Geplaatst: di okt 06, 2009 8:57 am
jammie schreef: ga nu even de tabel opzoeken in het RATE-book die laat zien dat de verschillende dateringsmethoden niet dezelfde datering geven als dat jij zegt.
Geplaatst: di okt 06, 2009 8:58 am
martien schreef:Dan zoek ik een lijstje waar dat dan weer wel in klopt.
di okt 06, 2009 9:33 am
jammie schreef:1. Mt. Ngauruhoe andesites, Conventional Age:1949,1953,1975, K-Ar: Not applicable, Rb-Sr 133±87, sm/Nd:197±160, Pb-Pb 3908±390
2. Uinkaret Plateau basalts, Conventional Age: <1,16 Miljoen, K-Ar: None, Rb-Sr 1143±220, Sm-Nd: 916±570, Pb-Pb: Not available
3. Somerset Dam layered mafic intrusion, Conventional Age: 216 Miljoen, K-Ar: 174±8, Rb-Sr 393±170, Sm-Nd: 259±76, Pb-Pb 1425±1000
4. Cardenas Basalt, Conventional Age: 1103 miljoen, k-Ar: 516±30, Rb-Sr: 1111±81 en 892±82, Sm-Nd 1588±170, Pb-Pb: 1385±950
5. Bass Rapids diabase still , Conventional Age 1070 miljoen, K-Ar: 841,5±164, Rb-Sr 1055±46, 1060±24, 1075±34, 1007±79, Sm-Nd: To much scatter, 1379±140, 1330±360,1336±380, Pb-Pb: 1250±130, To much scatter, 1584±420, 1327±230
6. Apache Group Basalts, Conventional Age: 1100 Miljoen, K-Ar: Too much scatter, Rb-Sr: 2295±300, Sm-Nd: Not enough spread, Pb-Pb: 1304±69
7. Apache Group diabase sills, Conventional Age: 1130 Miljoen, K-Ar: Too much scatter, Rb-Sr: 2067±380, Sm-Nd: Too much scatter, Pb-Pb 1142±98 en 1146±59
8. Brahma amphibolites, Conventional Age: 1740-1750 Miljoen, K-Ar: Too much scatter, Rb-Sr: 840±86 en 1240±84 Sm-Nd: 1678±60 en 1655±40, Pb-Pb: 1864±78 en 1883±53
9. Elves Chasm Grandiorite, Conventional Age: 1840 Miljoen, K-Ar: Not available, Rb-Sr: 1512±140, Sm-Nd: 1664±200, Pb-Pb: 1933±220
10. Beartooth andesitic amphibolite, Conventional Age: 2790 Miljoen, K-Ar: Too much scatter, Rb-Sr: 2515±110, Sm-Nd: 2886±190, Pb-Pb: 2689,4±8,6
di okt 06, 2009 9:34 am
Pb-Pb isochron of terrestrial and meteorite samples.
After Murthy and Patterson (1962) and York and Farquhar (1972) .
Scanned from Dalrymple (1986) with permission.
Most of the other measurements for the age of the Earth rest upon calculating an age for the solar system by dating objects which are expected to have formed with the planets but are not geologically active (and therefore cannot erase evidence of their formation), such as meteorites. Below is a table of radiometric ages derived from groups of meteorites:
--------------------------------------------------------------------------------
Type Number
Dated Method Age (billions
of years)
--------------------------------------------------------------------------------
Chondrites (CM, CV, H, L, LL, E) 13 Sm-Nd 4.21 +/- 0.76
Carbonaceous chondrites 4 Rb-Sr 4.37 +/- 0.34
Chondrites (undisturbed H, LL, E) 38 Rb-Sr 4.50 +/- 0.02
Chondrites (H, L, LL, E) 50 Rb-Sr 4.43 +/- 0.04
H Chondrites (undisturbed) 17 Rb-Sr 4.52 +/- 0.04
H Chondrites 15 Rb-Sr 4.59 +/- 0.06
L Chondrites (relatively undisturbed) 6 Rb-Sr 4.44 +/- 0.12
L Chondrites 5 Rb-Sr 4.38 +/- 0.12
LL Chondrites (undisturbed) 13 Rb-Sr 4.49 +/- 0.02
LL Chondrites 10 Rb-Sr 4.46 +/- 0.06
E Chondrites (undisturbed) 8 Rb-Sr 4.51 +/- 0.04
E Chondrites 8 Rb-Sr 4.44 +/- 0.13
Eucrites (polymict) 23 Rb-Sr 4.53 +/- 0.19
Eucrites 11 Rb-Sr 4.44 +/- 0.30
Eucrites 13 Lu-Hf 4.57 +/- 0.19
Diogenites 5 Rb-Sr 4.45 +/- 0.18
Iron (plus iron from St. Severin) 8 Re-Os 4.57 +/- 0.21
--------------------------------------------------------------------------------
After Dalrymple (1991, p. 291); duplicate studies on identical meteorite types omitted.
As shown in the table, there is excellent agreement on about 4.5 billion years, between several meteorites and by several different dating methods. Note that young-Earthers cannot accuse us of selective use of data -- the above table includes a significant fraction of all meteorites on which isotope dating has been attempted. According to Dalrymple (1991, p. 286) , less than 100 meteorites have been subjected to isotope dating, and of those about 70 yield ages with low analytical error.
Further, the oldest age determinations of individual meteorites generally give concordant ages by multiple radiometric means, or multiple tests across different samples. For example:
--------------------------------------------------------------------------------
Meteorite Dated Method Age (billions
of years)
--------------------------------------------------------------------------------
Allende whole rock Ar-Ar 4.52 +/- 0.02
whole rock Ar-Ar 4.53 +/- 0.02
whole rock Ar-Ar 4.48 +/- 0.02
whole rock Ar-Ar 4.55 +/- 0.03
whole rock Ar-Ar 4.55 +/- 0.03
whole rock Ar-Ar 4.57 +/- 0.03
whole rock Ar-Ar 4.50 +/- 0.02
whole rock Ar-Ar 4.56 +/- 0.05
Guarena whole rock Ar-Ar 4.44 +/- 0.06
13 samples Rb-Sr 4.46 +/- 0.08
Shaw whole rock Ar-Ar 4.43 +/- 0.06
whole rock Ar-Ar 4.40 +/- 0.06
whole rock Ar-Ar 4.29 +/- 0.06
Olivenza 18 samples Rb-Sr 4.53 +/- 0.16
whole rock Ar-Ar 4.49 +/- 0.06
Saint Severin 4 samples Sm-Nd 4.55 +/- 0.33
10 samples Rb-Sr 4.51 +/- 0.15
whole rock Ar-Ar 4.43 +/- 0.04
whole rock Ar-Ar 4.38 +/- 0.04
whole rock Ar-Ar 4.42 +/- 0.04
Indarch 9 samples Rb-Sr 4.46 +/- 0.08
12 samples Rb-Sr 4.39 +/- 0.04
Juvinas 5 samples Sm-Nd 4.56 +/- 0.08
5 samples Rb-Sr 4.50 +/- 0.07
Moama 3 samples Sm-Nd 4.46 +/- 0.03
4 samples Sm-Nd 4.52 +/- 0.05
Y-75011 9 samples Rb-Sr 4.50 +/- 0.05
7 samples Sm-Nd 4.52 +/- 0.16
5 samples Rb-Sr 4.46 +/- 0.06
4 samples Sm-Nd 4.52 +/- 0.33
Angra dos Reis 7 samples Sm-Nd 4.55 +/- 0.04
3 samples Sm-Nd 4.56 +/- 0.04
Mundrabrilla silicates Ar-Ar 4.50 +/- 0.06
silicates Ar-Ar 4.57 +/- 0.06
olivine Ar-Ar 4.54 +/- 0.04
plagioclase Ar-Ar 4.50 +/- 0.04
Weekeroo Station 4 samples Rb-Sr 4.39 +/- 0.07
silicates Ar-Ar 4.54 +/- 0.03
--------------------------------------------------------------------------------
After Dalrymple (1991, p. 286); meteorites dated by only a single means omitted.
Also note that the meteorite ages (both when dated mainly by Rb-Sr dating in groups, and by multiple means individually) are in exact agreement with the solar system "model lead age" produced earlier.
bronZo. Een lijstje.