40Ar/39Ar Age-Spectrum Data for Hornblende, Biotite, 

White Mica, and K-Feldspar Samples From Metamorphic 

Rocks in the Great Smoky Mountains of North Carolina 

and Tennessee

Open-File Report 2011–1250

U.S. Department of the Interior

U.S. Geological Survey

40Ar/39Ar Age-Spectrum Data for 

Hornblende, Biotite, White Mica, and 

K-Feldspar Samples From Metamorphic 

Rocks in the Great Smoky Mountains of 

North Carolina and Tennessee

By Michael J. Kunk and Ryan McAleer

Open-File Report 2011–1250

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2011

For more information on the USGS—the Federal source for science about the Earth, its natural and living 

resources, natural hazards, and the environment—visit http://www.usgs.gov or call 1–888–ASK–USGS.

For an overview of USGS information products, including maps, imagery, and publications, 

visit http://www.usgs.gov/pubprod/.

To order this and other USGS information products, visit http://store.usgs.gov/.

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Kunk, M.J., and McAleer, Ryan, 2011, 40Ar/39Ar age-spectrum data for hornblende, biotite, white mica, and K-feldspar 

samples from metamorphic rocks in the Great Smoky Mountains of North Carolina and Tennessee: U.S. Geological 

Survey Open-File Report 2011–1250, 56 p., available at http://pubs.usgs.gov/of/2011/1250/.
iii

Contents

Introduction.....................................................................................................................................................1

Methods...........................................................................................................................................................1

Sample Preparation ..............................................................................................................................1

Sample Analysis....................................................................................................................................1

Isotopic Data Reduction ......................................................................................................................4

Results .............................................................................................................................................................4

References Cited..........................................................................................................................................56

Tables

 1. Material dated, location of sample, and formation .........................................................................2

 2. 40Ar/39Ar analytical data ........................................................................................................................6

40Ar/39Ar Age-Spectrum Data for Hornblende, Biotite, 

White Mica, and K-Feldspar Samples From Metamorphic 

Rocks in the Great Smoky Mountains of North Carolina 

and Tennessee

By Michael J. Kunk and Ryan McAleer

Introduction

This report contains reduced 40Ar/39Ar data of hornblende, 

biotite, white mica and (or) sericite, and potassium-feldspar 

mineral separates and phyllite groundmass samples from 

metamorphic rocks of the Great Smoky Mountains in North 

Carolina and Tennessee. Included in this report are information 

on the location of the samples and a brief description of 

the samples. The data contained herein are not interpreted 

in a geological context, and care should be taken by users 

unfamiliar with argon isotopic data in the use of these results. 

No geological meaning is implied for any of the apparent ages 

presented below, and many of the individual apparent ages 

are not geologically meaningful. This report is primarily a 

detailed source document for subsequent publications that will 

integrate these data into a geological context. All the samples 

in this report were collected in and around the Great Smoky 

Mountain National Park in western North Carolina and eastern 

Tennessee. Table 1 is a listing of the location of all the samples 

and includes the sample number, the U.S. Geological Survey 

(USGS) 7.5-minute quadrangle that the sample is located in, the 

material dated, and the latitude and longitude of the sample site. 

In general, the samples are listed by mineral and (or) sample 

type and date of collection.

Methods

Sample Preparation

Samples were crushed, ground, and sized using 250-, 

180-, and 150-micrometer (mm) sieves. Mineral separates were 

produced using magnetic separation, heavy liquid separation, 

paper shaking, and hand picking to a purity of more than 99 

percent for biotite, white mica, and K-feldspar. Hornblendes 

were prepared to a purity of 99.9 percent using the same 

methods. The purity of sericite samples is variable but 

generally greater than 99 percent. Most samples were washed 

in acetone, alcohol, and deionized water (X3) in a Branson 

B220 ultrasonic cleaner to remove dust and then resieved 

by hand using a 100-mm sieve. Very fine-grained white mica 

(sericite) and phyllite groundmass samples were washed in the 

same series of solvents but without the use of the ultrasonic 

cleaner.

The samples were irradiated in duplicate in two separate 

packages (KD 32 and KD 43). Approximately 5 milligrams 

(mg) of biotite, 10 mg of white mica and (or) sericite and 

K-feldspar, 50 mg of groundmass samples, and 100 mg of 

hornblende were packaged in copper capsules and sealed 

under vacuum in fused silica tubes. Duplicate samples of 

biotite, white mica and (or) seracite and K-spar were loaded 

at about one-tenth the weights mentioned above. The samples 

were then irradiated in the central thimble facility at the 

TRIGA reactor (GSTR) at the USGS, Denver, Colorado. 

The monitor mineral used in both packages was MMhb-1 

hornblende with an age of 519.4 ±2.5 million years (Alexander 

and others, 1978; Dalrymple and others, 1981). The type 

of container and the geometry of samples and standards are 

similar to those described by Snee and others (1988).

Sample Analysis

All hornblende and groundmass samples and some of the 

other minerals samples were analyzed at the USGS, Denver 

on a VG Isotopes, Ltd. Model 1200 B mass spectrometer fitted 

with an electron multiplier using the 40Ar/39Ar step heating 

method of dating. Heating for 10 minutes per step followed a 

schedule of 5 to 15 steps. The heating schedules were designed 

such that the percentage of 39Ar released per step was limited 

to less than 20 percent of the total released for most samples.

The samples were heated in a small volume, 

molybdenum-lined, low-blank tantalum resistance furnace 

similar to that described by Staudacher (1978). Temperature 

was monitored by a W5Re-W26Re thermocouple and 

controlled by a proportional, programmable controller. 

The furnace and the rear manifold were pumped between 

steps with a turbo molecular pump. Two isolated ion pumps 
Table 1. Material dated, location of sample, and formation. [Fm, formation] Field no. Unit Rock type Mineral dated Latitude Longitude Quadrangle name 

Amphibole K02–9–19H Mesoproterozic rocks Biotite gneiss Amphibole N35° 26’ 52.4 W83° 24’ 03.7 Bryson City, N.C. 

K02–9–19I Mesoproterozic rocks Biotite amphibole gneiss Amphibole N35° 27’ 06.8 W83° 22’ 38.4 Bryson City, N.C. 

K04–7–13J Mesoproterozic rocks Amphibolite Amphibole N35° 32.287’ W83° 01.501’ Dellwood, N.C. 

K04–7–14C Mesoproterozic rocks Amphibolite Amphibole N35° 34.872’ W82° 59.241’ Clyde, N.C. 

White mica/sericite K02–9–18A Wilhite Fm Micaceous metasiltstone White mica N35° 41’ 20.2” W83° 47’ 53.4” Kinzel Springs, Tenn. 

K02–9–18B Metcalf Phyllite Phyllite White mica N35° 38’ 30.5 W83° 41’ 33.9” Wear Cove, Tenn. 

K02–9–18C Metcalf Phyllite Phyllite White mica N35° 39’ 09.9” W83° 41’ 50.4” Wear Cove, Tenn. 

K02–9–18D Metcalf Phyllite Phyllite White mica N35° 39’ 58.1” W83° 42’ 48.6” Wear Cove, Tenn. 

K02–9–19B Elkmont Fm Metasandstone White mica N35° 28’ 02.6” W83° 64’ 42.2” Tapoco, N.C. 

K02–9–19C Thunderhead Ss Metasandstone White mica N35° 26’ 57.2” W83° 50’ 15.1” Fontana Dam, N.C. 

K02–9–19D Anakeesta Fm Muscovite garnet schist White mica N35° 26’ 27.0” W83° 48’ 26.5” Fontana Dam, N.C. 

K02–9–19E Wehutty Fm Biotite schist White mica N35° 27’ 24.0” W83° 28’ 18.2” Bryson City, N.C. 

K02–9–19E1 Wehutty Fm Muscovite schist White mica N35° 27’ 24.0” W83° 28’ 18.2” Bryson City, N.C. 

K02–9–19F Thunderhead Ss Metasandstone White mica N35° 26’ 47.9” W83° 27’ 58.4” Bryson City, N.C. 

K02–9–19G Mesoproterozic rocks Mylonite White mica N35° 26’ 46.8” W83° 24’ 03.7” Bryson City, N.C. 

K02–9–19J Pegmatite Pegmatite White mica N35° 28’ 35.4” W83° 19’ 42.6” Whittier, N.C. 

K02–9–19K Wading Branch Fm Schist White mica N35° 28’ 27.6” W83° 19’ 13.7” Whittier, N.C. 

K02–9–19L Anakeesta Fm Schist White mica N35° 36’ 33.9” W83° 26’ 40.2” Clingmans Dome, N.C

K02–9–19M Diorite Metadiorite White mica N35° 43’ 37.1” W83° 28’ 47.3” Clingmans Dome, N.C

K04–4–28A Copperhill Fm Kyanite schist White mica N35° 24’ 50” W83° 42’ 55.5” Tuskeegee, N.C. 

K04–4–28B Ammons Fm Metagraywacke White mica N35° 23’ 36” W83° 35’ 46” Noland Ck, N.C. 

K04–4–28C Pegmatite Pegmatite White mica N35° 25’ 30” W83° 24’ 58” Bryson City, N.C. 

K04–4–28D Copperhill Fm Muscovite staurolite schist White mica N35° 26’ 43” W83° 22’ 40” Bryson City, N.C. 

K04–7–13A Copperhill Fm Muscovite schist White mica N35° 24.235’ W83° 18.780’ Whittier, N.C. 

K04–7–13B Copperhill Fm Graywacke White mica N35° 34.877’ W82° 21.056’ Smokemont, N.C. 

K04–7–13C Copperhill Fm Kyanite schist White mica N35° 31.424’ W83° 18.354’ Smokemont, N.C. 

K04–7–13D Copperhill Fm Kyanite schist White mica N35° 31.660’ W83° 14.228’ Bunches Bald, N.C. 

K04–7–13E Copperhill Fm Kyanite schist White mica N35° 31.169’ W83° 10.628’ Bunches Bald, N.C. 

K04–7–13F Copperhill Fm Kyanite schist White mica N35° 28.867’ W83° 10.629’ Silva North, N.C. 

K04–7–13G Copperhill Fm Kyanite schist White mica N35° 26.738’ W83° 10.630’ Silva North, N.C. 

K04–7–13H Cartoogechaye Kyanite schist White mica N35° 26.524’ W83° 10.631’ Hazelwood, N.C. 

K04–7–13I Cartoogechaye Muscovite biotite schist White mica N35° 25.858’ W83° 10.632’ Hazelwood, N.C. 
Table 1. Material dated, location of sample, and formation.—Continued[Fm, formation]

Field no. Unit Rock type Mineral dated Latitude Longitude Quadrangle name 

White mica/sericite—Continued

K04–7–13KK04–7–14AK04–7–14BK04–7–14EK04–7–14FK04–7–14GK04–7–14HK04–7–14JK04–7–14KK04–7–14LK04–7–14MK02–9–19AK02–9–20A

LongarmMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksWilhite FmPigeon Siltstone

QuartziteKyanite schistKyanite schistQuartz veinUltramyloniteMyloniteProtomylonitic saproliteMyloniteProtomyloniteMyloniteMyloniteSlateSiltstone

White micaWhite micaWhite micaWhite micaWhite micaWhite micaWhite micaWhite micaWhite micaWhite micaWhite micaGroundmassGroundmass

N35° 37.359’N35° 36.201’N35° 33.956’N35° 47.630’N35° 45.224’N34 45.522’N35° 42.743’N35° 50.474’N35° 50.538’N35° 55.502’N35° 43.508’N35° 33’ 25.9”N35° 43’ 37.1

W83° 10.633’W83° 56.247’W82° 57.476’W82° 54.895’W82° 56.356’W82° 55.722’W82° 49.712’W82° 45.143’W82° 41.929’W82° 37.206’W82° 32.969’W84 00’ 29.9”W83° 28’ 47.3”

Bunches Bal, N.C.Clyde, N.C. Clyde, N.C. Lemon Gap, N.C.Lemon Gap, N.C.Lemon Gap, N.C.Sandy Mush, N.C.Spring Creek, N.C.Marshall, N.C.Sams Gap, N.C.Weaverville, N.C.Tallassee, Tenn.Gatlinburg, Tenn.

Biotite

K02–9–19FK02–9–19HK02–9–19IK02–9–19KK04–7–13LK04–7–14AK04–7–14BK04–7–14CK04–7–14KK04–7–14M

Thunderhead FmMesoproterozic rocksMesoproterozic rocksWading Branch FmWehutty FmMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocksMesoproterozic rocks

Meta sandstoneBiotite gneissBiotite amphibole gneissKyanite schistKyanite schistMuscovite schistKyanite schistAmphiboliteProtomyloniteMylonite

BiotiteBiotiteBiotiteBiotiteBiotiteBiotiteBiotiteBiotiteBiotiteBiotite

N35° 26’ 47.9”N35° 26’ 52.4”N35° 27’ 06.8”N35°28’ 27.6”N35° 27.260’N35° 36.201’N35° 33.956’N35° 34.872’N35° 50.538’N35° 43.508’

W83° 27’ 58.4”W83° 24’ 03.7”W83° 22’ 38.4”W83° 19’ 13.7”W82° 29.775’W83° 56.247’W82° 57.476’W82° 59.241’W82° 41.929’W82° 32.969’

Bryson City, N.C.Bryson City, N.C.Bryson City, N.C.Whittier, N.C.Bryson City, N.C.Clyde, N.C.Clyde N.C.Clyde, N.C.Marshall, N.C.Weaverville N.C.

K-Feldspar

K02–9–19GK02–9–19JK04–7–14DK04–7–14IK04–7–14K

Mesoproterozic rocksPegmatiteMesoproterozic rocksMesoproterozic rocksMesoproterozic rocks

mylonitePegmatiteGranite-granodioriteMyloniteProtomylonite

K-feldsparK-feldsparK-feldsparK-feldsparK-feldspar

N35° 26 46.8”N35° 28 35.4”N35° 74.700’N35° 49.768’N35° 50.538’

W83° 24’ 03.7”W83° 19’ 42.6”W82° 55.745’W82° 47.968’W82° 41.929’

Bryson City, N.C.Whittier, N.C.Lemon Gap, N.C.Spring Creek, N.C.Marshall, N.C.
4 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

evacuated the front manifold and the mass spectrometer 

flight-tube between each incremental step. Prior to analyzing 

in the mass spectrometer, the gas was purified in the rear 

manifold by a SAES ST707 Zr-V-Fe getter operated at room 

temperature and a hot Re filament. A cold finger in the rear 

manifold, immersed in liquid N2

, was used to freeze out 

H2O. Gas was equilibrated with the front manifold, then 

isolated and cleaned in the front manifold with a SAES 

ST101 Al-Zr getter operated at 400°C and a Ti getter operated 

at 350°C. An activated charcoal finger submerged in a 

thermally equilibrated mixture of dry ice and acetone in the 

front manifold was used to remove gasses with a molecular 

weight greater than 60 or 80 (primarily other noble gasses) 

prior to the expansion of the argon-dominated gas into the 

mass spectrometer. The gas was further purified in the mass 

spectrometer by a second SAES ST101 active gas getter 

operated at room temperature. The SAES ST101’s successful 

operation could be monitored by the drop in counts of mass 

44 (dominated by CO2) after the first gas analysis cycle. Argon 

isotopes with masses 40 through 36 and CO2 (mass 44) were 

analyzed as a function of time in five analytical cycles. For 

40Ar, 39Ar, 38Ar, and 37Ar, peaks and baselines, were measured 

for five 1.28-second integrations in each of the five cycles. 

36Ar and baselines were measured for twenty 1.28-second 

integrations in each of the five cycles. After each analysis, the 

mass spectrometer was evacuated. All phases of the sample 

heating, cleanup, equilibration, and analysis were performed 

under computer control.

Many of the mineral samples were analyzed at the USGS 

in Denver with a MAP 216 mass spectrometer fitted with an 

electron multiplier using the 40Ar/39Ar step heating method 

of dating. The samples were heated as described above. 

The furnace and the rear and front manifolds were pumped 

between steps with a turbo molecular pump. An isolated ion 

pump was used to pump the mass spectrometer. Prior to mass 

spectrometer analysis, the gas was purified in the manifold 

by two SAES ST101 Al-Zr getters, one operated at room 

temperature and the other at 400oC, and a hot Re filament. The 

argon-rich gas was further purified by a third SAES ST 101 

getter operated at room temperature in the flight tube of the 

mass spectrometer. Argon isotopes with masses 40 through 36 

were analyzed as a function of time in six analytical cycles. 

Baselines were measured for 39Ar and 36Ar. The 36Ar baselines 

were subtracted from the 40Ar, 38Ar, 37Ar and 36Ar peaks. The 39Ar baseline was subtracted from the 39Ar peak to reduce the 

influence of the tail of the 40Ar peak. All phases of the sample 

heating, cleanup, equilibration, and analysis were performed 

under computer control.

Isotopic Data Reduction

All the Ar isotopic data were reduced using an updated 

version of the computer programs ArAr* (Haugerud 

and Kunk, 1988) or Mass spec (Deino, 2001) and decay 

constants recommended by Steiger and Jäger (1977). The 

isotopic measurements made in the analysis had baseline 

values subtracted and then were regressed to time zero, 

using standard linear regression techniques. These regressed 

values and associated statistical estimates of analytical 

uncertainties of the time zero peak values were used in the 

data reduction. Full system blanks were measured prior to the 

suite of analyses made on each sample and then subtracted 

from the analytical results. Error estimates of the blanks 

were quadratically combined with the analytical errors and 

propagated through the error equations. Corrections for 

interfering reactor-produced argon isotopes from Ca, K, and 

Cl in the sample were made using the production ratios given 

in Dalrymple and others (1981) and Roddick (1983). Errors 

in calculating ages or ratios include analytical errors in the 

analysis; decay factor uncertainties; measured atmospheric 

or calculated initial 40Ar:36Ar ratios; the irradiation parameter 

J; the production ratios of the various reactor induced argon 

producing reactions; the initial 38Ar:36Ar ratio; and the age of 

the monitor (Haugerud and Kunk, 1988).

The tables and associated figures in this report include 

the identification of individual step ages, plateau ages, total 

gas ages, and inverse isochron ages. Total gas ages represent 

the age calculated from the addition of all the measured argon 

peaks for all steps, in a single sample. The total gas ages 

are roughly equivalent to conventional K-to-Ar ages. No 

analytical precision is calculated for total gas ages. Plateau 

ages were determined using the definition of Fleck, and 

others (1977) as modified by Haugerud and Kunk (1988). 

Inverse isotope correlation analysis of the analytical data to 

assess if nonatmospheric argon components were trapped 

in any samples and to calculate an inverse isochron age was 

done using the method of York (1969). All stated analytical 

uncertainties are 1 standard deviation (s). Errors for the 

individual step ages do not include the error in the irradiation 

parameter J, errors for the production of interfering isotopes 

produced during neutron irradiation, or the uncertainty in the 

age of the monitor mineral. Only plateau and isochron ages 

include the uncertainty in the irradiation parameter J.

Results

The 40Ar/39Ar geochronologic results presented in 

this report include tabular data (table 2) and one to three 

graphical representations of the age spectrum data on facing 

pages. Biotite samples have no associated figures. Each 

sample starts with a line that gives the sample number, 

the J-value used with its analytical uncertainty, the sample 

weight in grams, and the packet and package number from 

the irradiation. The table includes a letter designation for 

the individual argon analysis, the temperature of the step, 

the percentage of potassium-derived 39ArK for each step, 

the radiogenic yield (percentage of 40Ar that is derived 

from the decay of potassium), moles of 39ArK, a corrected 40Ar:39ArK ratio from which the age can be directly 
Results 5

calculated, calculated apparent K:Ca and K:Cl ratios for 

each step (or asterisk if the measured 38Ar or 37Ar signal 

measured was less than the detection limit of the mass 

spectrometer), a calculated age for the step in millions of 

years, and an estimate of the precision of each age at the 1s

level. The sample precision includes estimates of the errors 

that are unique to a single sample and can be used only for 

comparisons with other steps of the same sample. This error 

estimate does not include the error in J. The second to last 

line in the age spectra datasets represents the total gas result 

for the sample. No analytical error is calculated for the age in 

this line because the age spectra are frequently disturbed and 

the error that could be calculated here would be geologically 

meaningless. The final line in the age specta datasets 

indicates if there was a plateau age. If the sample has an 

age plateau, then the percentage of 39Ar on the plateau, the 

steps on the plateau, and the plateau age and its precision 

are reported. Plateau ages include the error in the irradiation 

parameter J.

The figures associated with each age spectrum dataset 

include a graph that plots cumulative percent 39ArK of the 

individual heating steps against apparent age in millions of 

years. Errors in age are graphically displayed at the 2s level 

of confidence. In addition, some age spectra plots have an 

apparent K:Ca plot attached. For some samples, an inverse 

isotope correlation diagram is also included. Information 

within this diagram includes the isochron age and its error, the 

calculated initial 40Ar:36Ar ratio, the MSWD (mean standard 

weighted deviates) for the sample, and an indication of which 

points were used in the isochron. For additional information 

on the sample datasets, see Haugerud and Kunk (1988) and 

Deino (2001).
6 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

AMPHIBOLE

 K02-9-19H 

A 1000

B 1050

C 1100

D 1150

E 1175

F 1200

G 1250

H 1650

Total gas

No age plateau

 K02-9-19I 

A 1000

B 1100

C 1125

D 1150

E 1175

F 1250

Total gas

72.08

J=.012273 ±0.5%

2.5 97.5 2.73E-14 64.024

1.2 98.4 1.35E-14 30.629

2.7 98.4 2.95E-14 32.913

48.7 99.5 5.33E-13 29.410

13.0 99.4 1.42E-13 24.261

2.8 98.4 3.01E-14 27.718

10.6 99.2 1.16E-13 29.082

18.5 98.6 2.02E-13 27.109

99.2 1.09E-12 29.209

J=.012321 ±0.5%

3.9 98.3 1.02E-13 24.521

22.8 99.7 5.97E-13 22.467

20.1 99.9 5.25E-13 22.429

29.2 99.9 7.65E-13 22.419

5.3 99.7 1.38E-13 22.628

18.8 99.8 4.91E-13 22.788

99.7 2.62E-12 22.594

% gas released on plateau in steps 11000

C through 11500C

wt.=0.0501 g

0.2 37

0.1 44

0.1 30

0.1 29

0.1 36

0.1 25

0.1 26

0.1 29

0.1 30

wt.=0.0530 g

0.2 62

0.2 94

0.2 98

0.2 99

0.2 99

0.2 99

0.2 96

Plateau age =

97KD32

1046.05

575.69

612.07

555.96

470.18

528.22

550.62

518.14

552.69

101KD32

476.25

440.85

440.18

440.00

443.63

446.42

443.06

440.20

1.20

1.17

0.80

0.50

0.44

1.87

0.35

0.55

0.50

0.32

0.38

0.17

0.43

0.33

2.20
Results 7

K02-9-19I

Amphibole

Plateau age = 440.2 ± 2.2 Ma

1

.1

500

400

300

200

Apparent Age (Ma) K/Ca

0 39ArK Released (%) 100

K02-9-19H

Amphibole

1

.1

.01

500

400

300

200

Apparent Age (Ma) K/Ca

0 39ArK Released (%) 100

8.0E-5

6.0E-5

4.0E-5

2.5E-5

0

0 .008 .016 .024 .032 .040 

39Ar/40Ar

36Ar/40Ar

Isochron age = 395.4 ± 27.3 Ma

(

40Ar/36Ar)i

 = 8257.0 ± 641.7

MSWD = 1.539

No doints deleted

A K02-9-19H

G

H

H

F

E D

C

B

.00042

.00028

.00014

0

0 .008 .016 . 024 0.32 .040 .048 

39Ar/40Ar

36Ar/40Ar

Isochron age = 437.0 ± 2.7 Ma

(

40Ar/36Ar)i

 = 1858.2 ±155.9

MSWD = 0.752

No points deleted

K02-9-19I A

B E

F C,D
8 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-13J J=.009485 ±0.5%

A 950 0.8 14.1 2.67E-16 75.485

B 1000 0.4 55.6 1.34E-16 61.316

C 1050 0.1 90.3 4.27E-17 152.554

D 1100 0.2 92.4 5.59E-17 159.080

E 1150 0.2 92.6 6.43E-17 128.243

F 1175 0.2 83.1 5.88E-17 48.155

G 1200 0.2 87.7 6.43E-17 43.036

H 1225 0.3 91.7 1.12E-16 43.243

I 1250 0.8 94.0 2.75E-16 34.789

J 1275 2.9 97.0 9.57E-16 30.271

K 1300 9.4 98.3 3.07E-15 29.925

L 1325 25.9 99.5 8.39E-15 29.838

M 1350 54.0 98.8 1.75E-14 29.776

N 1400 3.8 98.1 1.23E-15 29.834

O 1450 0.5 78.6 1.48E-16 29.722

P 1650 0.2 36.5 5.46E-17 26.137

Total gas

84.1 % of gas released on plateau in steps 13250

C through 14500C

 K04-7-14C J=.009524 ±0.5%

A 950 0.5 83.6 2.83E-16 83.246

B 1000 0.2 89.1 8.85E-17 60.763

C 1050 0.3 92.8 1.69E-16 62.853

D 1100 0.3 92.9 2.01E-16 90.866

E 1150 0.4 89.5 2.09E-16 56.535

F 1175 0.3 89.7 1.62E-16 45.515

G 1200 0.5 91.4 3.02E-16 37.857

H 1225 0.7 94.0 4.10E-16 36.141

I 1250 1.0 94.7 5.55E-16 34.542

J 1275 3.2 97.1 1.83E-15 35.524

K 1300 8.5 98.0 4.96E-15 38.638

L 1325 38.0 99.0 2.21E-14 34.239

M 1350 7.9 98.9 4.61E-15 30.075

N 1400 36.2 98.8 2.10E-14 34.072

O 1450 1.6 96.9 9.24E-16 32.205

P 1650 0.4 86.3 2.44E-16 32.260

Total gas

No age plateau

wt.=0.01054 g

0.3 2

0.1 1

0.1 0

0.1 0

0.1 1

0.0 1

0.0 1

0.0 1

0.0 1

0.0 1

0.0 1

0.0 1

0.1 1

0.0 1

0.0 1

0.0 1

Plateau age =

wt.=0.010249 g

0.2 1

0.3 1

0.3 1

0.2 2

0.2 3

0.1 3

0.1 3

0.1 3

0.1 3

0.1 5

0.1 7

0.1 9

0.1 1

0.1 4

0.1 4

0.1 2

217KD43

974.16

827.03

1614.38

1659.45

1435.82

678.71

617.55

620.07

514.45

455.36

450.76

449.60

448.77

449.54

448.05

399.55

466.00

449.00

306KD43

1053.21

823.75

846.36

1124.80

777.14

649.66

555.46

533.65

513.10

525.74

565.29

509.18

454.39

507.01

482.63

483.35

518.00

16.86

6.85

14.55

12.23

10.24

10.73

10.09

6.01

2.82

1.13

0.44

0.37

0.45

0.80

5.00

21.32

2.00

3.83

9.30

5.02

4.47

4.35

5.38

3.08

2.44

1.88

0.79

0.43

0.49

0.46

0.48

1.04

4.13
Results 9

0.1

1

0 10 20 30 40 50 60 70 80 90 100

200

300

400

500

600

 449 ± 2 Ma

Apparent Age (Ma)

39ArK Released (%)

KO4-7-13J 

Amphibole

0.1

1

0 10 20 30 40 50 60 70 80 90 100

200

300

400

500

600

Apparent Age (Ma)

39ArK Released (%)

KO4-7-14C 

Amphibole

K/Ca K/Ca

0 0.005 0.010 0.015 0.020 0.025 0.030 0.035

0

0.0004

0.0008

0.0012

0.0016

0.0020

0.0024

0.0028

Isochron age = 449 ± 2 Ma (0.46%)

40Ar/36Ar Intercept = 350 ± 30 (9.68%)

MSWD = 3.7, Prob. = 0.02, n = 4

K04-7-13J 

Amphibole

39Ar/40Ar

36Ar/40Ar

K-N

A

B

F

G

H

I

J KMN

O

P

0 0.005 0.010 0.015 0.020 0.025 0.030

0

1.E-4

0.00020

0.00030

0.00040

B

C D

E F

G

H

I

J

K

L

N M

O

P

Isochron age = 465 ± 2 Ma (0.49%)

40Ar/36Ar Intercept = 2390 ± 40 (1.65%)

MSWD = 180, Prob. = 0.00, n = 16

K04-7-14C 

Amphibole
10 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

WHITE MICA 

 K02-9-18A J=0.012400 ±0.5%

A 650 0.3 6.2 1.80E-17 16.267

B 750 2.0 18.6 1.12E-16 18.094

C 850 3.8 87.5 2.10E-16 28.970

D 950 10.5 98.0 5.84E-16 33.977

E 1000 9.7 98.9 5.40E-16 38.545

F 1050 20.7 99.5 1.15E-15 39.908

G 1100 13.1 99.3 7.29E-16 40.719

H 1150 39.9 85.6 2.22E-15 40.649

Total gas 91.3 5.60E-15 38.628

53.0 % of gas released on plateau in steps 11000

C through 11500C

K02-9-18B J=.012368 ±0.5%

A 650 3.0 87 1.14E-14 13.140

B 750 6.0 99 2.28E-14 18.241

C 850 18.0 99.8 6.86E-14 17.567

D 950 35.2 99.8 1.34E-13 17.398

E 1050 27.0 99.9 1.03E-13 17.545

F 1100 9.0 99.9 3.43E-14 17.972

G 1150 1.5 97.4 5.65E-15 18.368

H 1200 0.5 92.6 1.74E-15 23.579

Total gas 99.3 3.82E-13 17.486

No age plateau

wt.=0.000111 g

0.0 2

1.6 4

2.2 26

3.8 366

8.4 546

8.8 1132

6.8 750

7.7 218

7.1 512

Plateau age =

wt.=0.0020 g

15.4 78

41.6 4131

79.4 ***

80.5 ***

24.2 ***

11.2 31382

2.8 466

0.4 188

53.1 3073

198KD32

331.48

365.17

553.67

634.26

704.75

725.26

737.36

736.32

706.01

736.90

#76KD32 

271.66

367.00

354.69

351.59

354.28

362.09

369.31

461.64

353.19

52.43

8.09

1.96

0.54

0.58

0.39

0.44

0.46

3.38

2.47

1.32

0.44

0.28

0.48

0.91

7.78

17.68
Results 11

K02-9-18A

White mica

Plateau age = 736.9 ± 3.4 Ma

800

600

400

200

Apparent Age (Ma)

0 39ArK Released (%) 100

K02-9-18B

White Mica

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100
12 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K02-9-18C J=.012401 ±0.5%

A 750 2.6 97.9 1.14E-14 24.926

B 800 3.6 98.3 1.56E-14 27.054

C 850 5.9 99.4 2.59E-14 31.856

D 900 18.5 99.9 8.10E-14 45.439

E 950 12.1 99.7 5.28E-14 44.160

F 1000 10.8 99.8 4.71E-14 44.835

G 1100 33.3 99.9 1.45E-13 48.803

H 1150 8.9 99.9 3.90E-14 50.945

I 1350 4.3 99.7 1.88E-14 51.785

Total gas 99.7 4.37E-13 45.110

No age plateau

 K02-9-18D J=0.012372 ±0.5%

A 650 3.3 3.4 6.10E-17 6.930

B 750 8.2 29.5 1.52E-16 13.321

C 850 14.7 87.7 2.72E-16 19.115

D 950 28.8 98.0 5.32E-16 18.246

E 1000 14.8 97.8 2.74E-16 18.105

F 1050 11.9 96.9 2.21E-16 18.280

G 1100 10.4 99.2 1.92E-16 19.942

H 1150 5.1 96.4 9.50E-17 22.466

I 1200 1.5 87.9 2.80E-17 34.292

J 1250 0.4 49.9 8.00E-18 62.667

K 1300 0.4 75.3 8.00E-18 91.895

L 1350 0.3 76.4 5.00E-18 147.423

Total gas 87.1 1.80E-15 19.066

55.6 % of gas released on plateau in steps 9500

C through 10500C

wt.=0.001464 g

33.0 792

32.6 1842

93.6 3237

182.5 8999

122.7 6233

148.6 4831

97.0 7247

205.9 6148

26.5 2298

124.0 6280

wt.=0.000382 g

1.6 5

23.9 17

4.0 308

8.1 1276

129.5 1139

5.5 506

45.3 827

0.0 270

0.6 73

0.4 14

0.2 22

0.1 14

29.5 745

Plateau age =

193KD32

485.90

521.91

600.61

806.24

787.85

797.58

853.75

883.36

894.83

801.53

79KD32

148.39

275.20

382.95

367.19

364.63

367.82

397.82

442.44

638.00

1035.46

1369.90

1872.78

382.06

366.79

2.21

1.79

0.86

0.30

0.33

0.55

0.21

0.66

0.73

14.72

3.92

1.24

0.65

1.26

1.55

1.75

3.43

10.30

38.20

24.50

40.83

1.86
Results 13

K02-9-18C

White mica

800

600

400

200

Apparent Age (Ma)

0 39ArK Released (%) 100

K02-9-18D

White mica

Plateau age = 366.8 ± 1.9 Ma

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100

.003

.002

.001

0

0 .01 .02 .03 .04 .05 

39Ar/40Ar

36Ar/40Ar

Isochron age = 363.3 ± 3.1 Ma

(

40Ar/36Ar)i

 = 415.2 ± 30.31

MSWD = 0.162

Points ABGHIJKL deleted

K02-9-18D A

D-F

G

J

B

C

L K

I

H

G
14 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K02-9-19B 

A 750

B 850

C 950

D 1000

E 1050

F 1100

G 1150

Total gas

No age plateau

 K02-9-19C

A 650

B 750

C 850

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1350

M 1450

N 1650

Total gas

No age plateau

2.6

8.0

41.8

7.8

8.6

24.3

6.8

0.3

1.1

1.8

5.4

4.8

15.9

13.6

11.9

24.9

10.8

3.5

3.5

2.5

0.1

99.5

99.8

99.9

99.9

99.9

100

99.8

99.9

5.2

26.1

86.7

98.0

98.7

99.3

99.5

99.6

99.7

98.8

99.0

98.7

98.1

100.0

98.0

J=.012347 ±0.5%

7.68E-15 19.516

2.35E-14 22.667

1.23E-13 25.332

2.30E-14 24.417

2.52E-14 26.890

7.16E-14 27.683

2.01E-14 25.274

2.94E-13 25.598

J=0.012371 ±0.5%

4.67E-17 7.442

1.86E-16 15.318

3.13E-16 18.962

9.61E-16 20.359

8.46E-16 20.052

2.84E-15 20.915

2.43E-15 20.071

2.13E-15 20.214

4.34E-15 21.195

1.88E-15 23.141

6.28E-16 22.636

6.12E-16 21.345

4.35E-16 22.360

1.79E-17 26.980

1.77E-14 20.960

wt.=0.00105 g

87.2 530

111.2 3180

254.3 ***

93.7 3164

97.0 1850

557.9 9434

165.7 ***

280.3 2970

wt.=0.000314 g

0.7 1

1.3 1

0.8 5

3.4 50

5.5 61

8.6 90

11.0 86

5.7 94

10.5 99

7.2 78

1.5 64

2.1 82

4.6 89

0.7 145

7.6 83

83KD32

389.47

445.15

490.95

475.35

517.20

530.40

489.97

495.45

78KD32

159.27

313.83

381.09

406.24

400.74

416.14

401.08

403.64

421.11

455.28

446.47

423.81

441.65

520.92

416.60

2.71

1.15

0.37

1.34

0.62

0.34

0.96

42.10

10.56

5.47

1.86

2.04

0.80

0.85

0.97

0.61

1.02

2.74

2.78

3.83

75.16
Results 15

K02-9-19B

White mica

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100

K02-9-19C

White mica

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100
16 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K02-9-19D J=.012341 ±0.5%

A 550 1.6 11.6 6.66E-15 3.369

B 650 1.8 86.2 7.65E-15 13.252

C 750 4.8 99.1 2.02E-14 19.947

D 850 12.6 99.7 5.27E-14 18.307

E 950 40.5 99.8 1.70E-13 17.249

F 1050 25.0 99.8 1.05E-13 17.308

G 1150 11.0 99.7 4.62E-14 17.278

H 1250 2.8 97.3 1.16E-14 18.618

Total gas 98 4.20E-13 17.275

76.5% gas released on plateau in steps 9500

C through 11500C

K02-9-19E J=.012354 ±0.5%

A 550 1.4 17.8 7.10E-15 8.243

B 650 1.3 79.6 7.04E-15 22.795

C 750 13.2 97.5 6.92E-14 32.089

D 850 29.8 99.5 1.56E-13 33.208

E 950 19.1 99 1.00E-13 33.368

F 1000 24.0 99.7 1.25E-13 33.721

G 1050 10.6 99.7 5.57E-14 33.404

H 1250 0.5 94.6 2.75E-15 27.659

Total gas 97.8 5.24E-13 32.727

No age plateau

wt.=0.0021 g

14.5 21

19.9 95

53.1 1811

60.7 ***

71.4 ***

85.6 ***

203.1 ***

17.1 902

83.9 114

Plateau age =

wt.=0.0022 g

17.5 30

22.6 73

191.9 1002

490.4 11237

269.0 2383

401.4 8958

130.2 ***

5.8 330

333.7 6088

115KD32

73.48

273.26

397.01

367.47

348.15

349.24

348.69

373.11

348.62

348.50

85KD32 

174.95

447.61

602.38

620.16

622.68

628.25

623.25

530.27

612.54

8.12

4.51

1.83

0.56

0.29

0.45

0.64

3.18

1.77

7.90

5.56

0.67

0.31

0.57

0.32

0.76

17.13
Results 17

K02-9-19D

White mica

Plateau age = 348.5 ± 1.8 Ma

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100

K02-9-19E

White mica

800

600

400

200

Apparent Age (Ma)

0 39ArK Released (%) 100
18 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

K02-9-19E1

A 550

B 650

C 750

D 850

E 950

F 1050

G 1100

Total gas

No age plateau

K02-9-19F 

A 750

B 800

C 850

D 900

E 950

F 1000

G 1100

H 1150

I 1350

Total gas

No age plateau

6.2

6.8

28.6

20.7

26.0

11.2

0.5

2.3

2.7

4.7

27.2

14.3

6.4

22.3

11.1

9.1

100

43.8

91.5

97.3

98

97.1

98.7

84.5

93.8

97

97.4

98.1

99.3

99.3

98.6

99.2

99.5

98.7

99

J=.012360

2.53E-14

2.76E-14

1.16E-13

8.35E-14

1.05E-13

4.51E-14

1.96E-15

4.04E-13

J=.012367

0.01483

0.01749

0.030315

0.17757

0.09316

0.041729

0.145361

0.07224

0.059122

0.6518

±0.5%

15.218

33.931

34.730

34.321

35.952

33.476

18.742

33.472

±0.5%

18.151

17.461

17.388

17.495

17.116

17.046

17.06

17.212

17.034

17.251

wt.=0.0022 g

62.6 61

153.8 297

344.9 1508

429.9 2626

441.2 1392

214.2 3098

8.5 179

340.5 1707

wt.=0.0021 g

29.42 678

56.31 1362

66.24 2620

255.48 294581

146.37 25094

82.17 3700

272.39 8793

254.77 62570

169.38 5752

205.39 93665

87KD32 

310.92

631.80

644.31

637.92

663.29

624.65

375.87

624.58

89KD32

365.32

352.71

351.37

353.33

346.37

345.09

345.34

348.15

344.86

348.85

0.75

1.00

0.28

0.38

0.19

0.63

12.19

1.38

1.1

1.07

0.23

0.3

0.51

0.21

0.49

0.55
Results 19

K02-9-19E1

White mica

800

600

400

200

Apparent Age (Ma)

0 39ArK Released (%) 100

8E-5

4E-5

0

0 .01 .02 .03 .04 .05 .06 

39Ar/40Ar

36Ar/40Ar

Isochron age = 343.4 ± 4.3 Ma

(

40Ar/36Ar)i

 = 694.7 ± 232.7

MSWD = 0.775

Points AI deleted

K02-9-19F A

G

C

B

I

H

F

E D

K02-9-19F

White mica

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100
20 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K02-9-19G

A 650

B 750

C 850

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1350

M 1450

N 1650

Total gas

No age plateau

 K01-9-19J

A 650

B 750

C 800

D 850

E 900

F 950

G 1000

H 1100

I 1150

J 1350

Total gas

No age plateau

0.5

1.0

1.5

4.9

7.9

16.2

16.4

13.8

18.5

10.2

3.3

2.7

2.8

0.4

1.1

3.0

3.7

6.1

18.2

20.2

10.5

29.8

4.6

2.7

0.0

9.5

80.2

95.5

98.0

99.1

99.1

99.6

99.2

96.2

95.8

93.1

92.0

37.7

96.3

64.3

97.6

99.3

98.6

98.9

99.5

99.4

99.3

99.4

99.4

98.8

J=0.012401 ±0.5%

*** 0.005

*** 6.939

*** 15.562

*** 16.345

*** 16.361

*** 16.221

*** 16.127

*** 16.177

*** 16.247

*** 16.053

*** 15.223

*** 14.364

*** 15.057

*** 20.831

*** 15.940

J=.012399 ±0.5%

5.69E-15 14.112

1.51E-14 18.679

1.84E-14 18.394

3.06E-14 18.108

9.03E-14 18.460

1.01E-13 17.503

5.22E-14 17.442

1.48E-13 17.787

2.28E-14 17.890

1.35E-14 17.896

4.97E-13 17.851

wt.=0.000175 g

0.7 0

1.1 0

1.3 0

3.4 25

8.2 63

11.6 102

7.8 99

11.4 89

12.7 100

5.8 73

1.6 65

2.2 71

3.2 0

0.4 1

8.7 81

wt.=0.0021 g

10.8 11

41.1 41

64.1 141

135.7 4931

259.8 40466

207.7 ***

105.5 20985

355.5 191109

80.3 5674

522.5 1755

236.1 67101

199KD32

0.12

148.94

318.41

333.04

333.34

330.73

328.98

329.90

331.22

327.59

312.03

295.79

308.91

414.65

325.30

197KD32

290.89

375.80

370.62

365.40

371.82

354.32

353.19

359.52

361.41

361.52

360.69

56.38

24.17

12.39

3.99

2.46

1.29

1.28

1.48

1.13

1.96

5.78

7.14

6.89

46.09

4.30

1.62

1.31

0.21

0.52

0.34

0.51

0.28

1.32

2.43
Results 21

K02-9-19G

White mica

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100

K02-9-19J

White mica

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100

.003

.002

.001

0

0 .01 .02 .03 .04 .05 .06 

39Ar/40Ar

36Ar/40Ar

Isochron age = 350.2± 15.1 Ma

(

40Ar/36Ar)i

 = 1511.0 ± 1123.9

MSWD = .114

Point A deleted

K02-9-19J

A

B-J
22 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent Apparent

K/Ca K/Cl

Apparent

age (Ma)

Error

(Ma)

 K02-9-19K

A 650

B 750

C 850

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1350

M 1450

N 1650

Total gas

No age plateau

 K02-9-19L

A 550

B 650

C 750

D 850

E 950

F 1050

G 1150

H 1250

Total gas

No age plateau

0.1

1.2

1.2

4.9

11.9

22.0

10.3

6.3

5.9

11.0

12.3

4.9

4.4

3.8

1.4

0.9

4.3

16.8

37.2

27.8

9.5

2.0

0.7

15.5

83.7

97.8

98.6

99.5

99.6

99.0

98.7

98.5

99.5

99.5

98.4

93.7

97.6

36.4

95.5

99.2

99.9

99.9

99.9

99.2

99.5

98.8

J=0.012353 ±0.5%

1.10E-17 0.409

1.95E-16 5.863

2.00E-16 17.028

8.08E-16 17.910

1.99E-15 17.519

3.65E-15 17.362

1.71E-15 17.295

1.05E-15 17.082

9.78E-16 17.069

1.83E-15 17.143

2.04E-15 17.066

8.07E-16 17.100

7.33E-16 17.476

6.27E-16 17.884

1.66E-14 17.167

J=.012362 ±0.5%

7.11E-15 10.084

4.55E-15 15.659

2.13E-14 17.661

8.32E-14 17.361

1.84E-13 17.676

1.38E-13 18.552

4.72E-14 19.376

9.92E-15 20.569

4.95E-13 17.959

wt.=0.000292 g

*** 3

3.2 3

2.7 138

5.2 1335

14.4 3196

19.5 4388

28.8 4517

3.2 1063

12.1 ***

18.3 2302

12.6 4371

5.7 2992

8.3 2342

*** 1184

14.4 3027

wt.=0.0020 g

19.0 31

12.2 291

57.9 3721

131.6 ***

238.5 ***

57.2 ***

96.7 16756

8.3 1358

138.9 1787

107KD32

9.08

126.14

344.40

360.55

353.41

350.53

349.31

345.39

345.14

346.52

345.09

345.73

352.63

360.08

346.96

110KD32

211.94

319.23

356.25

350.74

356.52

372.49

387.36

408.70

361.69

37.17

3.99

1.74

0.44

0.20

0.14

0.22

0.36

0.38

0.20

0.20

0.45

0.48

0.56

4.23

5.66

1.08

0.54

0.26

0.24

0.88

2.91
Results 23

K02-9-19K

White mica

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100

.003

.002

.001

0

0 .01 .02 .03 .04 .05 .06 

39Ar/40Ar

36Ar/40Ar

Isochron age = 339.4 ± 28.4 Ma

(

40Ar/36Ar)i

 = 1125.5 ± 2064.1

MSWD = 0.018

Points ABCN deleted

K02-9-19K A

E-M N

B

C

D

K02-9-19L

White mica

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100
24 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-4-28A M1

A 650

B 750

C 850

D 950

E 1050

F 1100

G 1150

H 1200

I 1250

J 1300

K 1350

L 1450

M 1650

Total gas

No age plateau

 K04-7-14B 

B 800

C 900

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1400

M 1650

Total gas

No age plateau

0.3

0.1

0.2

0.5

1.8

7.2

32.3

12.5

6.4

11.7

17.4

6.0

3.5

0.3

0.8

0.8

0.9

1.9

3.3

23.6

19.5

8.0

6.4

26.5

7.9

9.8

26.5

61.8

90.9

97.9

99.0

99.3

99.8

99.5

99.5

98.9

99.6

99.1

4.6

30.9

89.0

95.7

97.4

97.8

97.5

98.8

98.8

97.2

98.5

99.2

J=.009487

1.96E-16

7.52E-17

1.58E-16

3.70E-16

1.32E-15

5.24E-15

2.36E-14

9.11E-15

4.66E-15

8.52E-15

1.27E-14

4.39E-15

2.53E-15

J=.009524

2.33E-16

6.09E-16

5.65E-16

6.98E-16

1.44E-15

2.48E-15

1.76E-14

1.46E-14

6.02E-15

4.82E-15

1.98E-14

5.93E-15

±0.5%

5.098

6.420

13.706

21.865

23.001

22.758

22.046

21.943

21.771

21.790

21.874

22.309

22.669

±0.5%

3.572

6.852

20.180

25.556

26.149

24.437

22.088

21.907

22.085

22.443

21.756

21.948

wt.=0.00128 g

2.5

1.4

2.2

4.2

23.7

147.3

258.3

216.0

82.6

167.8

170.1

56.9

43.1

wt.=0.00108 g

4.3

4.5

5.4

12.6

24.0

51.5

115.1

257.1

83.8

65.5

74.7

14.1

3

3

2

2

5

50

108

50

21

3

3

19

11

3

3

5

6

8

16

74

77

33

24

3

20

222KD43

85.21

106.66

220.53

340.07

356.10

352.67

342.63

341.17

338.72

339.00

340.19

346.34

351.43

341.70

304KD43

60.36

114.05

317.15

393.01

401.18

377.49

344.44

341.87

344.40

349.47

339.72

342.45

342.70

10.22

13.02

4.09

1.75

0.67

0.30

0.47

0.23

0.32

0.31

0.50

0.39

0.46

12.43

2.87

1.44

1.09

0.77

0.49

0.34

0.35

0.25

0.34

0.29

0.32
Results 25

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-4-28A

White mica

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-4-28B 

White mica
26 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent Apparent

K/Ca K/Cl

Apparent

age (Ma)

Error

(Ma)

K04-4-28C M3 

B 750

C 850

D 950

E 1050

F 1100

G 1150

H 1200

I 1250

J 1300

K 1350

L 1450

M 1650

Total gas

No age plateau

K-04-4-28D M4 

C 850

D 950

E 1050

F 1100

G 1150

H 1200

I 1250

J 1300

K 1350

L 1450

Total gas

No age plateau

0.3

0.4

1.4

4.4

7.9

27.5

10.9

7.3

9.8

15.2

10.3

4.7

0.5

2.3

5.9

23.1

25.3

9.2

7.0

10.1

14.4

1.8

11.3

50.7

90.3

96.0

95.0

97.3

98.3

97.1

97.1

98.7

99.3

98.8

50.3

88.4

97.2

97.9

99.1

99.4

98.9

98.9

99.6

98.8

J=.009502

2.64E-16

3.22E-16

1.10E-15

3.51E-15

6.34E-15

2.21E-14

8.78E-15

5.86E-15

7.83E-15

1.22E-14

8.24E-15

3.75E-15

J=.009519

3.51E-16

1.53E-15

3.96E-15

1.55E-14

1.70E-14

6.15E-15

4.70E-15

6.76E-15

9.65E-15

1.23E-15

±0.5%

8.982

16.015

23.251

23.985

23.770

23.350

23.117

23.108

23.367

23.239

23.020

23.086

±0.5%

13.727

22.228

23.302

21.858

21.611

21.831

21.749

21.609

21.657

21.723

wt.=0.00110 g

2.7

3.3

11.2

68.3

166.4

223.7

190.1

89.5

160.8

276.2

271.0

163.9

wt.=0.00112 g

7.1

13.3

68.5

358.4

420.2

97.8

81.0

155.5

452.5

63.4

3

3

6

16

51

93

58

35

2

4

40

25

6

7

16

90

85

40

24

1

57

3

224KD43

147.75

255.54

360.12

370.40

367.40

361.50

358.24

358.11

361.74

359.94

356.87

357.80

359.80

226KD43

221.56

346.26

361.42

341.00

337.50

340.63

339.46

337.47

338.15

339.09

340.00

8.59

3.72

1.03

0.47

0.38

0.37

0.32

0.37

0.34

0.29

0.27

0.41

4.41

0.95

0.44

0.42

0.40

0.29

0.36

0.32

0.25

0.85
Results 27

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

39ArK

 Released (%)

Apparent Age (Ma)

K04-4-28C

White mica

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-04-4-28D 

White mica
28 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-13A J= .009455 ±0.5%

C 750 0.2 7.5 1.68E-16 8.192

D 800 0.1 15.1 1.19E-16 7.693

E 850 0.1 35.0 1.07E-16 13.491

F 900 0.2 59.2 1.43E-16 19.112

G 950 0.1 73.7 1.23E-16 20.816

H 1000 0.3 86.4 3.14E-16 22.343

I 1050 0.7 93.8 6.72E-16 22.978

J 1100 1.3 95.9 1.23E-15 22.746

K 1150 2.2 97.2 2.04E-15 22.279

L 1175 2.2 96.5 2.00E-15 21.947

M 1200 3.8 94.5 3.52E-15 21.666

N 1225 10.2 96.7 9.39E-15 21.432

O 1250 13.8 98.6 1.27E-14 21.240

P 1300 11.1 99.0 1.02E-14 21.284

Q 1350 6.7 98.0 6.17E-15 21.370

R 1400 5.2 97.3 4.78E-15 21.320

S 1450 6.8 97.9 6.23E-15 21.426

T 1500 33.2 98.7 3.06E-14 21.298

U 1550 1.2 92.3 1.13E-15 21.615

V 1650 0.4 73.8 3.33E-16 21.114

Total gas

51.9 % of gas released on plateau in steps 13500C through 15000C

 K04-7-13B J=.009452 ±0.5%

A 700 0.5 13.1 3.69E-16 6.120

B 800 0.3 49.3 2.18E-16 14.342

C 900 1.0 85.1 6.91E-16 19.307

D 1000 2.2 97.2 1.57E-15 23.525

E 1050 3.0 98.8 2.16E-15 23.827

F 1100 6.2 99.3 4.52E-15 24.239

G 1150 31.4 99.3 2.27E-14 24.628

H 1175 8.6 99.7 6.26E-15 23.186

I 1200 6.0 99.5 4.38E-15 23.160

J 1250 6.5 99.6 4.69E-15 23.358

K 1300 10.6 99.4 7.66E-15 23.361

L 1325 13.1 99.8 9.46E-15 23.958

M 1350 7.9 99.8 5.76E-15 24.913

N 1450 2.6 99.2 1.87E-15 26.139

O 1550 0.2 94.8 1.75E-16 28.931

Total gas

No age plateau

wt=0.00130 g

3.9 1

3.4 1

4.5 2

4.3 4

4.1 4

8.8 4

16.9 5

42.4 10

60.2 19

92.3 35

142.5 58

239.2 99

220.3 103

97.9 72

58.9 43

85.6 35

102.4 35

160.8 5

112.6 2

17.1 1

Plateau age =

wt.=0.00125 g

6.1 9

5.3 6

6.5 6

20.5 7

41.2 10

63.2 23

118.1 71

93.3 39

62.6 30

34.8 29

36.1 1

53.8 91

41.8 50

6.7 19

4.6 1

197KD43

134.58

126.68

216.58

299.67

324.13

345.76

354.68

351.43

344.86

340.18

336.20

332.89

330.16

330.78

332.01

331.30

332.80

330.98

335.48

328.37

331.70

331.70

199KD43

101.45

229.35

302.41

362.23

366.44

372.15

377.54

357.50

357.13

359.90

359.94

368.25

381.49

398.32

436.11

367.90

11.90

12.60

11.58

5.46

5.25

2.31

1.21

0.79

0.79

0.77

0.70

0.34

0.41

0.54

0.57

0.63

0.64

0.55

1.36

4.39

1.60

6.01

5.34

1.25

0.73

1.02

0.47

0.37

0.55

0.43

0.40

0.63

0.33

0.32

0.61

3.66
Results 29

 331.7 ± 1.6 Ma*

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13A 

White mica

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13B 

White mica
30 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-13C 

C 900

D 1000

E 1050

F 1100

G 1150

H 1200

I 1250

J 1300

K 1350

Total gas

No age plateau

 K04-7-13D 

A 700

B 800

C 900

D 1000

E 1050

F 1100

G 1150

H 1175

I 1200

J 1250

K 1300

L 1400

M 1650

Total gas

No age plateau

0.4

2.2

3.2

13.9

31.3

9.1

6.9

17.6

15.4

0.3

1.8

2.2

3.9

3.9

6.4

22.6

8.8

6.5

6.4

11.2

22.6

3.6

86.4

96.7

98.7

99.0

99.2

99.6

99.3

99.4

99.8

4.5

21.8

85.3

97.2

97.7

98.3

98.8

98.8

98.9

98.8

98.6

98.4

98.0

J=.009224

2.34E-16

1.44E-15

2.05E-15

9.04E-15

2.03E-14

5.93E-15

4.48E-15

1.14E-14

9.99E-15

J=.009201

1.25E-16

7.69E-16

9.48E-16

1.70E-15

1.69E-15

2.81E-15

9.94E-15

3.85E-15

2.85E-15

2.82E-15

4.93E-15

9.92E-15

1.58E-15

±0.5%

21.626

24.830

24.323

24.963

24.236

23.734

23.794

23.851

24.097

±0.5%

13.353

13.729

21.936

28.244

23.050

23.387

21.719

21.002

21.571

21.844

25.309

21.556

26.148

wt.=0.00102g

5.3

20.5

60.2

129.7

222.7

51.9

70.5

116.8

154.6

wt.=0.00100 g

5.1

6.9

10.4

34.6

81.7

254.5

219.8

90.3

142.5

104.3

122.4

***

78.3

4

6

17

76

89

43

25

2

85

5

11

10

9

17

33

68

53

38

30

2

5

6

201KD43

337.70

382.76

375.71

384.61

374.50

367.48

368.32

369.12

372.56

373.70

203KD43

209.05

214.61

331.68

416.76

347.00

351.60

328.68

318.73

326.62

330.40

377.67

326.43

388.93

339.00

3.16

0.72

0.57

0.22

0.33

0.34

0.29

0.28

0.28

35.84

2.70

10.62

7.79

9.13

6.50

12.08

9.87

9.32

9.84

6.65

8.48

6.24
Results 31

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13C 

White mica

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13D

White mica
32 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-13E J=.009472 ±0.5%

B 800 0.8 16.6 5.58E-16 11.230

C 900 1.3 75.4 8.88E-16 20.411

D 1000 2.8 96.5 1.85E-15 25.904

E 1050 3.5 98.7 2.30E-15 24.200

F 1100 15.0 99.3 9.91E-15 23.963

G 1150 25.4 99.2 1.68E-14 22.991

H 1200 10.4 99.5 6.85E-15 22.874

I 1250 6.7 99.2 4.44E-15 23.056

J 1300 10.2 99.0 6.76E-15 22.435

K 1350 16.4 99.7 1.08E-14 22.813

L 1400 5.0 99.4 3.33E-15 23.425

M 1650 2.5 97.9 1.66E-15 24.927

Total gas

No age plateau

 K04-7-13F J=.009477 ±0.5%

B 700 0.5 0.4 3.18E-16 2.468

C 750 0.5 5.5 3.56E-16 6.058

D 800 0.4 15.1 2.87E-16 7.352

E 850 0.4 41.8 2.76E-16 14.478

F 900 0.6 69.1 3.88E-16 19.265

G 950 0.6 84.2 3.71E-16 22.268

H 1000 1.3 93.0 8.50E-16 23.402

I 1050 2.5 97.0 1.62E-15 23.664

J 1100 5.4 97.7 3.49E-15 23.271

K 1150 34.3 98.7 2.23E-14 22.334

L 1175 9.9 99.4 6.45E-15 22.121

M 1200 6.0 99.0 3.90E-15 22.075

N 1225 3.6 98.6 2.34E-15 22.211

O 1250 3.3 98.6 2.13E-15 22.208

P 1300 8.0 98.2 5.23E-15 22.048

Q 1350 15.4 99.5 1.00E-14 21.944

R 1400 4.9 99.4 3.19E-15 22.141

S 1450 2.2 99.1 1.44E-15 22.448

Total gas

85.5 % of gas released on plateau in steps 11500C through 14000C

wt.=.00107 g

5.9 3

8.0 5

33.5 7

219.3 18

243.3 74

232.0 73

211.0 41

109.5 22

130.9 1

232.6 18

147.7 59

123.9 11

wt.=0.00102 g

3.8 2

6.0 1

5.5 1

8.0 6

8.2 6

17.3 6

30.5 5

92.8 11

133.0 30

344.8 103

287.4 51

212.8 27

85.6 16

115.3 16

82.4 1

298.5 63

297.6 15

492.6 10

Plateau age =

205KD43

182.36

318.86

395.86

372.33

369.03

355.45

353.81

356.35

347.62

352.94

361.53

382.41

357.00

207KD43

41.70

100.70

121.52

231.96

302.54

345.44

361.38

365.04

359.53

346.37

343.36

342.71

344.64

344.59

342.32

340.85

343.64

347.97

341.50

343.30

5.00

1.07

0.70

0.48

0.25

0.38

0.25

0.38

0.31

0.24

0.40

0.70

28.03

8.19

6.00

5.61

1.97

2.01

1.27

0.59

0.47

0.40

0.44

0.39

0.49

0.89

0.40

0.36

0.49

0.76

1.70
Results 33

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13E 

White mica

 343.3 ± 1.7 Ma*

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13F 

White mica
34 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-13G 

B 800

C 900

D 1000

E 1050

F 1100

G 1150

H 1175

I 1200

J 1250

K 1300

L 1350

M 1650

Total gas

No age plateau

 K04-7-13H 

A 700

B 800

C 900

D 1000

E 1050

F 1100

G 1125

H 1150

I 1175

J 1200

K 1250

L 1300

M 1350

N 1400

Total gas

No age plateau

0.8

0.9

1.3

1.0

2.0

3.6

3.7

11.9

25.3

10.8

6.0

32.6

1.0

0.2

0.9

3.6

2.5

16.2

20.7

9.9

5.7

3.9

4.4

6.4

14.0

10.7

8.3

38.1

85.0

94.7

96.9

97.7

97.8

98.7

98.8

99.3

98.4

98.1

21.9

66.6

88.1

94.7

96.9

97.7

99.7

99.1

98.3

98.8

98.7

98.8

99.1

99.5

J=.009472

4.76E-16

5.11E-16

7.47E-16

5.71E-16

1.14E-15

2.04E-15

2.10E-15

6.77E-15

1.44E-14

6.15E-15

3.39E-15

1.85E-14

J=.009479

4.24E-16

7.43E-17

3.99E-16

1.55E-15

1.08E-15

6.95E-15

8.87E-15

4.25E-15

2.43E-15

1.66E-15

1.88E-15

2.73E-15

6.01E-15

4.57E-15

±0.5%

4.037

9.193

19.692

23.124

22.969

22.699

22.368

22.625

21.960

21.963

21.782

21.834

±0.5%

15.103

18.545

21.163

24.227

23.615

25.657

22.791

23.123

22.742

23.256

26.774

23.659

23.726

22.818

wt.=0.00098 g

4.1

3.1

4.6

18.5

35.8

95.7

141.0

221.7

934.6

120.3

78.9

93.3

wt.=0.00100 g

3.0

8.1

6.4

31.1

***

193.1

251.3

141.8

89.0

181.8

65.4

124.1

155.3

211.4

3

3

4

5

6

11

20

70

71

33

13

2

2

4

4

7

22

54

89

57

36

27

18

1

2

60

209KD43

67.70

150.62

308.55

357.31

355.13

351.34

346.68

350.30

340.91

340.96

338.40

339.14

338.20

211KD43

241.38

292.15

329.83

372.95

364.42

392.72

352.87

357.54

352.18

359.40

408.03

365.04

365.97

353.25

365.00

6.26

2.80

1.13

1.26

0.84

0.55

0.52

0.33

0.37

0.38

0.50

0.35

11.11

15.10

10.43

11.95

11.71

10.52

11.59

12.17

11.69

12.07

14.45

14.73

14.35

12.28
Results 35

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13G 

White mica

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13H

White mica
36 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

K04-7-13I J=.009485 ±0.5%

B 800 0.3 2.4 2.44E-16 7.467

C 900 0.6 29.5 4.29E-16 12.785

D 1000 1.9 93.5 1.39E-15 21.605

E 1050 2.6 99.0 1.90E-15 21.578

F 1100 4.1 98.8 3.04E-15 21.010

G 1150 24.4 98.5 1.80E-14 20.428

H 1200 15.1 99.8 1.12E-14 20.361

I 1250 11.2 99.7 8.32E-15 20.432

J 1300 11.8 99.5 8.75E-15 20.440

K 1350 21.6 98.6 1.60E-14 20.358

L 1400 4.8 99.9 3.52E-15 20.537

M 1650 1.6 97.9 1.19E-15 21.385

Total gas

84.2 % of gas released on plateau in steps 11500C through 13500C

 K04-7-13K J=.009488 ±0.5%

B 800 1.0 4.5 7.94E-16 5.587

C 900 2.1 76.2 1.72E-15 17.478

D 1000 3.6 96.0 2.91E-15 21.900

E 1050 5.5 99.0 4.39E-15 22.369

F 1100 9.4 99.2 7.53E-15 22.057

G 1150 19.4 98.8 1.56E-14 22.240

H 1200 16.4 99.7 1.32E-14 21.897

I 1250 15.5 99.7 1.25E-14 21.904

J 1300 15.5 98.6 1.24E-14 22.228

K 1350 5.4 99.7 4.36E-15 22.429

L 1400 2.3 99.2 1.83E-15 22.544

M 1650 4.0 98.7 3.20E-15 23.296

Total gas

No age plateau

wt.=0.00109 g

2.7 2

2.9 2

13.7 6

30.3 13

36.5 27

97.9 83

70.4 72

47.1 48

45.6 2

77.5 9

48.0 43

32.6 7

Plateau age =

wt.=0.00125 g

5.6 6

8.5 10

37.3 14

104.7 24

128.4 54

193.4 71

177.3 68

99.9 57

104.6 2

36.6 4

7.5 37

18.8 21

213KD43

123.46

206.50

336.31

335.93

327.83

319.52

318.56

319.58

319.69

318.51

321.07

333.18

319.30

319.10

219KD43

93.18

276.81

340.59

347.23

342.81

345.41

340.55

340.65

345.24

348.07

349.69

360.27

340.60

13.41

3.44

0.79

0.50

0.43

0.27

0.20

0.27

0.29

0.35

0.31

0.70

1.50

7.72

0.73

0.45

0.33

0.25

0.39

0.33

0.21

0.44

0.30

0.53

0.38
Results 37

 319.1 ± 1.5 Ma*

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13I 

White mica

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-13K 

White mica
38 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-14A 

B 700

C 750

D 800

E 850

F 900

G 950

H 1000

I 1050

J 1100

K 1150

L 1175

M 1200

N 1225

O 1250

P 1275

Q 1300

R 1325

S 1350

T 1400

U 1450

V 1550

Total gas

No age plateau

 K04-7-14B 

B 800

C 900

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1400

M 1650

Total gas

No age plateau

0.2

0.2

0.2

0.2

0.2

0.4

1.0

1.9

3.8

32.3

11.8

7.2

3.4

2.7

2.7

2.9

3.3

5.2

10.1

5.7

4.7

0.3

0.8

0.8

0.9

1.9

3.3

23.6

19.5

8.0

6.4

26.5

7.9

3.2

6.7

26.5

49.7

66.3

85.3

91.3

94.7

94.6

96.6

98.9

98.3

96.9

96.6

96.9

96.5

96.7

97.5

98.6

98.2

95.5

4.6

30.9

89.0

95.7

97.4

97.8

97.5

98.8

98.8

97.2

98.5

99.2

J=.009524

1.33E-16

1.50E-16

1.12E-16

1.21E-16

1.17E-16

3.11E-16

7.05E-16

1.38E-15

2.79E-15

2.39E-14

8.75E-15

5.31E-15

2.49E-15

2.01E-15

1.99E-15

2.12E-15

2.43E-15

3.85E-15

7.40E-15

4.20E-15

3.44E-15

J=.009524

2.33E-16

6.09E-16

5.65E-16

6.98E-16

1.44E-15

2.48E-15

1.76E-14

1.46E-14

6.02E-15

4.82E-15

1.98E-14

5.93E-15

±0.5%

8.940

8.697

12.240

15.590

21.582

23.098

23.768

23.569

22.759

21.861

21.769

21.844

21.843

22.063

22.277

22.087

21.841

21.764

21.681

21.746

21.939

±0.5%

3.572

6.852

20.180

25.556

26.149

24.437

22.088

21.907

22.085

22.443

21.756

21.948

wt.=0.00120 g

3.2

1.7

1.3

2.4

2.8

5.1

11.5

29.9

50.2

106.6

89.4

68.4

35.8

24.1

55.1

28.3

52.9

352.1

82.2

59.3

84.3

wt.=0.00108 g

4.3

4.5

5.4

12.6

24.0

51.5

115.1

257.1

83.8

65.5

74.7

14.1

4

4

2

3

4

4

6

10

22

107

81

55

32

24

25

24

23

1

11

38

34

3

3

5

6

8

16

74

77

33

24

3

20

298KD43

147.42

143.56

198.92

249.75

337.25

358.72

368.14

365.35

353.94

341.22

339.90

340.97

340.95

344.08

347.12

344.42

340.93

339.83

338.66

339.58

342.33

341.20

304KD43

60.36

114.05

317.15

393.01

401.18

377.49

344.44

341.87

344.40

349.47

339.72

342.45

342.70

30.83

24.07

18.02

13.91

13.26

5.62

2.25

1.21

0.73

0.35

0.38

0.41

0.73

0.96

1.21

0.84

0.83

0.62

0.33

0.49

0.59

12.43

2.87

1.44

1.09

0.77

0.49

0.34

0.35

0.25

0.34

0.29

0.32
Results 39

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14A

White mica

0 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040 0.045

0

0.0004

0.0008

0.0012

0.0016

0.0020

0.0024

0.0028

Isochron age = 339.4 ± 1.6 Ma (0.48%)

40Ar/36Ar intercept = 355 ± 19 (5.47%)

MSWD = 2.5, prob. = 0.06, n = 5

K04-7-14A 

White mica

39Ar/40Ar

36Ar/40Ar

D

E

F

G

H

I J

K M PQONRS

U

V

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14B 

White mica
40 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent Apparent

K/Ca K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-14E

B 800

C 900

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1400

M 1650

Total gas

No age plateau

 K04-7-14F 

B 800

C 900

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1400

M 1650

Total gas

No age plateau

1.5

3.4

4.5

8.9

14.7

14.9

13.4

16.5

15.4

5.2

0.8

0.9

2.2

6.2

6.5

10.5

14.8

15.7

17.7

15.9

5.7

1.8

2.3

0.6

18.0

83.6

98.4

99.7

99.6

99.3

99.2

99.5

99.6

98.4

94.7

98.3

13.4

81.8

97.5

99.0

99.0

98.2

98.0

98.6

96.8

88.7

94.0

92.3

J=.009524

3.98E-16

9.23E-16

1.23E-15

2.44E-15

4.01E-15

4.06E-15

3.66E-15

4.52E-15

4.20E-15

1.43E-15

2.14E-16

2.40E-16

J=.009524

4.22E-16

1.21E-15

1.28E-15

2.05E-15

2.90E-15

3.08E-15

3.47E-15

3.11E-15

1.12E-15

3.60E-16

4.46E-16

1.26E-16

±0.5%

11.332

23.397

24.192

23.613

23.025

22.968

23.302

24.118

25.007

29.591

98.647

487.370

±0.5%

10.846

24.241

25.052

22.829

22.160

21.971

21.828

45.032

30.855

56.643

98.008

183.589

wt.=0.00110 g

3.4

3.8

9.1

12.2

15.6

12.5

9.7

10.8

7.4

1.7

0.1

0.0

wt.=0.009 g

2.0

2.5

4.2

5.3

6.1

5.5

1.2

0.2

0.1

0.1

0.0

0.0

8

9

13

17

24

19

15

28

22

2

0

1

6

10

13

15

21

30

29

14

6

0

0

0

314KD43

184.89

362.93

374.06

365.95

357.69

356.89

361.59

373.03

385.41

447.93

1195.09

3121.39

431.20

312KD43

177.35

374.75

386.04

354.93

345.46

342.78

340.75

643.87

464.79

778.35

1189.42

1824.02

449.00

6.93

1.09

0.71

0.52

0.37

0.43

0.32

0.33

0.34

0.70

3.73

5.75

7.01

0.92

0.78

0.54

0.38

0.42

0.45

0.69

0.99

2.44

1.98

7.04
Results 41

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14E 

White mica

10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14F 

Sericite
42 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

K04-7-14G J=.009523 ±0.5%

A 600 0.1 5.8 9.30E-18 18.245

B 800 3.1 11.7 4.45E-16 6.114

C 900 9.0 82.0 1.30E-15 16.948

D 950 7.9 94.7 1.14E-15 22.047

E 1000 10.9 98.0 1.58E-15 22.316

F 1050 13.2 98.2 1.90E-15 22.062

G 1100 19.0 98.0 2.74E-15 21.813

H 1150 14.6 97.4 2.11E-15 22.048

I 1200 13.3 97.8 1.92E-15 25.222

J 1250 4.8 95.9 6.86E-16 29.710

K 1300 1.9 91.3 2.80E-16 89.055

L 1400 1.7 97.9 2.49E-16 311.664

M 1650 0.4 95.7 6.06E-17 498.923

Total gas

No age plateau

 K04-7-14H J=.009522 ±0.5%

B 800 0.8 7.7 5.38E-16 5.351

C 900 3.6 79.3 2.40E-15 12.994

D 950 3.3 97.2 2.24E-15 21.680

E 1001 4.6 98.4 3.06E-15 23.694

F 1050 6.4 99.4 4.26E-15 23.104

G 1100 8.7 99.5 5.82E-15 22.150

H 1150 14.6 99.5 9.78E-15 21.532

I 1200 20.1 99.6 1.35E-14 21.461

J 1250 18.8 99.7 1.26E-14 21.456

K 1300 15.5 99.6 1.04E-14 21.500

L 1400 2.1 95.9 1.42E-15 22.406

M 1650 1.5 96.9 1.01E-15 26.354

Total gas

54.4 % of gas released on plateau in steps 12000

C through 13000C

wt.=0.00106 g

0.8 2

2.4 7

3.9 10

4.8 10

5.1 9

5.4 10

2.3 13

0.8 14

0.4 9

0.3 2

0.1 0

0.1 0

0.0 0

wt.=0.00130 g

6.1 8

14.6 20

28.1 20

52.3 23

126.1 31

162.9 51

146.8 74

174.5 74

145.8 60

131.9 43

31.0 0

23.6 3

Plateau age =

316KD43 

289.02

102.10

269.93

343.83

347.64

344.04

340.50

343.84

388.36

449.48

1107.96

2486.48

3156.08

455.00

318KD43

89.65

210.45

338.58

367.02

358.74

345.25

336.46

335.45

335.39

336.01

348.88

403.92

334.70

335.70

118.40

6.86

0.81

0.85

0.67

0.61

0.46

0.60

0.71

1.25

3.30

6.28

15.96

6.20

0.53

0.57

0.44

0.32

0.33

0.20

0.22

0.35

0.22

0.74

0.81

1.60
Results 43

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14G 

Sericite

 335.7 ± 1.6 Ma

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14H 

White mica
44 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-14J 

B 800

C 900

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1400

M 1650

Total gas

No age plateau

K04-7-14K 

B 800

C 900

D 950

E 1000

F 1050

G 1100

H 1150

I 1200

J 1250

K 1300

L 1400

M 1650

Total gas

No age plateau

1.9

5.2

6.0

8.9

11.0

12.3

18.0

19.0

5.1

3.1

6.7

2.8

1.1

2.1

2.5

5.4

9.5

10.9

14.6

22.0

15.2

13.0

1.9

1.8

3.6

59.9

94.5

97.8

98.6

91.8

99.1

98.9

96.1

95.4

97.1

96.1

7.0

56.7

96.2

98.9

99.1

99.0

98.9

99.5

99.1

98.7

97.1

95.2

J=.009521

4.15E-16

1.11E-15

1.29E-15

1.89E-15

2.35E-15

2.61E-15

3.83E-15

4.06E-15

1.08E-15

6.70E-16

1.43E-15

5.93E-16

J=.009516

2.23E-16

4.11E-16

5.00E-16

1.09E-15

1.91E-15

2.18E-15

2.93E-15

4.41E-15

3.03E-15

2.59E-15

3.74E-16

3.59E-16

±0.5%

4.876

13.679

17.095

18.514

19.230

19.690

20.337

20.887

20.258

27.044

45.433

56.409

±0.5%

8.746

14.952

22.982

23.913

23.641

22.692

22.113

22.561

23.502

27.370

77.998

39.150

wt.=0.00102 g

1.9

2.4

3.6

4.3

4.4

2.8

1.5

0.9

0.4

0.2

0.2

0.1

wt.=0.00115 g

1.6

1.3

2.1

2.8

2.7

1.9

0.8

0.4

1.1

1.0

0.1

0.3

6

10

12

12

15

23

33

22

5

1

0

1

4

4

5

7

13

20

21

25

16

1

0

1

322KD43

81.86

220.87

272.05

292.90

303.32

309.98

319.32

327.22

318.18

413.34

648.50

775.54

344.80

334KD43 

144.23

239.99

356.81

369.88

366.07

352.73

344.53

350.88

364.12

417.60

1001.56

571.29

377.80

11.67

1.16

0.68

0.47

0.49

0.49

0.50

0.43

0.95

1.10

0.95

1.51

13.88

2.24

1.60

0.77

0.59

0.54

0.38

0.34

0.42

0.51

3.44

1.94
Results 45

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14J 

Sericite

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14K 

Sericite
46 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

K04-7-14L J=.009519 ±0.5%

B 800 0.6 5.9 3.97E-16 3.239

C 900 1.4 69.5 9.60E-16 11.023

D 950 1.2 97.0 7.94E-16 22.238

E 1000 2.2 98.6 1.45E-15 23.879

F 1050 3.6 99.3 2.38E-15 23.888

G 1100 5.8 99.4 3.88E-15 23.363

H 1150 9.9 99.3 6.63E-15 23.400

I 1200 20.7 98.9 1.38E-14 23.766

J 1250 17.5 99.7 1.17E-14 22.870

K 1300 12.6 99.5 8.42E-15 23.077

L 1400 22.1 98.7 1.47E-14 24.400

M 1650 2.4 98.0 1.63E-15 25.423

Total gas

No age plateau

 K04-7-14M J=.009519 ±0.5%

A 600 0.8 11.1 6.14E-16 3.337

B 800 0.3 55.9 2.52E-16 5.572

C 900 0.9 85.6 6.56E-16 11.893

D 950 1.3 95.3 9.78E-16 19.922

E 1000 2.4 98.1 1.74E-15 23.383

F 1050 3.9 98.6 2.87E-15 23.166

G 1100 6.7 98.5 4.93E-15 22.242

H 1150 17.7 97.8 1.30E-14 21.496

I 1200 17.5 99.2 1.28E-14 21.397

J 1250 11.2 98.8 8.21E-15 21.408

K 1300 12.1 98.3 8.92E-15 21.388

L 1400 18.4 99.1 1.35E-14 21.485

M 1650 6.7 99.0 4.88E-15 21.616

Total gas

76.9 % of gas released on plateau in steps 12000

C through 13000C

wt.=0.00110 g

6.7 8

8.4 10

13.5 10

25.3 10

95.8 15

77.9 28

97.0 52

244.5 71

160.0 61

118.6 42

64.7 2

3.7 5

wt.=0.00108g

5.1 8

6.6 14

8.1 12

12.5 11

26.1 12

59.1 18

74.6 42

80.0 76

143.9 71

95.0 44

127.2 3

167.5 3

98.7 15

Plateau age =

328KD43 

54.78

180.01

346.41

369.51

369.64

362.28

362.80

367.92

355.33

358.26

376.79

390.99

361.80

330KD43

56.42

93.24

193.48

313.28

362.56

359.50

346.46

335.85

334.45

334.60

334.32

335.70

337.56

333.20

334.80

7.07

0.97

1.02

0.76

0.50

0.40

0.30

0.45

0.26

0.30

0.42

0.61

4.72

3.12

1.20

0.77

0.53

0.43

0.37

0.33

0.21

0.30

0.29

0.32

0.29

1.60
Results 47

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14L 

White mica

 334.7 ± 1.6 Ma*

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14M 

White mica
48 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

GROUNDMASS

 K02-9-19A 

A 550

B 650

C 750

D 850

E 950

F 1000

G 1050

H 1250

Total gas

No age plateau

 K02-9-20A 

A 550

B 650

C 750

D 850

E 950

F 1000

G 1050

H 1250

Total gas

No age plateau

2.4

14.1

28.7

27.5

13.2

7.4

5.9

0.9

0.8

4.3

13.2

22.0

42.3

13.8

1.8

1.7

84.1

99.3

99.8

99.7

99.5

99.3

98.4

90.1

99.1

65.5

97.9

99.6

99.8

99.9

99.9

99.3

99.2

99.5

J=.012306

1.26E-13

7.51E-13

1.53E-12

1.46E-12

7.05E-13

3.95E-13

3.12E-13

4.72E-14

5.33E-12

J=.012278

3.30E-14

1.81E-13

5.58E-13

9.28E-13

1.78E-12

5.83E-13

7.68E-14

7.24E-14

4.21E-12

±0.5%

10.694

18.662

21.626

22.882

24.733

25.182

25.531

30.046

22.274

±0.5%

12.917

13.705

19.233

19.177

20.650

22.874

32.952

42.629

20.689

wt.=0.0548 g

141.7

44.1

313.4

301.7

184.3

210.6

212.3

30.1

235.0

wt.=0.0538 g

4.7

3.7

12.2

15.4

11.0

2.4

0.3

0.2

10.2

41

436

***

86037

3561

4821

2314

241

24679

80

387

***

***

***

8022

563

321

1143

81KD32

223.04

372.94

425.69

447.58

479.34

486.98

492.88

567.58

437.00

112KD32

265.57

280.57

382.44

381.43

407.66

446.53

612.89

759.39

408.34

0.38

0.27

0.19

0.13

0.18

0.16

0.34

0.52

1.26

0.35

0.31

0.18

0.17

0.13

0.53

0.78
Results 49

K02-9-19A

Groundmass

1000

100

10

700

600

500

400

300

200

Apparent Age (Ma) K/Ca

0 39ArK Released (%) 100

K02-9-20A

Groundmass

100

10

1

.1

700

600

500

400

300

200

Apparent Age (Ma) K/Ca

0 39ArK Released (%) 

100

K02-9-20A

Groundmass

100

10

1

.1

700

600

500

400

300

200

Apparent Age (Ma) K/Ca

0 39ArK Released (%) 100
50 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

BIOTITE

K02-9-19F 

A 1450

 K02-9-19H 

A 1450

 K02-9-19I 

A 1450

 K02-9-19K 

A 1450

K04-7-13l

B 1450

K04-7-14A

B 1450

 K04-7-14B

B 1450

 K04-7-14C

B 1450

K04-7-14K

B 1450

 K04-7-14M

B 1450

K-SPAR

 K02-9-19G 

A 750

B 850

C 950

D 1000

E 1050

F 1075

G 1100

H 1150

I 1250

J 1450

Total gas

No age plateau

100

100

100

100

100

84

100

100

100

100

9.9

15.0

9.0

5.1

4.5

2.9

2.2

1.9

13.2

36.1

99.1

98.9

98.9

96.5

98.7

98.0

95.0

98.6

98.2

86.4

99.4

99.7

99.7

99.7

99.3

98.6

98.6

98.3

98.3

98.8

99

J=.012371

1.46E-13

J=.012351

1.53E-13

J=.012361

1.54E-13

J=.012350

1.27E-13

J = 0.009523

2.56E-14

J=.009524

2.52E-14

J=.009524

2.85E-14

J=.009524

3.09E-14

J=.009521

3.18E-14

J=.009524

2.72E-14

J=.012342

1.28E-13

1.94E-13

1.17E-13

6.65E-14

5.82E-14

3.15E-14

2.85E-14

2.42E-14

1.71E-13

4.67E-13

1.29E-12

±0.5%

23.266

±0.5%

23.896

±0.5%

22.320

±0.5%

18.843

± 0.5%

41.110

±0.5%

25.830

±0.5%

34.455

±0.5%

24.244

±0.5%

28.930

±0.5%

16.096

±0.5%

10.551

12.229

13.479

14.705

15.461

15.830

16.159

16.326

17.279

16.882

15.067

wt.=0.000493 g

59.3 446

wt.=0.000548 g

59.8 285

wt.=0.000515 g

39.1 307

wt.=0.000501 g

47.1 279

wt.=0.000585 g

42.86 20

wt.=0.540 g

32.5 16

wt.=0.506 g

26.8 4

wt.=0.577 g

11.8 4

wt.= 0.541g

17.2 4

wt. = 0.554 g

20.1 3

wt.=0.0018 g

115.9 115016

105.8 ***

55.5 26141

39.1 7753

50.8 3667

48.9 2367

32.9 1364

53.4 1288

84.6 1164

418.0 2705

202.2 15556

91KD32 

456.33

95KD32

466.55

99KD32

439.55

106KD32

377.42

296KD43

596.03

300KD43

396.79

302KD43 

511.97

308KD43

374.79

324KD43

438.92

332KD43

257.06

93KD32

220.83

253.59

277.60

300.86

315.05

321.93

328.06

331.15

348.72

341.43

307.68

0.17

0.22

0.18

0.22

0.60

0.44

0.47

0.31

0.33

0.29

0.36

0.24

0.31

0.66

0.58

1.05

1.16

1.54

0.21

0.12
Results 51

K02-9-19G

K-feldspar

700

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100
52 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K02-9-19J 

A 750

B 850

C 950

D 1050

E 1100

F 1150

G 1250

H 1450

Total gas

No age plateau

 K04-7-14D

A 550

B 650

C 700

D 800

E 900

F 950

G 1000

H 1050

I 1100

J 1150

K 1200

L 1215

M 1250

N 1275

O 1300

P 1350

Q 1450

R 1550

S 1650

Total gas

No age plateau

12.1

14.7

10.9

9.7

5.7

3.3

8.1

35.5

0.2

0.1

0.1

0.3

0.7

1.2

2.2

4.5

6.5

8.2

9.7

5.5

6.2

5.3

5.1

8.7

28.4

6.5

0.5

99.2

99.8

99.7

99.7

98.9

99.2

98.5

98.1

98.9

13.3

20.0

32.7

68.6

91.3

97.5

99.1

99.4

99.4

99.4

99.6

99.7

99.7

99.8

99.6

99.1

99.5

99.6

99.0

J=.012337

9.53E-14

1.16E-13

8.58E-14

7.67E-14

4.51E-14

2.64E-14

6.42E-14

2.80E-12

7.90E-12

J=.009524

1.87E-16

8.32E-17

1.12E-16

3.16E-16

7.60E-16

1.29E-15

2.43E-15

4.90E-15

7.16E-15

8.98E-15

1.06E-14

6.05E-15

6.80E-15

5.84E-15

5.62E-15

9.55E-15

3.10E-14

7.13E-15

5.59E-16

±0.5%

10.298

12.094

13.415

15.231

16.596

16.980

18.827

17.140

15.083

±0.5%

14.436

12.073

12.803

17.069

15.951

15.814

16.817

18.464

20.234

21.012

22.084

23.359

25.595

27.562

32.105

40.030

38.982

38.572

47.094

wt.=0.0020 g

186.6 ***

191.9 ***

132.3 ***

83.5 14449

141.0 4513

81.0 2270

121.1 2481

591.3 4065

303.6 3380

wt. =0.001185 g

2.4 5

2.9 6

2.7 7

4.6 7

6.3 11

12.8 14

27.0 18

36.0 33

36.0 60

31.6 89

29.4 65

35.5 49

34.1 34

36.2 34

35.3 27

40.3 2

59.5 34

39.3 15

11.5 4

103KD32

215.76

250.87

276.29

310.63

336.03

343.11

376.79

346.04

307.86

310KD43

232.40

196.35

207.57

271.74

255.14

253.10

268.02

292.24

317.93

329.09

344.38

362.39

393.55

420.52

481.32

582.69

569.60

564.47

668.49

455.00

0.27

0.30

0.27

0.28

0.50

1.49

0.44

0.16

11.21

16.43

13.02

2.52

0.99

0.64

0.40

0.29

0.30

0.24

0.38

0.32

0.35

0.33

0.43

0.83

0.42

0.45

1.82
Results 53

K02-9-19J

K-feldspar

700

600

500

400

300

200

100

Apparent Age (Ma)

0 39ArK Released (%) 100

100

200

300

400

500

600

700

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14D 

K-feldspar

0 10 20 30 40 50 60 70 80 90 100
54 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

Table 2. 40Ar/39Ar analytical data.-- Continued

Step Temperature

(

o

C)

39Ar

(% of total

Radiogenic

yield (%)

39Ark

(moles)

40Ar*/

39Ark

Apparent

K/Ca

Apparent

K/Cl

Apparent

age (Ma)

Error

(Ma)

 K04-7-14I

C 700

D 800

E 900

F 950

G 1000

H 1050

I 1100

J 1150

K 1200

L 1215

M 1250

N 1275

O 1300

P 1350

Q 1450

R 1550

Total gas

No age plateau

 K04-7-14K

C 700

D 800

E 900

F 950

G 1000

H 1050

I 1100

J 1150

K 1200

L 1215

M 1250

N 1275

O 1300

P 1350

Q 1450

R 1550

S 1650

Total gas

No age plateau

0.1

0.2

0.6

4.0

5.2

5.9

6.2

5.8

5.4

3.9

4.1

3.5

3.4

10.8

28.3

12.6

0.2

0.3

0.7

1.2

2.7

3.0

7.0

11.8

14.2

7.7

7.8

6.3

5.0

6.4

19.2

6.3

0.3

19.3

62.6

92.0

98.2

99.3

99.7

99.6

99.5

99.2

99.3

99.3

99.5

99.4

99.2

99.0

98.6

4.5

13.4

26.1

42.6

66.8

79.1

89.8

94.4

96.2

95.1

94.9

93.4

90.8

90.9

94.6

93.7

89.5

J=.009520

1.31E-16

2.38E-16

6.76E-16

4.21E-15

5.52E-15

6.21E-15

6.56E-15

6.12E-15

5.68E-15

4.07E-15

4.28E-15

3.70E-15

3.55E-15

1.14E-14

2.99E-14

1.32E-14

J=.009517

1.26E-16

1.65E-16

4.40E-16

7.56E-16

1.65E-15

1.87E-15

4.40E-15

7.35E-15

8.85E-15

4.83E-15

4.87E-15

3.90E-15

3.14E-15

3.96E-15

1.20E-14

3.91E-15

2.02E-16

±0.5%

24.242

48.982

38.946

14.315

13.777

14.436

15.106

15.617

16.176

16.664

17.280

18.105

18.843

21.466

27.624

28.273

±0.5%

6.221

20.346

18.850

17.232

17.459

18.383

18.765

19.397

20.082

20.489

20.922

21.365

21.921

22.779

25.528

25.767

31.455

wt.=0.001078 g

3.7 7

5.0 9

12.5 15

61.3 41

67.6 43

132.1 39

125.2 48

138.3 59

88.7 56

115.2 41

83.8 33

67.9 27

65.8 24

82.2 2

112.2 26

113.0 18

wt.=0.001121 g

2.1 5

1.7 5

2.5 5

4.9 7

9.5 11

12.9 22

15.0 36

13.1 69

11.3 73

9.7 47

9.0 31

12.8 26

14.7 20

14.2 25

16.9 2

24.0 9

3.0 1

320KD43 

374.62

690.51

568.95

230.49

222.34

232.31

242.41

250.06

258.40

265.65

274.75

286.88

297.66

335.46

421.20

430.02

336.80

326KD43

103.78

319.32

297.68

273.97

277.31

290.87

296.43

305.62

315.52

321.37

327.60

333.92

341.83

353.99

392.36

395.67

472.43

337.20

15.51

3.70

1.39

0.28

0.22

0.22

0.22

0.26

0.24

0.35

0.29

0.35

0.38

0.38

0.32

0.53

15.37

13.85

5.75

2.98

0.92

0.63

0.36

0.47

0.25

0.32

0.35

0.42

0.50

0.45

0.52

0.39

3.31
Results 55

100

200

300

400

500

600

700

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14I 

K-feldspar

0 10 20 30 40 50 60 70 80 90 100

100

200

300

400

500

600

700

39ArK

 Released (%)

Apparent Age (Ma)

K04-7-14K 

K-feldspar

0 10 20 30 40 50 60 70 80 90 100
56 40Ar/39Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. and Tenn.

References Cited

Alexander, E.C., Jr., Mickelson, G.M., and Lanphere, M.A., 

1978, Mmhb-1—A new 40Ar/39Ar dating standard, in

Zartman, R.E., ed., Short papers of the Fourth International 

Conference, Geochronology, Cosmochronology, and 

Isotope Geology: U.S. Geological Survey Open-File Report 

78–701, p. 6–8.

Dalrymple, G.B., Alexander, E.C., Lanphere, M.A., and 

Kraker, G.P., 1981, Irradiation of samples for 40Ar/39Ar 

dating using the Geological Survey TRIGA reactor: U.S. 

Geological Survey Professional Paper 1176, 55 p.

Deino, A.L., 2001, Users manual for mass spec v. 5.02: 

Berkeley Geochronology Center Special Publication 1a, 

119 p.

Fleck, R.J., Sutter, J.F., and Elliot, D.H., 1977, Interpretation 

of discordant 40Ar/39Ar age spectra of Mesozoic tholeiites 

from Antarctica: Geochimica Cosmochimica Acta, v. 41, 

p. 15–32.

Haugerud, R.A., and Kunk, M.J., 1988, ArAr*, a computer 

program for reduction of 40Ar-39Ar data: U.S.Geological 

Survey Open-File Report 88–261, 68 p.

Roddick, J.C., 1983, High precision calibration of 40Ar-39Ar 

standards: Earth and Planetary Science Letters, v. 47, 

p. 887–898.

Snee, L.W., Sutter, J.F., and Kelly, W.C., 1988, 

Thermochronology of economic mineral deposits: Dating 

the stages of mineralization at Panasqueira, Portugal, 

by high precision 40Ar/39Ar age spectrum techniques on 

muscovite: Economic Geology, v. 83, p. 335–354.

Steiger, R.H., and Jäeger, E., 1977, Subcommission on 

geochronology: Convention on the use of decay constants 

in geo–and cosmo-chronology: Earth and Planetary Science 

Letters, v. 36, p. 359–363.

York, Derik, 1969, Least squares fitting of a straight line with 

correlated errors: Earth and Planetary science Letters, v. 5, 

p. 320–324.

Kunk and McAleer

—

40Ar/ Ar Age-Spectrum Data for Samples From Metamorphic Rocks in the Great Smoky Mountains of N.C. a 39 nd Tenn.—OFR 2011–1250