Question

I give medals!!!! please help me!!!

Where did scientists initial get information to develop the geologic time scale?
A) they collected and studied rock samples in Africa
B) they studied rock layers and used fossils around the world
C) They conducted research at libraries
D) They didn't have any information; they just made an educated guess

Answer 1

http://pubs.usgs.gov/gip/fossils/numeric.html

Answer 2

The basic principals of Uniformitarianism were enough to give geologists a sequencial history of the earth but absolute dating using isotope data from igneous rocks gathered using several different techniques (strontium/rubidium, parent/daughter isotope decay rates) and with the combination of these two geologists were able to develop the geological time scale.