A metro Atlanta nonprofit is teaming up with college students to find the exact age of historic buildings using a unique area of study. While historical documents may say a building was constructed in a certain year, the wood used to create the structure could tell us a different story. Cobb Landmarks is using dendrochronology — the study of tree rings — to pinpoint when wood for metro Atlanta buildings was harvested for construction. Trevor Beemon, Cobb Landmarks’ executive director, said they are partnering with University of West Georgia students who, under the guidance of two professors, will take 12 to 15 samples from structures around metro Atlanta. …The partnership is “really the one chance” South Downtown has to learn about these buildings before they are redeveloped, Capps said.