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AngularUnconformity
ANGULAR UNCONFORMITY: Along Interstate-70, New Castle --- Rock layers were deposited, hardened, uplifted at an angle, eroded flat, and then more rock was deposited on top.
Pallasite
Meteorites are fragments of solid material coming from space, found on earth after surviving passage through the atmosphere. There are two general categories of meteorites: stony meteorites and iron meteorites. However, stony-iron meteorites also exist. For example, the meteorite in this image shows olivine (a silicate mineral) embedded in an iron-nickel matrix. This type of meteorite (known as pallasite) was found in the Thiel Mountains of Antarctica. Specimen on display at the Chicago Field Museum of Natural History.
Hyracotherium
Skull and foot of Hyracotherium, a small horse with 3 hooves on its hind feet. Specimens from the Paleocene of Colorado, on display at the Field Museum of Natural History, Chicago.
El Peñón de Guatapé
El Peñón de Guatapé is a granitic monolith that rises about 200 m above the surrounding landscape, in the Antioquia region of NW Colombia. These isolated landforms are also known as "inselbergs" and are typical of granitic rocks in tropical regions.
Lizard and fish
This iguanid lizard, on display at the Field Museum of Natural History, Chicago, is perfectly preserved in full articulation. Minimal decay after death is necessary for this type of fossilization. Specimen from the Eocene of Fossil Lake Basin, Wyoming. Note the close association with some fossil fish also perfectly preserved.
Tyrrell Museum
Tyrrell Museum, Shonisaurus sikanniensis the world’s largest-known marine reptile (21 m long)
Great Unconformity_2
View of the contact between Precambrian basement and the Cambrian Sawatch Quartzite (marked by the tree line, mid-way through the picture), in the vicinity of Glenwood Canyon, CO, US. This important contact, an erosional discontinuity called "the Great Unconformity," is found over large sections of the North American continent.
Ripple cross-lamination
Cross-sectional view of a calcareous mudstone to fine-sandstone bed, showing planar lamination passing upward to ripple-cross lamination. The symmetric shape of the ripples, the presence of foreset laminae dipping in opposite directions, and some lamina draping suggest that the cross-lamination was likely generated by wave-ripples. The sequence from planar lamination to ripple cross-lamination can be indicative of decreasing velocity of bottom currents (or changes in sediment grainsize and supply rate). Diameter of lens cap is 6 cm. Photo taken at the I-70 roadcut, near Morrison, Colorado (Cretaceous Dakota Group).
Sandstone
Thin section microphotograph (in cross-polarized light) of a poorly sorted sandstone from Pliocene strata of the Sorbas Basin, Spain, containing lithic fragments of metamorphic rocks and gypsum clasts. The high birefringence colors of muscovite contrast with the gray colors of quartz. Field of view is several cm wide.