Significant evolutionary stages of Selinitsa Cave (SW Peloponnese, Greece) were revealed by 3D mapping, as well as geomorphological study of the cave and the nearby landscape. Four marine terraces were identified in the area of the coastal cave at 6, 10.7, 16.6, and 30–32 m above sea level (asl), with the terrace at 16.6 m representing Marine Isotope Stage (MIS) 5. The widest karstified space of Selinitsa Cave clusters between 15.73 and 18.05 m above sea level (asl), with the peak lying at 16.4 m asl, corresponding to the level where the phreatic/epiphreatic zone was stable for a sufficient period of time. A tidal notch at 16.4 m asl at the cave entrance is correlated to the marine terrace at 16.6 m. Both features correspond to the sea-level stand at which intense karstification occurred. The tidal notch bears a horizontal arrangement of Lithophaga borings at the vertex. Sedimentological investigation of the Selinitsa fine-grained deposit revealed the paleohydrologic regime of the cave. It is characterized by “slack-water” facies, indicating very low water flow speeds, whereas the thickness of the deposit points to stable hydrological conditions for prolonged periods. The cave sediment height of 18.8 m asl indicates a flooding level higher than sea level. The overlying Plattenkalk flysch is most probably the major source of detritus, and the predominance of authigenic dolomite (>98% modal in the carbonate fraction) indicates a hyposaline environment related to mixing of sea water with percolating fresh water. The approach of this study shows the significance of 3D mapping, bio-geo-Relative Sea Level (RSL) indicators, and sedimentology in deciphering the paleogeographic evolution of coastal karstic systems and subsequently defining the paleoclimate regime of coastal areas in Greece and the eastern Mediterranean during the Late Quaternary.

Geochronology of detrital monazite is a valuable tool for interpreting the detrital petrology of sedimentary basins. Because of its hardness, monazite can be transported long distances by rivers, but because it is susceptible to dissolution under acidic conditions, second cycle monazite is rarely abundant. Monazite geochronology has been applied to sandstones from the latest Jurassic and Lower Cretaceous Missisauga and Logan Canyon formations of the Scotian basin, in order to assess sediment sources and dispersal pathways for the deltaic sandstones. These sandstones are the principal reservoir rocks for oil and gas in the Scotian Basin. A total of 324 detrital monazite grains were identified from Lower Cretaceous sandstones from ten offshore fields or individual wells, providing an east to west transect of the Scotian Basin. Monazite grains were characterized by secondary electron or backscattered electron images, showing external morphology, zoning and inclusions, together with WDS X-ray maps and variations in major element chemistry (REE, Th, Y). From these grains, 688 age determinations with 1sin errors < ±20% were obtained by electron microprobe analysis. Based on all these criteria, about 30 distinct types of monazite grain are recognized, that show distinctive variations in their geographic and stratigraphic distribution and abundance. The one analysed sample from the Naskapi N-30 well appears to have had a discrete river source, draining only the Meguma Terrane. On the one hand, grains with a 440-550 Ma age mode in the central Scotian Basin closely resemble the dominant grain type in the Chaswood Formation in Nova Scotia, suggesting supply from the inboard Appalachian terranes of New Brunswick. On the other hand, the central Scotian Basin also includes common grains with Proterozoic ages that are absent from the Chaswood Formation, suggesting important supply from a river draining through Cabot Strait from western Newfoundland, or perhaps with minor supply from Labrador and the North Shore of Quebec. The Lower Missisauga Formation at Thebaud and Venture has significantly more Neoproterozoic monazites compared with the Upper Missisauga Formation and Cree Member throughout the central Scotian Basin. In the eastern Scotian Basin, Proterozoic grains predominate, but most monazite types are also recognised in the central Scotian Basin. This distribution suggests different dominant river supply to Peskowesk compared with the central Scotian Basin, probably draining the eastern side of the Long Range and the Appalachian rocks of western Newfoundland.

The concealed Molai Zn-Pb±(Ag,Ge) stratiform deposit in southeastern Peloponnese is hosted in Triassic intermediate tuffs, ignimbrites and subaerial andesitic flows. The host rocks display trace element signatures of a Supra-Subduction Zone (SSZ) setting. Three ore-forming stages are recognized, with stages I and II related to formation of the epigenetic, stratiform, massive-to-semi-massive ore and a late stage III associated with vein-type mineralization. The O and D isotope geochemistry of gangue chlorite and epidote reveal mixing with fresh meteoric water during the weaning stages of the hydrothermal activity of the late stage II due to uplifting of the hydrothermal system. Sphalerite is the major ore phase, with three different varieties formed during stages I (Sp-I) and II (Sp-II and Sp-III). All sphalerite varieties coexist, depicting gradual change in the chemistry of the ore-forming fluids. Molai ores are characterized by elevated Ag and Ge contents. Tetrahedrite is the major Ag carrier, while among the three sphalerite varieties, early Sp-I comprises the highest Ge contents. The Molai Zn-Pb±(Ag,Ge) deposit is characterized by intermediate features between bimodal felsic massive sulfides and subaerial epithermal systems based on the shallow formation depth, the presence of hydraulic breccias associated with phase separation, the ore formation along high-angle faults, the relatively low ore-forming temperatures below 250 °C obtained from geothermometry, and the absence of the typical structure of bimodal felsic type ores.