The town will be placing a stone dust surface on the Danvers Rail Trail starting in the late spring or early summer. The town previously applied a gravel base along the 4.3-mile recreational trail. Workers will now install finely compacted stone dust on top of that base, according to Kate Day, the town’s senior planner. The work is being funded with a $50,000 state grant that the town jointly secured with the town of Wenham this past December. Part of the funds will pay for placing stone dust on a portion of Wenham’s rail trail — the section adjacent to the new Swamp Walk that was built over a marsh area in Danvers and Wenham.