Dating zircon grains row updating event in gridview in asp net using c
Chemistry of the augen gneiss indicates that their protoliths derived from shoshonitic to high-K calc-alkaline granitoids related to a post-collisional stage [16, 76], probably at the transition from compressional to extensional tectonics or even after the tectonic collapse of an intracontinental orogen .The emplacement age obtained from the protoliths of all granitic gneisses in CPT and their geochemical affinity share similarities with the granitoids widespread at the Northern edge of the West African Craton, especially in Morocco [77-79], Algerian Tuareg Shield  and Mauritania .According to , the inherited zircon age patterns in the augen gneisses and paragneisses from Aspromonte-Peloritani Unit in the Sicily bear evidence, on the whole, of East African provenance owing to age cluster in the range 900-1100 Ma reveled in this area.These authors evidence strong similarities between Sicily terranes and those of other areas in the Eastern Mediterranean region as Southern Israel, Jordan and Arabia and suggest an East African provenance as several pieces of basements in Mediterranean area, like Turkey, Greece, Sardinia and Cyclades .In these rock-types the Ordovician-Silurian ages represent clusters connected to a recrystallization event being the protoliths Neoproterozoic-Cambrian in origin.These ages were measured on cores displaying irregular and patchy microstructures sometimes strongly luminescent (Fig.Cathodoluminescence images of zircons in metabasic rocks, augen gneisses, fine grained leucocratic gneisses and amphybolitic gneisses showing characteristic oscillatory zoning interpreted as indicative of their magmatic origin.
6) has evidenced a widespread Neoproterozoic-Cambrian bimodal magmatism in an older basement of Calabria-Peloritani Terrane.
In the Calabria augen and fine grained leucocratic gneisses, the majority of the concordant ages forms a statistically significant cluster averaging at 543 Ma (n=20 ages from 562 to 532 Ma) mainly related to euhedral crystals without discontinuity between core and rim having U contents ranging from 659 to 241 ppm and Th/U ratios mostly comprised between 0.2 and 0.5; one domain analysed for REEs produces a highly fractionated pattern and a distinct negative Eu anomaly  interpreted as primary magmatic characters according to  or as recrystallized domains with memory of primary magmatic zircons .
The moderate variability and the high values of Th/U ratios seem to be more compatible with precipitation from a hybrid magma precursor of the augen gneisses  having mantle and crustal origin.
These gneisses are intimately associated with metasediments affected by Variscan metamorphism, but their zircon domains do not bear memory of this event, preserving only Pre-Cambrian/Silurian ages [16,18,23].
Only one sample (GO39, Table 1) preserves Devonian-Lower Permian ages interpreted as resetted ages due to thermal input of fluids relased by Late-Variscan plutonites .