Physiographic map of the United States
Trenton Falls is located in the central portion of New York State. This region of central New York, although technically at the northeastern edge of the interior cratonic platform, lies in a relatively complex terrain of eastern North America. West Canada Creek and its magnificent Trenton Gorge lie within a triple junction of geologic provinces, with the nearby exposure of the Adirondack Mountains, to the north (shaded gray below), and the eastern mobile belt, to the south and southeast (shaded pink).
Geologic map of New York State
Geologically, Trenton Falls lies within the relatively narrow outcrop belt flanking the southeastern side of the Adirondack Mountains. In this region, Cambrian to Ordovician strata are exposed and are observed to be onlapping the Precambrian Grenville rocks. The superposition of these lower Paleozoic (545 to 450 million years old) rocks over the top of 1.0 billion-year-old rocks of the Grenville Province represents a significant nonconformity.
The accepted type section of the Upper Ordovician Trenton Group is a locality along West Canada Creek approximately 15 miles northeast of Utica, New York. The original type section was described for the strata exposed along a 2.25 mile section of the gorge of West Canada Creek between Trenton Falls (the village), and Prospect, New York. In this region, West Canada Creek flows from north to south and descends over several beautiful waterfalls, which are collectively referred to as Trenton Falls.
In their report on the "Sections and Thicknesses of the Lower Silurian Formations on West Canada Creek and in the Mohawk Valley ", Charles S. Prosser and Edgar R. Cumings (1896) documented the physical thickness of strata exposed in the gorge and the relative outcrop position for these units.
As West Canada Creek descends nearly 300 feet through the gorge, it does so over several small cascading rapids as well as four larger waterfalls. From base to summit they are named: Sherman Fall, Lower High Falls, Upper High Falls, and Mill Dam Falls. Still further upstream, at the village of Prospect, is yet another waterfall commonly referred to as Prospect Falls.
A series of cascade rapids add additional stratigraphic section to the Trenton Falls Gorge, in addition to the major falls. The lowermost set of rapids below Sherman Fall is referred to by Prosser and Cumings as "The Narrows", due to the deep, narrow incision by West Canada Creek at this point. Historically, this cascade, referred to as the "Cascade of the Alhambra", opens up at its base near the present day village of Trenton Falls where West Canada Creek descends over one last waterfall known as Village Falls.
The uppermost set of rapids, above Mill Dam Falls, was known as "Rocky Heart". This set of rivulets is no longer visible due to construction of a hydro-electric dam and flooding of the site. This region of the gorge was originally named because of the appearance of large potholes ground into the limestone bedrock. During repeated flooding episodes, these depressions were carved by cobbles and boulders moved in the turbulent eddying currents typical of West Canada Creek. Due to the interactions of some of these potholes and joints within the bedrock, nearly spade or heart-shaped features were generated.
Refer to the satellite imagery shown at right for views of the general geographic position of each of the main geomorphic features within the gorge, as described above. This orthoimage was originally produced by the NYS Statewide Digital Orthoimagery Program. The imagery (1-meter color infrared orthoimagery, NAD83, UTM Zone 18) was created and downloaded from the online GIS viewer at the 1-mile scale, as separate .gif images. Each 1 mile square image was then spliced using digital photography software. The original raster image is based on color infrared aerial photography (corrected for sensor and terrain relief displacements) with red tones indicating vegetation vigor. The rollover image is the same image with the red colors selectively replaced with green tones in order to show approximate true coloration.
Some additional features to mention include: 1) the upper water reservoir arm constructed to divert most of the water out of West Canada Creek above Prospect Falls (in the upper right hand corner); 2) the lower reservoir catchment behind the power dam; 3) the long pipeline running along the west side of the gorge from the power dam downslope to the power house located at the base of the chasm; 4) the approximate position of Charles Walcott and William Rust's fossil quarry on "Gray's Brook" is about .75 miles west of upper High Falls along a small south flowing tributary; 5) the predominance of agricultural land in the areas adjacent to the falls (the main industry of the area is dairy farming); and 6) the intensity of wooded cover in the immediate vicinity of the chasm.
Topographic and approximate bedrock outcrop map of the Trenton Falls region
(from a portion of the Remsen, New York 7.5' quadrangle)
West Canada Creek, along its drainage from the Adirondacks to the Mohawk River, forms the geographical boundary between Oneida and Herkimer counties. Moreover, it divides the town of Trenton on the west from the town of Russia on the east. With respect to its position on the USGS 1:24,000 scale quadrangle maps, Trenton Falls lies in the southeastern portion of the Remsen, N.Y. 7.5' quadrangle as shown to the right. The contour interval is 20 feet on this map.
The topographic maps are scanned reproductions of the 1947 edition based on a polyconic projection using the North American datum 1927. As such, when comparing the topographic map with the orthoimagery from above (dated 1999) be aware that there are some changes with respect to landmarks and geomorphic features, most notably, the enlargement of the Prospect Quarry on the west side of the chasm. In the orthophoto above you will see the old pit just to the left of the creek. Modern improvements to the quarry include opening a newer and deeper section to the south and southwest. The quarry has expanded down dip in order to maximize production of Steuben Limestone, the clean crystalline limestone unit which is one of the primary quarry products.
The overlay map (colored version) indicates the approximate position where various Trenton Limestone Formations crop out in the region. The relative positions of each stratigraphic unit include: (from bottom to top) Kings Falls Formation, Sugar River Formation, Denley Formation, Rust Formation, and Steuben Formation. They have been projected based on their relative thickness assuming dips of nearly 30 degrees near the Prospect Fault (seen as dashed line) and dips leveling out downstream to about 5 degrees. Measurements by H.P. Cushing, 1909, indicate that near the downstream outlet of the gorge, dips reverse direction across a synclinal hinge.
Schematic cross-section from Trenton Falls to Prospect, New York
The Trenton gorge exposes the Trenton Limestone through the course of approximately 2.25 miles of West Canada Creek between Prospect, New York (in the north) and Trenton Falls Village (in the south). Through this portion of its drainage, West Canada Creek "has cut a deep narrow gorge through the Trenton limestone. This gorge, with nearly vertical walls, varies in depth from 100 to about 200 feet and is commonly known as "Trenton chasm." In all there are six waterfalls including those in the main gorge section, each varying in height from a few feet to 128 feet. The principal falls are: Sherman Fall, about 30 feet high and a short distance above the power house; High Falls (1/4 mile south of the railroad bridge) consisting of an upper and a lower part with a total fall of 128 feet; the falls at the dam (just north of the railroad bridge) about 40 feet high; and Prospect Falls (at the upper end of the gorge) 25 to 30 feet high. According to the topographic map, the total drop of the stream within the 2.25 miles is about 360 feet." Miller, 1909).
As demonstrated in the figure above, the Trenton chasm has a complicated structural geology with both synsedimentary (occurring at the time of deposition) structural features, and postsedimentary structural features including faults and folds. A brief discussion of these features will be presented in the discussion on the tectonic setting of Trenton Falls.