John Cancalosi / Cross-Section of Utah Septarian Nodule, Utah. A type of geode, Utah Septarian Nodules are found about 15 miles east of Zion National park. They were formed in an ancient sea floor during the Cretaceou...

John Cancalosi / Fossil Fly (species unknown) from the Early Cretaceous Period. Santana Formation, Brazil

John Cancalosi / Fossil Dragonfly (Cordulagomphus fenestratus) from the Lower Cretaceous Period, 125 million years old. Araripe basin, Brazil

Graham Eaton / Vertically dipping Cretaceous Chalk exposed at Swyre and Bat's Head, near Weymouth, Dorset UK. A post-glacial channel can be seen at the top of the nearer headland, as cream coloured sand and grav...

Graham Eaton / Vertically dipping Cretaceous Chalk exposed at Bat's Head, near Weymouth, Dorset UK. Isolated from the headland is a small sea stack that once formed part of main cliff. A natural arch at the base...

Graham Eaton / Sea Stacks of Cretaceous age Chalk near Old Harry Rocks, Studland, Dorset, March. These stacks are locally called The Pinnacles.

John Cancalosi / Confuciusornis sp. fossil. This genus was a primitive crow-sized bird from the Early Cretaceous Yixian and Jiufotang Formations of China, dating from 125 to 120 million years ago

Will Watson / Karst Bridge, a natural limestone arch from, Cretaceous Period with Cainozoic folding located within Primeval Beech Forest, Carpathian Biosphere Reserve, UNESCO World Heritage Site, Zakarpattia Oblast...

Will Watson / Karst Bridge, a natural limestone arch from, Cretaceous Period with Cainozoic folding located within Primeval Beech Forest, Carpathian Biosphere Reserve, UNESCO World Heritage Site, Zakarpattia Oblast...

Will Watson / Karst Bridge, a natural limestone arch from, Cretaceous Period with Cainozoic folding located within Primeval Beech Forest, Carpathian Biosphere Reserve, UNESCO World Heritage Site, Zakarpattia Oblast...

Graham Eaton / Rotated normal fault in Cretaceous chalk with erosion, small caves at base. Chalk beds vertical and parallel with the cliff, Durdle Door, Jurassic Coast, Dorset, England, April 2012.

Graham Eaton / Vertical beds of Cretaceous chalk, with layers of flint and rotated normal faults, Jurrasic Coast, near Durdle Door, Dorset, England, UK.