Quartzites and associated schists found on Pine Mtn and the ridges nearby are here grouped under a single formation name--Pine Mtn [Mountain] formation. The quartzites give place to siliceous and micaceous schists near the Monroe-Pike Co. line, and the continuation of these formations far into Monroe Co. was not noted. Mica schists may usually be found enclosing the quartzite layers, and in some instances, as on the ridges of northern Upson Co., there is a gradual transition from one rock type to the other. In most places there is not great width to these schists, but in northwestern part of Upson Co., excavations along Macon and Birmingham RR expose them almost continuously from a point 6.5 mi northwest of Thomaston to near Flint River. Within this distance, the strike changes form N. 35 deg E. on the southeast to N. 25 deg W. on the northwest. There are also changes of dip indicating existence of one or two synclines. The quartzite layers are of medium to fine grain, usually containing considerable secondary mica. In some places disseminated crystals and groups of pyrite are found. The schists are usually of fine and rather even texture and are composed mainly of mica and quartz. Small lenses and stringers of secondary quartz are very abundant. No positive evidence as to age, but absence of intrusions of Roan gneiss, presence of one intrusion of a later dioritic rock showing some metamorphism and nature of formation would seem to favor its tentative classification as either Precambrian or Early Cambrian.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Unit referred to as Pine Mountain series in this report. Includes Hollis quartzite below and Manchester formation (new).

Source: GNU records (USGS DDS-6; Reston GNULEX).

Unit referred to as Pine Mountain group. In Thomaston quad, includes Hollis quartzite below and Manchester formation above. Overlies Woodland gneiss; underlies schist-gneiss migmatite. Age shown as Precambrian(?).

Source: GNU records (USGS DDS-6; Reston GNULEX).

Crystalline rocks of GA are grouped into 11 belts, in part using names proposed by Adams (1933: Jour. Geology, v. 41, no. 2). Pine Mountain series includes quartzites and schists of Pine and Oak Mountains in southwestern part of Wacoochee belt. Four formations are recognized (ascending): Sparks schist, Hollis quartzite, Chewacla marble, and Manchester schist. Chewacla marble, which has its type locality in AL, is not known in GA. Adams believed that series is Paleozoic, but it is here assigned to the Precambrian.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Pine Mountain Group is the upper unit of the Pine Mountain Block. It consists of a series of metasediments composed of metaorthoquartzites, graphite-muscovite schist and aluminous metasediments. Irregular occurrences of dolomitic marble are found scattered throughout the sequence in the western part of the outcrop belt. Stratigraphic sequence of units within the group is uncertain. Hollis Quartzite, is changed to Hollis Metaorthoquartzite to avoid confusion with nonmetamorphic sandstones. Rocks mapped as Hollis may be two units: a massive thick-bedded unit and a thin-bedded unit. The thin-bedded unit, may be part of the Manchester sequence. The Chewacla Marble of Lee Co., AL, is an irregularly occurring dolomite unit in contact with the Hollis. The Manchester Schist, the uppermost unit, consists of interlayered schists and metaquartzites and is poorly exposed in AL.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Metasedimentary Pine Mountain Group of eastern AL and western GA may correlate with Jacksons Gap Group, Murphy Marble belt, and Lower to Middle Cambrian cratonic cover of the Valley and Ridge province. Includes Manchester Formation (AL & GA), Hollis Quartzite (AL & GA), Chewacla Marble/Schist facies of Hollis Quartzite (AL), Sparks Schist (GA), and Halawaka Schist (AL).

Source: GNU records (USGS DDS-6; Reston GNULEX).

The Pine Mountain Group, as used by Clarke (1952) in the Pine Mountain anticlinorium in the Bill Arp thrust sheet in northern GA and AL is accepted for USGS use, assigned to the Ocoee Supergroup in GA, and is revised to include the Hollis Quartzite, Manchester Schist, Mountain Creek Formation, and Chewacla Marble in GA, and the Chewacla Marble in AL. The Sparks Schist, originally described as the lowest unit of the Pine Mountain, is assigned to the underlying Wacoochee Complex. Age is Late Proterozoic.

Source: GNU records (USGS DDS-6; Reston GNULEX).

In the Pine Mountain belt (Pine Mountain window), Middle Proterozoic basement rocks are represented by Wacoochee Complex and its components, Whatley Mill Gneiss and Halawaka Schist. Overlying early Paleozoic cover sequence is represented by Pine Mountain Group, which consists of (ascending) Hollis Quartzite, Manchester Schist, and Chewacla Marble (Bentley and Neathery, 1970; Sears and others, 1981; and Crickmay, 1952). Report includes geologic sketch map.

Source: GNU records (USGS DDS-6; Reston GNULEX).