What is relative dating and radiometric dating Freeadulthookup
6 The problems with contamination, as with inheritance, are already well-documented in the textbooks on radioactive dating of rocks.7 Unlike the hourglass, where its two bowls are sealed, the radioactive “clock” in rocks is open to contamination by gain or loss of parent or daughter isotopes because of waters flowing in the ground from rainfall and from the molten rocks beneath volcanoes.
Similarly, as molten lava rises through a conduit from deep inside the earth to be erupted through a volcano, pieces of the conduit wallrocks and their isotopes can mix into the lava and contaminate it.
To make matters even worse for the claimed reliability of these radiometric dating methods, these same basalts that flowed from the top of the Canyon yield a samarium-neodymium age of about 916 million years,5 and a uranium-lead age of about 2.6 billion years!Yet lava flows that have occurred in the present have been tested soon after they erupted, and they invariably contained much more argon-40 than expected.1 For example, when a sample of the lava in the Mt. Helens crater (that had been observed to form and cool in 1986) ( age yield incorrect old potassium-argon ages due to the extra argon-40 that they inherited from the erupting volcanoes, then ancient lava flows of unknown ages could likewise have inherited extra argon-40 and yield excessively old ages.There are similar problems with the other radioactive “clocks.” For example, consider the dating of Grand Canyon’s basalts (rocks formed by lava cooling at the earth’s surface).Based on these observations and the known rate of radioactive decay, they estimate the time it has taken for the daughter isotope to accumulate in the rock.However, unlike the hourglass whose accuracy can be tested by turning it upside down and comparing it to trustworthy clocks, the reliability of the radioactive “clock” is subject to three unprovable assumptions.