The US Geological Survey is conducting market research to identify qualified businesses for X-Ray Fluorescence (XRF) analysis of split sediment cores, as outlined in the attached Statement of Work. This is a sources sought notice for planning purposes only, not a request for proposals, and the government will not pay for any response costs. The applicable NAICS code is 541380 (Testing Laboratory) with a $16.5 million size standard, and the Product Service Code is B526. Responses must be submitted electronically to yangzhideng@usgs.gov by 07/22/2026 at 1200 PST. No budget amount or performance location is specified in the description.