Despite numerous debates conducted in the last two decades, the concept of intrusion related gold systems IRGS remains controversial and sometimes befuddling. The key issue drifts from case to case, i.e., initial to subsequent proposed classifications, presence of gold in reduced fluids-porphyritic environments, non-porphyry gold in orogenic terrains and participation of non-magmatic gold fluids in depositional processes. Trying to avoid atypical or particular aspects of certain deposits, a genuine metallogenetic depiction intends to enhance the intrusion related systems meaning. Gold is either a major constituent or a mere byproduct. A vertical metal zonation develops from surface to depth: Au, Ag → Cu, Pb, Zn → Cu, Au → Cu, Mo (Au), W → Fe, Cu, Au (Co,W) → U, Ce, La. Whether the relationship between different intrusion related occurrences is well known at shallow depth (epithermal, mesothermal, porphyry), so far less knowledge and understanding is assigned to deep seated mineralization (porphyry, Iron Oxides- Copper-Gold/IOCG). A specific relationship between those two deep seated ore styles emerges, that is the IOCG, confined to magmatic-hydrothermal type, is situated in the root zone of a deep porphyry system. Complementary information about updated classic exploration tools encompasses specifically geochemical association, geophysical signature, key alteration minerals, Au/Ag ratio and, last but not least, type minerals that contain/include gold in each intrusion related environment. A further valuable tool is given by the estimate of Au grade range specific to each gold bearing mineral sample in shallow or deep seated setting.
A high resolution taxonomy and classification framework is developed for the representatives of the calcareous benthic foraminiferal family Bolivinoididae; this family consists of 24 species assigned to three genera.This new classification includes data pertaining of the test ultrastructure, ornamentation and porosity, which are obtained with the aid of careful and extensive study of the specimens under the scanning electron microscope.Two new taxa are described: Bolivinoides antiquum -n.sp. and Swiecickina -n.gen.A biostratigraphical framework consisting of eleven biozones based on bioevents given by species of the genera Bolivinoides and Swiecickina is developed for the middle Santonian-Maastrichtian stratigraphical interval; its resolution is more than double when compared to those of the previously developed biostratigraphical frameworks based on the representatives of this group.
A high-resolution biostratigraphical zonation based on planktic foraminifera is developed for the Upper Cretaceous. It consists of twenty-five biozones defined with the aid of serial and coiled planktic foraminiferal taxa and presents the highest resolution developed with planktic foraminifera for this Series. All the index species used in biozonation are part of the practical classification associated with the evolutionary classification. The new biozonation represents a first in using data directly derived from the Theory of Evolution and its evolutionary classification extension in an application of paleontology such as biostratigraphy. By this the Theory of Evolution becomes a direct provider of data in applied studies.
Quantitative and semi-quantitative analyses of calcareous nannofossils were performed on samples collected from Bozdovec Section (Albanian-Thessalian intramontane basin, Albania). The calcareous nannofossil assemblages are dominated by: small reticulofenestrids, Cycligargolithus floridanus, Coccolithus pelagicus, Sphenolithus spp., Reticulofenestra scrippsae, Helicosphaera spp., Clausicoccus spp., Reticulofenestra bisecta, Cycligargolithus abisectus. Biostratigraphically, the studied outcrop is assigned to the Late Oligocene NP25 - Sphenolithus ciperoensis Zone. In the Mediterranean area, this interval can be correlated with the MNP25a - Sphenolithus ciperoensis Zone, while according to the zonation for low to middle latitudes the investigated material would belong to the CNO5 - Sphenolithus ciperoensis TZ. High amounts of small reticulofenestrids and sphenoliths point to warm well stratified paleoenvironment.
A geochemical study of the Neogene volcaniclastic deposits from the south-eastern part of the Zărand Basin (Apuseni Mts., Romania) was performed. The investigated rocks are represented by medium-K calc-alkaline andesites. Their geochemical features are similar with those of other Neogene volcanic rocks from the Apuseni Mts. However, the investigated rocks also display a few particularities: limited variation of some major oxides and trace elements content, much lower content of Nb or of light REE. As for the other Neogene volcanic rocks from Apuseni area, the geochemical evidence supports a magma source located close to the boundary between crust and garnet-free lithospheric mantle, minor fractional crystallization processes affecting the magma. A subduction signature was identified for the investigated samples, and, similar to other Neogene volcanic rocks from Apuseni Mts., was interpreted as being related to some enrichment in fluids of the magma source. Based on the location and geochemical similarities with those of other Neogene volcanic rocks from the Apuseni Mts, the assumed age range of volcanic activity generating the volcaniclastic rocks of the study area is 13.8-10 Ma, while the source of the volcaniclastic material is most probably the Bontău volcanic structure.
