Here is one example of an isochron, based on measurements of basaltic meteorites (in this case the resulting date is 4.4 billion years) [Basaltic1981, pg. Skeptics of old-earth geology make great hay of these examples.
For example, creationist writer Henry Morris [Morris2000, pg.
Also shown below (click for a larger version) is a photo of the paleosol taken from the other side of the road. 100 dpi photo of the same outcrop taken from the opposite side of the road showing from bottom to top (regolith of Butler Hill Granite, dark paleosol formed on top of the granite, shaly Lamotte Formation (basal), Lamotte sandstone (top). Science has determined the age of the Earth to be 4.54 /- 0.05 Ga As mentioned in the opening of this article, there are at least three pieces of independent evidence that argue strongly against a young earth stance.
I will deal with each of these issues in this essay and answer some of the ye-criticisms.
However, human beings love to see factual precision, and we want to know how old something is.
Please remember that all dating methods, even those termed "absolute," are subject to margins of error. That is a very small amount of possible error range. Modern studies almost always use two or more methods to confirm dating work and to build confidence in the results obtained.
it is produced solely by a process of radioactive decay after the formation of the mineral.The veracity of the radiometric dating method has become a major point of fund-raising efforts by creationists at "One major obstacle to accelerated decay is an explanation for the disposal of the great quantities of heat which would be generated by radioactive decay over short periods of time.For example, if most of the radioactive decay implied by fission tracks or quantities of daughter products occurred over the year of the Flood, the amount of heat generated would have been excessive, given present conditions.Dating is not necessary to demonstrate that evolution is a fact.Chronological sequence is all that is really required.The weathered granite is overlain by a shaly regolith and the Lamotte sandstone overlaps this irregular surface. form such a formidable obstacle to the idea of a 6000 year old earth and a global flood that most creationists either ignore these topics, or offer outlandish peripheral refutations of the ideas (more on these in a a later paragraph).This photo is updated as the old photo was improperly formatted (the update was made solely to provide proper perspective and to highlight the absurdity of Tas Walker's 'analysis' rather than to Walker's blustering about 'changing the story'). What is it about these topics that send ye-creationists running for the cover?Figure 1: Paleosol located between the 1470 Ma Butler Hill Granite and the Cambrian Lamotte Sandstone.Photo taken by author in Missouri along State Highway 67.The dating method is usually performed on the mineral zircon.The mineral incorporates uranium and thorium atoms into its crystal structure, but strongly rejects lead.For each dating or chronological method there is a link in the box at right to take you to that section of this page.There, you will find a brief description of the method, plus links to take you to other webpages with more extensive information.In a related article on geologic ages (Ages), we presented a chart with the various geologic eras and their ages.