Uranium 238 dating rocks
Uranium 238 dating rocks - Wife sharing mobile chat
Part 2 explains how scientists run into problems when they make assumptions about what happened .
Most people think that radioactive dating has proven the earth is billions of years old.
This is the same age that we get for the basalt layers deep below the walls of the eastern Grand Canyon.4 How could both lavas—one at the top and one at the bottom of the Canyon—be the same age based on these parent and daughter isotopes?
One solution is that both the recent and early lava flows inherited the same rubidium-strontium chemistry—not age—from the same source, deep in the earth’s upper mantle.
Nevertheless, geologists insist the radioactive decay rates have always been constant, because it makes these radioactive clocks “work”!
New evidence, however, has recently been discovered that can only be explained by the radioactive decay rates not having been constant in the past.9 For example, the radioactive decay of uranium in tiny crystals in a New Mexico granite ( yields a uranium-lead “age” of 1.5 billion years.
No geologist was present when the rocks were formed to see their contents, and no geologist was present to measure how fast the radioactive “clock” has been running through the millions of years that supposedly passed after the rock was formed.
No geologists were present when most rocks formed, so they cannot test whether the original rocks already contained daughter isotopes alongside their parent radioisotopes.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).When we look at sand in an hourglass, we can estimate how much time has passed based on the amount of sand that has fallen to the bottom.Radioactive rocks offer a similar “clock.” Radioactive atoms, such as uranium (the parent isotopes), decay into stable atoms, such as lead (the daughter isotopes), at a measurable rate.To date a radioactive rock, geologists first measure the “sand grains” in the top glass bowl (the parent radioisotope, such as uranium-238 or potassium-40).