30 Applications of Igneous Petrology, Geochemistry, and Geochronology to Understanding Earth and Other Planetary Systems

This session invites contributions that explore igneous systems through traditional and nontraditional methods. Studies that link crustal evolution, planetary formation, resource potential, and comparative planetology across temporal and spatial scales are especially encouraged.

Tuesday, 10 March 2026
1:30 PM - 3:30 PM
RCC, 104

It’s not Bermuda: Geochemical and petrologic support for The Southeast American Hotspot Track of Cretaceous volcanics in the Mississippi Embayment.

Paper number: 30-0
Program: Technical Sessions
Time: 1:30 PM – 1:45 PM

Authors

Abstract

Southeast Laurentia has many Cretaceous-aged suites of alkalic volcanics with unknown origins and lack geochemical data. The primary goal of the research is to define the origins of Cretaceous-aged volcanism and volcanic materials in and around the Mississippi Embayment (MSE) through geochemical analyses via fusion inductively coupled plasma mass spectroscopy (F-ICP-MS). The MSE is within the Mississippi Valley Graben (MVG), an area of significant intraplate seismic activity and volcanism throughout geologic history. Throughout the MSE and surrounding region are suites of ultramafic and alkalic intrusive complexes and associated volcanic suites from the Cretaceous (~145–66 Ma), these suites include peridotite xenoliths, lamprophyre, kimberlite, phonolite, and carbonatite compositions. Geochemical (Major/Trace/REE) and petrologic analyses performed indicate deep mantle origins (≥150 km) for samples within a linear trend of volcanic provinces, providing context for hotspot volcanism being the mode of formation. REE curves indicate magma evolution in the presence of garnet. For samples from Magnet Cove, AR, they indicate similar evolution trends but are not as profound.  The proximity to each other and linearity of these volcanic suites suggest a possibility of a weak, short-lived, east moving hotspot passing beneath SE Laurentia during the Mesozoic.

Geological Society of America Abstracts with Programs. Vol. 58, No. 1

doi: 10.1130/abs/2026SE-411627

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