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.
Our geologic time scale was constructed to visually show the duration of each time unit. This was done by making a linear time line on the left side of the time columns. Thicker units such as the Proterozoic were longer in duration than thinner units such as the Cenozoic. We also have a printable version of the Geologic Time Scale as a .pdf document. You can print this timescale for personal use. Author: Hobart M. King, Ph.D.