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.
The result is the geologic column (on next page), which breaks relative geologic time into units of known relative age. Note that the geologic column was established and fairly well known before geologists had a means of determining numeric ages.