Juana Lopez Member facts for kids
Quick facts for kids Juana Lopez MemberStratigraphic range: Turonian |
|
|---|---|
| Unit of | Carlile Formation |
| Underlies | Niobrara Formation |
| Overlies | Codel Sandstone member of the Carlile |
| Thickness | 0–6 feet (0.0–1.8 m) |
| Lithology | |
| Primary | Sandstone with abundant carbonate fossil grains |
| Other | Gravel, Codel fragments |
| Location | |
| Coordinates | 35°29′12″N 106°12′04″W / 35.4866°N 106.2010°W |
| Country |  United States |
| Type section | |
| Named for | Mesita Juana Lopez Grant, six miles northwest of Los Cerrillos, New Mexico |
| Named by | Rankin |
| Year defined | 1944 |
Juana Lopez refers to both the uppermost member of the Carlile Shale formation and to the environment that caused it to form. This unit is calcareous sandstone of Turonian age, Upper/Late Cretaceous series in the southern and western Colorado and northern and central New Mexico.
Where present, the Juana Lopez is "the most enigmatic" member of the Carlile Shale. It consists of sand with a large content of indistinguishable grains of fragmented coral, shells (especially inoceramid prisms), sharks teeth, bone, etc. It smells of sulfur when freshly broken. It formed on wide, shallow marine shelf, with strong wave action, but with little sediment coming in from land. It was exposed on the land surface between the retreat of the Greenhorn cycle and the advance of the Niobrara cycle of the Western Interior Seaway.
Images for kids
-
Concretion and ammonite cast from the Juana Lopez Member
