This paper began as an attempt to understand the geology of the Boston Basin for purposes determining a risk profile and remediation plan as part of a Clean Water Act legal notice. That research resulted in an assessment that no coherent, evidence-based explanation for the geology of the Boston Basin exists in the published literature. However, the literature captured extensive evidence that could be analyzed under new theories and methodologies. Over a century of geological surveys, engineering boring logs, and geotechnical investigations have documented a suite of anomalies that the prevailing glacial framework cannot explain: fault-controlled kaolinization to depths exceeding 300 feet, rock recrystallization at 175–250°C with no documented heat source for 400 million years, a chondritic mineral fingerprint, shock-hardened megaclasts, varve-less fossil-less marine clay, and platinum group elements at five times background concentrations. Reconstructing the geology from original data and modern impact science, this paper concludes that the most parsimonious and only coherent explanation for the full suite of documented anomalies in the Boston Basin is a bolide swarm impact. Further, existing geological consensus already dates the mass debris event that shaped most of the superficial geology in the area at 12,900 years before present – already acknowledging the timeline is consistent with the Younger Dryas Impact Hypothesis. The revelation this paper presents is simply a new analysis of the same underlying data – but this time through impact science rather than glacial theories. The Boston Basin presents a comprehensive case study of hydrothermal/shock impact caused by a bolide swarm hitting a thick ice sheet in a marine environment. If this revised analysis is correct, then the Boston Basin is not a glacial landscape. Boston is an impact site. Further, by the dates already established in Boston geological consensus – Boston is ground zero for the Younger Dryas Impact Hypothesis – the previously missing impact crater. US EPA Region 1 confirmation of CERCLA petition & Clean Water Act notice: Tuesday March 31 2026 Additional Resources: Change.org Petition for a Formal Reassessment of the Geology of the Boston Basin (Massachusetts), https://www.change.org/p/petition-for-a-formal-reassessment-of-the-geology-of-the-boston-basin-massachusetts Gjøvik, Ashley Marie. “Bolide Impact Origin of Norwegian Fjords: Physical Model, Erosion Mechanics, and Implications for Global Fjord Formation”. The Journal of Decolonized Ecology and Evolution 1, no. 1 (April 5, 2026). https://doi.org/10.5281/zenodo.19432096. Gjøvik, A. M. (2026). A CERCLA Petition and Clean Water Act Citizen Suit Notice regarding the South Bay, Fort Point Channel, Roxbury Creek, and Dorchester Brook in Boston, Massachusetts. Zenodo. https://doi.org/10.5281/zenodo.18634019 (txt) Gjøvik, A. M. (2026). “Living Organisms Morphologically Consistent with Gunflint Chert Microfossils (ca. 1.9 Ga) Recovered in South End, Boston, Massachusetts”. The Journal of Decolonized Ecology & Evolution 1, no. 1 (March 18, 2026). https://doi.org/10.5281/zenodo.19086003. Gjovik, Ashley, The South Bay, ashleygjovik.com/southbay