Love Ranch Formation Explained

Love Ranch Formation
Type:Formation
Period:Eocene
Prilithology:Conglomerate
Otherlithology:Siltstone, sandstone
Namedfor:Love Ranch
Namedby:Kottlowski, Flower, Thompson, and Foster
Year Ts:1956
Region:New Mexico
Country:United States
Coordinates:32.5506°N -106.578°W
Underlies:Palm Park Formation, Rubio Peak Formation
Overlies:McRae Formation
Thickness:2100feet

The Love Ranch Formation is a geologic formation in southern New Mexico. It was likely deposited during the late Paleocene and early Eocene epochs.

Description

The formation consists of boulder conglomerate interbedded with calcareous reddish siltstone and poorly-sorted, coarse-grained, arkosic sandstone. The lower beds tend to be more coarse. The formation is exposed in the western foothills of the San Andres Mountains and Organ Mountains. The formation unconformably overlies the McRae Formation and is conformably overlain by the Palm Park Formation or Rubio Peak Formation.

The formation is interpreted as alluvial fans and stream and playa deposits of sediments eroded from the Laramide Rio Grande uplift. This uplift dates to the latest Cretaceous and was initially tilted gently to the northeast, where McRae Formation beds accumulated in a shallow Love Ranch basin. Tectonism paused for perhaps 10 million years, producing an unconformity that separates the McRae from the Love Ranch Formation. The clasts within the conglomerate beds of the formation record the progressive erosion of beds from the uplift backwards in time, from Cretaceous volcanic clasts at the base of the formation to Precambrian clasts in its upper beds. The formation covered all but the highest ground in the uplift, which was subsequently completely buried by volcaniclastics and flows of the Mogollon-Datil volcanic field.

Palynomorphs from a buried section of the formation suggest its age is late Paleocene to early Eocene.

Fossils

The only fossils found in the formation are plant fragments.

History of investigation

The formation was first named by F.E. Kottlowski and coinvestigators in 1956 for exposures near the headquarters of Love Ranch, northeast of Las Cruces, New Mexico.

See also

References