Fluting, grooved and drumlinized bedrock west of Bloody River. Aerial view looking west in the direction of the ice movement. Thursday 6 August, 1959.

Fluorite, Westmoreland, New Hampshire. An excellent example of the octahedral cleavage fluorite.

Fluorite, Rosiclare, Illinois. Typical cleavage octahedra.

Fluorite, Cave-in-Rock, Illinois. A group of large purple cubic crystals.

Flow lines of ice over and around drumlin.

Ice sections from depth of 71 (top) and 300 metres (bottom) at Byrd Station are magnified 3.25 diameters (a grid square represents one square centimeter). The numerous tiny gray, white and black spherules are air bubbles trapped by the ice. With increased depth, ice crystals tend to become larger and air bubbles smaller. The deeper ice was deposited as anow about 1,600 years ago (Scientific American, Spet. 1962, p. 133).

Pennsylvanian landscape in the swampy lowlands showing characteristic vegetation and sprawling amphibians. Plants: 1. a tree fern, 2. 'Lepidodendron', a scale tree, 3. 'Sigillaria', a scale tree, 4. 'Cordaites', a precursor of the conifers, 5. 'Calamites', a scouring rush. Animals: 6. 'Diplovertebron', a primitive amphibian, 7. 'Ecyops' (?), a large amphibian, 8. 'Eogyrinus', one of the largest amphibians, 9. 'Seymouria', a primitive reptile, 11. 'Varanosaurus', a reptile, 12. 'Meganeuron', a giant dragonfly like insect. (Dunbar, 1960, p. 218).

Floodplain deposits. A. Schmetic plan of deposits alonf Mississippi River near Lake Providence, Louisiana. B. Schematic cross section of floodplain deposits of a meandering river, showing lenses of deposits of channel deposits (dotted, clay plugs in solid black) in matrix of interchannel deposits. Length of area shown, several tens of miles; large vertical exaggeration. Dunbar and Rodgers, 1957, p. 34.

Flood plain terrace along South Saskatchewan River in Saskatoon. View from 25th Street bridge toward Bessborough. December, 1962.

Flaxville Pliocene (?) gravels at base overlain by about 2 feet basal till and up to 10 feet of stony ablation till. South edge of Loring Plateau where road descends into the Milk River Valley, outcrop along Loring-Malta road. April 1964.

Flat-topped dolomite fill stone showing different sized striations in many directions. West of Halbrite, Sask. May, 1962.

Flat irons. Strata on end. Utah.

"Flaring" of gully. Where gully at left has out through the drift into the underlying Bear Paw Shale noticeable "flaring" occurs and a wide bowl-shaped valley is formed, which is widened mainly by miniature pedimentation on the Bear Paw shales and which is used as a city dump area because it is a relatively hidden depression. Swift Current, old city dump. November 7, 1962.

Flank of Cantaur field looking west along north boundary of T. 16, R. 16, W.3. Saline Lake in foreground.

First and last of the titanotheres. Right, Eotitanops of the Eocene epoch, left, Brontotherium of the Oligocene epoch. The latter stood about 8 feet high at the shoulders.