Gloucester Times: Cape Ann’s Granite Landscape

February 5, 2015
By Gail McCarthy Staff Writer

Read on Gloucester Times

There is some coincidence that geologist Martin E. Ross, who holds a doctorate in his field, made his home in Rockport, a town that sits on igneous rock molded by glacial action millennia ago.

With his expertise, he has “underground” information about Cape Ann that eludes most of us, and his new book gives a rock-y history of the region and lists the Top 10 places to view the geologic features described.

“Cape Ann granite is only 426 million years old compared to granites farther south that are about 630 million years old,” he said. “Cape Ann granite is young compared to rocks to the south and west in Massachusetts.”

Years ago, Ross began writing brief guide books about certain rocky scenic spots on Cape Ann, which he sold at Toad Hall Bookstore in Rockport. The guides provide information about places to visit, from Halibut Point State Park in the north, to Rafe’s Chasm in the southern area of Cape Ann, to Stage Fort Park near downtown Gloucester.

“The idea behind these booklets was to provide visitors with information about sites they could visit and teach them about the geology at the same time. They sold well and I decided it may be time to do a book,” said Ross, who serves as associate professor of geology in the Department of Marine and Environmental Sciences at Northeastern University in Boston.

The 181-page book, “Cape Ann: Its Physical and Environmental Geology,” is illustrated with more than 125 photographs, maps, and diagrams.

In a recent interview, Ross explained that most of what has been written about the geology of Cape Ann has been for other geologists with little material available at a layman’s level. His new book is intended for a general audience and beginning geology students.

The first half of the book presents basic geological principles as well as the geologic history of Cape Ann. Ross uses local examples to explain the different processes and features of geology, particularly igneous rocks because that is what Cape Ann is made of. The book also includes a chapter on the environmental geology of the region, which includes problematic land-use practices.

One chapter focuses on plate tectonics with a brief account of its role in forming Cape Ann.

The second half of the book consists of a field guide with detailed descriptions of the geology at 10 accessible locations along the shore of Cape Ann to help readers find and observe the geologic features Ross writes about.

The selected localities described in detail are: Rafe’s Chasm, Stage Fort Park, Good Harbor Beach, a road cut at the end of Route 128, Rockport’s southern beaches, The Headlands in Rockport, Front and Back beaches in Rockport, Andrews Point, Halibut Point State Park and Lanes Cove.

“The idea was to give the public something they can use. That’s why the first half has enough of what you need to appreciate Cape Ann’s physical environment in a new way,” said Ross.

Cape Ann contains an abundance of the types of igneous rocks (basalts) that Ross had been studying to the south of Cape Ann as well as in the Pacific Northwest and, before that, Wyoming — Ross, who grew up in Oregon, moved east when he began work as a professor in Boston in 1978.

Meanwhile, his ongoing research in eastern Massachusetts has focused on basaltic dikes and Cape Ann turns out to have hundreds of them. A dike is a sheet-shaped body of rock formed when magma from the Earth’s core forces its way into a fracture. Ross has walked the entire Cape Ann coast mapping the dikes and collecting samples for study.

His research encompasses a detailed field and laboratory investigation of the many basaltic igneous rocks present on the “Avalon terrane” of eastern Massachusetts. He also is continuing on his decades-long investigation of the basalt lava flows and related volcanics of the northwestern United States.

Although the historic fishing legacy of Cape Ann is well known, Ross hopes to fill the void for the public about the area’s geologic history.

“This book introduces the layman to Cape Ann’s geology as well as environmental problems resulting from our inattention to geologic processes when making land use decisions. My intent is to provide, in one volume, enough information to allow a non-geologist or beginning geologist to directly observe and understand geologic features and processes using Cape Ann as the vehicle,” he wrote in the preface.

The book is available at Toad Hall Bookstore, 47 Main St. in Rockport, and online.

Gail McCarthy may be contacted at 978-283-7000 x2706 or


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