Featured Photos

Slickensides made of epidote along the surface of one of several small, inactive, brittle fault s on the Boston Harbor islands.

Mass. State Geologist Steve Mabee and USGS Geologist and EDMAP/STATEMAP program coordinator Doug Howard discuss how geologic mapping addresses pressing societal issues on top of South Sugarloaf in South Deerfield. The view is looking south into rocks of the the Mesozoic Deerfield and Hartford Basins. The Connecticut River and Holyoke and Mt. Tom Ranges are in the background.

This week's photo is of finely laminated sandstone cropping out at Squaw Rock in Squantum.

Looking up slope from the toe of one of 3 major landslides that occurred during Tropical Storm Irene in Savoy, MA

MGS staff taking notes in front of an outcrop of layered diabase on Calf Island.

Silliminite in the Nashoba Formation near Westford, MA

Ripple Marks in the Lower Jurassic Turner's Falls Sandstone at Barton's Cove along the Connecticut River.

This DEM is of bare-earth returns from a LiDAR survey of the Nashua River watershed. The area shown is of Shirley, MA, and beautifully depicts the juxtaposition of drumlins, an esker network, and other glacial deposits overlying areas of shallow bedrock (NE part of photograph). The floodplain of the Nashua River can be seen in the SE corner. Route 2 is just south of the image.

A closeup of a microcline porphyroclast withinin a thin mylonite zone in Northborough.

The mylonite zone in question is one of many branches of the now dormant, but long-active, Clinton Newbury Fault Zone that transects Massachusetts from Worcester to Newburyport-- just one of the several ancient fault zones that play a significant role in the geologic history of the Commonwealth.

What are those dark blobs? They are what geologists call "magma pillows". What we are looking at in the photo is part of a preserved magma chamber (the volcanoes it is related to have eroded away).