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We examined the impact of three different sample preparation methods on bulk soil geochemistry data obtained from a hand‐held, portable X‐ray fluorescence (pXRF) spectrometer. We generated data from a soil core recovered from the surface, downward into unaltered loess, and into a buried soil at a site in eastern Iowa. Samples were scanned (i) directly from field‐moist soil cores; (ii) after drying, grinding, and being loosely massed in plastic cups; and (iii) as pressed‐powder pellets. Data derived using these methods were compared with data obtained from a standard benchtop X‐ray fluorescence (XRF) unit. Generally, the results indicated that data from pressed powder pellets often provide the best correlation to benchtop XRF data, although the results were sometimes element or compound specific. Calcium oxide, Fe2O3, and K2O generally provided the strongest correlations between pXRF‐ and XRF‐reported values; SiO2 data were more problematic. Field‐moist pXRF scans generally underestimated element concentrations, but the correlations between pXRF and benchtop XRF measurements were greatly improved after applying pXRF‐derived calibration standards. In summary, although element/compound data provided by pXRF showed significant relationships to benchtop XRF data, the results are improved with proper sample preparation (i.e., drying, grinding, pressing) and usually by calibrating the pXRF data against known standards. [ABSTRACT FROM AUTHOR]

The deep submergence research vehicle Shinkai 6500, diving on the Challenger segment of the Mariana forearc, encountered a superstructure of nascent arc crust atop a younger mantle with entrained fragments of metamorphosed crust. A plutonic block from this crust collected at 4900 m depth has a crystallization age of 46.1 Ma and mixed boninitic-arc tholeiitic geochemical signatures. A hornblende garnetite and two epidote amphibolites were retrieved from depths between 5938 m and 6277 m in an area dominated by peridotite. The garnetite appears to represent a crystal cumulate after melting of deep arc crust, whereas the amphibolites are compositionally similar to enriched mid-ocean ridge basalt (MORB). The initial isotopic compositions of these crustal fragments are akin to those of Eocene to Cretaceous terranes along the periphery of the Philippine plate. The garnetite achieved pressures of 1.2 GPa or higher and temperatures above 850 °C and thus could represent a fragment of the delaminated root of one of these terranes. This sample has coeval Sm-Nd, Lu-Hf, and 40Ar-39Ar ages indicating rapid ascent and cooling at 25 Ma, perhaps in association with rifting of the Kyushu-Palau arc. Peak P-T conditions were lower for the amphibolites, and their presence on the ocean floor near the garnetite might have resulted from mass wasting or normal faulting. The presence of relatively fusible crustal blocks in the circulating mantle could have contributed to the isotopic similarity of Mariana arc and backarc lavas with Indian Ocean MORB. [ABSTRACT FROM AUTHOR]

The article offers tips for improving the delivery of inhaled nasal medications. It suggests that patients should keep his or her mouth open during spraying. It notes that it is not possible to sniff the medicine into the back of the throat with the mouth open. According to the article, opening the mouth improves delivery to the treatment area and decreases the effects of bad taste or dry mouth when antihistamines are inhaled.

Abstract: The Mariana fore-arc southeast of Guam consists of ophiolitic lithologies related to subduction initiation and early-arc development. Ages of zircons extracted from gabbroic rocks within this sequence are , synchronous with similar rocks from the Bonin fore-arc 1700 km to the north. Basalts collected from the Izu fore-arc are similar to those of the Bonin and Mariana fore-arcs extending the distance of this ophiolitic geology to the entire 3000 km length of the IBM fore-arc. The Tonga fore-arc has similar lithologies and ages, suggesting that subduction began nearly simultaneously along much of the western margin of the Pacific plate. We postulate that closing of the Tethyan suture provided the trigger for subduction initiation in the Western Pacific. The volume of basalt erupted near western Pacific trenches associated with subduction initiation and early-arc development in the early Eocene could rival the volumes of large igneous provinces. The eruption of these basalts corresponds with the height of the Early Eocene Climatic Optimum (EECO), when global atmospheric temperatures were likely at or near their Cenozoic maximum. Therefore, CO2 vented during this volcanism as well as that associated with the North Atlantic Igneous Province, the Siletzia terrane, and slab rollback and detachment beneath central and east Asia were likely responsible for the EECO. [Copyright &y& Elsevier]