Accuracy And Precision ◽  
Icp Ms ◽  
Age Variations ◽  
History Of ◽  
Peak Metamorphism ◽  
Superior Craton

<p>The Pontiac subprovince consists of metaturbidites, plutons and thin ultramafic rock layers of Archean age and lies south of the Cadillac-Larder Lake (C-LL) fault zone which is the boundary between the Pontiac and the extensively mineralized Abitibi Greenstone Belt. The sediments show a Barrovian metamorphic gradient which increases southwards, away from the C-LL fault. The most likely tectonic provenance for the Pontiac sedimentary rocks is that they represent a relic accretionary prism with material derived from both the Abitibi and an older terrane. Zircon U-Pb dating shows that deposition occurred not later than 2685±3 Ma ago and recent, robust Lu-Hf dating of garnets bracketed Pontiac's peak metamorphic conditions at 2658±4 Ma. For this study we used a recently developed LA-ICP-MS/MS method for in-situ Rb-Sr dating of biotite and plagioclase in samples ranging in metamorphic grade (biotite to sillimanite zones) from the Pontiac subprovince. Calibration of the instrument was achieved by repeated ablations on several reference materials (see Hogmalm et al. 2017) which also provided the monitoring of accuracy and precision throughout the analyses. Results show a range in dates between 2550 Ma and 2200 Ma with an average of 2440±50 Ma (2σ). Samples from the staurolite and kyanite zones have a larger range with respect to the other zones, but no significant differences are observed in the data with any method of data handing. These dates are ≈300Ma younger than the peak metamorphism in the area and this is attributed to either overgrowth and re-setting of the Rb-Sr system by a second metamorphic/hydrothermal event, or diffusional resetting with core-rim age variations. Possible influence from the adjacent late syntectonic to post-tectonic monzodiorite-monzonite-granodiorite-syenite (MMGS) plutons dated 2671±4 Ma and the garnet-muscovite-granite series (GMG) dated ≈2650 Ma cannot be ruled out. This study provides insights about the metamorphic history of the sequence and supports previous findings regarding resetting of some isotopic systems with relatively low closure temperatures (≈350-400°C) by later thermal events.</p>

scholarly journals Preservation of Biological Diversity of Domestic Animals in Hungary

2002 ◽  
pp. 18-29
Author(s):  
Imre Bodó
Keyword(s):  
Mating Systems ◽  
Biological Diversity ◽  
Domestic Animals ◽  
Domestic Animal ◽  
Ex Situ ◽  
The World ◽  
History Of ◽  
Near Future ◽  
Selection Of

Since the 1992 Rio de Janeiro UNO Congress domestic animals belong also officially to the genetic diversity of the world. Non commercial domestic animal breeds should be maintained for many cultural and technical reasons. Conservation and preservation of living beings is nowadays in the programme of many regional, national and international organizations.The preservation of domestic animals is possible in situ (at the original place and conditions) and ex situ (by cryogenic methods).There are three era in the history of preservation of domestic animals: the epoch of spontaneous maintenance, the period of sporadic national activities and the era of international programme.Some of the questions to be solved by scientific research: the principles of selection of the candidate populations for maintenance, the different degrees of endangeredness, the necessary population size to be subsidized, the problem of inbreeding, the best mating systems etc.In Hungary the maintenance of endangered domestic animal breeds is based upon the low.The following breeds are on the list of protected breeds:− the Hungarian Grey cattle,− the Lipizzan, Shagya, Nonius, Gidran, Furioso,Kisbér Halfbred, Murinsulaner and Hucul horses,− the Racka, Tsigai and Cikta sheep,− the Mangalitsa pig,− the Hungarian yellow, white, speckled and the Transsylvanian naked necked hen,− the Bronze Turkey,− the Frizzle Feathered goose.Hopefully in the near future the breeders of traditional domestic animal breeds will find the possible niches for their special products.

scholarly journals Preserving grapevine variety Fioletoviy Ranniy in the collection in vitro

2021 ◽  
Vol 273 ◽  
pp. 01007
Author(s):  
Valentina Puzirnova ◽  
Natalia Doroshenko
Keyword(s):  
Biodiversity Conservation ◽  
Sustainable Management ◽  
Future Generations ◽  
Ex Situ ◽  
Grapevine Variety ◽  
The World ◽  
History Of ◽  
Slow Growing

The paper is devoted to the problem of plant biodiversity conservation. This problem is acute all over the world. Lower Don Region has a centuries old history of viticulture and winemaking. There are many valuable vine varieties which are worthy of preservation for future generations. Classical methods no longer cope with this task. Applying advances of biotechnology in addition to traditional methods of ex situ and in situ biodiversity conservation allows sustainable management of genetic resources. This article summarizes the study of methods for creation slow growing collection for grapevine variety Fioletoviy Ranniy. Keeping plants in a slow-growing collection is one of the best ways to preserve biodiversity. This study analyzed the effect of various media compounds on vigor of vine in order to elongate the time between replantings.

New Insights into the Origin of the World-Class Jinding Sediment-Hosted Zn-Pb Deposit, Southwestern China: Evidence from LA-ICP-MS Analysis of Individual Fluid Inclusions

2021 ◽  
Author(s):  
Lan Mu ◽  
Ruizhong Hu ◽  
Xianwu Bi ◽  
Yongyong Tang ◽  
Tingguang Lan ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Southwest China ◽  
Critical Role ◽  
Previous Suggestion ◽  
Inductively Coupled ◽  
Icp Ms ◽  
The World ◽  
World Class ◽  
Homogenization Temperatures ◽  
Very High

Abstract The Jinding deposit in the Lanping basin, southwest China, is the largest sandstone-hosted Zn deposit in the world and the second largest Zn-Pb deposit in China. However, questions related to the metal compositions and origin of the ore fluids remain. In this study, microthermometry and laser ablation-inductively coupled plasmamass spectrometry (LA-ICP-MS) were employed to determine the properties and compositions of individual fluid inclusions trapped in sphalerite and calcite. The results show that the fluid inclusions trapped in sphalerite and calcite have similar homogenization temperatures (79°–173°C with the majority 100°–130°C), salinities (10.3–29.1 wt % NaCl + CaCl2 equiv with the majority 24.5–27.4 wt % NaCl + CaCl2 equiv), and concentrations of alkali and alkali earth elements (e.g., Na, Ca, Mg, K, Sr, Ba, Li, Rb, and Cs). However, the concentrations of ore and associated metals (e.g., Pb, Sb, Ag, and Tl) in the fluid inclusions hosted by sphalerite are significantly higher than those hosted by calcite. Based on these observations, we propose that the sulfides including sphalerite were precipitated from a low-temperature, high-salinity, Ca-rich, metal-rich fluid, while the gangue minerals such as calcite crystallized subsequently from fluids depleted in metals due to prior precipitation of sulfides, and that the high salinities of the fluid inclusions are likely due to a combination of seawater evaporation and subsequent dissolution of evaporitic sequences during fluid percolation. The LA-ICP-MS analyses reveal that the fluid inclusions have K/Na, Rb/Na, and Cs/Na ratios within the range of modern basinal brines, and Li/Na, Ba/Na, and Ca/Na ratios share similar compositions with the ore fluids of basement interacted deposits in the world. The Jinding ore fluids contain ~200 to 650 ppm Pb, based on the data of fluid inclusions trapped in sphalerite. The estimated concentrations of Zn in the ore fluids are also very high at ~200 to 6,500 ppm. Our results reveal that anomalously metal rich fluids played a critical role in the formation of the giant Jinding sediment-hosted Pb-Zn deposit. We concur with the previous suggestion that sulfide precipitation at Jinding occurred when ascending metal-rich brines encountered an H2S-rich, Ca-rich fluid, which was produced by interaction of hydrocarbons with evaporites, in the cap of the Jinding dome.

scholarly journals Overview in situ U - Pb isotopic dating method on cassiterite. Application to determine for Sn - W mineralization age of the Lung Muoi deposit in the Pia Oac region, Cao Bang province

2020 ◽  
Vol 61 (5) ◽  
pp. 1-10
Author(s):  
Luyen Dinh Nguyen ◽  
Hieu Trung Pham ◽  
Nhuan Van Do ◽  
Thai Ngoc Tran ◽  
Thu Thi Le ◽  
...  
Keyword(s):  
New Age ◽  
Mineral Research ◽  
Isotopic Dating ◽  
Icp Ms ◽  
The World ◽  
Dating Method ◽  
Mineralization Age

In recent years, the U - Pb isotopic dating method for cassiterite minerals has been used by many scientists around the world in the field of mining and mineral research. This paper presents an overview of the history, development and results achieved using this dating method in the field of mining and mineral research in the world. The LA - ICP - MS U - Pb isotopic dating method for cassiterite minerals was used at the Lung Muoi Sn - W deposit in Pia Oac region, Cao Bang province. The result of LA - ICP - MS U - Pb cassiterite isotopic dating shows the Sn - W mineralization in the Lung Muoi deposit crystallized at 88 Ma. The new age results in this paper are very consistent with the previously published results of the Pia Oac granite.

scholarly journals On Mercury in Alluvial Deposits

The Geologist ◽  
1858 ◽  
Vol 1 (9) ◽  
pp. 386-389
Author(s):  
J. J. W. Watson
Keyword(s):  
Precious Metal ◽  
Mineral Deposits ◽  
Alluvial Deposits ◽  
French Army ◽  
History Of ◽  
The Town

Dr. Phipson, of Paris, has drawn attention, in the April number of the Geologist, to the observations which have been made of the presence of mercury in the soil and substrata of the town of Montpellier, and, in your June number, another correspondent notices the finding of the same metal under circumstances so decidedly adventitious, however, as to possess, I think, rather archæological than geological interest. The occurrence of this precious metal in rocks and mineral deposits of such ages as we should hesitate to assign for its matrix, most probably arises from its fluid nature admitting of its easy transport to distances far remote from those formations in which it exists in situ; and, as furnishing something like the history of its presence in such apparently abnormal situations, the following account of its discovery at Ajaccio, in the Island of Corsica, may, perhaps, be considered worthy of insertion:—In the year 1811, a M. Matthieu, an Engineer Officer of the French Army, was entrusted by Napoleon with the mineral survey of the Island, but, being re-called to his military duties in 1814, was cut off before Leipzig, leaving in the possession of his widow the notes he had made of his survey. These notes do not appear ever to have been officially communicated, but among them was a memorandum to the effect that a deposit of mercury existed at Ajaccio.

Rubidium-strontium age studies and geochemistry of acid veins in the Freetown complex, Sierra Leone

1977 ◽  
Vol 41 (320) ◽  
pp. 501-511 ◽  
Author(s):  
R. D. Beckinsale ◽  
J. F. W. Bowles ◽  
R. J. Pankhurst ◽  
M. K. Wells
Keyword(s):  
Sierra Leone ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Fluid Phase ◽  
Cooling History ◽  
Isotopic Methods ◽  
History Of ◽  
Basic Rocks ◽  
Age Studies

SummaryThe stratigraphical limits on the age of the Freetown intrusion, Sierra Leone, are very wide, yet the intrusion has not previously been accurately dated by isotopic methods, despite a number of attempts. Rubidium-strontium dating of acid veins contemporaneous with the early stages of the prolonged cooling history of the intrusion provides an age of 193 ± 3 Ma. The veins consist of quartz and orthoclase with relict minerals, principally plagioclase, from thehost gabbro. Electron-microprobe analysis of the altered minerals of the veins, and the petrography of the vein and adjacent host gabbro clearly demonstrate that the veins were formed from a granitic fraction, differentiated in situ from the surrounding solid gabbro with the assistance of a hydrous fluid phase within the incipient vein. This assertion is supported by the identical, low value of the initial 87Sr/86Sr ratio (0·70389) obtained from both the acid and basic rocks, and the technique described here may be useful in dating other, similar, intrusions.

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