CONSERVATION EFFORTS AND CHALLENGES OF A FOSSILIZED EOSPERMATOPTERIS TREE STUMP FROM GILBOA, NEW YORK

We are in the process of conserving a 700-pound Devonian Eospermatopteris tree stump from Gilboa, NY that showed signs of decay within a year of being improperly stored in a humid and warm environment. Starting in the Devonian, plants evolved vascular systems, allowing them to reach large sizes. Eospermatopteris is widespread in Middle Devonian strata, including the Gilboa Fossil Forest within the Hamilton Group in Upstate New York, the source of our specimen. Donated to Wellesley College in the 1920s, our Eospermatopteris stump was in good condition when displayed in a climate controlled setting until it was temporarily moved to a warm and humid environment during the renovation of our Science Center in 2021. It quickly began to degrade, with fist-size pieces falling off in sheets, likely due to pyrite weathering. To halt decay, the stump was consolidated using the highest recommended concentration (20x) of Primal Rhoplex WS24, a consolidant used to stabilize wet samples, wrapped in a layer of tinfoil, and covered in a plaster jacket, then moved to a drier environment inside the new Science Center. In order to move forward in our conservation efforts, different solutions of recommended adhesives (Paraloid B-72 and Butvar B-76) were tested on pieces of the stump that had already broken off. We decided to use both 10% and 30% solutions of Paraloid B-72 to restore the stump; the 10% solution that tends to creep into deep cracks is applied first, followed by the 30% solution that is also used to attach loose pieces on the surface. We are removing the plaster jacket in increments, cleaning the surface of the stump, and applying the two types of adhesive to the stump using squeeze bottles with applicators. Photographs of the unwrapped stump facilitate location of fragile areas where extra caution is needed. After consolidation, we plan to install an acrylic dome over the stump to ensure a climate controlled environment with low humidity.