Earth:Mission Valley Formation

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Short description: Geologic formation in San Diego County
Mission Valley Formation
Stratigraphic range: Paleogene
TypeGeologic formation
UnderliesPomerado Conglomerate
OverliesStadium Conglomerate
Thickness0–60 metres (0–197 ft)
Lithology
Primarysandstone
Location
RegionSan Diego County, California
CountryUnited States
Type section
Named forMission Valley, San Diego

The Mission Valley Formation is a marine sandstone geologic formation in the Mission Valley region of southwestern San Diego County in Southern California .[1][2]

Geology

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

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

Eulipotyphlans

Eulipotyphlans reported from the Mission Valley Formation
Genus Species Presence Material Notes Images
Proterixoides P. davisi Several calcaneums, astragali and a navicular.[4]

Ferae

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

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

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Kennedy, Michael P. (1975). Geology of the San Diego metropolitan area, California. California Division of Mines and Geology. https://archive.org/details/geologyofsandieg00kennrich. 
  2. ↑ Geiconsultants.com: Geologic Formations of Western San Diego County[yes|permanent dead link|dead link}}], by Jeffrey D. Brown, R.G., C.E.G. − circa 1996.
  3. ↑ ((Various Contributors to the Paleobiology Database)). "Fossilworks: Gateway to the Paleobiology Database". http://www.fossilworks.org/cgi-bin/bridge.pl?action=home. 
  4. ↑ 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): 1–17. ISSN 0272-4634. https://www.jstor.org/stable/44865966. 
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Tomiya, Susumu (2013-05-20). "New carnivoraforms (Mammalia) from the middle Eocene of California, USA, and comments on the taxonomic status of 'Miacis' gracilis" (in English). Palaeontologia Electronica 16 (2): 1–14. doi:10.26879/364. ISSN 1094-8074. https://palaeo-electronica.org/content/2013/435-eocene-carnivoraforms. 
  6. ↑ 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12 6.13 6.14 6.15 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. https://www.jstor.org/stable/1380040. 
  7. ↑ 7.0 7.1 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)" (in English). Palaeontologia Electronica 21 (3): 1–28. doi:10.26879/756. ISSN 1094-8074. https://palaeo-electronica.org/content/2018/2309-new-primate-from-california. 

Further reading




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