STRUCTURAL ANALYSIS OF FRACTURE SYSTEMS AND LINEAMENTS IN THE MOOSE RIVER RECREATION AREA, CENTRAL ADIRONDACKS, NEW YORK

Systematic field mapping of fractures in the E part of the Moose River recreation area (Adirondacks) revealed strong correlation between fracture trends and lineaments in infrared images. The region is mostly underlain by high-grade foliated granitic & pelitic gneiss that occur in a map-scale antiform-synform pair. The limb between the folds forms a valley between Cellar & Little Moose mts. Major topographic and structural trends are parallel in the study area, but, most lineaments cross the bedrock structure. In the area of Wilson Ridge, lineaments (1-1.5 km) trend NNE across the E-W striking foliation. In the area of Cellar mt., there are three distinct lineament trends. The longest lineaments (5-8 km) trend E-W & cross the axis of the Wakely mt. antiform, the core of which occurs on Cellar Mt. A 2nd set of lineaments, 0.5-2 km long, trend NNE, crosscut the antiform and have the greatest aerial density. A minor 3rd set of lineaments (1-2 km) occurs on the northern flank of Cellar mt. that trend NW. Fractures were mapped at 1:24,000, and the dominant set strikes N-NNE and dip 65-80W. This fracture set occurs as continuous joints that trace for many meters, have a spacing from 0.5 to 2 m and often form master fractures up to 100 m long. The 2nd of fractures strikes E-W, dips steeply N & S, and is parallel to the 2nd set of lineaments. This set of fractures is parallel to the bedrock foliation along Wilson Ridge suggesting that anisotropy in the bedrock may have controlled their development. However, in the core of the Wakely Mountian, antiform this same set of fractures crosses the folded foliation at a high angle. In outcrop this set of fractures forms cliff faces that extend vertically 10’s of meters and horizontally up to 100 m. It is interesting to note that there is little correlation between the bedrock structure, and the dominant lineament & fracture trends.