Science 245/ Checkpoint Wk 2

The geologist column is a covering of sediment rock that is found on the entire earth. This sediment is layers of flood deposits of sandstone, limestone and shale which completely cover the landmass. These layers make up the earth crust which is called the standard geological column. These strata are a rock that resembles fossils that has gone through the process of aging over the distances as one another is undisturbed layer by layer. Whereas, inhibiting characteristics of an aged rock as each stratum becomes younger than the one beneath the other. (Michael Allay, 2004)
These fossiliferous layers can be traced across the continents and correlated with rocks in other countries. Therefore the thick layer of strata has aided scientist to analyze the history of life on earth for the past millions of years.   However, the fossils have been classified into groups, periods, and eras to help determined the particular layer strata fossil was found and relative age. The age can be determined in variety of categories of Stratigraphy ; Biochronology;   and Radiometric dating.
All three localities I in figure 3.6 on page 68 are of the same relative age. They are the same fossil types in description and of the same mineral, and of the same height. However, the third locality will never be a layer D because of possibility of erosion which resulted in non existence. In my point of view the fossils came from the Jurassic, Triassic, and Cetaceous time period. Whereas, showing characteristics from the Mesozoic era. Because of analyze information on the rock scientist can assume the rock formation were formed between 65.6 million years ago and 251 million years ago.

Michael Allaby.”faunal succession.” A Dictionary of Ecology. 2004. Retrieved December 18, 2010 from