PCP-PIRE interns Hannah O’Neill and Daniel Mercado sit on either side of a normal fault within the 19-million-year-old Cucaracha Formation. The line between Daniel’s right hand and Hannah’s feet marks the fault plane, the surface that formed when the rocks on the left side of the picture “slipped” 10 meters downwards, potentially during an earthquake millions of years ago. Photo credit Aaron Wood. Lillian Pearson, a PCP-PIRE intern, stands next to the welded tuff of the 19-million-year-old Cucaracha Formation. Welded tuffs form when particles of hot volcanic ash adhere or weld together after an ancient volcanic eruption. Zircon crystals from the welded tuff were radiometrically dated by PCP-PIRE scientists in order to know the age of the fossil animals and plants found in the rocks immediately below and above the tuff, such as the ancient soil that PCP-PIRE intern Adam Freierman is standing on. Photo credit Aaron Wood. These rust-red imprints are the part and counter-part of a fossil leaf preserved in the 21-million-year-old Las Cascadas Formation of the Panama Canal Basin. The midrib, or central vein, can be seen on each imprint with a few veins branching off to either side of the midrib. Photo credit Nathan Jud.