Donald Johanson woke up on the morning of November 24, , feeling lucky. The paleoanthropologist—then a professor at Case Western Reserve University in Cleveland—was several weeks into his third expedition to Hadar, Ethiopia, a site that had proven to be a treasure trove of early fossil remains. His international field team had already found leg bones and several jaws that were among the oldest examples of hominids—the family of bipedal primates that includes humans and their ancestors—and Johanson was convinced that an even bigger discovery was in the offing. When an American graduate student named Tom Gray announced he was leaving to scout out a nearby fossil site, Johanson had a hunch he should tag along. Feel good.
Dating Fossils in the Rocks | National Geographic Society
Fossils are precious gifts from the geologic past: signs and remains of ancient living things preserved in the Earth's crust. The word has a Latin origin, from fossilis meaning "dug up," and that remains the key attribute of what we label as fossils. Most people, when they think of fossils, picture skeletons of animals or leaves and wood from plants, all turned to stone. But geologists have a more complicated view.
Dating , in geology , determining a chronology or calendar of events in the history of Earth , using to a large degree the evidence of organic evolution in the sedimentary rocks accumulated through geologic time in marine and continental environments. To date past events, processes, formations, and fossil organisms, geologists employ a variety of techniques. These include some that establish a relative chronology in which occurrences can be placed in the correct sequence relative to one another or to some known succession of events.
Lake Turkana has a geologic history that favored the preservation of fossils. Scientists suggest that the lake as it appears today has only been around for the past , years. The current environment around Lake Turkana is very dry. Over the course of time, though, the area has seen many changes. Over time the sediment solidified into rock.