The geology of New Pond Farm includes ridgetop outcrops of bedrock (mostly along Baldy-Ridge Trail) glacier deposits (most evident where carved away by Blackmans Pond Brook), and stream sediments in the lowlands (underlying our pastures).
The bedrock which underlies the farm was originally deposited as sediment in the Iapetus Ocean (before the Atlantic). It was caught up on the continental collision of North America and Africa. This collision formed the Appalachian mountains 286 Million years ago. The heat and pressure of the collision changed or metamorphosed the sedimentary rock into metamorphic rock called gneiss.
The bedrock gneiss contains metamorphic minerals which grew during metamorphism (period of heat and pressure). The most notable minerals are shiny micas, both muscovite (white) and biotite (black) and red garnet. The garnets are very hard and resist weathering. Look for them sticking out of the rock like measles or chickenpox. In the sunshine, they are deep red.
The glaciers that once covered New England are evident on the Farm. Glacial erratics (large boulders perched precariously on the ridge top), cobbles, boulders, sand and clay all deposited by the glaciers. The top of Mt. Baldy was smoothed by the glacier. Now rounded with a steep side to the southeast, Mt. Baldy was probably once a towering peak. The steep face was created by ice sliding over the mountain and plucking rock off the back side.