DEFINITION OF The Highlands The Highlands are correlative with the central granulite terrainof the Canadian Grenville province. The Green Mountains ofVermont may also be correlative with the Highlands, althoughother Proterozoic massifs in the northern Appalachians such asthe Chain Lakes massif may be exotic to Laurentia. The Highlandsare dominated by meta-igneous rocks, including abundantanorthosite bodies. The largest anorthosite intrusion isthe Mount Marcy massif located in the east-central Adirondacks;additional anorthosite massifs are the Oregon andSnowy Mountain domes that lie to the south-southwest ofMount Marcy. The anorthosite bodies are part of the suite ofrocks known as the AMCG suite; anorthosites, mangerites,charnockites, granitic gneisses. Between the Marcy massif andthe Carthage-Colton mylonite zone is an area known as theCentral Highlands. Here, the rock types consist of AMCGrocks and hornblende gneisses, both of which exhibit variableamounts of deformation. The Southern Highlands are comprisedof granitic gneisses from the AMCG suite with infoldedmetasedimentary rocks that are strongly deformed. Within theSoutheastern Highlands, metasedimentary rocks are found;these metasedimentary rocks may be correlative with rocks inthe Northwest Lowlands. The following sections briefly reviewthe important Highland suites.
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