Date File Created	Name of Creator
8/16/07	Sarah Evans
GeoRef Data	2007-043674
DN	GeoRef
TI	Deciphering the source and contamination history of peraluminousmagmas using delta (super 18) O of accessory minerals; examples fromgarnet-bearing plutons of the Sierra Nevada Batholith
AU	"Lackey, Jade Star; Valley, John W; Hinke, Hans J"
AF	"University of Wisconsin at Madison, Department of Geology andGeophysics, Madison, WI, United States (USA)"
SO	"Contributions to Mineralogy and Petrology, vol.151, no.1, pp.20-44,Jan 2006"
EI	1432-0967
IS	0010-7999
CD	CMPEAP
LA	English
NT	Includes appendices
FE	"References: 82; illus. incl. 4 tables, geol. sketch maps"
PY	2006
PT	Serial; Analytic
CP	International (III)																																										
LL	"Latitude:N361500,N371500 Longitude:W1183000,W1200000"																																										
DE	accessory minerals; alkaline earth metals; California; chemicalcomposition; chemical ratios; crystal chemistry; Dinkey Dome;diorites; garnet group; geochemistry; Goddard Terrane; Grant Grove;Idaho Batholith; igneous rocks; intrusions; isotope ratios; isotopes;Jurassic; Kings Sequence; magma contamination; magmas; major elements;melange; Mesozoic; metals; mineral composition; models; nesosilicates;O-18/O-16; ophiolite; orthosilicates; oxygen; peralkalic composition;petrography; plutonic rocks; plutons; provenance; Sierra NevadaBatholith; silicates; spectra; Sr-87/Sr-86; stable isotopes;strontium; textures; Tharps Peak; trace elements; United States; X-rayfluorescence spectra																																										
CL	05A Igneous and metamorphic petrology; 02D Isotope geochemistry																																										
CY	"GeoRef, Copyright 2007, American Geological Institute."																																										
UD	200712																																										
AN	2007-043674																																										
Sample Data																																											
Item	SiO2	Al2O3	CaO	MgO	Na2O	K2O	Fe2O3	MnO	TiO2	P2O5	LOI	Rb	Sr	Ba	Y	Zr	Nb	Rock_class	Rock_type	Location_name	LatDD	LongDD	Loc_prec	Age	Max_age	Min_age	Age	Min_age	Age	Age	Age	D18O	D18O	D18O	D18O	D18O	D18O	D18O	D18O	D18O	D18O	Material	State
Units	wt %	wt %	wt %	wt %	wt %	wt %	wt %	wt %	wt %	wt %	wt %	ppm	ppm	ppm	ppm	ppm	ppm				DD	DD		Ma	Ma 	Ma 	Ma	Ma 	Ma	Ma	Ma	permill	permill	permill	permill	permill	permill	permill	permill	permill	permill		
Method	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1				2	2		3	4	4	5	5	6	7	8	9	10	11	18	12	13	14	15	16	17		
Sample Name																																											
1S1	73.4	14.3	1.84	0.4	4.33	2.7	1.88	0.05	0.13	0.05	0.5	82	157	980	25	89	10	granodiorite	plutonic	Tharps Peak	36.4065	-118.9488	0.0001	109.5								11.13	9.97	7.85	7.9	7.93						whole rock	California
1S2	73.5	14.5	2.09	0.42	4.21	2.64	2.04	0.06	0.15	0.06	0.3	73	184	982	25	95	11	granodiorite	plutonic	Tharps Peak	36.4089	-118.9488	0.0001	109.5								11.2	9.83	7.75		7.64						whole rock	California
1S3	72.8	14.5	1.51	0.38	4.07	3.44	1.99	0.03	0.12	0.03	0.3	76	148	1910	32	94	10	granodiorite	plutonic	Tharps Peak	36.406	-118.9523	0.0001	109.5								11.13	10.03	7.67	7.65	7.89						whole rock	California
1S4	72	14.8	2.1	0.48	4.27	2.97	2.06	0.07	0.16	0.05	0.35	71	188	1120	30	88	8	granodiorite	plutonic	Tharps Peak	36.4105	-118.9466	0.0001	109.5								11.44	11.03	8.44		8.25						whole rock	California
1S5	73.6	13.9	1.63	0.46	3.49	3.61	2.51	0.06	0.23	0.12	0.45	140	148	1020	31	165	14	granite	plutonic	Cactus Point	36.4875	-119.8393	0.0001		99	70						10.28	9.19	6.74	6.77	7.15						whole rock	California
1S23	74.7	14.3	0.69	0.15	3.73	5.08	1	0.03	0.06	0.01	0.25	111	83	709	17	93	10	granite	plutonic	Grant Grove	36.7189	-118.9614	0.0001		106			98				11.51	10.56	7.81	7.93	7.86						whole rock	California
1S24	73.4	14.1	0.64	0.12	3.44	5.26	0.58	0.02	0.04	0.02	0.45	107	69	603	15	71	10	granite	plutonic	Grant Grove	36.7191	-118.9616	0.0001		106			98				11.52	10.38	7.44	7.83	8.03						whole rock	California
1S27	75.6	14.3	0.16	0.07	1.95	5.48	0.53	0.04	0.2	0.02	1.85	172	14	151	45	57	11	granite	plutonic	Grant Grove	36.714	-118.9745	0.0001		106			98				13.36	12.84	7.56	7.91	8.97	10.68					whole rock	California
1S28	76.4	14	0.27	0.07	3.21	4.67	0.66	0.02	0.03	-0.01	0.95	140	11	103	42	94	12	granite	plutonic	Grant Grove	36.7147	-118.9755	0.0001		106			98				12.98	12.47	7.76	8.89	8.44		8.1				whole rock	California
1S29	75.9	14.2	0.37	0.09	3.35	4.69	0.61	0.05	0.02	0.02	0.8	142	12	114	31	55	11	granite	plutonic	Grant Grove	36.7153	-118.9771	0.0001		106			98				12.83	12.05	7.85	8.78	8.51			10			whole rock	California
1S30	68.9	16.7	1.56	0.61	3.58	5.47	2.26	0.06	0.26	0.07	0.75	138	261	1400	19	119	14	granite	plutonic	Grant Grove	36.7385	-119.0052	0.0001		106			98				11.23	9.94									whole rock	California
1S51	76.7	13.2	0.4	0.13	3.78	4.34	1.15	0.07	0.03	0.04	0.4	213	22	134	35	60	23	granite	plutonic	Dinkey Dome	37.104	-119.09	0.0001						90			10.83	9.71	7.09		7.76						whole rock	California
1S52	76	13.7	0.25	0.12	3.74	4.36	1.38	0.09	0.04	0.04	0.6	248	25	158	46	59	33	granite	plutonic	Dinkey Dome	37.1011	-119.0898	0.0001						90			11.01	9.8	6.96		7.51						whole rock	California
1S53	76.4	13.5	0.37	0.11	3.82	4.3	1.22	0.08	0.03	0.04	0.35	226	19	115	37	59	26	granite	plutonic	Dinkey Dome	37.0999	-119.0943	0.0001						90			10.79	9.57	7.06		7.53			8.49			whole rock	California
1S54	75.6	13.9	0.38	0.11	3.67	4.42	1.35	0.08	0.03	0.04	0.65	224	18	121	38	51	24	granite	plutonic	Dinkey Dome	37.0986	-119.1006	0.0001						90			11.03	9.9	7.21		7.81	8.34		8.46			whole rock	California
1S58	75	13.5	1.22	0.34	3.46	3.93	1.79	0.08	0.15	0.04	0.7	179	124	383	47	116	21	granite	plutonic	Dinkey Dome	37.082	-119.1362	0.0001						90			10.86	9.9	7.62		7.77						whole rock	California
1S67	75.6	13.2	1.49	0.37	2.67	4.9	1.42	0.02	0.19	0.02	0.3	113	225	1080	14	121	8	granodiorite	plutonic	Snow Corral Meadow 	37.0469	-119.0753	0.0001						90			10.64	9.54	8.65		7.5				5.3	4.81	whole rock	California
1S77	76.9	13.2	0.43	0.13	3.82	3.91	1.34	0.08	0.02	0.03	0.4	199	19	102	37	50	20	granite	plutonic	Dinkey Dome	37.0993	-119.1087	0.0001						90			11.3	9.81	6.99		7.63						whole rock	California
1S79	73.4	14.3	1.78	0.45	3.85	3.55	2.28	0.07	0.21	0.07	0.35	174	172	501	31	139	25	granite	plutonic	Dinkey Dome	37.0963	-119.1105	0.0001						90			10.82	9.96	7.73		7.67						whole rock	California
1S80	74.5	13.8	1.36	0.39	3.58	3.96	2.01	0.06	0.18	0.07	0.25	208	134	461	33	119	25	granite	plutonic	Dinkey Dome	37.0942	-119.1181	0.0001						90			11.33	10.3	7.77		7.72						whole rock	California
1S81	72.7	14.4	1.33	0.39	3.58	4.25	1.94	0.06	0.2	0.06	0.25	206	134	509	36	117	25	granite	plutonic	Dinkey Dome	37.0901	-119.1262	0.0001						90			10.65	9.79	7.56		7.76						whole rock	California
1S82	73.4	13.9	1.32	0.38	3.55	4.11	1.93	0.05	0.18	0.07	0.5	194	136	440	35	124	26	granite	plutonic	Dinkey Dome	37.0883	-119.1326	0.0001						90			11.01	9.79	7.9		7.73						whole rock	California
3S51	74.19	13.69	1.49	0.17	3.6	4.11	2.35	0.05	0.2	0.03	0.3	140	211	1220	58	278	19	granite	plutonic	Dinkey Dome	37.1347	-119.0789	0.0001						90			11.2	10.06			8.02				6.06		whole rock	California
1S92	74.8	14.51	1.19	0.29	3.7	3.53	1.11	0.03	0.11	0.06	0.95	77	146	865	17	54	8	trondhjemite	plutonic	Ward Mountain	37.124	-119.7352	0.0001							115		12.34	11.17	8.04								whole rock	California
1S93	69.4	16.41	3.71	0.8	4.57	1.16	2.48	0.04	0.37	0.12	0.75	36	493	502	10	101	5	trondhjemite	plutonic	Ward Mountain	37.1953	-119.7214	0.0001							115		11.4	9.91									whole rock	California
1S95	73.9	14.6	1.62	0.35	3.95	3.58	1.05	0.02	0.14	0.06	0.4	92	251	962	14	75	9	trondhjemite	plutonic	Hensley Lake	37.1142	-119.867	0.0001						116			11.75	10.5	8.41	8.47	8.68						whole rock	California
1S96	72.1	15.7	2.48	0.52	4.37	2.61	1.57	0.04	0.2	0.07	0.35	71	368	909	12	86	8	trondhjemite	plutonic	Hensley Lake	37.1081	-119.8667	0.0001						116			11.8	10.38	8.39		8.72						whole rock	California
1S128	76.5	13.1	0.3	0.16	3.35	5.19	0.75	0.08	0.07	0.05	0.5	201	51	304	36	60	26	granite	plutonic	Rawson Creek	37.1346	-118.4552	0.0001				165					10.72	5.27	7.09	6.55	7.89					3.84	whole rock	California
1SG4	75.2	13.8	0.73	0.2	3.67	5.01	0.93	0.04	0.1	0.01	0.3	141	65	353	38	88	12	granite	plutonic	Smith Grade	37.0299	-122.1352	0.0001								111	13.04	11.87	9.8	10.35	8.65						whole rock	California
3S34	52.46	18.58	7.72	4.08	2.97	1.91	9.72	0.15	1.26	0.26	0.65	55	498	904	29	148	12	diorite	plutonic	Grant Grove	36.7925	-118.9756	0.0001		106			98				11.79	8.4			7.53						whole rock	California
3S48	52.04	17.26	8.07	5.2	1.84	1.35	11.9	0.14	1.13	0.32	0.8	53	601	329	12	85	6	diorite	plutonic	Dinkey Dome	37.1138	-119.0816	0.0001						90			11.59	8.59			7.54						whole rock	California
1S13																		granite	plutonic	Grant Grove	36.7334	-118.9446	0.0001		106			98				11.71		7.62								whole rock	California
1S14																		granite	plutonic	Grant Grove	36.7326	-118.9434	0.0001		106			98				11.05										whole rock	California
1S15																		granite	plutonic	Grant Grove	36.7326	-118.9438	0.0001		106			98				11.17		7.61								whole rock	California
1S17																		granite	plutonic	Grant Grove	36.7329	-118.9459	0.0001		106			98				11.31		7.59								whole rock	California
1S18																		granite	plutonic	Grant Grove	36.7327	-118.9469	0.0001		106			98				11.14		7.86								whole rock	California
1S19																		granite	plutonic	Grant Grove	36.7326	-118.9471	0.0001		106			98				11.43		7.9								whole rock	California
1S20																		granite	plutonic	Grant Grove	36.7323	-118.9475	0.0001		106			98				11.15		7.62								whole rock	California
1S21																		granite	plutonic	Grant Grove	36.7317	-118.9492	0.0001		106			98				11.31		7.69								whole rock	California
1S31																		granite	plutonic	Grant Grove	36.7407	-119.0262	0.0001		106			98				11.84	10.69	8.08								whole rock	California
1S32																		granite	plutonic	Grant Grove	36.7415	-119.0266	0.0001		106			98				11.58		8.09								whole rock	California
1S33																		granite	plutonic	Grant Grove	36.7417	-119.029	0.0001		106			98				11.48	10.9	7.94		7.95						whole rock	California
1S34																		granite	plutonic	Grant Grove	36.7417	-119.0311	0.0001		106			98				12.01		7.76		7.94						whole rock	California
1S35																		granite	plutonic	Grant Grove	36.7425	-119.0328	0.0001		106			98				11.81	10.81	7.97		8.07						whole rock	California
1S36																		granite	plutonic	Grant Grove	36.744	-119.0343	0.0001		106			98				12.07	11.23	7.92		7.92						whole rock	California
1S37																		granite	plutonic	Grant Grove	36.7437	-119.0366	0.0001		106			98				13.8	12.97	8.22		8.8						whole rock	California
1S38																		granite	plutonic	Grant Grove	36.7436	-119.0364	0.0001		106			98				13.75		8.12		8.97						whole rock	California
3S41																		granite	plutonic	Dinkey Dome	36.7439	-119.0355	0.0001						90			11.98	11.21	7.95		8.06	9.89					whole rock	California
3S42																		granite	plutonic	Dinkey Dome	36.744	-119.0367	0.0001						90			14.03	12.79	7.98		8.47	11.54					whole rock	California
3S43																		granite	plutonic	Dinkey Dome	36.744	-119.0369	0.0001						90			13.91	12.23	8.1		9	11.02	9.52				whole rock	California
1SG5																		granite	plutonic	Smith Grade	37.0296	-122.1345	0.0001								111	13.19		10.55								whole rock	California
1SG6																		granite	plutonic	Smith Grade	37.0282	-122.1338	0.0001								111	12.76		9.54								whole rock	California
3S27																		diorite	plutonic	Cactus Point	36.5143	-118.8048	0.0001		99	70							9.36			8.25						whole rock	California
Method Data																																											
1	XRF	488																																									
2	TABLE	2007-043674																																									
3	REG_COR	1990-053218																																									
4	REG_COR	1982-050991																																									
5	REG_COR	2006-029607																																									
6	REG_COR	1992-049811																																									
7	REG_COR	1982-034005																																									
8	REG_COR	1992-039501																																									
9	MS:QTZ	2007-043674																																									
10	MS:WR	2007-043674																																									
11	MS:GAR	2007-043674	"""Garnet-I, darker-colored than Garnet-II"""																																								
12	MS:ZIRC	2007-043674																																									
13	MS:SILLIMANITE	2007-043674																																									
14	MS:SPINEL	2007-043674																																									
15	MS:ANDALUSITE	2007-043674	
16	MS:TIT	2007-043674	"""Primary Titanite"""
17	MS:TIT	2007-043674	"""Secondary Titanite"""
18	MS:GAR	2007-043674	Garnet-II is lighter colored than Garnet-I
Reference Data			
georef#	1982-050991		
TI	"Uranium-lead isotopic ages from the Sierra Nevada Batholith,California"		
AU	"Chen, James H; Moore, James G"		
AF	"Univ. Calif., Dep. Geol. Sci., Santa Barbara, CA, United States (USA)"		
AF	"U. S. Geol. Surv., United States (USA)"		
SP	"USGSOP, Non-USGS publications with USGS authors"		
SO	"Journal of Geophysical Research, vol.87, no.B6, pp.4761-4784, 10 Jun1982"		
IS	0148-0227		
LA	English		
FE	"References: 61; illus. incl. 82 anal., 5 tables, geol. sketch maps"		
PY	1982		
PT	Serial; Analytic
CP	United States (USA)
LL	"Latitude:N360000,N370000 Longitude:W1180000,W1193000"
DE	absolute age; age; batholiths; California; Central California; dates;Fresno County California; geochronology; granites; igneous rocks;intrusions; Inyo County California; isotopes; lead; Mesozoic; metals;nesosilicates; orthosilicates; plutonic rocks; plutons; ratios; SierraNevada Batholith; silicates; titanite; titanite group; Tulare CountyCalifornia; U/Pb; United States; zircon; zircon group
CL	"03, Geochronology"
CY	"GeoRef, Copyright 2006, American Geological Institute."
UD	1982
AN	1982-050991
georef#	1992-039501
TI	"Cretaceous metamorphism and plutonism in the Santa Cruz Mountains,Salinian Block, California, and correlation with the southernmostSierra Nevada"
AU	"James, Eric William"
AF	"Univ. Tex. at Austin, Bur. Econ. Geol., Austin, TX, United States(USA)"
SO	"Geological Society of America Bulletin, vol.104, no.10, pp.1326-1339,Oct 1992"
IS	0016-7606
CD	BUGMAF
DE	absolute age; alkaline earth metals; apatite; California; CentralCalifornia; Cretaceous; dates; emplacement; evolution; geochronology;igneous rocks; intrusions; isotopes; Mesozoic; metals; metamorphicrocks; metamorphism; metaplutonic rocks; monazite; nesosilicates;orthosilicates; phosphates; plutonic rocks; plutons; Salinian Block;San Francisco Bay region; Santa Cruz County California; Santa CruzMountains; Sierra Nevada Batholith; silicates; Sr-87/Sr-86; stableisotopes; strontium; titanite; titanite group; U/Pb; United States;zircon; zircon group
AB	"New data on the ages of plutonism and metamorphism in the northernSanta Cruz Mountains, part of the enigmatic Salinian block ofCalifornia, clarify the area's geologic history. Uranium/lead dates onzircon, monazite, sphene, and apatite and initial Pb and Sr isotopicratios provide a ""fingerprint"" for comparison to the rest of theSalinian block and to other terranes.The U/Pb zircon dates of plutonicrocks in the Santa Cruz Mountains fall into three groups. Emplacementages of the two younger, undeformed groups are 91 Ma and between 99and 103 Ma. Individual zircon analyses range from concordant tosignificantly discordant but have simple crystallization histories,coupled with either inheritance of Precambrian zircon or Pb loss. Theolder group of plutons includes recrystallized granite towell-foliated orthogneisses that share the regional fabric. Analysesfrom the older group are slightly discordant, and multistage historiesthat include inheritance, Pb loss, and homogenization of Pb complicateinterpretation of their age. Emplacement ages for the older group areEarly Cretaceous-greater than about 103 Ma and probably less than 130Ma.Foliated and unfoliated plutons from the older group appear tobracket the age of Salinian deformation and metamorphism between about103 and 130 Ma. Lower-intercept ages for detrital zircon from schistand quartzite further support a Cretaceous metamorphic age. Thedetrital zircon population contains a component at least 1.6 Ga,probably close to 1.7 Ga. Uranium/lead cooling ages measured on spheneand apatite are 96 to 93 and 93 to 88 Ma, respectively. This coolinghistory appears to be a response to intrusion and rapid cooling of theyoungest plutons.Common Pb and Sr initial isotopic ratios areradiogenic compared with ratios of oceanic rocks and the western partsof the Cordilleran batholiths, but they are the least radiogenic inthe Salinian block and fit the local geographic gradient of Pb and Srinitial ratios. Linear variation of Pb-isotope ratios betweenradiogenic wall rock and the least radiogenic rocks and correlation ofinherited zircon with elevated Pb-isotope ratios suggest that plutonsassimilated wall rock.Isotopic data and geologic histories of basementrocks in the northern Santa Cruz Mountains fit the geographic patternsdocumented in the rest of the Salinian block. More intriguingly, theSanta Cruz Mountains plutons are strikingly similar to parts of thesouthern Sierra Nevada batholith. Ages of plutonism and metamorphism,U/Pb zircon discordance systematics, petrography, and initial Srisotopes match closely between the Santa Cruz Mountains crystallinerocks and units in the southernmost Sierra Nevada batholith. Thesedata reinforce the long-standing view that the Salinian block andSierra Nevada batholiths were adjacent during their formation. Priorto right-slip of about 310 km on the San Andreas fault, the probablewestward continuation of the low-angle Rand fault system into thesouthern Sierra Nevada and the Salinian block appears to have offsetthese two crystalline suites about 125 km."
LA	English
FE	"References: 88; illus. incl. 3 tables, geol. sketch maps"
PY	1992
PT	Serial; Analytic
CP	United States (USA)
LL	"Latitude:N365955,N373400 Longitude:W1220000,W1220900"
CL	03 Geochronology; 05A Igneous and metamorphic petrology
CY	"GeoRef, Copyright 2006, American Geological Institute."
UD	1992
AN	1992-039501
georef#	1990-053218
TI	"Geochemistry of the garnet-bearing Tharps Peak Granodiorite and itsrelation to other members of the Lake Kaweah Intrusive Suite,southwestern Sierra Nevada, California"
AU	"Liggett, David L"
AF	"Calif. State Univ., Dep. Geol. Sci., Northridge, CA, United States(USA)"
MT	The nature & origin of Cordilleran magmatism
ED	"Anderson, J. Lawford"
AF	"Univ. South. Calif., Dep. Geol. Sci., Los Angeles, CA, United States(USA)"
SO	"Memoir - Geological Society of America, vol.174, pp.225-236, 1990"
IS	0072-1069
CD	GSAMAQ
IB	813711746
LA	English
FE	"References: 44; illus. incl. 2 tables, geol. sketch map"
PY	1990
PT	Serial; Analytic
CP	United States (USA)
DE	alkaline earth metals; assimilation; California; crystallization;fugacity; garnet group; geochemistry; granites; granodiorites; igneousrocks; isochrons; isotopes; Lake Kaweah Intrusive Suite; majorelements; metals; metaluminous composition; minor elements;nesosilicates; O-18/O-16; orthosilicates; oxygen; P-T conditions;partitioning; peraluminous composition; plutonic rocks; rare earths;Rb/Sr; Sierra Nevada; Sierra Nevada Batholith; silicates; Sr-87/Sr-86;stable isotopes; strontium; Tharps Peak Granodiorite; United States;Wukchumni Granodiorite; zoning
CL	02D Isotope geochemistry; 05A Igneous and metamorphic petrology
CY	"GeoRef, Copyright 2006, American Geological Institute."
UD	1990
AN	1990-053218
georef#	2006-029607
TI	U/Pb zircon ages for high-silica granites in the central Sierra NevadaBatholith; implications for crustal generation in continental arcs
AU	"Wenner, Jennifer M; Coleman, Drew S"
AF	"University of Wisconsin, Geology Department, Oshkosh, WI, UnitedStates (USA)"
AF	"University of North Carolina, United States (USA)"
MT	"Geological Society of America, 2003 annual meeting"
AU	Anonymous
CF	"Geological Society of America, 2003 annual meeting, Seattle, WA,United States, Nov. 2-5, 2003"
SO	"Abstracts with Programs - Geological Society of America, vol.35, no.6,pp.326, Nov 2003"
IS	0016-7592
CD	GAAPBC
DE	absolute age; batholiths; California; continental crust; Cretaceous;crust; dates; geochemistry; granites; Grant Grove; igneous rocks;intrusions; Inyo County California; Inyo Mountains; island arcs; magmacontamination; magmas; Mesozoic; mixing; nesosilicates;orthosilicates; plutonic rocks; provenance; Rawson Creek; SierraNevada Batholith; silicates; siliceous composition; U/Pb; UnitedStates; White Mountains; zircon; zircon group
AB	"Recent work in the Sierra Nevada batholith suggests that plutonism isepisodic, with large volumes of granodiorite emplaced in relativelyshort time periods ( approximately 10-15 m.y.). Two major magmaticepisodes are now recognized in the eastern Sierra and White/InyoMountains--one in the Jurassic ( approximately 180-165 Ma) and one inthe Cretaceous (the Sierra crest magmatic episode approximately 98-88Ma). The later event is responsible for growth of a large part of thehigh Sierra and comes toward the end of a general eastward sweep ofmagmatism. We present new U-Pb zircon ages for four high-silicagranites exposed across the central Sierra Nevada batholith thatdemonstrate the importance of these high silica rocks in the overallpattern of magmatism. In the west-central Sierra, a new U-Pb zirconage for the granite of Grant Grove is approximately 98 Ma, and for thegranite of Lodgepole is approximately 115 Ma. To the east, theEvolution Basin Alaskite yields a preliminary age of 92-94 Ma and agarnetiferous phase of the granite mapped as the leucogranite ofRawson Creek gives an age of approximately 165 Ma. This last agedistinguishes the garnetiferous phase from the leucogranite of RawsonCreek proper, which has been dated at about approximately 95 Ma (Sternet al., 1981). These new ages bear on the question of the generationand modification of crust in continental arcs. Several studies suggestthat the voluminous granodiorites in the Sierran arc are the productsof mixing between coexisting dioritic and granitic magmas. The U-Pbdates presented here demonstrate that the history of high-silicamagmatism in the arc mirrors that of diorites and granodioritesexposed nearby. Consequently, the geochronology permits thecoexistence of the three magma types. This combined with fieldevidence for mixing, the bulk geochemistry, and the isotopegeochemistry of rocks across the range of composition stronglysupports the hypothesis that magma mixing is an important process ingeneration of the intermediate composition rocks. Isotope geochemistryalso suggests very little involvement of old crustal material, even inthe most siliceous lithologies, consistent with the idea that theSierra crest magmatic event was responsible for growth of a largevolume of new crust in the arc."
LA	English
PY	2003
PT	Serial; Conference document; Analytic; Abstract only
CP	United States (USA)
LL	"Latitude:N354500,N373000 Longitude:W1154000,W1184500"
CL	05A Igneous and metamorphic petrology; 03 Geochronology
CY	"GeoRef, Copyright 2006, American Geological Institute. Referenceincludes data supplied by the Geological Society of America, Boulder,CO, United States"
UD	200609
AN	2006-029607
georef#	1982-034005
MT	"Isotopic U-Pb ages of zircon from the granitoids of the central SierraNevada, California"
AU	"Stern, T W; Bateman, P C; Morgan, B A; Newell, M F; Peck, D L"
SP	"USGS, Publications of the U. S. Geological Survey"
SO	"U. S. Geological Survey Professional Paper, Report: P 1185, 17 pp.,1981"
IS	1044-9612
CD	XGPPA9
RP	P 1185
DE	absolute age; age; batholiths; California; Cretaceous; dates;geochronology; granites; igneous rocks; intrusions; Jurassic;Mesozoic; nesosilicates; orthosilicates; plutonic rocks; plutons;Sierra Nevada; Sierra Nevada Batholith; silicates; U/Pb; UnitedStates; USGS; zircon; zircon group
AB	"Sixty-two samples from well-established comagmatic granitoid sequencesand certain unassigned formations and plutons of the central part ofthe Sierra Nevada Batholith have been dated by the isotopic U-Pbmethod on zircon. The distribution of ages is consistent with theinterpretation that, in this area, a belt of Cretaceous granitoidstrending about N. 20 degrees W. crosses a belt of Jurassic granitoidstrending about N. 40 degrees W.--from New Publications of theGeological Survey, Jan. 1982."
LA	English
NT	Date Issued: 1982001982
FE	illus. incl. 62 anal.
PY	1981
PT	Serial; Report; Monographic
CP	United States (USA)
LL	"Latitude:N350000,N402000 Longitude:W1180000,W1210000"
CL	"03, Geochronology"
CY	"GeoRef, Copyright 2006, American Geological Institute."
UD	1982
AN	1982-034005
georef#	1992-049811
MT	"Plutonism in the central part of the Sierra Nevada Batholith,California"
AU	"Bateman, Paul C"
AF	"U. S. Geological Survey, USA,  (United States)"
SP	"USGS, Publications of the U. S. Geological Survey"
SO	"U. S. Geological Survey Professional Paper, Report: P 1483, 186 pp., 2sheets, 1992"
IS	1044-9612
CD	XGPPA9
RP	P 1483
DE	absolute age; areal geology; batholiths; California; CentralCalifornia; crystallization; diorites; emplacement; evolution; FresnoCounty California; geologic maps; granites; granodiorites; igneousrocks; intrusions; Inyo County California; Madera County California;magmas; maps; Mariposa County California; Mariposa Quadrangle;Mesozoic; metaigneous rocks; metallogeny; metamorphic rocks; mineralcomposition; Mono County California; petrology; plutonic rocks;plutons; Sierra Nevada Batholith; tonalite; Tuolumne CountyCalifornia; United States; USGS
AB	"This volume summarizes the results of more than 35 years of study bymembers of the U.S. Geological Survey of the bedrock geology of thecentral part of the Sierra Nevada Batholith between 37 degrees and 38degrees N lat. It includes a colored map showing the bedrock geologyof the Mariposa, California 1 degrees by 2 degrees Quadrangle at thescale of 1:250,000. The tectono-stratigraphic setting, constitution,composition, age, and structure of the batholith are described, andthe origin of the plutonic rocks is considered."
LA	English
FE	"2 tables, geol. sketch maps"
PY	1992
PT	Serial; Report; Map; Monographic
CP	United States (USA)
MP	"Scale: 1:250,000. Type: colored geologic maps"
LL	"Latitude:N370000,N380000 Longitude:W1180000,W1200000"
CL	"05A, Igneous and metamorphic petrology"
CY	"GeoRef, Copyright 2006, American Geological Institute."
UD	1992
AN	1992-049811