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.
Subdivision of periods into epochs can be done only for the most recent portion of the geologic time scale. This is because older rocks have been buried deeply, intensely deformed and severely modified by long-term earth processes.