Radiometric dating indicates that the earth is approximately how old
An additional assumption is that the carbon-14 to carbon-12 ratio is a constant. One vital assumption about carbon-14 dating is that the rate of production and decay of carbon-14 is in equilibrium. “Several other geochronologists have also suggested that the C ratio in trees from Australia and Europe (Mac Kie, et. “Long-age chronologists have assumed that the rate of formation of C.
Radiometric dating works best for igneous rocks, because sedimentary rocks consist of grains from multiple rocks of different ages (Lutgens and Edward, 203). Sr, and Incompatible Element Variations in Cale Alkaline andesites and Plateau Lavas From South America. Aside from radiometric dates that appear to be older than expected, there are also examples of dates that appear to be younger than expected by evolutionists. Bentonite in Tennessee from the Ordovician period, expected to be 475 million years was dated to be 44 million years using Rb-Sr dating (Adams, J. Ponta Grossa Formation shale in Brazil from the Devonian period, expected to be around 370 million years ended up being 173±16 million years using Rb-Sr dating (Cordani, U. Rhyolite tuff in Florida from the Silurian period, expected to be 400 million years was dated to be 173±4 million years according to K-Ar dating (Lowry, W. North American Geosynclines-Test of Continental-Drift Theory. American Association of Petroleum Geologists Bulletin 1-2) (Woodmorappe, 199). “Detailed dating studies using pre-Tertiary whole rock basalt and dolerite specimens have been made…and limited optimism for the method appears justified. Cosmic rays, which are high-energy particles, shatter the nuclei of gas atoms, releasing neutrons.The second assumption is that no daughter atoms were originally present in the sample, this is something that simply cannot be guaranteed since it was not witnessed. United States Geological Survey Professional Paper Bulletin 13) (Woodmorappe, 193). Uranium-Daughter Migration and U/Pb Isotope Apparent Ages of Uranium Ores, Shirley Basin, Wyoming. Basalts in Patagonia, Argentina from the Tertiary period, expected to be less than 70 million years were dated to be 500 million years using Rb-Sr dating (Hawkesworth, C. “Since no one was there to measure the amount of C)” (Riddle, 2007).The third assumption is that the sample remained a “closed system” from the time of formation. Chichester, England: Ellis Horwood Ltd., 441, p.287) (Woodmorappe, 19). Uranium ores in Wyoming from the Tertiary period, expected to be 55 million years were dated to be 200-280 million years using Pb dating (Ludwig, K. The half-life of carbon-14 is 5,730 years, so by measuring the ratio of carbon-14 relative to carbon-12 and comparing it to the ratio in living organisms, geochronologists can come up with an age for the organism.“Unfortunately, the U-Pb and Th-Pb systems rarely stay closed in silicate rocks, due to the mobility of Pb, Th, and especially U, under conditions of low-grade metamorphism and superficial weathering” (Dickin, A. A very revealing discovery showed that different layers of a given mollusk shell contained different uranium concentrations, showing that uranium is mobile in biogenic carbonates (Schroeder, 199). If this is the level of subjectivity involved in radiometric dating, can we be certain about the data that does get published? On the Nature of the Excess Argon in Some Minerals. A Nogales Formation tuff in Arizona from the Tertiary period, expected to be 10 million years was dated to be 153±10 million years by K-Ar dating (Marvin, R. “However, even in the early days of radiocarbon dating, comparisons between archeologically established Egyptian chronologies and C levels have varied over time, though fortunately the magnitude of these variations can be assessed, at least since the Late Glacial” (Bradley, 19).Geochronologists know about these challenges and assumptions, but some of their solutions should be critically questioned, “It is common geochronological practice to regard the oldest age obtained from a suite of geologically contemporaneous rocks as a best estimate of the true age, radiogenic Ar loss implicitly being assumed to be the only perturbing mechanism” (Mitchell, 19). Now we will take a look at some radiometric dates that are older than expected by evolutionists. Geochemistry International 9(6):1090) (Woodmorappe, 192). Here are some examples of radiometric ages that were unexpectedly older than anticipated by evolutionists. Another assumption is that the level of carbon-14 is constant throughout the atmosphere. San Diego, CA: Institute for Creation Research, 1999.“Subsequent researchers, however, have failed to show that the rate of production is in equilibrium with the rate of decay. On the other hand, Suess (1965) has revised Libby’s original estimate on the decay rate down to 13.3 atoms/gm-min” (Johannsen, 1980:5).
Since the rate of production exceeds the rate of decay, any assumptions about equilibrium would be invalid and the dates obtained would be skewed. “Uranium Distributions in Recent Skeletal Carbonates.” The American Association of Petroleum Geologists Bulletin 54.5 (1970).
We will examine some of these assumptions, take a look at some “unexpected” radiometric dates, see some examples of discordant dates, and explore some of the specific challenges of individual methods. Plants absorb carbon-14 during photosynthesis, and humans and animals consume plants, so they end up with carbon-14 as well.
The first assumption in radiometric dating is that the radioactive decay rates of elements are constant, but some research suggests that this may not be the case, “Not only have radioactive decay rates been slightly altered in the laboratory but several researchers believe they have found evidence in pleochroic halos that decay rates have changed through geological time.” (Johannsen, 1980:5). Radiometric Ages of Igneous Rocks From Pima, Santa Cruz, and Cochise Counties, Southeastern Arizona. When plants, animals, and humans die, carbon-14 starts to decay into nitrogen-14.
By measuring the amounts of both parent and daughter isotopes in a sample relative to each other scientists can predict how long ago the parent isotope was formed. Absolute Dating of Bentonites by Strontium-Rubidium Isotopes. However, rarely do all the calculated ages agree” (Stern, 1981:5).
Five radioactive isotopes are commonly used in radiometric dating. Age of the Rose Dome Granite, Woodson County, Kansas. K-Ar Ages of Intrusive Rocks of the Central Peloncillo Mountains, Hidalgo County, New Mexico. Geological Society of America Bulletin 27) (Woodmorappe, 191). The paleomagnetism and K-Ar age of Upper Carboniferous Rocks from Andscollo Province of Neuquen, Argentina. Applicability of the Rubidium-Strontium Method to Shales and Related Rocks. “When determined by several methods (K-Ar, Rb-Sr and fission track), radiometric ages for coexisting minerals in a metamorphic or igneous rock generally differ because of different closure temperatures for retention of daughter products or tracks” (Itaya, 191). A Triassic Time Scale Dilemma: K-Ar Dating of Upper Triassic Mafic Igneous Rocks, Eastern USA and Canada, and Post-Upper Triassic Plutons, Western Idaho, USA. “In general, dates in the “correct ball park” are assumed to be correct and are published, but those in disagreement with other data are seldom published nor are discrepancies fully explained” (Mauger, 19).
Yet another unprovable assumption in carbon-14 dating is that the level of carbon-14 and carbon-12 in the earth’s atmosphere has remained fairly consistent throughout history, and natural disasters have had little influence on these levels.