185:
291:"The materials composing the Sonoma volcanics were erupted probably from several vents within the area, and intermittently over a period perhaps more than 1 million years long. The materials were extremely varied in chemical composition and in eruptive character, so that they formed a complex assemblage of flows, dikes, plugs, mudflows, breccias, pumice beds, and intercalated bodies of stratified material mostly volcanic in composition but sedimentary in deposition. Except for dikes and plugs, the materials were highly lenticular."
40:
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288:. These bodies are parts of a once-continuous mass that probably extended from San Pablo Bay northward into southern Lake County, and from Green Valley in Solano County westward to Santa Rosa Valley. The Sonoma volcanics are several thousand feet thick."
272:"The Sonoma volcanics underlie and form most of the mountain areas bordering the Napa and Sonoma Valleys except for small areas underlain by the older sedimentary and metamorphic rocks. A thick extensive body of tuffs and flows forms the
280:. The volcanic rocks crop out in a narrow, discontinuous strip along the west side of the alluvial plain of Napa Valley, and on that side also they extend northward to Mount St. Helena. They compose most of the
409:"Invertebrate paleontology of the Wilson Grove Formation (late Miocene to late Pliocene), Sonoma and Marin Counties, California, with some observations on its stratigraphy, thickness, and structure"
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397:"Geology, Tephrochronology, Radiometric Ages, and Cross Sections of the Mark West Springs 7.5' Quadrangle, Sonoma and Napa Counties, California"
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366:. United States Geological Survey, in cooperation with the California Geological Survey, Scientific Investigations Map 2918.
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and flank the east and north sides of Sonoma Valley. They occur along the west side of Sonoma Valley, where they form the
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R.J. McLaughlin; A.M. Sarna-Wojcicki; R.J. Fleck; W.H. Wright; V.R.G. Levin & Z.C. Valin (2004).
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362:
Graymer, R.W., Moring, B.C., Saucedo, G.J., Wentworth, C.M., Brabb, E.E. and
Knudsen, K.L. (2006).
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327:. California Academy of Science Proceedings, 4th serial, v. 11, no. 19. pp. 521–601.
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418:"Geologic Map and Map Database of Eastern Sonoma and Western Napa Counties, California"
324:
Tertiary and
Quaternary History of the Petaluma, Point Reyes and Santa Rosa Quadrangles
416:
R.W. Graymer; E.E. Brabb; D.L. Jones; J. Barnes; R.S. Nicholson; R.E. Stamski (2007).
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east of Napa and extends from
Jamison Canyon northward into the area north of
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A geological section of the Coast Ranges north of the bay of San
Francisco,
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This article about a specific United States geological feature is a
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Charles L. Powell; James R. Allen & Peter J. Holland (2004).
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California
University, Dept. of Geol. Sci. Bull., v. 4, p. 39-87.
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257:. The formation serves as the parent material for many of the
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227:, perlitic glass, diatomaceous mud, pyroclastic tuff,
345:"Geology and Ground Water in Napa and Sonoma Valleys"
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Geologic formation of volcanic origin in
California
364:"Geologic Map of the San Francisco Bay Region"
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1318:Natural history of Sonoma County, California
376:: CS1 maint: multiple names: authors list (
1313:Natural history of Napa County, California
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1293:Landforms of Sonoma County, California
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1298:Landforms of Napa County, California
1288:Geology of Sonoma County, California
1212:
1210:
1162:= kiloannum (thousands years ago);
178:Osmont (1905), and Dickerson (1922)
1226:. You can help Knowledge (XXG) by
1166:= megaannum (millions years ago);
14:
1323:Geologic formations of California
1170:= gigaannum (billions years ago).
343:Fred Kunkel; J. E. Upson (1960).
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1191:
1180:
1:
609:Pleistocene (11.7 ka–2.58 Ma)
321:Roy Ernest Dickerson (1922).
207:origin that is widespread in
1328:United States geology stubs
572:Geological history of Earth
219:. Most of the formation is
54:of the Sonoma Volcanics at
1344:
1209:
845:Mississippian (323–359 Ma)
840:Pennsylvanian (299–323 Ma)
604:Holocene (present–11.7 ka)
420:. U. S. Geological Survey.
411:. U. S. Geological Survey.
350:. U. S. Geological Survey.
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1129:Paleoarchean (3.2–3.6 Ga)
979:Terreneuvian (521–539 Ma)
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402:. U.S. Geological Survey.
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26:
1124:Mesoarchean (2.8–3.2 Ga)
969:Miaolingian (497–509 Ma)
814:Guadalupian (260–272 Ma)
666:Paleocene (56.0–66.0 Ma)
656:Oligocene (23.0–33.9 Ma)
1273:Volcanism of California
1119:Neoarchean (2.5–2.8 Ga)
1084:Orosirian (1.8–2.05 Ga)
1079:Statherian (1.6–1.8 Ga)
1022:Cryogenian (635–720 Ma)
912:Llandovery (433–444 Ma)
819:Cisuralian (272–299 Ma)
630:Pliocene (2.59–5.33 Ma)
191:of the Sonoma Volcanics
1089:Rhyacian (2.05–2.3 Ga)
1058:Calymmian (1.4–1.6 Ga)
1017:Ediacaran (539–635 Ma)
964:Furongian (485–497 Ma)
809:Lopingian (252–260 Ma)
635:Miocene (5.33–23.0 Ma)
192:
1094:Siderian (2.3–2.5 Ga)
1053:Ectasian (1.2–1.4 Ga)
974:Series 2 (509–521 Ma)
661:Eocene (33.9–56.0 Ma)
307:Osmont, V.C. (1905),
187:
56:Rockville, California
1134:Eoarchean (3.6–4 Ga)
1027:Tonian (720 Ma–1 Ga)
907:Wenlock (427–433 Ma)
897:Pridoli (419–423 Ma)
223:in age and includes
77:Huichica Formation (
1303:Mayacamas Mountains
1283:Pliocene California
1189: •
1178: •
1176:Geologic time scale
938:Middle (458–470 Ma)
902:Ludlow (423–427 Ma)
871:Middle (383–393 Ma)
766:Middle (237–247 Ma)
735:Middle (164–174 Ma)
282:Mayacamas Mountains
28:Stratigraphic range
1187:Geology portal
1048:Stenian (1–1.2 Ga)
943:Early (470–485 Ma)
876:Early (393–419 Ma)
771:Early (247–252 Ma)
740:Early (174–201 Ma)
709:Early (100–145 Ma)
704:Late (66.0–100 Ma)
201:geologic formation
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89:Neroly Sandstone (
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1068:Paleoproterozoic
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730:Late (145–164 Ma)
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595:(present–2.58 Ma)
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286:Sonoma Mountains
278:Mount St. Helena
274:Howell Mountains
245:and interbedded
197:Sonoma Volcanics
50:and interbedded
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154:United States
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1228:expanding it
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1108:Archean Eon
1070:(1.6–2.5 Ga)
955:(485–539 Ma)
924:(444–485 Ma)
888:(419–444 Ma)
857:(359–419 Ma)
831:(299–359 Ma)
800:(252–299 Ma)
788:(252–539 Ma)
752:(201–252 Ma)
721:(145–201 Ma)
680:Mesozoic Era
580:Cenozoic Era
499:Serravallian
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189:Geologic map
160:Type section
1144:Hadean Eon
922:Ordovician
693:Cretaceous
593:Quaternary
489:Burdigalian
142:, Northern
136:Napa County
79:Pleistocene
45:Pyroclastic
1267:Categories
1146:(4–4.6 Ga)
1110:(2.5–4 Ga)
1039:(1–1.6 Ga)
645:Paleogene
525:Piacenzian
484:Aquitanian
295:References
255:lava flows
217:California
215:counties,
144:California
1173:See also:
953:Cambrian
886:Silurian
855:Devonian
750:Triassic
719:Jurassic
509:Messinian
504:Tortonian
165:Named for
98:Lithology
74:Underlies
1278:Terranes
798:Permian
619:Neogene
520:Zanclean
494:Langhian
389:Readings
372:cite web
247:volcanic
243:breccias
240:andesite
233:rhyolite
225:obsidian
221:Pliocene
205:volcanic
175:Named by
127:Location
111:rhyolite
107:andesite
86:Overlies
68:volcanic
48:breccias
32:Pliocene
261:in the
150:Country
103:Primary
91:Miocene
1152:
267:Sonoma
251:basalt
229:pumice
213:Sonoma
199:are a
132:Region
121:basalt
400:(PDF)
348:(PDF)
259:soils
236:tuffs
117:Other
52:tuffs
1224:stub
378:link
265:and
263:Napa
211:and
209:Napa
195:The
138:and
109:and
64:Type
203:of
1269::
1168:Ga
1164:Ma
1160:ka
374:}}
370:{{
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249:(
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58:.
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