What is Puddingstone?

Puddingstone is rock made up of a mixture of different, irregular-sized grains and pebbles held together by a finer matrix, usually formed from quartz sand. It is found in different varieties and in different areas. But the purple-based stone found in Morris County is rare and has never been found anywhere else in New Jersey. The plum or purple tint in the stones comes from iron oxide materials; flecks in the stone are white quartz pebbles. Geologists say the stones are a glacial deposit, a sedimentary rock that has been slightly metamorphosed by heat and date from the Devonian period, 350 million to 400 million years ago. They are believed to be a remnant of an ancient mountain range. (Courtesy of the Daily Record, August 23, 2007)