Geochronology of Pliocene volcanism in the Dzhavakheti Highland (the Lesser Caucasus). Part 2: Eastern part of the Dzhavakheti Highland. Regional geological correlation

Petrogenesis of mafic collision zone magmatism: The Armenian sector of the Turkish–Iranian Plateau

“…There is a K-Ar groundmass age from a dolerite of the Akhurian river basin in Shirak of 2.5 ± 0.2 Ma (Chernyshev et al, 2002). Similar valley-filling flows in Southern Georgia are also dated using K-Ar methods to a range of 3-2 Ma (Lebedev et al, 2008a(Lebedev et al, , 2008b, confirming earlier assumptions from geological and palaeontological data (Shirtladze, 1958, Kharazyan, 1983. There is a switch in magnetic polarity between the lower and upper part of the Valley Series flow sequences, although several switches occurred during the Lower Pleistocene (Kharazyan and Shirinyan, 1981 and references therein; Cohen et al, 2013).…”

Multiple origins of Bondi Cave and Ortvale Klde (NW Georgia) obsidians and human mobility in Transcaucasia during the Middle and Upper Palaeolithic

“…The data from three laboratories/ techniques are in very good agreement, namely EDXRF , NAA (Blackman et al, 1998), PIXE, ICP-AES and ICP-MS (this work). The EDXRF analysis of a single sample from a fourth laboratory agrees with the preceding ones but for Na, Al, Fe, Co and U (Lebedev et al, 2008). A good agreement was also found for the major element data obtained by electron microprobe (EMP) (Frahm, 2010).…”

“…There are numerous obsidian boulders on the dome slopes, which are then broken down into pebbles that are carried downslope and downstream by the Paravani River to the Krami River which constitutes the main secondary sources. The Chikiani obsidian presently appears to have a homogeneous composition, though there are some variations in several trace element contents, as Y, Sr, Zr, and Ba (Blackman et al, 1998;Keller and Seifried, 1990;Lebedev et al, 2008). The obsidian relates to extrusions of Middle Pliocene date as demonstrated by two fission ages of 2.34 AE 0.10 and 2.63 AE 0.10 Ma (Chataigner et al, 2003) and a K/Ar age of 2.70 AE 0.15 Ma (Lebedev et al, 2008).…”

“…The Chikiani obsidian presently appears to have a homogeneous composition, though there are some variations in several trace element contents, as Y, Sr, Zr, and Ba (Blackman et al, 1998;Keller and Seifried, 1990;Lebedev et al, 2008). The obsidian relates to extrusions of Middle Pliocene date as demonstrated by two fission ages of 2.34 AE 0.10 and 2.63 AE 0.10 Ma (Chataigner et al, 2003) and a K/Ar age of 2.70 AE 0.15 Ma (Lebedev et al, 2008). This area is of relatively easy access from the lake Tsalka area to the north and from the south along the Paravani River (Fig.…”

“…EDXRF-1, Keller et al (1996): in italic, measurements on one sample; other elements, average on 4 samples. EDXRF-2, Lebedev et al (2008): measurement on a single sample. EMP: Frahm (2010), average on 13 samples; element contents on a single sample first averaged when several measurements were made.…”