To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

Mesa Rica Sandstone

From Wikipedia, the free encyclopedia

Mesa Rica Sandstone
Stratigraphic range: Albian
TypeFormation
Unit ofDakota Group
UnderliesPajarito Formation
OverliesTucumcari Shale, Glencairn Formation
Thickness33 meters (108 ft)
Lithology
PrimarySandstone
Location
Coordinates35°13′37″N 104°13′23″W / 35.227°N 104.223°W / 35.227; -104.223
RegionNew Mexico, Oklahoma
CountryUnited States
Type section
Named forMesa Rica
Named byDobrovolny, Summerson, and Bates
Year defined1947
Mesa Rica Sandstone (the United States)
Mesa Rica Sandstone (New Mexico)

The Mesa Rica Sandstone is a geologic formation in Oklahoma and New Mexico. It preserves fossils dating back to the Cretaceous period.[1]

Description

The Mesa Rica Sandstone consists of crossbedded white to buff sandstone. The sandstone is massive and medium- to coarse-grained. It is a very mature sandstone, consisting of almost pure quartz and kaolin, which may reflect its provenance as reworked sediments of the Morrison Formation, or may be due to a slow rate of deposition that permitted meteoric water (water originating as rain or snow) to circulate through the sediments for an unusually long time.[2] In some locations, there is minor quartz-pebble conglomerate at the base of the formation, which lies on the Tucumcari Shale[3] or Glencairn Formation. It is overlain by the Pajarito Formation and has a thickness of up to 33 meters (108 ft).[1]

The formation was laid down in a low-accommodation deltaic environment.[2]

Fossils

Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation.[4]

The upper part of the formation preserves dinosaur trackways and is part of the "dinosaur freeway" megatracksite of New Mexico, Colorado, and Oklahoma. Dinosaur tracks were discovered in the formation at the spillway of Clayton Lake State Park in 1982, at Mosquero Creek in 1986, and at Mills Canyon in 1995. The Mills Creek site shows twelve distinct trackways. The Clayton Lake trackways are unusual in showing trail dragging traces. The trackways here are accessible by a trail with interpretive signage but are rapidly eroding in the lake spillway. Most of the tracks at the three sites have been identified as Charirichnium leonardii.[5]

The Mosquero Creek tracks represent 81 individual ornithopod dinosaurs, of two distinct species, and includes a rare limping track.[5] The trackways also preserve evidence of movement as a group.[6]

The lower part of the Mesa Rica Sandstone preserves marine invertebrate fossils, including the ammonite Mortoniceras equidistans (Cragin)[7]

History of investigation

The unit was first named the Mesa Rica sandstone member of the Purgatoire Formation by Ernest Dobrovolny, Charles Summerson, and Robert Bates in 1947.[3] It was raised to formation rank by Robert Griggs and Charles Read in 1959, who also abandoned the use of the Purgatoire Formation in northeastern New Mexico.[8]

See also

Footnotes

References

This page was last edited on 13 February 2024, at 08:27
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.