30 New advances in geological and geophysical research on the Appalachian orogen. (Posters)

We invite contributions that discuss new research on the Appalachian orogen. Submissions should include, but are not limited to, geological or geophysical studies or works comprising a combination of both methods.

Monday, 23 March 2026
1:30 PM - 5:30 PM
CCC, Ballroom C

New Earth MRI airborne magnetic and radiometric data collected over southern New England

Paper number: 30-2
Program: Technical Sessions
Time: 1:30 PM – 1:30 PM

Authors

Abstract

We present preliminary results from an Earth Mapping Resources Initiative (Earth MRI) airborne magnetic and radiometric survey collected May-Oct 2025 over the Connecticut Valley and surrounding area. The survey, covering parts of Connecticut, Massachusetts, New Hampshire, Rhode Island, and Vermont, extends from Long Island Sound in the south to north of Keene, NH and is ~200 km N-S by 125 km E-W. Potential applications of this effort include mapping of potential geohazards such as pyrrhotite used in construction, earthquakes, and radon, and natural resource studies including both critical and industrial minerals.

The survey was flown with E-W flight lines spaced 250 m apart along a draped surface with a nominal height of 120 m above ground. However, over more populated areas (~40% of the survey area) the clearance was lifted to 330 m above ground for safety reasons.

Post-processed data were not available at the time of this abstract, but field data show key relations to known geology and structure. Numerous magnetic lineaments are present and trend mostly N-NNE except in the southeastern part of the survey over the Avalon terrane, where they show more complex and variable patterns. The highest magnetic anomalies follow mapped structural trends and generally correspond to Proterozoic and Paleozoic granitic and mafic gneiss as well as amphibole-bearing units. Several ovate magnetic highs are associated with mapped intrusions and/or domes, but several others do not show clear associations; these may represent buried features. The Mesozoic Hartford-Deerfield rift basin is associated with smooth magnetic anomalies, attributable to non-magnetic sedimentary basin fill and deeper magnetic sources beneath the basin (most likely Paleozoic metamorphic and igneous rock). The exception is multiple narrow (< 1 km wide) anomalies corresponding to Mesozoic basalt flows, dikes, and sills; several of the latter appear to show post-emplacement deformation. Similar narrow anomalies outside the rift basin are associated with Mesozoic dikes. West and north of the rift basin, metasedimentary rocks are associated with relatively smooth magnetic anomalies.

Upcoming studies will include ground-truthing geophysical anomalies at outcrops via magnetic susceptibility and other petrophysical measurements, and, conversely, using the airborne data to assist mapping in areas covered with vegetation or inaccessible due to land use.

Geological Society of America Abstracts with Programs. Vol. 58, No. 2

doi: 10.1130/abs/2026NE-411113

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