306:, a sandstone similar to the underlying Vaqueros; additionally, north of the river the Rincon Formation grades into this sandstone to the east. Northeast of Blue Canyon and the Little Pine Fault, in the backcountry of easternmost Santa Barbara County and Ventura County, the Rincon Formation disappears, and the Temblor Formation rests unconformably on the much older
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Radon migrates upwards from its source, entering buildings wherever the bottom is imperfectly sealed, for example through cracks in a concrete slab. If a structure is poorly ventilated – such as when the windows remain shut during the cool season – radon can accumulate to a hazardous level. Some of
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per liter (pCi/L), the U.S. EPA action level, and 26% had measured levels of radon over 20 pCi/L. According to the U.S. EPA, non-smokers exposed to radon at the 20 pCi/L level over a lifetime had a risk of dying from lung cancer at 36 in 1000, as opposed to 7 in 1000 at the 4 pCi/L level, and 2 per
337:
The Rincon
Formation weathers to a distinctive loamy, black soil with a high expansion-contraction potential, presenting a risk to structures built on soils derived from the formation. Landslides and slumps are frequent on soils produced from the Rincon, although they usually are not large, limited
333:
At that time only clay- and mud-sized grains could reach the deposition location, since it was far from the shore, and sediment accumulated slowly. The unit represents a period of around 7.5 million years – from 24 Ma (million years before present) to 17.5 – covering, with the
Vaqueros Formation,
255:
Thickness of the unit at the surface ranges from about 1400 to 1700 feet south of the mountain crest, averaging 1600 feet. It is less thick north of the mountains, attaining a maximum thickness of around 1000 feet at the western end of its range, and thinning to the east. In the subsurface under
394:
employed in houses on the Rincon
Formation since the discovery of the problem in the 1990s include building ventilation systems for the air space beneath the structure, performing "soil suction" in which the gas is pulled directly from the soil under the building, and active house pressurization,
313:
The Rincon Shale was deposited on the deep sea floor during the time at which the
Miocene sea reached its greatest depth. The faunal assemblage found as fossils and fragmentary fossils indicates that the sea was tropical to subtropical at this time. During this period the sea deepened due to
358:
remains in particular are abundant, and the various types have allowed staging of the layers into Upper
Zemorrian and Lower and Upper Saucesian. Within Santa Barbara County, two significant fossil finds (aside from microfossils) have been made in the Rincon Formation. In Ventura County, the
477:
Minor, S.A., Kellogg, K.S., Stanley, R.G., Gurrola, L.D., Keller, E.A., and Brandt, T.R., 2009, Geologic Map of the Santa
Barbara Coastal Plain Area, Santa Barbara County, California: U.S. Geological Survey Scientific Investigations Map 3001, scale 1:25,000, 1 sheet, pamphlet, 38
380:
of uranium, which is present in the Rincon at around 20 to 30 parts per million (ppm). A 1993 study found that approximately 74% of homes built on the Rincon
Formation, or on alluvium or soils derived from the Rincon Formation, showed interior radon concentrations in excess of 4
578:
Richard G. Stanley, et al. "Stratigraphic
Revelations Regarding the Rincon Shale (Lower Miocene) in the Santa Barbara Coastal Area, California." American Association of Petroleum Geologists Pacific Section Meeting, Ventura, California, April 27–29, 1994. Abstract available
260:
the thickness is variable but generally less than onshore. In well cores in the Hondo
Offshore Oil Field the thickness is around 600 feet, while in the abandoned Coal Oil Point field it is 900 feet, and in the Cuarta Offshore Oil Field it is over 1200 feet thick.
639:
Donald
Carlisle, Haydar Azzouz: "Discovery Of Radon Potential In The Rincon Shale, California – A Case History Of Deliberate Exploration." International Journal of Indoor Environment and Health. Vol 3, Issue 2, pp. 131-142, June 1993. Abstract available
551:
Gregory A. Miles and Catherine A. Rigsby. "Lithostratigraphy and Depositional Environments of the Vaqueros and Upper Sespe/Alegria Formations, Hondo Field, Santa Barbara Channel, California." SEPM Core Workshop No. 14. San Francisco, June 3, 1990.
252:. At the ground surface, the contact with the Vaqueros is obvious along the south slope of the mountains, for it is almost always defined by the line dividing the rounded, grassy foothills from the more rugged, chaparral-covered sandstones upslope.
240:. The unit is mapped from Ventura County westward along the south slope of the Santa Ynez Mountains, as well as on portions of the north slope. It also occurs in a few places north of the Santa Ynez Fault, but outcrops nowhere north of the
341:
As is common with shale units, the formation has a low permeability, and therefore where oil and gas reservoirs occur in the area it serves as the impermeable cap keeping the hydrocarbons in place. Some of these reservoirs include the
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Naturally high in uranium, the Rincon Formation is a notorious source of radon gas emissions in Santa Barbara and Ventura Counties, making them the counties with the greatest radon hazard in California. Radon is a byproduct of
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1000 at the average indoor radon level in the United States of 1.3 pCi/L. Smokers were at a much greater risk, with fully 260 out of 1,000 expected to die of lung cancer with a lifetime exposure of 20 pCi/L of radon.
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shale are found in the middle of the unit, and they outcrop noticeably in the region west of Goleta. The base of the unit, which rests conformably on the shallower-water Vaqueros Formation, contains a
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as the band at the base of the mountains which supports grasses rather than chaparral. Outcrops of the unit are infrequent, with the best exposures on the coastal bluffs near
196:, it weathers readily to a rounded hilly topography with clayey, loamy soils in which landslides and slumps are frequent. It is recognizable on the south slopes of the
236:, on the east side of Rincon Mountain, where the formation is exposed in the south-flowing Los Sauces Canyon, north of U.S. Highway 101 and in the vicinity of the
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Ron Churchill: "Radon Mapping: Santa Barbara and Ventura Counties." California Department of Conservation, Division of Mines and Geology, 1997.
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439:. Geology/Geologic Hazards. March 19, 2004. p. 2, 4, 11. Accessed at www.cityofgoleta.org/Modules/ShowDocument.aspx?documentid=649
363:; a detailed study suggested that the sea bottom they inhabited was around 2,000 meters deep, very near to the edge of the
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468:. Vol. I (1998), Vol. II (1992), Vol. III (1982). PDF file available on CD from www.consrv.ca.gov. p. 616, 646, 652
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628:
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occur within the unit, and the unit is capped by one as well, which forms the base of the conformably overlying
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Kenneth L. Finger, "Ostracoda from the Lower Rincon Formation (Oligo-Miocene) of Southern California".
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California Department of Conservation, Division of Oil, Gas, and Geothermal Resources (DOGGR).
302:. North of the Santa Ynez River, the Rincon is typically capped not by the Monterey but by the
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Close-up of the Rincon Shale in a road cut, showing weathered, highly fractured surface.
346:, Gaviota Offshore Gas Field, Cuarta Offshore Oil Field, Molino Gas Field, and others.
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exposure of the formation along Los Sauces Creek has yielded ten different species of
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Weathered outcrop of the Rincon Formation, Sycamore Canyon, Santa Barbara, California.
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491:. Bulletin 186, California Division of Mines and Geology. San Francisco, 1966. 51.
414:. Bulletin 186, California Division of Mines and Geology. San Francisco, 1966. 42
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Microfossils are common in the Rincon, and have been helpful in dating the unit.
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The Rincon Formation is massive to poorly bedded, and consists of predominantly
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Geology of the central Santa Ynez Mountains, Santa Barbara County, California
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Geology of the central Santa Ynez Mountains, Santa Barbara County, California
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Landfill, and in road cuts. The geologic unit is notorious as a source of
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244:. In the subsurface it frequently is found in well cores, underlying the
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forces, as the area of deposition was at the collision boundary of the
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County of Santa Barbara. Paleontological Resources section from the
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Rincon Mountain (east slope, Los Sauces Canyon), Ventura County
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had been completely buried beneath the American plate.
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Lompoc Wind Project Final Environmental Impact Report
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California Oil and Gas Fields, Volumes I, II and III
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Natural history of Santa Barbara County, California
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615:, Vol. 29, No. 1 (1983), pp. 78-109. Stable URL:
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176:age, abundant in the coastal portions of southern
656:: United States Environmental Protection Agency]
665:Martha Lannon, "Radon, how dangerous is it?"
281:to silty shale and mudstone, with occasional
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713:Geology of Santa Barbara County, California
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184:. Consisting of massive to poorly bedded
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681:Radon reduction technologies: U.S. EPA
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204:, in the San Marcos Foothills, at the
708:Geology of Ventura County, California
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617:https://www.jstor.org/stable/1485653
265:Lithology and deposition environment
395:which keeps the gas from entering.
334:the entirety of the lower Miocene.
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698:Geologic formations of California
569:DOGGR, p. 652, 654, 658, 660, 666
294:layer. Several thin layers of
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435:City of Goleta, California.
338:to about 15 feet in depth.
180:, California eastward into
125:Coastal southern California
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534:. Prentice Hall, 1997.
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521:Dibblee (1966), p. 48-49
224:Type locality and extent
172:geologic unit of Lower
669:, Goleta, California.
654:Health Risk from Radon
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500:Dibblee (1966), 42-43
437:Background Report #16
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258:Santa Barbara Channel
216:content, released by
723:Santa Ynez Mountains
530:Deborah R. Harden.
399:References and notes
326:, shortly after the
212:related to its high
198:Santa Ynez Mountains
178:Santa Barbara County
667:Goleta Valley Voice
392:mitigation measures
25:Stratigraphic range
703:Miocene California
598:2010-07-05 at the
532:California Geology
512:Dibblee (1966), 43
487:Dibblee, Thomas.
455:Dibblee (1966), 42
423:Dibblee (1966), 28
410:Dibblee, Thomas.
300:Monterey Formation
275:
250:Vaqueros Formation
248:and overlying the
246:Monterey Formation
232:of the unit is in
69:Vaqueros Formation
59:Monterey Formation
728:Transverse Ranges
613:Micropaleontology
378:radioactive decay
365:continental shelf
344:Ellwood Oil Field
304:Temblor Formation
285:. Two layers of
218:radioactive decay
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238:Rincon Oil Field
162:Rincon Formation
78:500 to 1700 feet
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19:Rincon Formation
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350:Paleontology
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279:argillaceous
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166:Rincon Shale
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161:
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138:Type section
292:glauconitic
170:sedimentary
154:Kerr, 1936
50:sedimentary
692:Categories
383:picocuries
602:. 3.12-4
361:ostracoda
296:bentonite
287:siliceous
210:radon gas
194:siltstone
143:Named for
110:sandstone
102:siltstone
83:Lithology
75:Thickness
55:Underlies
596:Archived
316:tectonic
283:dolomite
206:Tajiguas
190:mudstone
151:Named by
117:Location
106:mudstone
65:Overlies
214:uranium
174:Miocene
168:) is a
130:Country
88:Primary
29:Miocene
556:
542:p. 433
538:
202:Naples
192:, and
122:Region
560:p. 47
371:Radon
186:shale
98:Other
92:shale
642:here
581:here
554:ISBN
536:ISBN
390:the
322:and
256:the
228:The
164:(or
160:The
112:beds
47:Type
694::
505:^
478:p.
444:^
428:^
367:.
310:.
220:.
188:,
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27::
644:.
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