Tufa belong to a group of crust-like carbonate deposits that are formed through the organically and inorganically controlled precipitation of calcium carbonates from fresh water. Other members of this group are travertines, sinters, and lacustrine...

Tufa is the name for an unusual geological form of calcite rock. Tufa is a rough, thick, rock-like calcium carbonate deposit that forms by precipitation from bodies of water with a high dissolved calcium content. Tufa is not to be confused with tuff...

Reese Hoffa is unknown no more. He won the shot put Saturday while training partner Adam Nelson took second for a 1-2 U.S. finish on the opening night of the world track and field championships.Hoffa, who once donned a mask at a meet and called...