Sweetwater Formation

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| name = Sweetwater Formation

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| type = Formation

| age = Paleogene

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| region = California

| country = United States

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The Sweetwater Formation is a geologic formation in California. It preserves fossils from the Late Eocene period.{{Cite journal |last1=Walsh |first1=Stephen L. |last2=Demere |first2=Thomas A. |date=1991 |title=Age and Stratigraphy of the Sweetwater and Otay Formations, San Diego County, California |url=https://archives.datapages.com/data/pac_sepm/086/086001/pdfs/131.htm |language=en-US |pages=131–148}} It underlies the Otay Formation, which reserves fossils of the Oligocene to Miocene periods of the Cenozoic Era.

It is located in the Peninsular Ranges province. The formation is composed of the angular-conglomerate, gritstone, sandstone and mudstone facies.{{Cite journal |last=Scheidemann |first=Robert C. Jr. |last2=Kuper |first2=Herman T. |date=1979 |title=Stratigraphy and Lithofacies of the Sweetwater and Rosarito Beach Formations, Southwestern San Diego County, California and Northwestern Baja California, Mexico |url=https://archives.datapages.com/data/pac_sepm/027/027001/pdfs/107.htm |language=en-US |pages=107–118}}