We present results of laboratory investigation slag-like artifacts, found on an archaeological site near Boršice, known by occurrence artifacts from the Early Neolithic (5 700–5 000 BC), Bronze and Medieval Ages. The grey-coloured foamy reach up to 5 cm in size often display original lava-like surface. These slags are formed especially strongly potassic (15–23 wt. % K2O) silicic (54–72 SiO2) gl...

The oldest remnants of life on Earth from various localities in the Isua supracrustal belt Greenland date back to >3.7 billion years ago (Ga). They are form graphite, whose biogenicity is controversial. Previous studies used presence and isotopic composition nitrogen graphite along argue both for against biogenicity. To determine if chemistry can indeed serve as a biosignature, we investigated ...

Carbonatite volcanism remains poorly understood compared to silicic due the scarcity of carbonatite volcanoes worldwide and because volcanic H2O CO2—major components in systems—are not well preserved rock record. To further our understanding genesis, we utilize non-traditional thallium (Tl) isotope system Khanneshin carbonatites Afghanistan. These contain 250–30,000 ng/g Tl have ε205Tl values (...