The headwaters of fluvial systems on the East European Plain between the boundaries of the Marine Isotope Stage 2 (MIS 2) and MIS 6 glaciations evolved during the last 150. 000 years. At least three main events of high surface runoff caused intensive erosion: at the end of MIS 6. at the end of MIS 2 and in the Middle Holocene. https://www.roneverhart.com/10mm-Male-GRAV-Angled-Quartz-Banger-45/