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1

An Algorithmic-type Classification of Tetravalent One-regular Graphs Using Computer Algebra Tools

Ghasemi M.

Fundamenta Informaticae

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2014

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Vol. 135, nr 3

211--228

EN

A finite graph is one-regular if its automorphism group acts regularly on the set of its arcs. In the present paper, tetravalent one-regular graphs of order 7p2., where p is a prime, are classified using computer algebra tools.

2

Przydatność skał pochodzenia wulkanicznego w budownictwie i drogownictwie

Machowiak K.

Kruszywa : produkcja - transport - zastosowanie

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2013

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Nr 1

48--54

PL

W niniejszej publikacji przybliżono podstawowe zagadnienia dotyczące skał wulkanicznych. Zaprezentowano genezę i formy występowania skał wulkanicznych w Polsce, dokonano opisu ich podstawowych odmian, parametrów fizykomechanicznych oraz cech strukturalnych i mineralogicznych. Zwrócono również uwagę na naturalne zjawiska, które mogą mieć wpływ na pogorszenie jakości eksploatowanego surowca.

EN

In this publication the basic concept of volcanic rocks is presented. The origins and possible forms of occurrence of volcanic rocks in Poland are described as well as was their basic varieties, physical and mechanical parameters and the structural and mineralogical characteristics. Attention was also drawn to the natural phenomena that may deteriorate the quality of the raw material during exploitation.

3

Refining the granite, gneiss and schist interrelationships within the Lusatian-Izera Massif, West Sudetes, using SHRIMP U-Pb zircon analyses and new geologic data

Żelaźniewicz A., Fanning C., M., Achramowicz S.

Geologia Sudetica

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2009

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Vol. 41

67-84

EN

The eastern part of the Lusatian-Izera Massif, West Sudetes, comprises different types of gneissose rocks, collectively known as the Izera gneisses, with a subordinate component of petrographically varied mica schists. Coarse-grained gneisses and their protoliths have been dated at 515-480 Ma, but the lack of age data for other rocks has impeded accounts of their mutual relationships and, thus, the region's geological evolution. This paper reports new sensitive high-mass resolution ion microprobe (SHRIMP) U-Pb zircon data, and some new field and petrographic observations, for three representative rock types: 1) the Złotniki schist (a fine-grained quartz-albite-chlorite-sericite-biotite schist); 2) a fine-grained gneiss that grades to 'porphyroblastic' granite and which occurs on the slopes of Mt. Stóg Izerski; 3) a leucogranite found just the south of the village of Kotlina. A volcanogenic intercalation in the Złotniki Lubańskie schists developed at 560 Ma and contained xenocrystic zircons that grew in the source at 620 Ma and 600-580 Ma. The schists are interpreted as the metamorphosed equivalent of the Lusatian greywackes, which were derived from a dissected arc and deposited in a convergent-margin basin along northern peri-Gondwana. The zircons from the fine-grained gneisses yielded four age groups: 515 +- 7 Ma, 500 +- 12 Ma, 487 +- 13 Ma and 471 +- 8 Ma. Similar age groups of zircons can also be found in the coarse-grained metagranites. Rifting of Gondwana during the mid-Cambrian-early Ordovician was a protracted thermal event lasting ~30-45 m.y., with episodic attenuation of the mainland crust every ~5-10 m.y. before continental fragments finally became separated. Each episode successively promoted an increased heat flux from the mantle that facilitated melting of the crust, causing metamorphism and fusion of the Precambrian Lusatian-Izera basement and a final phase of S-type felsic magmatism. The leucogranite sample yielded zircons in two age groups, 508 +-5 Ma and 483.1 +- 3.6 Ma, with low Th/U ratios, which is interpreted as a product of an anatectic melting at deeper crustal levels. These leucogranites are in close spatial relation with belts of mica schist, which could mean that these granites used some rheologically weak zones that were introduced into the Izera pluton where large fragments of country rocks were trapped within the ~500 Ma granites.

4

The petrogenesis of late Precambrian felsic alkaline magmatism in south Sinai, Egypt

Azer M.

Acta Geologica Polonica

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2006

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Vol. 56, no. 4

463-484

EN

Alkaline felsic magmatism represents the final phase of the late Precambrian acid magmatism in south Sinai. The studied felsic suites occur as dyke-like intrusions, exhibit features characteristic of A-type granites. There were two main cycles of magmatic activity separated by a period of magmatic quiescence, which led to a composition gap between them. The earlier cycle includes quartz syenite that represents the precursor of the A-type granite series in south Sinai, whereas the second cycle includes more felsic volcanic-subvolcanic intrusive complexes. Intrusion of the two cycles was controlled by the preexisting structure and individual igneous bodies were emplaced in an extensional tectonic regime during a phase of fracturing and uplift at the end of the Pan-African orogeny. The high variability in geochemical signature of A-type magmas in south Sinai suggests a variety of petrologic processes and reservoirs which reflects the participation of an intraplate mantle reservoir and enolved continental crust. Kenrichment in the rhyolite is a primary feature and attributed to the effect of volatiles which accumulated in the upper part of the magma chamber. In general, A-type magmas in south Sinai can be differentiated according to their magma source and tectonic setting into (1) non-primitive A-type magma (ANP) and (2) primitive A-type magma (AP). The non-primitive A-type magma is commonly known in Sinai as Iqna granite, which belongs to the highly fractionated, late- to post-orogenic, calc-alkaline I-type granites. The primitive A-type magma shows within-plate geochemical characteristics and was emplaced in an anorogenic setting. It is distinguished further into: (i) a magma having characteristics indicative of OIB-mantle contribution (A[1]), and (ii) magma derived from crustal sources (A[2]).