Best Answer: Hi, Answer: estÃ¡ means is. Comments: There are two words for is in Spanish: estar and ser. EstÃ¡ is the third person singular, present indicative ...
The Largest division in the geological time scale is the Precambrian Era.It lasted from around 4.6 billion years ago to 570 million years ago.
http://geology.com/time/geologic-time-sc... It divides the earths geologic history into periods, eons and epochs to help us date when events happened. For example, dinosaurs died out at the KT boundary, ont he geologic time scale that is roughly 65 million years ago between the Cretaceous Period and Tertiary Period.