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Microprobe Study (microprobe + study)

Distribution by Scientific Domains
Earth and Environmental Science60%
Physics and Astronomy40%

Selected Abstracts

An electron microprobe study of P645/T390: Evidence for an Early Helladic III Lerna,Aegina connection

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 8 2002
Michael J. Dorais
Middle Helladic Aeginetan Ware is widely distributed throughout the Aegean. It is characterized by a "gold mica or volcanic ash" fabric and is abundant at Lerna on the Argive plain, Greece, in the Middle Helladic and Late Helladic I periods. A group of Early Helladic III ceramics at Lerna includes P645/T390, which also has a volcanic fabric. We have sampled all the major rock types of the separate volcanic episodes on Aegina, Methana, and Poros and analyzed the constituent minerals with the electron microprobe. These analyses provide a reference standard against which the mineralogy of P645/T390 and other potential Aeginetan wares can be compared. The compositions of amphibole, clinopyroxene, plagioclase, and biotite in P645/T390 are identical to the same minerals in dacites on Aegina, suggesting an origin on that island. Compositional mismatches with the minerals of Methana and Poros indicated the ceramic was not manufactured at these locations. This narrow-necked jar represents the earliest occurrence of Aeginetan Ware on mainland Greece that has been confirmed by a quantitative method. © 2002 Wiley Periodicals, Inc. [source]

A comparative electron microprobe study of "Aeginetan" wares with potential raw material sources from Aegina, Methana, and Poros, Greece

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 6 2002
Michael J. Dorais
Qualitative stylistic evidence from ceramic vessels and limited petrographic analysis suggested that a distinctive group of ceramics with visible inclusions of biotite (Gold Mica Fabric) was produced on the island of Aegina, Greece, during the Middle Helladic and Late Helladic I periods. To quantitatively evaluate this provenance, we sampled all potential source rocks on Aegina, Methana, and Poros. Electron microprobe analysis of amphibole in these samples revealed that each of these volcanic centers has its own unique mineralogical signature. Comparative analyses of amphibole in Zerner's original stylistic "Gold Mica Fabric" type sample with the reference samples reveal that two sherds are Aeginetan. Three additional sherds from this sample may have a non-Aeginetan provenance, probably from a back-arc setting outside the Saronic Gulf. These results suggest that the hypothesis of a single source production site for Aeginetan Ware should be reexamined. © 2002 Wiley Periodicals, Inc. [source]

A nuclear microprobe study of the distribution and concentration of carbon and nitrogen in Murchison and Tagish Lake meteorites, Antarctic micrometeorites, and IDPs: Implications for astrobiology

METEORITICS & PLANETARY SCIENCE, Issue 11 2003
G. Matrajt
We observed that IDPs are richest in both elements. All the MMs studied contain carbon, and all but the coarse-grained and 1 melted MM contained nitrogen. We also observed a correlation in the distribution of carbon and nitrogen, suggesting that they may be held in an organic material. The implications for astrobiology of these results are discussed, as small extraterrestrial particles could have contributed to the origin of life on Earth by delivering important quantities of these 2 bio-elements to the Earth's surface and their gas counterparts, CO2 and N2, to the early atmosphere. [source]

Spoliation of a rigid gas permeable contact lens by sodium chloride: A free volume microprobe study

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2009
M. V. Deepa Urs
Abstract The interaction of one of the major inorganic ions present in tears, viz., sodium chloride (NaCl), with a rigid gas permeable contact lens, poly(Fluorosilicone acrylate) (FP92) has been investigated using Positron Annihilation Lifetime Spectroscopy (PLS) and refrac-tive index measurement. We monitored the changes in its free volume size and number density in the presence of NaCl solute trans-ported through diffusion. Based on PLS results, we propose that the adhesion of sodium chloride salt to the fluorine and methacrylate sites of FP92 results in zones of excess salt concentration. The changes in refractive index of the contact lens material due to the salt adhesion, correlates well with the changes in free volume of the material. Presence of sodium chloride perturbs the free volume of the lens material and hence its polarizability (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Mineral Geochemical Compositions of Tourmalines and Their Significance in the Gejiu Tin Polymetallic Deposits, Yunnan, China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2010
Runxing JIA
Abstract: The Gejiu tin polymetallic deposits are located in the southeastern part of Yunnan Province in China. A detailed electronic microprobe study has been carried out to document geochemical compositions of tourmalines from the deposits. The results indicate a systematic change of mineral geochemical compositions, which might be used as a mineral geochemical tracer for post-magmatic hydrothermal fluid, basin fluid and their mixture. The tourmalines from granite are schorl with Fe/(Fe+Mg) ratios of 0.912,1.00 and Na/(Na+Ca) ratios of 0.892,0.981. Tourmalines as an inclusion in quartz from the ore bodies are dravite with Fe/(Fe+Mg) ratios of 0.212,0.519 and Na/ (Na+Ca) ratios of 0.786,0.997. Tourmalines from the country rocks are dravite with Fe/(Fe+Mg) ratios of 0.313,0.337 and Na/(Na+Ca) ratio of 0.599,0.723. Tourmalines from cassiterite-tourmaline veins that occur in crannies within the country rocks show distinct optical zoning with alternate occurrence of dravite and schorl, Fe/(Fe+Mg)=0.374,0.843, Na/(Na+Ca)=0.538,0.987. It suggests that schorl in granite and dravite in carbonatite are related to magmatic fluid and basin fluid respectively. When magmatic fluid rose up and entered into crannies of the country rocks, consisting mainly of carbonatite, basin fluid would be constantly added to the magmatic fluid. The two types of fluid were mixed in structural crannies of the sedimentary basin accompanied with periodic geochemical osculations to form material records in chemical composition zonings of tourmalines. [source]