Goat Seep Formation
{{Short description|Geologic formation in Texas and New Mexico, US}}
{{Infobox rockunit
| name = Goat Seep Formation
| image =
| caption =
| type = Formation
| age = {{Geological range|Guadalupian}}
| period = Guadalupian
| prilithology = dolomite, limestone
| otherlithology = sandstone
| namedfor = Goat Seep (spring)
| namedby = King
| year_ts = 1942
| region = Texas
New Mexico
| country = United States
| coordinates = {{coord|31.9040|N|104.8805|W|display:inline}}
| unitof =
| subunits =
| underlies = Capitan Formation
| overlies = Cherry Canyon Formation
| thickness = {{convert|1200|ft|m|abbr=on}}
| extent =
| area =
| map = {{Location map+ | United States#Texas
| relief = 1
| width = 250
| float = center
| places =
{{Location map~ | United States#Texas
| lat_deg = 31.9040
| lon_deg = -104.8805
| mark = Red pog.svg
| marksize = 12
}}
}}
| map_caption =
}}
The Goat Seep 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 Bartlett Peak ({{coord|31.9177|N|104.8817|W|display=inline}}) and nearby areas in Guadalupe Mountains National Park.
Description
The Goat Seep Formation consists of up to {{convert|1200|ft||sp=us}} of massive to thickly bedded light grey to white dolomite. The lower part of the formation contains some sandstone beds. It grades below into the Cherry Canyon Formation and is overlain by the Capitan Formation, a younger Permian reef. The Capitan Formation and Goat Seep Formation are quite similar, but are separated by an unconformity marked by ledges of dark limestone.{{cite web |last1=Scholle |first1=Peter |title=Permian Reef Complex Virtual Field Trip, Stop I-1: West Face of Guadalupe & Delaware Mountains |url=https://geoinfo.nmt.edu/tour/federal/parks/PermianReef/stops/pmstop1_1.html |website=New Mexico Bureau of Geology & Mineral Resources |publisher=New Mexico Tech |access-date=4 February 2022}}{{cite journal |last1=King |first1=Philip B. |title=Geology of the Southern Guadalupe Mountains, Texas |journal=U.S. Geological Survey Professional Paper |series=Professional Paper |date=1948 |volume=215 |doi=10.3133/pp215|url=https://digital.library.unt.edu/ark:/67531/metadc1036553/ }}
The formation represents a fossil reef, and grades laterally into the shelf limestones of the Grayburg and Queen Formations.{{cite journal |last1=Hayes |first1=P.T. |title=Geology of the Guadalupe Mountains, New Mexico |journal=U.S. Geological Survey Professional Paper |date=1964 |volume=446 |doi=10.3133/pp446|doi-access=free }} It is regarded as a precursor to the Capitan reef.{{cite journal |last1=Crawford |first1=G.A. |year=1979 |title=Sedimentology of Goat Seep Dolomite (Guadalupian, Permian), Guadalupe Mountains, West Texas and New Mexico |journal=AAPG Bulletin |volume=63 |number=3 |pages=437-437 |url=https://archives.datapages.com/data/bulletns/1977-79/data/pg/0063/0003/0400/0437.htm |access-date=7 February 2022}} The reef was built mostly by red (Solenopora) and green (Dasycladaceae) algae and cyanobacteria (Girvanella) with calcareous sponges, bryozoa, and hydrocorals also playing a role.{{cite journal |last1=Kuznetsov |first1=V. G. |title=Reef Construction in the Second Half of the Permian and Biotic Crisis at the Permian–Triassic Boundary |journal=Stratigraphy and Geological Correlation |date=December 2018 |volume=26 |issue=7 |pages=755–770 |doi=10.1134/S086959381807002X}}
Fossils
Portions of the formation are highly fossiliferous, and these include beds very rich in fusulinids. However, dolomitization (conversion of the original limestone 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 Guadalupia zitteliana, several genera of brachiopods, some poorly preserved gastropods, and a species of trilobite, Anisopyge 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.{{cite journal |last1=Crandall |first1=K.H. |title=Permian Stratigraphy of Southeastern New Mexico and Adjacent Parts of Western Texas |journal=AAPG Bulletin |date=1929 |volume=13 |issue=8 |pages=927-944 |doi=10.1306/3D93286C-16B1-11D7-8645000102C1865D}} W.B. Land assigned the same beds to the Dog Canyon Limestone,{{cite journal |last1=Lang |first1=W.B. |title=The Permian Formations of the Pecos Valley of New Mexico and Texas |journal=AAPG Bulletin |date=1937 |volume=21 |issue=7 |pages=833-898 |doi=10.1306/3D932EDE-16B1-11D7-8645000102C1865D}} 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.{{cite journal |last1=King |first1=P.B. |title=The Permian of West Texas and Southeastern New Mexico: Part 1 |journal=AAPG Bulletin |date=1942 |volume=26 |issue=4 |pages=535-649 |url=https://archives.datapages.com/data/bulletns/1938-43/data/pg/0026/0004/0500/0535.htm?doi=10.1306%2F3D933466-16B1-11D7-8645000102C1865D |access-date=7 February 2022}} N.D. Newell and coinvestigators renamed the formation as the Goat Seep Dolomite, due to its extensive dolomitization, and reassigned the shelf facies originally assigned to the formation to the Queen Formation.{{cite book |first1=N.D. |last1=Newell |first2=J.K. |last2=Rigby |first3=A.G. |last3=Fischer |year=1953 |title=The Permian reef complex of the Guadalupe Mountains region, Texas and New Mexico, a study in paleoecology |location=San Francisco |publisher=W. H. Freeman and Co. |pages=42-43}}
See also
{{Portal |Earth sciences|Texas|Paleontology}}