Identification of Leaf Fossils
Highly susceptible to decay, bacteria, oxidation and insects, the successful fossilization of leaves requires a rapid burial in an environment free of oxygen, such as in a swamp or lake bed.
Fossilization
Fossilization occurs when a fragile leaf is pressed within fine particles of clay, resulting in a thin carbon impression. It is extremely rare to find an actual fossilized leaf, due to the rapid decay of the organic material.
Geological Age
A fossils' geological age is based on the age of the surrounding rock. The exact age of strata is determined by measuring the uranium to lead breakdown in sedimentary rocks (one gram of uranium forms 1/7,000 gram of lead every million years, according to "Fossils, a Guide to Prehistoric Life"). As a result, the age of any fossils embedded in the rock, is inferred.
Shape and Structure
Leaf edges are either smooth or serrated. While some leaf fossil shapes are unique, most are indistinguishable from modern day leaves, such as maples, willows, poplars and oaks.
Classification and Size
Vascular plants are the most common plant fossils and are classified as psilopsids, sphenopsids, lycopods, ferns, gymnosperms or angiosperms. Leaf fossils usually measure 2 to 4 inches in length, though a few have been measured at over 6 feet long.
Tips
Use regional volumes on fossils, enlist the aid of geologists at universities or museums, or visit your local library for help in identifying leaf fossils.
Tags: Identification Leaf, Identification Leaf Fossils, Leaf Fossils