Local fossils show a Florida-like past

BRANDON Journeying back in time 20 million years ago, a local time traveler would see a strangely altered landscape of rugged mountains clad in trees unfamiliar in todays northern New England woodssuch as magnolia, live oak, palms, and towering dawn redwood, the living fossil ancestor of the sequoias. At the base of the ancient Green and Taconic mountains, the time traveler would slog through low-lying primeval swamps and forests of bald cypress, and other plants familiar mostly to visitors of Florida and Asia. Perhaps the strangest experience to our imaginary time traveler would be the oppressive, humid climate of prehistoric Vermont more like a contemporary Florida summer day than even a typical summer day along todays Otter Creek Valley. But such was western Vermonts vanished environment during most of the Cenozoic era, between 13 and 63 million years ago. Little evidence of this prehistoric world remains except for the Brandon Lignite deposits. These unusual deposits of brown coal are on private property near Forest Dale, adjacent to the old Shay farm property. There, a rich array of plant fossilsleaves, twigs, cones, seed pods and pollenhas been collected and studied over several decades. Soft lignite coal is only found in Vermont in the Brandon area. It was formed in the same way as anthracite and bituminous coal. However, the biggest difference is in the temperature at metamorphosis. Lignite, formed as plant sediments in cooler underground conditions than other coal, is more akin to peat than familiar coal. In 1902, Brandons Horn-Crockett Company operated a large kaolin clay mine and milling operation in Forest Dale, along a small tributary of the Otter Creek. Brandons kaolin deposit, mined for 20 years, yielded 80,000 tons of the stuffa hydrated material of silica of alumina with a composition of approximately 46 percent SiO2; 40 percent Al2O3, and 14 percent H2O. In the Brandon area, kaolinfrom the Chinese word kau-ling, meaning high ridgeformed alongside lignite and other minerals. It occurs in hexagonal plates and is found frequently in odd, worm-like bunches. Geologically, Brandons kaolin comes from the weathering of Green Mountain quartzites and gneisses, rocks rich in soda-feldspar. Throughout the 20th century, kaolin was important in the manufacture of paper for newspapers and magazines. Today, kaolin is still a staple of the paper industry, but it has new applications in industry, in diverse products such as insecticides and plastics. Brandons commercial kaolin deposits were also found in conjunction with other rich Cenozoic ore depositspaint ochre, manganese, and iron ores. The Horn-Crockett operation, and other mining interests, also extracted ochre, manganese and iron ores in the area. However, the lignite was only mined in limited quantity, around 1910, during a coal shortage. Since the 1940s, several Harvard University geologists have visited the Brandon Lignite deposit to collect fossils and learn more about the regions prehistory. In 1947, Harvard geology graduate student Bill Stockman spent several weeks studying the lignite. In 1984, holding a PhD as director of coal research at the College of Earth and Mineral Science at Penn State University, he revisited the site to collect tiny fossil seeds. In 1974, Harvard University geologist Brice Tiffney built a cabin on site and spent the summer collecting fossils in the old Horn-Crockett mineshafts 200 feet below ground level. Members of the University of Vermonts Department of Geology have also studied the Brandon Lignite fossils. A collection of Brandon plant fossils are exhibited publicly at UVMs newly renovated Perkins Museum of Geology.

Vote on this Story by clicking on the Icon


Use the comment form below to begin a discussion about this content.

Sign in to comment