La Tuna Formation | |
---|---|
Stratigraphic range: | |
Type | Formation |
Underlies | Berino Formation |
Overlies | Rancheria Formation, Helms Formation |
Thickness | 340–423 ft (104–129 m) |
Lithology | |
Primary | Limestone |
Other | Chert, shale |
Location | |
Coordinates | 31°58′0″N106°31′30″W / 31.96667°N 106.52500°W |
Region | New Mexico |
Country | United States |
Type section | |
Named for | La Tuna (Anthony, New Mexico) |
Named by | L.A. Nelson |
Year defined | 1937 |
The La Tuna Formation is a geologic formation in the Franklin Mountains of southern New Mexico and western Texas and the Hueco Mountains of western Texas. It preserves fossils dating back to the Bashkirian Age of the early Pennsylvanian. [1] [2]
The unit consists mostly of massive gray limestone with minor interbedded shale. The limestone is locally cherty [2] [3] and the upper beds include some thin shale lenses and algal mounds. [4] The total thickness is 340–423 ft (104–129 m). [5] [1] The formation lies on the Helms Formation [5] or Rancheria Formation [2] and is overlain by the Berino Formation. [5]
The formation contains detrital zircon grains of Cambrian age, which provides supporting evidence for a landmass thought to be present in Pennsylvanian time in the location of the modern Florida Mountains. [6] It is thought to have been laid down in the Horquilla Seaway, a continental shelf environment on the southwest coast of Pangaea. [3]
The formation contains crinoids and other fossils consistent with deposition in the Morrowan (Bashkirian). [1] The upper beds include some algal mounds. [4] The formation contains a diverse gastropod fauna, [7] as well as the foraminiferan Millerella , the demosponge Chaetetes . [8] [9] and the coral Petalaxis . [3] The base of the formation contains earliest Morrowan conodonts. [10] The red alga Masloviporidium delicatum has been reported in the formation. [11] Cordaites has been reported within a sandstone bed within the formation. [3]
The unit was designated the La Tuna Member of the Magdalena Group by L.A. Nelson in 1937. [12] In 2001, B. Kues recommended abandoning the Magdalena Group and raising its members, including the La Tuna, to formation rank. [4] Spencer G. Lucas and Karl Krainer have recommended demoting the La Tuna Formation in New Mexico to member rank within the Horquilla Formation. [3]
The Cherry Canyon Formation is a geologic formation found in the Delaware Basin of southeastern New Mexico and western Texas. It contains fossils characteristic of the Guadalupian Age of the Permian Period.
The Bell Canyon Formation is a geologic formation found in the Delaware Basin of southeastern New Mexico and western Texas. It contains fossils characteristic of the Guadalupian Age of the Permian Period.
The Bishop Cap Formation is a geologic formation in the Franklin Mountains of southern New Mexico and western Texas and the Hueco Mountains of western Texas. It preserves fossils dating back to the Moscovian to Kasimovian Ages of the early Pennsylvanian.
The Helms Formation is a geologic formation in Texas and New Mexico. It preserves fossils dating back to the Chesterian (Serpukhovian) Age of the Carboniferous period.
The Bone Spring Formation is a geologic formation found in the Delaware Basin in Texas and New Mexico. It preserves fossils dating back to the Leonardian Age of the Permian Period.
The Capitan Formation is a geologic formation found in western Texas and southeastern New Mexico. It is a fossilized reef dating to the Guadalupian Age of the Permian period.
The Hueco Formation is a geologic formation in west Texas and southern New Mexico. It preserves fossils dating back to the early Permian period.
The San Andres Formation is a geologic formation found in New Mexico and Texas. It contains fossils characteristic of the late Leonardian (Kungurian) Age) of the Permian Period.
The Red House Formation is a geologic formation found in the Caballo Mountains in New Mexico. It preserves fossils dating back to the middle to late Pennsylvanian.
The Sandia Formation is a geologic formation in New Mexico, United States. Its fossil assemblage is characteristic of the early Pennsylvanian.
The Bursum Formation is a geologic formation in New Mexico. It preserves fossils dating back to the Early Permian period.
The Berino Formation is a geologic formation in the Franklin Mountains of southern New Mexico and western Texas. It preserves fossils dating back to the middle Pennsylvanian.
The Madera Group is a group of geologic formations in northern New Mexico. Its fossil assemblage dates the formation to the middle to late Pennsylvanian period.
The Osha Canyon Formation is a geologic formation in the Nacimiento Mountains of New Mexico. It contains fossils characteristic of the Bashkirian stage of the Pennsylvanian period.
The Lead Camp Limestone is a geologic formation in the San Andres Mountains of New Mexico. It preserves fossils dating back to the middle Pennsylvanian.
The Gobbler Formation is a geologic formation in the Sacramento Mountains of New Mexico. It preserves fossils dating back to the Moscovian Age of the Pennsylvanian Period.
The Queen Formation is a geologic formation in southeastern New Mexico and west Texas. It preserves fossils dating back to the late Guadalupian Epoch of the Permian period.
The Victorio Peak Formation is a geologic formation found in the Delaware Basin in Texas and New Mexico. It preserves fossils dating back to the Leonardian Age of the Permian Period.
The Horquilla Formation is a geologic formation exposed in southern Arizona and New Mexico. It preserves fossils dating back to the Pennsylvanian.
The Canutillo Formation is a geologic formation that is exposed in the Franklin Mountains near El Paso, Texas. The formation is Middle Devonian in age.