The Adirondack Lowlands is part of the Adirondack Mountains and has a complex geology. The domain contains the Upper Marble Formation, a sequence of shallow-water carbonates, evaporates and talc schists that sit upon the Popple Hill gneiss which is composed of metamorphosed mudstones, slates, sandstones, and volcanogenic sequences. The Popple Hill gneiss, in turn, overlies the Lower Marble Formation, a unit consisting of calcitic marbles, calc-silicates, quartzites, gneisses and tourmaline-rich units.
Additionally, various mafic rocks are distributed throughout the three main rock suites and diverse igneous rocks intruded ca. 1150-1200 million years ago (Ma). The rocks of the Lowlands were deformed and metamorphosed between ca. 1190 - 1140 Ma at a temperature of 600 deg to 650 deg C and pressure of 6 to 7 kilobars.