Hubbard Park Tower Earthcache
Hubbard Park Tower is situated on an upland knoll composed primarily of Devonian-aged granitic and metamorphic bedrock typical of the northern Appalachian orogeny. This region records a complex geological history of tectonic collision, mountain building, and erosion that spans over 400 million years. The granitic stone used in the tower construction is consistent with regional plutonic intrusions associated with the Acadian orogeny, and displays coarse-grained texture dominated by quartz, feldspar, and mica. The topography of the park, while influenced by underlying bedrock structure, has also been significantly shaped by the Pleistocene glaciations. During the last glacial maximum, around 20,000 years ago, the Laurentide Ice Sheet covered the Montpelier region with an ice thickness estimated at over one kilometer. As the glacier advanced and later retreated, it abraded and scoured the bedrock, depositing glacial till and erratics throughout the area. Evidence of glacial modification includes smoothed bedrock surfaces, striations, and transported boulders resting incongruently upon local lithology. From the summit of the tower, one can observe a glacially influenced landscape, including the Winooski River Valley to the south—likely a subglacial meltwater channel or an enlarged pre-glacial valley—and the distant Green Mountains, themselves composed of highly metamorphosed Paleozoic sediments and intrusives. This region exemplifies a classic New England post-glacial terrain: rolling hills, dendritic drainage patterns, and vegetative regrowth on glacially scoured surfaces. This EarthCache provides an opportunity to examine both the bedrock geology and the surficial geomorphology shaped by ice, offering insights into the dynamic processes that formed and continue to influence Vermont’s physiographic character.
TO QUALIFY TO LOG THIS EARTHCACHE YOU MUST ANSWER THE FOLLOWING QUESTIONS.
1. Describe what type of rock you see near Hubbard Tower. What color and texture does it have?
2. Can you find any signs of previous glacial activity in the area?
3. Examine the stone used in the construction of Hubbard Tower. Based on appearance, (color, grain size, mineral context and texture.) What type of rock do you think it is? Do you think it is local to the Montipelier region? Support your answer with at least two observations.