Early radioisotopic age constraints to the Campanian formations of your WIB consisted of K–Ar analyses of biotite and feldspar from interbedded bentonites115,116, with assumed uncertainties to the order of ± five%, and these analyses are usually not talked over further more listed here. Biotite ages, specifically, are viewed as of https://www.generationgenius.com/videolessons/fossil-record-video-for-kids/