Thursday, November 6, 2014

Radiometric dating - Erroneous Radiometric dates.

As stated before rocks are not dated by plugging them in to an ACME dating machine. Dating labs do not measure time but measure isotopes ratios. Are these ratios the result of radioactive decay over time or other processes that have taken place in the rock? 

Uinkaret Plateau
Ages of Rocks in Millions of Years

K-Ar Rb-Sr Rb-Sr Isochron Pb-Pb Isochron
0.01 1230 - 1310 1300 - 1380 2390 - 2810 
1.0 - 1.4 1260 - 1380    
2.63 1310 - 1370    
3.6 1320 - 1440    
3.67 1360 - 1420    

Some times different methods used on the same rock, produce different ages. Further more the same method can produce different ages on different parts of the same rock. Some times these are close but other times they are vary different.


Anomalous dates

 Some times radiometric dating produces impossible results.

Uranium-Thorium-Lead Method
Ages in Billions of Years

Apollo Sample # Low High Age Inconsistencies 
extremes in billions 
of Years
14310 5.3 11.2   5.9
14053 5.4 28.1 22.7
15426 4.6 16.2 11.6
66095 5.6 14.1   8.5

Some soil from the Moon has been dated as more than a billion older than the uniformitarian age for the Moon. It was explained by processes of heating and cooling soil had been through.

Some rocks dated older than the
4.5 billion year evolutionary age for Earth.

Description Method "Date" in 
billion years.
Diamonds from magma  K-Ar Isochron 6.0 +- 0.3 
Rock  Rb-Sr Isochron 8.75 
Rock  Rb-Sr 8.3
Rock  Re-Os 11


Recent or young  volcanic rocks producing excessively old K-Ar "ages":

Name Location Real Date K-Ar date
Kilauea Iki basalt Hawaii AD 1959 8.5±6.8 Ma
Mt. Etna basalt Sicily May 1964 0.7±0.01 Ma
Medicine Lake 
Highlands obsidian
Glass Mountains, 
California 
<500 years 12.6±4.5 Ma
Hualalai basalt Hawaii AD 1800-1801 22.8±16.5 Ma
East Pacific Rise basalt Pacific Ocean <1 Ma  690±7 Ma
Olivine basalt  Nathan Hills,Victoria 
Land, Antarctica
<0.3 Ma 18.0±0.7 Ma
Anorthoclase in 
volcanic bomb
Mt Erebus, 
Antarctica
1984 0.64±0.03 Ma
Kilauea basalt  Hawaii <200 years 21±8 Ma
Kilauea basalt,  Hawaii <1,000 years 42.9±4.2 Ma; 
30.3±3.3 Ma
Sea mount basalt Near East Pacific Rise <2.5 Ma 580±10 Ma; 
700±150 Ma
East Pacific Rise basalt  Pacific Ocean <0.6 Ma 24.2±1.0 Ma

  Examples of  negative ages

Name Date Ar-Ar age
Glass Mountain  AD 1579 - 1839 -130,000 
-30,000 years
Mt. Mihara AD 1961 - 70,000  years
Sakurajima AD 1946 -200,000 years

G.B. Dalrymple, "40Ar/36Ar Analyses of Historic Lava Flows," Earth and Planetary Science Letters,6 (1969): pp. 47-55.

Some rocks have been measured with negative radiometric ages, in some case in terms of millions of years. Isochron dating can also produce negative ages, by producing a negative slope. K-Ar and Ar-Ar can result in negative ages when atmospheric argon is considered. So if these are real dates then you can hold a rock in your hand that wont form for hundreds of thousands or even millions of years yet.

Now in all fairness Ar-Ar dating can get the right age for a sample of known age, but it can also date samples as way too old, but without a known date there is no way of knowing when it is too old. One key factor is the fact that Ar-Ar dating need a standard of "known" age. If standard is of historically known age, such as would likely be used for testing Ar-Ar dating on sample of known age, then one would be more likely to get the correct age. For allegedly older samples K-Ar is used to "date" the standard and as such it still has the same problems as K-Ar dating.




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