stripes
This large granite-syenite body extending for more than 25 km westwards from Cape Ann Island is only slightly peralkaline, as indicated by the occasional presence of aegirine-augite and a little riebeckite; fayalite is also found. Analyses for trace elements, including REE, will be found in Buma et al., (1971). Pegmatites are abundant and among other minerals carry alkali amphibole, lepidomelane, hedenbergite and fayalite (Warren and McKinstry 1924), together with a suite of REE-bearing minerals. A solvsbergite dyke at Andrew's Point has been described by Martin (1977). It contains aegirine and riebeckite, which also occur in granitic inclusions, and is suggested to have been produced by metasomatism of Cape Ann granite.
BUMA, G., FREY, F.A. and WONES, D.R. 1971. New England granites: trace element evidence regarding their origin and differentiation. Contributions to MIneralogy and Petrology, 31: 300-20.
LYONS, P.C. and KRUEGER, H.W. 1976. Petrology, chemistry, and age of the Rattlesnake pluton and implications for other alkalic granite plutons of southern New England. Memoir, Geological Society of America, 146: 71-102.
MARTIN, R.F. 1977. The association hypersolvus granite-subsolvus granite-"solvsbergite" at Andrew's Point, Cape Ann, Massachusetts: a case of localized fenitization. American Journal of Science, 277: 273-87.
TOULMIN, P.III. 1964. Bedrock geology of the Salem Quadrangle and vicinity, Massachusetts. Bulletin, United States Geological Survey, 1163-A: 1-79.
WARREN, C.H. and MCKINSTRY, H.E. 1924. The granites and pegmatites of Cape Ann, Massachusetts. Proceedings of the American Academy of Arts and Sciences, 59: 313-57.
ZARTMAN, R.E. and MARVIN, R.F. 1971. Radiometric age (late Ordovician) of the Quincy, Cape Ann, and Peabody granites from eastern Massachusetts. Bulletin of the Geological Society of America, 82: 937-57