scholarly journals Overview of Gemstone Resources in China

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1189
Author(s):  
Xiao-Yan Yu ◽  
Zheng-Yu Long ◽  
Yi Zhang ◽  
Li-Jie Qin ◽  
Cun Zhang ◽  
...  
Keyword(s):  
Basaltic Magma ◽  
Anhui Province ◽  
Granitic Magma ◽  
The Past ◽  
Mineralogical Characteristics ◽  
Iron Deposits

Gemstones are minerals of gem qualities used for adornment and decoration with the attributes of beauty, durability and rarity. Traditionally, although China has been regarded as the most important source for nephrite, over the past decades, a large variety of gemstone resources have been newly discovered in China owing to continuous exploration works. The vast land with various geological and geochemical backgrounds is rich in gemstone resources with potential for new deposits discoveries. In pegmatites, gemstones are related to granitic magma events and mainly occur in pegmatitic cavities, such as tourmaline, aquamarine, spodumene, spessartine, moonstone, quartz, apatite, and topaz. The eruption of Tertiary basaltic magma provides gem-quality sapphire, spinel, olivine, garnet, and zircon. The supergene oxidation zones of some copper and iron deposits in Hubei and Anhui province host gem-quality turquoise and malachite. Moreover, the formation of the nephrite deposit in China is mostly related to the carbonatite and serpentinite rocks involved in the metamorphic-metasomatic processes. This paper comprehensively introduces the distribution of gemstones deposits, as well as the gemological and mineralogical characteristics of gemstones in China. Our present investigation provides insights into the gemstone potential of China for further exploitation.

Enabling Community Well-being Self-Monitoring in the Context of Mining: The Naskapi Nation of Kawawachikamach

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Robert Klinck ◽  
Ben Bradshaw ◽  
Ruby Sandy ◽  
Silas Nabinacaboo ◽  
Mannie Mameanskum ◽  
...  
Keyword(s):  
Indigenous Peoples ◽  
Well Being ◽  
Aboriginal Community ◽  
Self Monitoring ◽  
Community Engaged Research ◽  
The Past ◽  
Mineral Development ◽  
Iron Deposits ◽  
Term Monitoring

The Naskapi Nation of Kawawachikamach is an Aboriginal community located in northern Quebec near the Labrador Border. Given the region’s rich iron deposits, the Naskapi Nation has considerable experience with major mineral development, first in the 1950s to the 1980s, and again in the past decade as companies implement plans for further extraction. This has raised concerns regarding a range of environmental and socio-economic impacts that may be caused by renewed development. These concerns have led to an interest among the Naskapi to develop a means to track community well-being over time using indicators of their own design. Exemplifying community-engaged research, this paper describes the beginning development of such a tool in fall 2012—the creation of a baseline of community well-being against which mining-induced change can be identified. Its development owes much to the remarkable and sustained contribution of many key members of the Naskapi Nation. If on-going surveying is completed based on the chosen indicators, the Nation will be better positioned to recognize shifts in its well-being and to communicate these shifts to its partners. In addition, long-term monitoring will allow the Naskapi Nation to contribute to more universal understanding of the impacts of mining for Indigenous peoples.

A quantitative study of five thousand years of volcanism on Sao Miguel, Azores

1978 ◽  
Vol 288 (1352) ◽  
pp. 271-319 ◽  
Keyword(s):  
Quantitative Study ◽  
Basaltic Magma ◽  
Volcanic Eruptions ◽  
Lava Flows ◽  
Explosive Eruptions ◽  
Lateral Movement ◽  
The Past ◽  
Pumice Fall ◽  
Eruptive Fissures ◽  
Fall Deposits

The activity of the three stratovolcanoes on the island of Sao Miguel is documented by tephrochronology, and during the past 5000 years a total of some 57 volcanic eruptions have taken place, mostly of magnitudes 4-6 on Tsuya’s scale. Approximately half were trachytic, and half basaltic. Each stratovolcano has a caldera within which each has had one historic eruption. The trachytic eruptions were predominantly explosive, and most took place from vents situated within the calderas. Isopach and isograde maps of most of the resulting pumice fall deposits are given. The basaltic eruptions produced both lava flows and pyroclastics, and isopach and isograde maps are given for some of the main fall deposits. The Agua de Pau volcano has had particularly large explosive eruptions, several of them (including Fogo A, the largest in the past 5000 years) being of plinian type. The output of the three volcanoes over the 5000 years is equivalent to 4.6 km 3 of dense rock, at which rate the exposed parts of the volcanoes could have accumulated in 150000 years. At least half of the erupted material is trachytic, a proportion typical of the entire accessible parts of the volcanoes. The 50 known eruptive vents of the past 5000 years are distributed in a zone 55 km long by 8 km wide which may lie above a major fracture zone. Some eruptive fissures trend obliquely across this zone, suggesting right-lateral movement along the fracture. Basaltic eruptions were confined to a much smaller area than in the preceding millennia perhaps due to the formation, at the time of the great Fogo A eruption 5000 years ago, of a broad trachytic magma chamber underlying the Agua de Pau and Furnas volcanoes which basaltic magma has since been unable to penetrate.

Hydrothermal Melting of Shales

1961 ◽  
Vol 98 (1) ◽  
pp. 56-66 ◽  
Author(s):  
P. J. Wyllie ◽  
O. F. Tuttle
Keyword(s):  
Water Vapour ◽  
Basaltic Magma ◽  
Liquidus Curve ◽  
Igneous Rocks ◽  
Granitic Magma ◽  
Refractive Indices ◽  
Chemical Characteristics ◽  
Complete Fusion ◽  
Partial Fusion

AbstractPT curves for the beginning of melting of five analysed shales in the presence of water vapour under pressure are 20° C. to 40° C. higher than the corresponding curve for granite. About 150° C. above the beginning of melting, the shales are half-melted; this is higher than the liquidus curve of most granites. Refractive indices of the quenched liquids (1·495–1·505) indicate a granitic or granodioritic composition. Quartz, cordierite, mullite, hypersthene, anorthite, etc., are developed in the partially fused shales. Partial fusion of shales by a granitic magma, even if superheated, would produce a liquid no more basic than granodiorite. The chemical characteristics of the shales are compared with average igneous rocks, and there appears to be no possibility that fusion of shales could produce a basaltic magma. Complete fusion would produce a melt with composition distinct from normal igneous magmas.

Mafic-silicic layered intrusions: the role of basaltic injections on magmatic processes and the evolution of silicic magma chambers

1996 ◽  
Vol 87 (1-2) ◽  
pp. 233-242 ◽  
Author(s):  
R. A. Wiebe
Keyword(s):  
Basaltic Magma ◽  
Mafic Magma ◽  
Silicic Magma ◽  
Granitic Magma ◽  
Magma Chambers ◽  
Mechanical Mixing ◽  
Diffusive Convection ◽  
Type Granite ◽  
Mafic Magmas ◽  
Silicic Magmas

ABSTRACT:Plutonic complexes with interlayered mafic and silicic rocks commonly contain layers (1–50 m thick) with a chilled gabbroic base that grades upwards to dioritic or silicic cumulates. Each chilled base records the infusion of new basaltic magma into the chamber. Some layers preserve a record of double-diffusive convection with hotter, denser mafic magma beneath silicic magma. Processes of hybridisation include mechanical mixing of crystals and selective exchange of H2O, alkalis and isotopes. These effects are convected away from the boundary into the interiors of both magmas. Fractional crystallisation aad replenishment of the mafic magma can also generate intermediate magma layers highly enriched in incompatible elements.Basaltic infusions into silicic magma chambers can significantly affect the thermal and chemical character of resident granitic magmas in shallow level chambers. In one Maine pluton, they converted resident I-type granitic magma into A-type granite and, in another, they produced a low-K (trondhjemitic) magma layer beneath normal granitic magma. If comparable interactions occur at deeper crustal levels, selective thermal, chemical and isotopic exchange should probably be even more effective. Because the mafic magmas crystallise first and relatively rapidly, silicic magmas that rise away from deep composite chambers may show little direct evidence (e.g. enclaves) of their prior involvement with mafic magma.

The fluid dynamics of crustal melting by injection of basaltic sills

1988 ◽  
Vol 79 (2-3) ◽  
pp. 237-243 ◽  
Author(s):  
Herbert E. Huppert ◽  
R. Stephen ◽  
J. Sparks
Keyword(s):  
Continental Crust ◽  
Basaltic Magma ◽  
Source Region ◽  
Thermal Relaxation ◽  
Silicic Magma ◽  
Granitic Magma ◽  
Low Density ◽  
Magma Chambers ◽  
Theoretical Investigations ◽  
High Level

ABSTRACTWhen basaltic magma is emplaced into continental crust, melting and generation of granitic magma can occur. We present experimental and theoretical investigations of the fluid dynamical and heat transfer processes at the roof and floor of a basaltic sill in which the wall rocks melt. At the floor, relatively low density crustal melt rises and mixes into the overlying magma, which would form hybrid andesitic magma. Below the roof the low-density melt forms a stable layer with negligible mixing between it and the underlying hotter, denser magma. Our calculations applied to basaltic sills in hot crust predict that sills from 10-1500 m thick require only 2-200 years to solidify, during which time large volumes of overlying layers of convecting silicic magma are formed. These time scales are very short compared with the lifetimes of large silicic magma systems of around 106 years, and also with the time scale of 107 years for thermal relaxation of the continental crust. An important feature of the process is that crystallisation and melting occur simultaneously, though in different spots of the source region. The granitic magmas formed are thus a mixture of igneous phenocrysts and lesser amounts of restite crystals. Several features of either plutonic or volcanic silicic systems can be explained without requiring large, high-level, long-lived magma chambers.

scholarly journals The distribution and psychological distress related to COVID-19 of spine patients in a Grade-A tertiary hospital in Anhui province, China

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110105
Author(s):  
Yongshun Zheng ◽  
Xingfang Zhang ◽  
Shiyuan Fang ◽  
Fan Zhang
Keyword(s):  
Psychological Distress ◽  
Emergency Response ◽  
Spine Surgery ◽  
Tertiary Hospital ◽  
Anhui Province ◽  
The Public ◽  
Descriptive Research ◽  
The Past ◽  
Psychological Scale ◽  
Surgery Department

The COVID-19 pandemic may cause psychological distress, changes in numbers and distributions of patients in spine surgery patients, which all affect the strategies of spine surgery treatment. These changes may be related to the number of new COVID-19 cases per day since they are visual indicators of the changes in the epidemic and are of interest to the public. This descriptive research took the spine surgery department as an example in a Grade-A tertiary hospital in Anhui province, China. The number and distribution of patients from January 24 to April 2, 2020 was collected and compared with the past 5 years. A psychological scale was constructed to assess the psychological distress of patients and the number of new COVID-19 cases per day in Anhui, China was collected each day from January 24 to April 2, 2020. Also, this research compared these variables with the emergency response or the number of new COVID-19 cases per day. All distributions dropped dramatically during first-level emergency response and then back to normal. The psychological distress of patients was relatively higher at the beginning of the outbreak and then gradually returned to normal. The trends between the psychological distress of patients and the number of new COVID-19 cases per day were similar. The number of new COVID-19 cases per day could be used to predict psychological distress, changes in patient numbers and distributions, which was beneficial for the department of spine surgery to adjust its treatment strategy during the epidemic.

scholarly journals Iron deposits in the knee joints of a thalassemic patient

2013 ◽  
Vol 2 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Charalambos P Economides ◽  
Elpidoforos S Soteriades ◽  
Michalis Hadjigavriel ◽  
Ioannis Seimenis ◽  
Apostolos Karantanas
Keyword(s):  
Medial Meniscus ◽  
Left Knee ◽  
Knee Joints ◽  
Current Case ◽  
Thalassemic Patient ◽  
The Past ◽  
Clinical Complications ◽  
Iron Deposits ◽  
Magnetic Resonance Imaging Mri

The overall prognosis for patients with ß-thalassemia has improved considerably during the past decades mainly due to regular blood transfusions, improvements in chelation therapy, and enhanced surveillance with imaging studies examining iron overload and other clinical complications. However, the prolonged survival of these patients leads to the development of other health problems including degenerative diseases such as arthropathies, which require further attention since they have a significant impact on the quality of life. In the current case report, we present a 45-year-old white man with ß-thalassemia complaining of non-traumatic pain and restriction in the range of motion of both knees. Magnetic resonance imaging (MRI) revealed a tear in the medial meniscus of the left knee as well as iron deposits in both knees. Histological findings confirmed the presence of hemosiderin in both joints. To our knowledge, this is the first reported case of macroscopically documented iron deposits in the knee joints of a patient with ß-thalassemia using MRI.

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