The Hayner Ranch Formation is a
geologic formation found near the
San Diego Mountains of
New Mexico. It is estimated to have been deposited during the
Miocene epoch.
Description
The Hayner Ranch Formation consists of about of red to tan
volcaniclastic conglomerate
Conglomerate or conglomeration may refer to:
* Conglomerate (company)
* Conglomerate (geology)
* Conglomerate (mathematics)
In popular culture:
* The Conglomerate (American group), a production crew and musical group founded by Busta Rhymes
** Co ...
,
mudstone
Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology. ...
, and
sandstone. It is the lowest formation of the
Santa Fe Group
The EAC Invest A/S, formerly known as the Santa Fe Group and East Asiatic Company ( da, italic=yes, Det Østasiatiske Kompagni or ''ØK'') is a multinational holding and investment company, based in Copenhagen, Denmark.
History
The East Asiat ...
in the San Diego Mountains area, overlying older volcanic rock of the
Spears Group
The Spears Group is a group of geologic formations exposed in and around the northeast Mogollon-Datil volcanic field of southwestern New Mexico. It has a radiometric age of 33 to 39 million years, corresponding to the Eocene to Oligocene epochs ...
. The formation fills
paleovalleys eroded in the underlying volcanic beds.
The formation is particularly well exposed in a
half graben between the East and West
Selden Hills
Selden Hills are a range of hills in Doña Ana County, New Mexico, USA. They lie just over a mile northwest of Radium Springs east of the Rio Grande at the lower end of Rincon Valley. They are named for Fort Selden
Fort Selden was a United St ...
; in Selden Canyon to the west; at its
type section in the Tonuco Uplift; and in the Rincon Hills to the north, where it is coarser (including boulder conglomerates) and partially silicified. The formation is interpreted as
stream
A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...
and
floodplain deposits near the axis of a broad
closed basin. The narrow (12 km) half graben is tilted to the northeast and has its
footwall on the
Caballo Mountains
The Caballo Mountains, ( Spanish: "horse") are a mountain range located in Sierra
Sierra (Spanish for "mountain range" and "saw", from Latin '' serra'') may refer to the following:
Places Mountains and mountain ranges
* Sierra de Juárez, a m ...
block, where displacement was about . Study of the formation and others in the area support at least four episodes of block faulting starting 35 million years ago, almost all along faults trending north–south.
The formation records the unroofing of the Caballo Mountains. Clasts in the lower part of the formation are
derived from the underlying
Spears Group
The Spears Group is a group of geologic formations exposed in and around the northeast Mogollon-Datil volcanic field of southwestern New Mexico. It has a radiometric age of 33 to 39 million years, corresponding to the Eocene to Oligocene epochs ...
and those higher in the formation from the
Eocene Palm Park and
Love Ranch Formations. However, clasts from the
Doña Ana Mountains are absent from the formation, showing that these mountains had not yet been unroofed during deposition of the formation.
The formation has been studied as a model for the critical early stages of
diagenesis of
continental red beds of
Pennsylvanian Pennsylvanian may refer to:
* A person or thing from Pennsylvania
* Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timesca ...
to
Triassic age. and as a model for diagenesis in the Santa Fe Group.
History of investigation
The formation was first defined by Seager ''et al.'' in 1971, and assigned to the Santa Fe Group.
Footnotes
References
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* {{cite journal , last1=Walker , first1=Theodore R. , last2=Waugh , first2=Brian , last3=Grone , first3=Anthony J. , title=Diagenesis in first-cycle desert alluvium of Cenozoic age, southwestern United States and northwestern Mexico , journal=GSA Bulletin , date=1 January 1978 , volume=89 , issue=1 , pages=19–32 , doi=10.1130/0016-7606(1978)89<19:DIFDAO>2.0.CO;2, bibcode=1978GSAB...89...19W
Neogene formations of New Mexico