B1: Geology of the Bald Mountain-Saddleback Wind Range, West-Central Maine

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Bald Mountain, between Wilton and Weld in west-central Maine (Fig. 1), hosts one of the largest continuous exposures of bedrock in this part of the state. It is a popular hiking destination and field site for undergraduate students. Bald has been a stop on an International Geological Congress (IGC) field trip (Moench, 1989) and two previous New England Intercollegiate Geological Conference (NEIGC) field trips (Reusch and Powers, 2006; Reusch et al., 2010).

Breakthroughs in understanding the geology of the Bald Mountain field site occurred during the fall of 2009, when digital photography was first employed to identify several marker beds with certainty, and during the fall of 2010, when repetitions of marker beds demanding cryptic thrust faults were first recognized (Hansen and Reusch, 2011).

Here, we describe the details of the microstratigraphy and structures within a field site located on the northeast ridge of the mountain, extending several hundred meters along the ridge. This site, which can be framed pedagogically as a microcosm of William Smith’s study area, has a great potential for introducing geology students to the principles of stratigraphy, structural geology, and geologic mapping. The bulk of this paper is based on a field guide for the Geological Society of Maine summer 2012 field trip (Reusch et al., 2012). Detailed (1cm = 10 m [1:1000 scale]) mapping is presented for the northeastern side of Bald. Mapping of the far side of Bald and Saddleback Wind is in progress.

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Guidebook for Field Trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference