Mission Valley Formation
| Mission Valley Formation | |
|---|---|
| Stratigraphic range: Paleogene | |
| Type | Geologic formation |
| Underlies | Pomerado Conglomerate |
| Overlies | Stadium Conglomerate |
| Thickness | 0–60 metres (0–197 ft) |
| Lithology | |
| Primary | sandstone |
| Location | |
| Region | San Diego County, California |
| Country | United States |
| Type section | |
| Named for | Mission Valley, San Diego |
The Mission Valley Formation is a marine sandstone geologic formation in the Mission Valley region of southwestern San Diego County, California.[1][2]
Geology
[edit]The formation's sandstone characteristics are: soft and friable, light olive gray, fine to medium grained, and composed mostly of quartz and potassium feldspar.[1] The Mission Valley Formation thins from the west to the east, with a maximum thickness of 0–60 metres (0–197 ft).[1]
It overlies the Stadium Conglomerate formation and underlies the Pomerado Conglomerate formation.[1]
Fossil content
[edit]It preserves fossils dating back to the Paleogene period of the Cenozoic Era.[3] The formation's rocks can contain a molluscan fauna in the western and central exposures and a land-mammal fauna in the eastern exposures.[1]
Mammals
[edit]Eulipotyphlans
[edit]| Eulipotyphlans reported from the Mission Valley Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Proterixoides | P. davisi | Several calcaneums, astragali and a navicular.[4] | |||
Ferae
[edit]| Ferae reported from the Mission Valley Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Ceruttia | C. sandiegoensis | "SDSNH locality 4888, State Road 125 North (Unit II, Mid Brown Siltstone)".[5] | SDSNH 92504 and SDSNH 92503.[5] | A carnivoraform. | |
| cf. 'Miacis' | cf. 'M.' hookwayi | SDSNH locality 4715, State Route 125 Grossmont.[5] | SDSNH 84969 "right dentary fragment with p2, m1, and m2".[5] | A miacid. | |
| Procynodictis | P. progressus | SDSNH locality 3870, Scripps Ranch North Site 70.[5] | "SDSNH 54413 (left dentary fragment with p2-m2); SDSNH 54414 (right dentary fragment with m1-2); SDSNH 54416 (left maxillary fragment with P4-M1)".[5] | A miacid. | |
Primatomorphs
[edit]| Primatomorphs reported from the Mission Valley Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Hemiacodon | H. sp. | V-72157.[6] | Isolated fragmentary teeth.[6] | An omomyid, most similar to H. gracilis. | |
| ?Macrotarsius | ?M. sp. | V-72150 & V-73138.[6] | Isolated molars.[6] | An omomyid also known from the Friars Formation, closely similar to M. jepseni. | |
| Microsyops | M. sp. cf. M. annectens | V-72158.[6] | Isolated & fragmentary molar (UCMP 101619).[6] | A microsyopid. | |
| Notharctus | N. sp. | V-72157.[6] | Damaged isolated molar (UCMP 113256).[6] | A notharctine similar to N. robustior. | |
| Omomys | O. powayensis | V-71180, V-72157 & V-72158.[6] | Teeth.[6] | An omomyid also known from the Friars Formation. | |
| Pelycodus | P. sp. | V-73138.[6] | Maxillary fragment (UCMP 113210).[6] | A notharctine. | |
| Uintasorex | U. montezumicus | V-71180, V-71211, V-72157, V-72158, V-72176, V-72177, V-72179, V-73138 & V-73139.[6] | Isolated teeth.[6] | A microsyopid also known from the Friars Formation. | |
| Walshina | W. esmaraldensis | SDSNH localities 3426 and 4020.[7] | Teeth.[7] | An omomyid also known from the Sespe & Santiago formations. | |
| Washakius | W. woodringi | V-71211, V-72157, V-72158, V-72176, V-72179 & V-73138.[6] | Teeth & jaw elements.[6] | An omomyid also known from the Friars Formation. | |
See also
[edit]
- Geology of San Diego County, California
- Paleogene Period in California
- List of fossiliferous stratigraphic units in California
- Paleontology in California
References
[edit]- ^ a b c d e Kennedy, Michael P. (1975). Geology of the San Diego metropolitan area, California. California Division of Mines and Geology.
- ^ Geiconsultants.com: Geologic Formations of Western San Diego County[permanent dead link], by Jeffrey D. Brown, R.G., C.E.G. − circa 1996.
- ^ Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.
- ^ PENKROT, TONYA A.; ZACK, SHAWN P. (2016). "Tarsals of Sespedectinae (?Lipotyphla) from the Middle Eocene of Southern California, and the Affinities of Eocene 'Erinaceomorphs'". Journal of Vertebrate Paleontology. 36 (6): e1212059. Bibcode:2016JVPal..36E2059P. doi:10.1080/02724634.2016.1212059. ISSN 0272-4634. JSTOR 44865966.
- ^ a b c d e f Tomiya, Susumu (2013-05-20). "New carnivoraforms (Mammalia) from the middle Eocene of California, USA, and comments on the taxonomic status of 'Miacis' gracilis". Palaeontologia Electronica. 16 (2): 1–14. doi:10.26879/364. ISSN 1094-8074.
- ^ a b c d e f g h i j k l m n o p Lillegraven, Jason A. (1980). "Primates from Later Eocene Rocks of Southern California". Journal of Mammalogy. 61 (2): 181–204. doi:10.2307/1380040. ISSN 0022-2372. JSTOR 1380040.
- ^ a b López-Torres, Sergi; Silcox, Mary T.; Holroyd, Patricia A. (2018-09-22). "New omomyoids (Euprimates, Mammalia) from the late Uintan of southern California, USA, and the question of the extinction of the Paromomyidae (Plesiadapiformes, Primates)". Palaeontologia Electronica. 21 (3): 1–28. doi:10.26879/756. ISSN 1094-8074.
Further reading
[edit]- "General Plan Final Program EIR: 3.11 Paleontological Resources" (PDF). City of San Diego.
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