** watch future Linda Hall Library lectures live at new.livestream.com/lindahall ** November 5, 2019, at Johnson County Community College Presented by Bill Shefchik, geologist (retired), Burns & McDonnell Engineering Company in Kansas City, Missouri In this first Deeper Dive session, the focus is on the earliest geologic history of the earth and of Northern Scotland in particular, by digging down into some of the scientific techniques that tell Scotland’s three-billion-year story. Incredible detective work with radioactive isotopes, phenomenal chemical trace-element studies of some quite-boring looking rocks, and beautiful studies of minerals that make up the rocks combine to tell how our earth first developed a crust.