Lecture 16 Dacite Source Region.ppt - UC...
Transcript of Lecture 16 Dacite Source Region.ppt - UC...
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EPS 101/271 Lecture 16:
Dacite “Rhyolite” Source Region
Geodetic Markers and
Accuracy of the GPS units we use
1871 Department formed by Joseph LeConte
Chronology:
1887 Charles Palache graduates from Berkeley High and
1893 Charles Palache publishes the results of the first
1887 Charles Palache graduates from Berkeley High and enters Cal as a Freshman, continues on in graduate school
1892 Andrew Lawson teaches the first “systematic field geology class in the US” using Berkeley Hills
doctoral thesis in geology at UC: “The Soda Rhyolite North of Berkeley” UC Bulletin of the Dept. of Geology, v. 1, p. 61-72
1902 Lawson and Palache publish “The Berkeley Hills- A Detail of Coast Range Geology” Bulletin of the Dept.of Geology,v. 2, p. 349-450
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L ’ fi fi ld l 1892
The start of our BerkeleyField Tradition
Lawson’s first field class 1892
Strawberry Creek
Lawson and Palache’s mapof the Berkeley Hills
Rhyolite Tuffs
Claremont Canyon
Missing the Hayward Fault
Stadium
Recall the explanationof the Miocene
Global vsLocal control onlithology
stratigraphicsequence
Global climatic change
Sudden global cooling
F ti f lFormation of polarice caps
Marine Regression causing thelitho-sequence
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Rhyolites and
SiO2 (Silica)
Basalts Dacites
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Brimhall 2004
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Constraints on the Origin of Rhyolite Tuffs in the Berkeley/Oakland Hills
Basalts
Tecuya Formation in S CA
Mixing lines as the resultof ridge/trench collision
RhyolitesFranciscan
of ridge/trench collision
Initial Cole and Basu (1992)
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Source region for rhyolitemagmas involves continentalcrust: Franciscan or itsderivatives eg Orinda
RhyoliteMonoliths
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Are the Rhyolite and Daciterelated ? Use Zircons ZrSiO4
Fractional Fusion ?
(IUGS Classification))
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DiatremeIndian Rock
10.9 11.3
Grizzly PeakOrinda
1303 old core88.3
K and J
Not very rounded-close to their source
Indian RockMonoliths
10.0
11.3EuhedralEuhedral Zircons: Dating rhyolitic
magma crystallization
DaciteDiatreme
Grizzly Peak Dacite Tuffs
Sibley VolcanoPark Dacite
Tuffs
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RhyodaciteDiatreme
Indian Rock Monoliths DetritalEuhedral
Detrital Zircons: Age, source region and provenance of persistent mineral grains
Orinda Formation
Grizzly PeakRhyodacite Tuffs
Detrital
Franciscan Provenance
Sibley Park Tuff
T K J Tr
Detrital
Geodetic Markers
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http://www.metzgerwillard.us/Setup.aspx
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3-D Physical standards- analogous to chemical standards NIST
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Click on the PID nameeg HT1891 so that theNGS data sheet appearsbelow.
Be careful to observe whichellipsoid is referencedeg NAD83 is NAD83CONUSNote: NAD 83 CONUS not NAD27 W. USA
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Systematic Error and accuracy (relative to HT1892)= 2.33 meters
This map was made at PID HT1891 using 80-10 second averaging times for the Globalsat BC-337 GPS with a SiRFstarIII chipset (WAAS)
Random Error (relative to mean):Easting 1 = 0.73 mNorthing 1 =1.63 mSum random error and precision:
1 =SQRT(ADE2+ADN2)= 1.79m2 m3
SystematicError (black)VectorAccuracy
Total Error = Systematic +/- Random Error1 Total Error = 2.33+/- 1.79m
1 0.54 < Total Error < 4.12 m 2 0 <Total Error < 6.23 0< Total Error < 7.69 95%
DataCloudwidthPrecision
1m