Saugus, Essex Co., Massachusetts, USA
|Latitude & Longitude (WGS84):||42° 27' 53'' North , 71° 0' 38'' West|
|Latitude & Longitude (decimal):||42.46472,-71.01056|
|Köppen climate type:||Dfa : Hot-summer humid continental climate|
The town of Saugus was incorporated in 1815.
Mineral ListMineral list contains entries from the region specified including sub-localities
3 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
252.17 - 541 Ma
|Paleozoic intrusive rocks|
Age: Paleozoic (252.17 - 541 Ma)
Lithology: Intrusive igneous rocks
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. 
541 - 635 Ma
|Lynn Volcanic Complex|
Age: Ediacaran (541 - 635 Ma)
Stratigraphic Name: Lynn Volcanic Complex
Comments: Part of Milford-Dedham Zone (Tertiary and Older Rocks). Secondary unit description per MA023 as reported in USGS Geologic Names lexicon (ref. MA024): Lynn Volcanic Complex is confined to block north of Boston basin between northern border fault and Walden Pond fault. Similar in lithology to Mattapan Volcanic Complex. Both units consist largely of partly porphyritic rhyolite and rhyodacite flows, welded ash-flow tuffs, vitric tuff, lapilli tuff, lithic tuff, flow breccias, breccia pipes, and extrusion domes. Mattapan's rhyolite and rhyodacites are thinner and less varied in composition and texture than Lynn's; volcanic breccias are absent in Lynn. Both units are reported to lie nonconformably on Dedham Granite and unnamed plutonic-volcanic complex of eastern MA. Bell (1976) cites location in Saugus where Lynn overlies both Middlesex Fells Volcanic Complex and diorite intruded into it. Inclusions of Lynn found in Dedham Granite at Pine Hill in Medford (Zarrow, 1978, cited in Naylor, 1981). Lynn has no overlying strata. Both Lynn and Mattapan have been treated as the same age by numerous workers. Billings (1982) accepted Proterozoic Z age of Mattapan (based on U-Th-Pb zircon date of 602+/-3 Ma by Zartman, in Kaye and Zartman, 1980), but questioned reliability of zircon ages from volcanic rocks; he preferred to correlate Lynn rocks with Newbury Volcanic Complex because of Lynn's proximity and lithologic similarity to Newbury. Author feels that proximity argument is not strong because Lynn is geographically and structurally closer to Mattapan rocks. Zarrow (1978, cited in Naylor, 1981) has shown rare-earth element pattern in Lynn rocks to be identical to that in part of Mattapan. Author feels it is reasonable to assume that Lynn and Mattapan are parts of same volcanic complex, and that Lynn in Proterozoic Z in age (Goldsmith, 1991).
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052.