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Mar 6

Analysis Seminar: Grassmannian codes from stratified frames

Mar 6, 2026, 11:30 AM - 12:30 PM

Mar 6

Topology, Algebraic Geometry, and Dynamics Seminar (TADS): Feynman graph integral on K\”ahler manifolds

Mar 6, 2026, 1:30 - 2:30 PM

Mar 6

Dissertation Defense - Paul Montgomery, PhD Bioinformatics & Computational Biology

Mar 6, 2026, 3:00 - 5:00 PM

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12 Feb (GEOL) Allen Gellis, Geomorphology

Feb 12, 2026, 4:30 - 5:30 PM

Speaker: Allen Gellis, Department of AOES, George Mason University 

Time: Thu, 12 Feb, 4:30pm ET

Location: Exploratory 1309 and via Zoom (for link, email lhinnov@gmu.edu)

Title: Sediment Fingerprinting: Provenance in a Watershed Context 

Host: Linda Hinnov

 

Abstract: Sediment provenance, in the geologic sense, commonly refers to the source rocks and tectonic setting from which sediment was derived, as well as the pathways it followed before being deposited in a sedimentary basin. Sediment fingerprinting is related, but focuses on identifying modern sources of fluvial sediment, typically the silt and clay fraction (<63µm), within a watershed context. 

Sediment fingerprinting is based on characterizing the geochemical properties of potential upstream “sources” and comparing them to "target" sediment collected at a downstream delivery point.  By using statistical mixing models, the relative contributions of different land uses or geomorphic sources can be determined.

Because sediment is a major pollutant worldwide — degrading aquatic ecosystems, contaminating water supplies, reducing recreational opportunities, and impairing navigation channels — determining its sources is imperative for developing effective and targeted management strategies to mitigate sediment inputs. Consequently, sediment fingerprinting represents an effective approach to assist land managers in this endeavor. This talk will focus on the methods used in sediment fingerprinting, selected case studies, management implications, and future research needs.

 

Bio: Allen Gellis is currently an adjunct professor at George Mason University. Before this, he was a Research Geomorphologist with the U.S. Geological Survey, where he was stationed in San Juan, Puerto Rico; Albuquerque, New Mexico; Baltimore, Maryland; and Reston, Virginia. Allen received his Ph.D. and M.S. degrees in Geology from Colorado State University and his B.S. in Geology from SUNY Albany. He is a Fellow of the Geological Society of America. His research has focused on a variety of geomorphic topics, including sediment fingerprinting, sediment budgets, arroyos, sediment yields to Chesapeake Bay, and stream restoration. 


 

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