| 词条 | Poway Formation |
| 释义 |
| name = Poway Formation | image = | caption = | type = Formation | age = Paleogene | period = Paleogene | prilithology = | otherlithology = | namedfor = | namedby = | region = San Diego County, California | country = United States | coordinates = | unitof = | subunits = | underlies = | overlies = | thickness = | extent = | area = | map = | map_caption = }} The Poway Formation is a geologic formation in San Diego County, Southern California. It preserves fossils dating back to the Paleogene period.[1] Poway clastsVolcanic clastic rock cobbles of rhyolite, in a sandstone matrix in this area are named Poway clasts.[2] The ancient Ballena River brought rhyolite-gravel, or “Poway" clasts, from a region in present-day Sonora, Mexico to the Pacific Ocean. Its sediments deposited into alluvial fan-submarine canyon-submarine fan complex extending for miles offshore. Remnants of submarine fan facies outcrops are found as far west as the northern Channel Islands. Inland Ballena River deposits outcrop discontinuously over {{convert|16|mi|km}} in a west-southwest trend from Whale Mountain to San Vicente Reservoir, here the river was up to {{convert|2|mi|km}} in width through Peninsular Ranges.[3] See also{{Portal|Paleogene|California|Cenozoic|Earth sciences|Paleontology}}
References1. ^{{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= Various Contributors to the Paleobiology Database|url= http://www.fossilworks.org/|accessdate= 8 July 2014|deadurl= yes|archiveurl= https://web.archive.org/web/20140731140924/http://fossilworks.org/|archivedate= 31 July 2014|df= }} {{Clear}}{{California-geologic-formation-stub}}{{Paleogene-stub}}2. ^San Diego Mesa College: Tecolote Canyon: A Geologic Overview {{webarchive|url=https://web.archive.org/web/20150710045447/http://classroom.sdmesa.net/dbarrie/tecolote_canyon.htm |date=2015-07-10 }} — with Poway Clasts image. 3. ^Geiconsultants.com: "Geologic Formations of Western San Diego County"{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}, by Jeffrey D. Brown, R.G., C.E.G., GEI Consultants, Inc. − c.1996. 4 : Paleogene California|Geology of San Diego County, California|Poway, California|Geologic formations of California |
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