Why was the precambrian era so long?

Because it started when the Earth was formed and ended when humans found good fossils. It is just a blank area.

Explanation:

Precambrian Oldest and longest era of Earth's history, lasting from the formation of the Earth c. 4.6 billion years ago to the beginning of a good fossil record c. 590 million

sediment layers stop spreading when they reach a barrier or they run out of sedimentary material. lateral spreading is the movement of gently to steeply sloping, saturated soil deposits caused by earthquake-induced liquefaction. i hope this . : )

answerpeople organize large projects such as levee-building;