Provenance of sediments during subduction of Palaeotethys: Detrital zircon ages and olistolith analysis in Palaeozoic sediments from Chios Island, Greece
Abstract Detrital zircon geochronology and analysis of fossiliferous olistoliths from Chios Island, Greece, are used here to constrain terrane accretion processes and the provenance of crustal sources for sediments during the subduction of (a branch of) the Palaeotethys Ocean. U/Pb ages obtained by ion microprobe (SHRIMP-II) analyses of detrital zircons from a Carboniferous greywacke belonging to the tectonostratigraphic Lower Unit of Chios gave major age groups of 2150–1890 Ma, 640–540 Ma, 505–475 Ma and 365–322 Ma. Detrital zircons from a Permian–Triassic sandstone yielded prominent age clusters of 2200–1840 Ma, 1100–910 Ma, 625–560 Ma and 385–370 Ma. The lack of zircon ages between 1.8 a…
Mineral chemical and geochronological constraints on the age and provenance of the eastern Circum-Rhodope Belt low-grade metasedimentary rocks, NE Greece
Abstract In north-eastern Greece the mid-greenschist facies Makri Unit and the anchizonal Melia Formation belong to the eastern Circum-Rhodope Belt that forms the uppermost tectonostratigraphic unit of the Rhodope metamorphic nappe pile. The two metasedimentary successions had different source areas, although they now lie in close proximity in the Rhodope Massif. The U–Pb isotopic ages of detrital zircons from a metasandstone of the Makri Unit analysed using LA–SF–ICP–MS and SHRIMP-II gave age clusters at ca. 310–290 Ma and at ca. 240 Ma for magmatic zircons, which may have been derived from Carboniferous–Permian basement rocks of the Thracia Terrane (Lower Tectonic Unit of the Rhodope Mass…
Geochemical constraints on the provenance and depositional setting of sedimentary rocks from the islands of Chios, Inousses and Psara, Aegean Sea, Greece: implications for the evolution of Palaeotethys
The provenance and depositional setting of Late Palaeozoic and Early Mesozoic clastic sediments from the eastern Aegean archipelago are examined here for the first time using whole-rock geochemistry and composition of detrital chrome spinel. Major- and trace-element data for Late Palaeozoic and Permo-Triassic clastic sediments from the Lower and Upper Units of Chios are compatible with an acidic to intermediate source, minor input of (ultra)mafic detritus and recycling of older sedimentary components. Chondrite-normalized REE profiles are uniform with light REE enrichments (La N /Yb N c . 7.7), negative Eu anomalies (Eu/Eu* c . 0.67) and flat heavy REE patterns (Gd N /Yb N c . 1.5), indicat…
Rutile chemistry and thermometry as provenance indicator: An example from Chios Island, Greece
Abstract In the present study we focused on detrital rutile separated from 12 psammitic samples that belong to three different sedimentary successions (Carboniferous, Permo-Carboniferous, Permo-Triassic) occurring on Chios Island, Greece. The Ti, Cr, Al, Fe, Nb, Zr, Si, and V contents of the rutiles were obtained by electron-microprobe analyses to trace their provenance. The Cr and Nb concentrations of the analysed rutile grains show a wide range and indicate that this mineral in the Carboniferous succession is mainly derived from metamafic rocks, whereas in the Permo-Carboniferous and Permo-Triassic successions stem from a metapelitic source. The calculated formation temperatures using the…
Geochemistry, provenance and stratigraphic age of metasedimentary rocks from the eastern Vardar suture zone, northern Greece
Abstract Uppermost Palaeozoic and Mesozoic sediments from the Vardar suture zone in northern Greece record a cycle of Neotethyan oceanic basin opening and closure and their analysis places tight constraints on the geotectonic evolution of the area. The oldest post-Carboniferous sedimentary unit in the study area is the Examili Formation, which comprises mainly metaarkoses and metaquartzites, and was deposited in an intracontinental rift-related sedimentary basin in proximity to the Vertiskos Terrane during the Permian–Triassic. The Melissochori Formation (former Svoula flysch) comprises predominantly metasandstones with significant carbonate content and was deposited in front of a Carbonife…
Geochemical constraints on the provenance and depositional setting of sedimentary rocks from the islands of Chios, Inousses and Psara, Aegean Sea, Greece: implications for the evolution of Palaeotethys
The provenance and depositional setting of Late Palaeozoic and Early Mesozoic clastic sediments from the eastern Aegean archipelago are examined here for the first time using whole-rock geochemistry and composition of detrital chrome spinel. Major- and trace-element data for Late Palaeozoic and Permo-Triassic clastic sediments from the Lower and Upper Units of Chios are compatible with an acidic to intermediate source, minor input of (ultra)mafic detritus and recycling of older sedimentary components. Chondrite-normalized REE profiles are uniform with light REE enrichments (LaN/YbN c. 7.7), negative Eu anomalies (Eu/Eu* c. 0.67) and flat heavy REE patterns (GdN/YbN c. 1.5), indicating an up…