This is a hand-colored diagram depicting geological strata at Gill, Massachusetts. It's a cross-section view of a landscape, showing layers of different rock types. On the left, there's a hill composed of red sandstone, topped with greenstone and slate. The layers are angled, suggesting tilting or folding. Moving towards the center, the landscape transitions to a broad expanse of slate, with visible layering indicated by diagonal lines. On the right side, there's another hill, this one made of granite and gneiss, with a mix of red and gray tones. Labels are written above each rock type, identifying them as 'GREEN-STONE', 'SLATE', 'RED SANDSTONE', 'GRANITE', and 'GRANITE & GNEISS'. Below the diagram, in large, bold letters, is the text 'STRATA AT GILL, Mass.' with a small number 'E2' in the bottom right corner. The overall style is illustrative and scientific, resembling a geological survey diagram from the 19th century.