James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 1
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 2
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 3
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 4
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 5
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 6
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 7
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 8
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 9
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 10
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 11
James St. John: Rhyolitic pumice (El Cajete Pumice, Upper Pleistocene, 55-60 ka; Route 4 roadcut, Valles Caldera, New Mexico, USA) 12