scholarly journals Whole-rock chemical composition of some samples from two drill hole cores in the Capps coal field, Beluga coal area, south-central Alaska

1982 ◽  
Author(s):  
T.K. Hinkley ◽  
K.S. Smith ◽  
J.L. Peard ◽  
M.L. Tompkins
Keyword(s):  
Chemical Composition ◽  
Drill Hole ◽  
Coal Field ◽  
South Central

Saponite, Corrensite and Chlorite-Saponite Mixed-Layers in the Sancerre-Couy Deep Drill-Hole (France)

Clay Minerals ◽  
1994 ◽  
Vol 29 (1) ◽  
pp. 47-61 ◽  
Author(s):  
D. Beaufort ◽  
A. Meunier
Keyword(s):  
Chemical Composition ◽  
Drill Hole ◽  
X Ray Diffraction ◽  
Parental Relationships ◽  
Clay Deposits ◽  
Fe Content ◽  
Three Samples ◽  
Structural Formulae ◽  
Layer Mineral ◽  
Mixed Layers

AbstractThe clay deposits in fractures of the metamorphic basement under the Paris Basin sedimentary formations at Sancerre-Couy (France) are composed of trioctahedral species which are exceptionally well crystallized. Three samples were chosen in order to study the chemical composition of 100% expandable saponite, 50% expandable corrensite and 10% expandable chlorite-saponite mixed-layer mineral C90–S10 Two sets of microchemical analyses were performed in order to determine the variations of the composition on large and small numbers of particles. X-ray diffraction (XRD) and Mössbauer spectrometry were performed on purified samples.The mathematical decomposition of Si, Al and Mg histograms established from microanalyses of a large number of crystals of saponite, corrensite and C90–S10 evidences bimodal populations. The total Fe content of the three species is unimodal whatever the chemical composition of the surrounding rock and the Fe2+/Fe3+ ratio. The structural formulae established from a large number of microanalyses of a few particles show that there are no parental relationships between saponite, corrensite and C90–S10. The expandable layer of corrensite is characterized by a high charge. It is proposed that the tetrahedral sheets adjacent to the brucitic sheet and the exchangeable interlayer in a 2 : 1 unit are identical in corrensite.

scholarly journals Chemical composition of rainwater collected from 2006 to 2009 in Mexico City and at a rural site at Morelos State, south central Mexico

2020 ◽  
Vol 37 (1) ◽  
pp. 1-8
Author(s):  
Rocío García-Martínez ◽  
Alejandro Carrillo-Chavez ◽  
Ricardo Torres-Jardón ◽  
Alejandro Ramirez-Guzmán ◽  
Moisés López-Carrasco
Keyword(s):  
Chemical Composition ◽  
Mexico City ◽  
Atmospheric Transport ◽  
Sampling Site ◽  
Air Pollutant ◽  
Rural Site ◽  
Central Mexico ◽  
Strong Positive Correlation ◽  
Back Trajectories ◽  
South Central

The objective of the study was to evaluate the chemical composition of rainwater in urban and suburban areas of central Mexico to identify the possible sources of rainwater contamination. The rainwater was collected at Universidad Nacional Autónoma de Mexico, Campus Ciudad Universitaria (CU), in the southern part of Mexico City at 2200 meters above sea level (m a.s.l.). CU has many green areas with high to moderate traffic densities where air quality presents serious problems of pollution by particulate matter. The other sampling site is a forested rural area (Tlalnepantla), State of Morelos, Mexico, a suburban area 86 km to the south of Mexico City. A total of 145 rainwater samples were collected in the rain period from 2006 to 2009. The ions analyzed were the following: SO42-, NO3-, Cl-, HCO3-, Na+, K+, Ca2+, Mg2+, NH4+ and H+. Ammonium was the most abundant cation in both sites and is one of those responsible for the neutralization of acidic compounds in the atmosphere. The relative abundance of the inorganic anions present in the rainwater was in the following order: SO42- > NO3- > Cl-, for the alkaline metals the order was Ca2+ >Mg2+ > Na+ > K+ and Ca2+ >Mg2+ >K+ >Na+ for CU and Morelos, respectively. A correlation analysis shows a strong positive correlation among the ions, indicating that the most important source was anthropogenic. Air mass back trajectories were associated with the SO42-, Ca2+, Mg2+, NH4+ and H+ concentrations observed on each rainy day. Four factors were used in the statistic analysis and was weighted within each factor. Weights greater than 0.5 are considered to be significant components of each factor. The four factors explain 84.7 % of the total variance of all of the data for CU and 66.9 % for Morelos. All of these factors were associated with all of the analyzed ions. Air pollutant back trajectories were used to understand atmospheric transport and to identify the origins and pathways of air masses influencing the concentrations of the measured ions in rainwater.

Compositional and Stylistic Analysis of Aztec-Era Ceramics: Provincial Strategies at the Edge of Empire, South-Central Veracruz, Mexico

2006 ◽  
Vol 17 (4) ◽  
pp. 541-559 ◽  
Author(s):  
Thanet Skoglund ◽  
Barbara L. Stark ◽  
Hector Neff ◽  
Michael D. Glascock
Keyword(s):  
Chemical Composition ◽  
Stylistic Analysis ◽  
Documentary Evidence ◽  
Postclassic Period ◽  
South Central ◽  
Basin Of Mexico ◽  
Late Postclassic ◽  
Provincial Capital

We use a provincial perspective combined with compositional and stylistic data and historic accounts to propose three provincial strategies for imperial interactions—bolstering, resistance, and emulation—and note a fourth, exodus. A sample of three Late Postclassic period (A.D. 1350–1521) pottery types differs in chemical composition between two localities in south-central Veracruz, Mexico. Sherds from the Aztec provincial capital of Cuetlaxtlan along the lower Cotaxtla River are compared to those from the Lower Blanco River where Callejón del Horno is located. The composition of stamped-base bowls, Texcoco Molded censers, and Aztec III-style Black-on-orange bowls is distinct in samples from the two localities, with only scant evidence of exchange. A few vessels of Aztec III Black-on-orange were imported from the Basin of Mexico to Cuetlaxtlan. The stylistic characteristics on Aztec III-style Black-on-orange vessels do not distinguish the two Veracruz localities, but there are differences between them and illustrated vessels from the Basin of Mexico. The Cuetlaxtlan province was subject to unusual imperial investments, which may account partly for the emulation of imperial styles. Despite documentary evidence of rebellions, another factor was local decisions to use a prestigious exogenous style.

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