| Roxbury Conglomerate | |
|---|---|
| Stratigraphic range: Ediacaran: 595–570 Ma | |
 Roxbury Conglomerate in a monument on the Gettysburg Battlefield | |
| Type | Geological formation |
| Unit of | Boston Bay Group |
| Sub-units | Brookline Member, Dorchester Member, and Squantum Member |
| Underlies | Cambridge Argillite |
| Overlies | Mattapan Volcanic Complex and Middlesex Fells Volcanic Complex |
| Thickness | 1,310 meters (4,300 ft) approximate maximum |
| Lithology | |
| Primary | sandstone, conglomerate, and diamictite |
| Other | argillite |
| Location | |
| Country | United States of America |
| Extent | Boston Basin, eastern Massachusetts |
| Type section | |
| Named for | Roxbury, Massachusetts |
| Named by | Hitchcock (1841)[1] and Shaler (1869)[2] |
The Roxbury Conglomerate, also informally known as Roxbury puddingstone, is a name for a rock formation that forms the bedrock underlying most of Roxbury, Massachusetts, now part of the city of Boston. The bedrock formation extends well beyond the limits of Roxbury, underlying part or all of Quincy, Canton, Milton, Dorchester, Dedham, Jamaica Plain, Brighton, Brookline, Newton, Needham, and Dover. It is named for exposures in Roxbury, in the Boston area. It is the Rock of the Commonwealth in Massachusetts. [3][4][5]
- ^ Hitchcock, Edward (1841) Final report on the Geology of Massachusetts. J. S. & C. Adams, Amherst, Massachusetts. 2 vols., 831 pp.
- ^ Shaler, N. S. (1869) "Note on the geological section at Chestnut Hill Reservoir, Massachusetts". Boston Society of Natural History Proceedings. 13:172–177.
- ^ N/A, N/A. "Rock or rock emblem of the commonwealth". malegislature.gov. Commonwealth of Massachusetts. Retrieved August 1, 2023.
- ^ Zen, E., R. Goldsmith, Richard N. M. Ratcliffe, P. Robinson, R. S. Stanley, N. L. Hatch Jr., A. F. Shride, E. G. A. Weed, and D. R. Jones (1983) "Bedrock geologic map of Massachusetts". Special Map, 3 sheets, scale 1:125,000. U.S. Geological Survey, Reston, Virginia.
- ^ Goldsmith, R. (1991) Stratigraphy of the Milford-Dedham zone, eastern Massachusetts; an Avalonian terrane. In N. L. Hatch, ed., pp. E1–E62, Chapter E, "The bedrock geology of Massachusetts". Professional Paper. no. 1366-E. U.S. Geological Survey, Reston, Virginia.