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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