Warwickite from St. Lawrence County, New York: Mineral association, chemical composition, cation ordering, and splitting of the warwickite M1 site

2020 ◽  
Vol 58 (2) ◽  
pp. 183-190
Author(s):  
Marian V. Lupulescu ◽  
Alix M. Ehlers ◽  
John M. Hughes ◽  
David G. Bailey
Keyword(s):  
New York ◽  
Structural Formula ◽  
Mining District ◽  
Mineral Association ◽  
Empirical Formulas ◽  
Dolomitic Marble ◽  
Atomic Arrangement ◽  
Lawrence County ◽  
A Site ◽  
Insight Into

ABSTRACT Warwickite has been discovered in the Edwards and Balmat #3 mines in the Balmat-Edwards mining district, St. Lawrence County, New York, located in the Adirondack Lowlands. The samples from the two mines are similar in chemistry and atomic arrangement but differ chemically from previously described samples; they are among the most Fe-poor samples described to date. The warwickite in the Edwards Mine sample occurs as 1–2 mm-diameter green crystals associated with pink spinel, forsterite, phlogopite, and pyrite in an impure dolomitic marble, whereas warwickite in the specimens from the Balmat #3 mine, approximately 10 km distant, occurs as brown to amber colored, slender, elongate, millimeter-size crystals in a calcitic marble in association with pink spinel, phlogopite, anhydrite, pyrite, and galena. Chemical analyses of the two specimens by electron microprobe show similar empirical formulas of (Mg1.43Ti0.36Al0.18Cr3+0.02Zr0.01)Σ2.00B0.98O4 (Edwards Mine) and (Mg1.39Ti0.40Al0.18Cr3+0.01Zr0.01Fe2+0.01)Σ2.00B0.94O4 (Balmat mine). The atomic arrangement of a specimen from each mine was determined, and the high-precision refinements provide new insight into the warwickite structure. The M1 site in warwickite is split into two sites to accommodate two occupants with differing bonding requirements; the M1 site contains Mg and the M1′ site hosts Ti, with the two sites being separated by approximately 0.2 Å. The optimized structural formula for both warwickite samples is similar to [M1(Mg0.84Al0.14Ti0.024+)2.74M1′(Ti0.914+Mn0.082+Mg0.01)1.30]Σ4.04M2(Mg0.86Al0.10Ti0.044+)4.00B4O16], demonstrating ordering of Mg at M1 and M2 and Ti at M1′. The site-splitting demonstrates how divalent Mg and tetravalent Ti can exist at a site in solid solution by ordering the two cations at split sites.

Collector’s Note: Balmat Mining District Update, St. Lawrence County, New York

2020 ◽  
Vol 95 (5) ◽  
pp. 463-466
Author(s):  
Steven C. Chamberlain ◽  
Michael R. Walter
Keyword(s):  
New York ◽  
Mining District ◽  
Lawrence County

scholarly journals The Atomic Arrangement of Cr-rich Tourmaline from the #1 Mine, Balmat, St. Lawrence County, New York, USA

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 398 ◽  
Author(s):  
Steven Dannenberg ◽  
Devany Di Paolo ◽  
Alix Ehlers ◽  
Kyle McCarthy ◽  
Mark Mancini ◽  
...  
Keyword(s):  
New York ◽  
Structural Changes ◽  
Bond Valence ◽  
Northwestern Part ◽  
Atomic Arrangement ◽  
Octahedral Sites ◽  
A Value ◽  
Low Concentrations ◽  
Lawrence County ◽  
Bond Valence Sum

Chromium-bearing tourmalines are rare. Chromium-rich tourmaline from the northwestern part of the Adirondack Mountains in the Adirondack Lowlands is among the most chromium-rich tourmalines found to date. The mineral, with >21.0 wt. % Cr2O3, is from the marble-hosted talc–tremolite–cummingtonite schist in the #1 mine in Balmat, St. Lawrence County, New York. The atomic arrangement of the sample (a = 16.0242(3) Å, c = 7.3002(2) Å) was refined to R1 = 0.0139. The composition, from chemical analyses and optimization of the formula, is X(Ca0.22Na0.69K0.01) Y(Cr3+1.68Mg0.80Ti0.13V0.06Mn0.02Fe0.02Li0.29) Z(Al3.11Cr3+1.18Mg1.70Fe0.01) T(Si5.93Al0.07) B3O27 OH3.99 F0.01. There has been extensive debate over the ordering of Cr3+ between the tourmaline Y and Z octahedral sites. Recent work has suggested that, at low concentrations (<~1.03 apfu), the substituent Cr3+ is ordered into the Y-site, whereas, at greater concentrations, the substituent is disordered over both octahedral sites. An analysis of nine recently published, high-precision structures of chromium-bearing tourmaline, in combination with the Adirondack tourmaline, suggests that structural changes to the Y-site at low concentrations of Cr3+ induce changes in the Z-site that make it more amenable to incorporation of the Cr3+ substituents by increasing <Z–O>. The bond lengths change to lower the bond-valence sum of Cr3+ in the Z-site of the chromium-dravite, making that site more amenable to the substituent. Calculations suggest that the Z-site begins to accept substituent Cr3+ when the bond valence sum of that ion in Z reduces to a value of ~3.36 valence units.

Jazz Bubble

2018 ◽  
Author(s):  
Dale Chapman
Keyword(s):  
New York ◽  
Political Economy ◽  
Social Practice ◽  
Global Economy ◽  
First Century ◽  
Music Culture ◽  
Social Trends ◽  
Governmental Organizations ◽  
Early Twenty ◽  
A Site

Hailed by corporate, philanthropic, and governmental organizations as a metaphor for democratic interaction and business dynamics, contemporary jazz culture has a story to tell about the relationship between political economy and social practice in the era of neoliberal capitalism. The Jazz Bubble approaches the emergence of the neoclassical jazz aesthetic since the 1980s as a powerful, if unexpected, point of departure for a wide-ranging investigation of important social trends during this period. The emergence of financialization as a key dimension of the global economy shapes a variety of aspects of contemporary jazz culture, and jazz culture comments upon this dimension in turn. During the stateside return of Dexter Gordon in the mid-1970s, the cultural turmoil of the New York fiscal crisis served as a crucial backdrop to understanding the resonance of Gordon’s appearances in the city. The financial markets directly inform the structural upheaval that major label jazz subsidiaries must navigate in the music industry of the early twenty-first century, and they inform the disruptive impact of urban redevelopment in communities that have relied upon jazz as a site of economic vibrancy. In examining these issues, The Jazz Bubble seeks to intensify conversations surrounding music, culture, and political economy.

scholarly journals Development of Fragility Curves for Piping and Slope Stability of River Levees

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 738
Author(s):  
Nicola Rossi ◽  
Mario Bačić ◽  
Meho Saša Kovačević ◽  
Lovorka Librić
Keyword(s):  
Slope Stability ◽  
Fragility Curves ◽  
Safety Margin ◽  
Water Levels ◽  
Flood Event ◽  
Soil Parameters ◽  
Design Code ◽  
A Site ◽  
Insight Into

The design code Eurocode 7 relies on semi-probabilistic calculation procedures, through utilization of the soil parameters obtained by in situ and laboratory tests, or by the means of transformation models. To reach a prescribed safety margin, the inherent soil parameter variability is accounted for through the application of partial factors to either soil parameters directly or to the resistance. However, considering several sources of geotechnical uncertainty, including the inherent soil variability, measurement error and transformation uncertainty, full probabilistic analyses should be implemented to directly consider the site-specific variability. This paper presents the procedure of developing fragility curves for levee slope stability and piping as failure mechanisms that lead to larger breaches, where a direct influence of the flood event intensity on the probability of failure is calculated. A range of fragility curve sets is presented, considering the variability of levee material properties and varying durations of the flood event, thus providing crucial insight into the vulnerability of the levee exposed to rising water levels. The procedure is applied to the River Drava levee, a site which has shown a continuous trend of increased water levels in recent years.

Media Coverage and Solidarity after Tragedies: The Reporting of School Shootings in Two Nations

2012 ◽  
Vol 11 (6) ◽  
pp. 845-874 ◽  
Author(s):  
James Hawdon ◽  
James Hawdon ◽  
Atte Oksanen ◽  
James Hawdon ◽  
Atte Oksanen ◽  
...  
Keyword(s):  
New York ◽  
Media Coverage ◽  
New York Times ◽  
Virginia Tech ◽  
School Shootings ◽  
Considerable Research ◽  
National Comparison ◽  
The Media ◽  
Insight Into ◽  
Cross National

Abstract Although considerable research analyzes the media coverage of school shootings, there is a lack of cross-national comparative studies. Yet, a cross-national comparison of the media coverage of school shootings can provide insight into how this coverage can affect communities. Our research focuses on the reporting of the school shootings at Virginia Tech in the U.S. and Jokela and Kauhajoki in Finland. Using 491 articles from the New York Times and Helsingin Sanomat published within a month of each shooting we investigate how reports vary between the nations and among the tragedies. We investigate if one style of framing a tragedy, the use of a “tragic frame,” may contribute to differences in the communities’ response to the events.

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