Alte datari de lave de pe tot globul. Desi considerata recente ca varsta dau prin masurare radiometrica varste uriase.
However, this dogmatic statement is inconsistent with even Dalrymple's own work 25 years earlier on 26 historic, subaerial lava flows, 20% of which he found had non-zero concentrations of 40Ar* (or excess argon) in violation of this key assumption of the K-Ar dating method.2 The historically dated flows and their "ages" were:
Hualalai basalt, Hawaii (AD 1800-1801) 1.6±0.16 Ma; 1.41±0.08 Ma
Mt. Etna basalt, Sicily (122 BC) 0.25±0.08 Ma
Mt. Etna basalt, Sicily (AD 1972) 0.35±0.14 Ma
Mt. Lassen plagioclase, California (AD 1915) 0.11±0.03 Ma
Sunset Crater basalt, Arizona (AD 1064-1065) 0.27±0.09 Ma; 0.25±0.15 Ma
Far from being rare, there are numerous reported examples of excess 40Ar* in recent or young volcanic rocks producing excessively old K-Ar "ages":3
Akka Water Fall flow, Hawaii (Pleistocene) 32.3±7.2 Ma
Kilauea Iki basalt, Hawaii (AD 1959) 8.5±6.8 Ma
Mt. Stromboli, Italy, volcanic bomb (September 23, 1963) 2.4±2 Ma
Mt. Etna basalt, Sicily (May 1964) 0.7±0.01 Ma
Medicine Lake Highlands obsidian,
Glass Mountains, California (<500 years old) 12.6±4.5 Ma
Hualalai basalt, Hawaii (AD 1800-1801) 22.8±16.5 Ma
Rangitoto basalt, Auckland, NZ (<800 years old) 0.15±0.47 Ma
Alkali basalt plug, Benue, Nigeria (<30 Ma) 95 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 old) 21±8 Ma
Kilauea basalt, Hawaii (<1,000 years old) 42.9±4.2 Ma; 30.3±3.3 Ma
East Pacific Rise basalt (<1 Ma) 690±7 Ma
Seamount basalt, near East Pacific Rise (<2.5 Ma) 580±10 Ma; 700±150 Ma
East Pacific Rise basalt (<0.6 Ma) 24.2±1.0 Ma
ther studies have also reported measurements of excess 40Ar* in lavas.4 The June 30, 1954 andesite flow from Mt. Ngauruhoe, New Zealand, has yielded "ages" up to 3.5±0.2 Ma due to excess 40Ar*.5 Austin investigated the 1986 dacite lava flow from the post-October 26, 1980, lava dome within the Mount St. Helens crater, which yielded a 0.35±0.05 Ma whole-rock K-Ar model "age" due to excess 40Ar*.6 Concentrates of constituent minerals yielded "ages" up to 2.8±0.6 Ma (pyroxene ultra-concentrate).
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