ge·o·chro·nol·o·gy 
(jē′ō-krə-nŏlə-jē)
(jē′ō-krə-nŏlə-jē)n.
The chronology of the earth's history as determined by geologic events.
ge′o·chron′o·logic (-krŏn′ə-lŏjĭk), ge′o·chron′o·logi·cal adj.
ge′o·chron′o·logi·cal·ly adv.
ge′o·chro·nolo·gist n.