STROMATOLITES IN THE FRANKLIN MARBLE,
NEW JERSEY HIGHLANDS

Stromatolites were discovered in the 1.2 billion-year-old Franklin Marble from the New Jersey Highlands during routine fieldwork by Rich Volkert of the New Jersey Geological Survey. Stromatolites are the fossilized remains of colonies of cyanobacteria that often have a characteristic dome-shaped laminated structure. The laminations are thin mats that were constructed by the microorganisms as they trapped fine grains of calcium carbonate on their sticky filaments. A new organic mat was then constructed over the sediment, trapping another layer of sediment and producing the next lamination. The Franklin Marble was formed from limestone deposited in a marine (ocean) environment during the Precambrian Era. Stromatolites in the marble provide tangible evidence for the occurrence of ancient biological activity in this environment in New Jersey.