Comment by metalman

The most profound story of this type is the account of finding a leaf, in 10's of million year old clay, that when exposed, was green, but then very very rapidly oxidised and crumbled.Ref: from somewhere in the great lakes region? 90's mag, likely sciam.Also similar storys of other very ancient soft tissues, somewhat contentious, though it is understood that,unless lithified, ancient organic remains are exceptionaly fragile and do crumble quickly without meticulous and complicated preservation tecniques, the three common reasons for presevation in situ are freezing ,water saturation, or drying/mumification. The shear volume of artifacts that humans have, and are leaving behind, insures plenty of interesting finds availible into the far future.