Authors:E. M. Warrington, A. J. Stocker and N. Y. Zaalov
A wealth of knowledge resulted from the investigations into gross deviations from the great circle path (GCP) outlined below. The magnitude and variances of the deviations from the GCP have been quantified and the associated geophysical conditions and signal characteristics identified. Research is currently being undertaken aimed at incorporating the knowledge gained from the experiments into techniques that will be of direct operational application. The main activities in this area include the development of ionospheric models coupled with ray tracing studies (some preliminary results of which were presented here) both to confirm the cause of the large bearing deviations and to assess the impact of the presence of the high latitude ionospheric features causing the deviations on paths other than those subjected to experimental investigation.
Authors:Péter Árkai, Kenneth J. T. Livi and Péter Horváth
Metamorphic mineral assemblages in low-temperature metaclastic rocks often contain paragonite and/or its precursor metastable phase (mixed K-Na-white mica). Relationships between the bulk rock major element chemistries and the formation of paragonite at seven localities from Central and SE-Europe were studied, comparing the bulk chemical characteristics with mineral assemblage, mineral chemical and metamorphic petrological data. Considerable overlaps between the projection fields of bulk chemistries of the Pg-free and Pg-bearing metaclastic rocks indicate significant differences between the actual (as analyzed) and effective bulk chemical compositions. Where inherited, clastic, inert phases/constituents were excluded, it was found that a decrease in Na/(Na+Al*) and in K/(K+Al*) ratios of rocks favors the formation and occurrence of Pg and its precursor phases (Al* denotes here the atomic quantity of aluminum in feldspars, white micas and “pure” hydrous or anhydrous aluminosilicates). In contrast to earlier suggestions, enrichment in Na and/or an increase in Na/K ratio by themselves do not lead to formation of paragonite. Bulk rock chemistries favorable to formation of paragonite and its precursor phases are characterized by enrichment in Al and depletion in Na, K, Ca (and also, Mg and Fe2+). Such bulk rock chemistries are characteristic of chemically “mature” (strongly weathered) source rocks of the pelites and may also be formed by synand post-sedimentary magmatism-related hydrothermal (leaching) activity. What part of the whole rock is active in determining the effective bulk chemistry was investigated by textural examination of diagenetic and anchizone-grade samples. It is hypothesized that although solid phases act as local sources and sinks, transport of elements such as Na through the grain boundaries have much larger communication distances. Sodium-rich white micas nucleate heterogeneously using existing phyllosilicates as templates and are distributed widely on the thin section scale. The results of modeling by THERMOCALC suggest that paragonite preferably forms at higher pressures in low-T metapelites. The stability fields of Pg-bearing assemblages increase, the Pg-in reaction line is shifted towards lower pressures, while the stability field of the Chl-Ms-Ab-Qtz assemblage decreases and is shifted towards higher temperatures with increasing Al* content and decreasing Na/(Na+Al*) and K/(K+Al*) ratios.
Authors:Petya Kovacheva, Boyan Todorov and Rumyana Djingova
FAO 2006: World Reference Base for Soil Resources. A Framework for International Classification Correlation and Communication. World Soil Resources Report 103. — Food and Agriculture Organization of the United Nations, Rome, 128 pp
/2000. (VI. 2.) KöM-EüM-FVM-KHVM együttes rendelet a felszín alatti víz és a földtani közeg minőségi védelméhez szükséges határértékekről (Unified Order No. 10/2000 of Environmental, Health, Agricultural and Land Development and Communication and Water
2009 : Annual precipitation series wavelet analysis of well-irrigation area in Sanjiang Plain . – In: Li , D. , Z. Chunjiang (Eds): Computer and Computing Technologies in Agriculture . CCTA 2008. IFIP Advances in Information and Communication
both by longitudinal ridges and circular pits, ordered in a honeycomb-like fashion. Both sides of the specimen bear this kind of surface pattern. This specimen does not belong to any known local amphibian (Z. Szentesi, personal communication, 2016), or
Authors:Dorottya Kovács, Gergely Dabi and Balázs Vásárhelyi
fracture systems was a convenient tool to determine the variables required for DFN modeling, as shown in this study. The studied specimens showed a very small number of interconnected fractures and the hydrological communication between fractures is