Field Study Gallery

FG-CD-87 Dinosaur geology: Sedimentary sequence at Ghost Ranch, New Mexico

FG-CD-87
Dinosaur geology: Sedimentary sequence at Ghost Ranch, New Mexico
Triassic Chinle Formation (red, foreground); Jurassic Entrada Formation (red/white cliffs); Jurassic Morrison Formation (slopes); Cretaceous Dakota Sandstone (upper cliffs). Aside for having been the residence of the artist Georgia O'Keeffe, Ghost Ranch, near Abiquiu, New Mexico, is also famous for the discovery of a mass mortality site of the dinosaur "Coelophysis". An expedition of the American Museum of Natural History led by Edwin Colbert found the site in 1947. Coelophysis was a small carnivorous dinosaur of the late Triassic.
Francois Gohier
Please note that prints are for personal display purposes only and may not be reproduced in any way

© Francois Gohier / ardea.com

FG-EA-731

FG-ea-731
GEOLOGY: K-T boundary - The K-T boundary claystone layer at the Sussex locality, Wyoming, USA
At bottom of the image is the mudstone of the Lance Formation (Cretaceous). On top is a coal bed of the Tullock Member of the Fort Union Formation (Tertiary). The K-T boundary layer is the gray to white kaolinitic claystone, less than 2 cm thick, at about the middle of the photo. On top of it is a darker, laminated layer a few millimeters thick, containing sand grains, many of them showing multiple sets of parallel fractures ("shocked quartz") under the microscope. Iridium can be detected in the claystone layer and in the carbonaceous layer immediately above it.
Francois Gohier

© Francois Gohier / ardea.com

Black Bear (in cinnamon color phase) equiped with ear tags and radio collar for research purposes

TOM-1461
Black Bear (in cinnamon color phase) equiped with ear tags and radio collar for research purposes
Wyoming - Grand Teton National Park - Western U.S.
Ursus americanus
Tom & Pat Leeson
Please note that prints are for personal display purposes only and may not be reproduced in any way

© Tom and Pat Leeson/ardea.com