The Goat Seep Formation is a
geologic formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
found in western
Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...
and southeastern
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe, New Mexico, Santa Fe
, LargestCity = Albuquerque, New Mexico, Albuquerque
, LargestMetro = Albuquerque metropolitan area, Tiguex
, Offi ...
. It is a
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
ized
reef
A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic processes—deposition (geology), deposition of ...
dating to the
Guadalupian
The Guadalupian is the second and middle series/ epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ...
Age of the
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Pale ...
period.
The formation underlies Bartlett Peak () and nearby areas in
Guadalupe Mountains National Park
Guadalupe Mountains National Park is an American national park in the Guadalupe Mountains, east of El Paso, Texas. The mountain range includes Guadalupe Peak, the highest point in Texas at , and El Capitan used as a landmark by travelers on the ...
.
Description
The Goat Seep Formation consists of up to of massive to thickly bedded light grey to white
dolomite. The lower part of the formation contains some
sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicates ...
beds. It grades below into the
Cherry Canyon Formation
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.Kues and Giles 2004, p.100
Descripti ...
and is overlain by the
Capitan Formation
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 formation underlies El Capitan in Guadalupe Mountains National ...
, a younger Permian reef. The Capitan Formation and Goat Seep Formation are quite similar, but are separated by an
unconformity
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval o ...
marked by ledges of dark limestone.
The formation represents a fossil reef, and grades laterally into the shelf limestones of the
Grayburg and
Queen Formations.
It is regarded as a precursor to the Capitan reef. The reef was built mostly by red (''
Solenopora
The extinct Solenoporaceae have traditionally been interpreted as a group of red algae ancestral to the Corallinales.
The genus from which they take their name, ''Solenopora'', originates in the Ordovician. Unlike the Corallinaceae, this family ...
'') and green (
Dasycladaceae
The Dasycladaceae is one of the two extant families of green algae of the order Dasycladales. When found in Palaeozoic limestones, they typically indicate depositional depth of less than 5m.See the NCBIbr>webpage on Dasycladaceae Data extract ...
) algae and
cyanobacteria (''
Girvanella'') with calcareous sponges,
bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a ...
, and
hydrocoral
Anthoathecata, or the athecate hydroids, are an order of hydrozoans belonging to the phylum Cnidaria. A profusion of alternate scientific names exists for this long-known, heavily discussed, and spectacular group. It has also been called Gymnob ...
s also playing a role.
Fossils
Portions of the formation are highly fossiliferous, and these include beds very rich in
fusulinids. However,
dolomitization (conversion of the original
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...
to dolomite) has resulted in very poor preservation of most of these fossils. The fusulinid ''
Parafusulina rothi'' has been identified in a few locations. Other tentative identifications are of the
sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...
''
Guadalupia
''Guadalupia'' is an extinct genus of sea sponges. It includes a number of extinct species including: ''Guadalupia auricula'', ''G. cupulosa'', ''G. ramescens'', ''G. microcamera'', and ''G. vasa''.[brachiopod
Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, ...]
s, some poorly preserved
gastropods
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. ...
, and a species of
trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...
, ''
Anisopyge
''Anisopyge'' is an extinct genus of trilobite belonging to the order Proetida and family Phillipsiidae. Specimens have been found in Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the ...
perannulata''.
[
]
History of investigation
The beds were first described by K.H. Crandall and assigned to the Chupadera Formation, a unit recognized in central New Mexico but since abandoned. W.B. Land assigned the same beds to the Dog Canyon Limestone, but P.B. King found this name too similar to that of a unit in the oil fields of Oklahoma, and he renamed the unit as the Goat Seep Limestone.[ N.D. Newell and coinvestigators renamed the formation as the Goat Seep Dolomite, due to its extensive dolomitization, and reassigned the shelf ]facies
In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formatio ...
originally assigned to the formation to the Queen Formation.
See also
* List of fossiliferous stratigraphic units in Texas
* Paleontology in Texas
References
{{Reflist
Permian geology of Texas
Permian formations of New Mexico