Department or Program



The East Andover 7.5’ Quadrangle is located in Oxford County, Maine, and encompasses a multitude of stratigraphic units, from Silurian metasedimentary units to Devonian intrusives, along with a unique gem bearing pegmatite. Originally mapped by in 1976 by Moench and Hildreth as the southwest corner of the Rumford 15’ Quadrangle, the East Andover 7.5’ Quadrangle has now been remapped at a 1:8,000 scale as part of the Earth Mapping Resources Initiative (Earth-MRI), a USGS and MGS funded project that aims to locate potential deposits of rare elements such as lithium and cesium, elements commonly found in the LCT pegmatite class. This work further analyzes the structures seen within the field: two stages of folding, F1 and F2, as well as identifying a shear zone and a late brittle fault shown by a silicified zone. Also investigated is the existence of the Plumbago Mountain Fault (PMF) through detailed field investigation. The PMF is a pre-metamorphic listric fault reported in old literature but with no consensus on its existence sin field. The preliminary results from our field investigation further corroborates that fault either does not exist in East Andover 7.5’ Quadrangle or remained unidentified.

Level of Access

Open Access

First Advisor

Shreya Arora

Date of Graduation


Degree Name

Bachelor of Science

Number of Pages


Components of Thesis

2 pdf files

Open Access

Available to all.