tl;dr: Norwegian glacial archaeologists with Secrets of the Ice have recovered 48 prehistoric arrows this field season from melting ice patches in Innlandet, including slate, bone, and freshwater mussel shell arrowheads dating back 5,000-6,000 years to the Stone Age. As the oldest ice finally melts after 6,000-7,000 years, finds are shifting from Viking Age to much older artifacts. Researchers estimate most archaeologically significant ice patches will vanish within 20 years.