Date File Created	Name of Creator
11/27/07	Taylor Brown
GeoRef Data	2005-031003
DN	GeoRef
TI	"Using U-Pb ages of Miocene tufa for correlation in a terrestrialsuccession, Barstow Formation, California"
AU	"Cole, Jennifer M; Rasbury, E Troy; Hanson, Gilbert N; Montanez, IsabelP; Pedone, Vicki A"
AF	"State University of New York at Stony Brook, Department ofGeosciences, Stony Brook, NY, United States (USA)"
AF	"University of California at Davis, United States (USA); CaliforniaState University-Northridge, United States (USA)"
SO	"Geological Society of America Bulletin, vol.117, no.3-4, pp.276-287,Apr 2005"
RL	[U
RL	http://www.gsajournals.org/]
IS	0016-7606
CD	BUGMAF
DE	absolute age; Barstow Formation; calcite; California; carbonates;Cenozoic; chemically precipitated rocks; correlation; dates;depositional environment; lacustrine environment; Miocene; Neogene;precision; San Bernardino County California; sedimentary rocks;terrestrial environment; Tertiary; tufa; U/Pb; United States
AB	"Sedimentary rocks and associated fossils are the direct record of pastlife and its environmental context. Few methods allow direct andprecise dating of this important archive, making it difficult tocorrelate climate, biologic, and tectonic events preserved interrestrial records. We sampled lacustrine tufa calcite from themiddle member of the Miocene Barstow Formation to further test thefeasibility of uraniumlead dating of terrestrial carbonates. Fivesamples yield U-Pb ages (2sigma ) of 14.81+ or -0.39 Ma, 15.30+ or-0.25 Ma, 15.39+ or -0.15 Ma, 16.14+ or -0.40 Ma, and 16.24+ or -0.23Ma. These precise ages are consistent with existing ages from K-Ar and(super 40) Ar/ (super 39) Ar dating of intercalated volcanic ashes.Our most precise U-Pb age on tufa has an uncertainty of <1% (150ka), which is equivalent to uncertainties for K-Ar ages from the sametime period. Our results indicate that U-Pb dating of carefullysampled and screened sedimentary carbonates provides much needed ageconstraints in purely terrestrial sequences and can be a powerful toolfor correlation even in deposits with structural complexity and rapidfacies changes."
LA	English
NT	With GSA Data Repository Item 2005058																				
FE	"References: 57; illus. incl. sects., 4 tables, geol. sketch maps"																				
PY	2005																				
PT	Serial; Analytic																				
CP	United States (USA)																				
LL	"Latitude:N350000,N351000 Longitude:W1170000,W1171500"																				
CL	"03, Geochronology"																				
CY	"GeoRef, Copyright 2007, American Geological Institute. Referenceincludes data supplied by the Geological Society of America, Boulder,CO, United States"																				
UD	200511																				
DO	10.1130/B25553.1																				
AN	2005-031003																				
JV	117																				
JI	4-Mar																				
JP	276-287																				
Sample Data																					
Item	LatDD	LongDD	Loc_prec	Age	Max_age	Min_age	Age	Max_age	Min_age	Age	Max_age	Min_age	U	Pb	Location_Name	Rock_Class	Rock_Type	Sample_Description	Material	Collected_by	State
Units	DD	DD		Ma	Ma	Ma	Ma	Ma	Ma	Ma	Ma	Ma	ppm	ppm							
Method	1	1		2	2	2	3	3	3	4	4	4	5	5							
Sample Name																					
OCT-10A	35.02197314	-117.0205421	0.001	15.48	15.69	15.27	16.6	17.6	15.6	15.39	15.54	15.24	175	3.86	Owl Canyon Campground	Tufa	Sedimentary	Tufa from northeast face of ridge	Whole Rock	Cole et al	California
OWL-S-4	35.02197314	-117.0205421	0.001	15.21	15.46	14.96	13.5	15.5	11.5	15.3	15.55	15.05	160	3.23	Owl Canyon Campground	Tufa	Sedimentary	Tufa from southwest face of ridge	Whole Rock	Cole et al	California
OW-11	35.02197314	-117.0205421	0.001	14.83	15.33	14.33	14.5	16.1	12.9	14.81	15.2	14.42	108	2.83	Owl Canyon Campground	Tufa	Sedimentary	Tufa from northeast face of ridge	Whole Rock	Cole et al	California
OCE-1	35.08253336	-117.0227841	0.01	17.2	19	15.4	38	66	10	16.14	16.54	15.74	18.1	5.07	Phytoherm locality	Tufa	Sedimentary		Whole Rock	Cole et al	California
OW-17	35.06201128	-116.9863461	0.01	16.36	16.51	16.21	17	19.4	14.6	16.24	16.47	16.01	134	12.7	Alluvium Deposit	Tufa	Sedimentary	Tufa from deposit covered by Quaternary alluvium	Whole Rock	Cole et al	California
Method Data																					
1	TABLE	2005-031003																			
2	U-PB6:CALCITE	52																			
3	U-PB7:CALCITE	52																			
4	U-PBC:CALCITE	52																			
5	XRF	52