Mountains have been built and eroded, continents and oceans have moved great distances, and the Earth has fluctuated from being extremely cold and almost completely covered with ice to being very warm and ice-free. These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth’s surface is moving and changing. As these changes have occurred, organisms have evolved, and remnants of some have been preserved as fossils. A fossil can be studied to determine what kind of organism it represents, how the organism lived, and how it was preserved. However, by itself a fossil has little meaning unless it is placed within some context. The age of the fossil must be determined so it can be compared to other fossil species from the same time period. Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms. For example, based on the primate fossil record, scientists know that living primates evolved from fossil primates and that this evolutionary history took tens of millions of years. By comparing fossils of different primate species, scientists can examine how features changed and how primates evolved through time. However, the age of each fossil primate needs to be determined so that fossils of the same age found in different parts of the world and fossils of different ages can be compared.
Radiometric Dating and the Geological Time Scale
Clearly visible in the canyon walls are the light-colored granites, such as the Zoroaster Granite, which are stark against the darker, folded strata of the Vishnu Schist and the other metamorphic rock units of the Granite Gorge Metamorphic Suite1 see lowest purple and green shading in diagram. These are former sedimentary and volcanic strata that have been transformed by heat and pressure, possibly during the intense upheavals when the dry land was formed on Day 3 of Creation Week.
These were originally basalt lava flows several meters to tens of meters thick.
Geology: Geology, the fields of study concerned with the solid Earth. Included are sciences such as mineralogy, geodesy, and stratigraphy. An introduction to the geochemical and geophysical sciences logically begins with mineralogy, because Earth’s rocks are composed of .
So, how do we know how old a fossil is? There are two main methods determining a fossils age, relative dating and absolute dating. Relative dating is used to determine a fossils approximate age by comparing it to similar rocks and fossils of known ages. Absolute dating is used to determine a precise age of a fossil by using radiometric dating to measure the decay of isotopes, either within the fossil or more often the rocks associated with it.
Relative Dating The majority of the time fossils are dated using relative dating techniques. Using relative dating the fossil is compared to something for which an age is already known. For example if you have a fossil trilobite and it was found in the Wheeler Formation. The Wheeler Formation has been previously dated to approximately million year old, so we know the trilobite is also about million years old.
Scientists can use certain types of fossils referred to as index fossils to assist in relative dating via correlation. Index fossils are fossils that are known to only occur within a very specific age range. Typically commonly occurring fossils that had a widespread geographic distribution such as brachiopods, trilobites, and ammonites work best as index fossils. If the fossil you are trying to date occurs alongside one of these index fossils, then the fossil you are dating must fall into the age range of the index fossil.
Dating Fossils – How Are Fossils Dated?
Important We believe any unbiased reader will realize that we were fair with our treatment of the two models in the table above. Yet, although the theory of evolution matches the facts in some cases, evolution is still an unproven theory. By now, you may believe it should be your first choice also. Unlike many others that preceded us, we attempted to find a clear defense of evolution for two reasons:
The Dating Rocks and Fossils Using Geological Methods article in Nature’s excellent Scitable series of online articles in the Nature Education Knowledge Project. 2. University of California, Berkeley Museum of Paleontology’s Understanding Deep Time online resource.
Leibnitz reworked Descartes’s cosmogony. Protogea was published much later in An essay toward a Natural History of the Earth. Woodward came down fairly strongly for the view that the flood was an act of God that could not be accounted for by normal physical processes. He also postulated hydrological sorting to account for the ordering of fossils. Whiston added comets to Burnet’s cosmogony as the source of the waters of the flood.
Lectures and Discourse of Earthquakes and Subterranean Eruptions. Hooke believed that the fossils were the remains of extinct species and could not be accounted for by the Flood.
The Radiometric Dating Game Radiometric dating methods estimate the age of rocks using calculations based on the decay rates of radioactive elements such as uranium, strontium, and potassium. On the surface, radiometric dating methods appear to give powerful support to the statement that life has existed on the earth for hundreds of millions, even billions, of years. We are told that these methods are accurate to a few percent, and that there are many different methods.
We are told that of all the radiometric dates that are measured, only a few percent are anomalous. This gives us the impression that all but a small percentage of the dates computed by radiometric methods agree with the assumed ages of the rocks in which they are found, and that all of these various methods almost always give ages that agree with each other to within a few percentage points.
Our understanding of the shape and pattern of the history of life depends on the accuracy of fossils and dating methods. Some critics, particularly religious fundamentalists, argue that neither fossils nor dating can be trusted, and that their interpretations are better.
Tiny pores on plant leaves and needles called stomata regulate carbon dioxide absorption and water vapor release. Stomata numbers decrease during times of high atmospheric CO2, and increase when atmospheric CO2 is low. The SI-CO2 relationship varies according to plant species, habitat altitude, and other factors.
Correlation charts are constructed using modern plant specimens by determining their SI numbers and corresponding CO2 concentrations. When SI and CO2 ranges are fully characterized for a plant species, the charts are used as to estimate CO2 levels for related species in the geologic past. To determine plant age Carbon14 methods are usually used to about 40, years ago. For older material, other dating methods are used.
The way it really is: little-known facts about radiometric dating
Acknowledgements Introduction his document discusses the way radiometric dating and stratigraphic principles are used to establish the conventional geological time scale. It is not about the theory behind radiometric dating methods, it is about their application, and it therefore assumes the reader has some familiarity with the technique already refer to “Other Sources” for more information.
As an example of how they are used, radiometric dates from geologically simple, fossiliferous Cretaceous rocks in western North America are compared to the geological time scale. To get to that point, there is also a historical discussion and description of non-radiometric dating methods.
Creation Versus Evolution: We compare the theory of evolution with the Bible’s creation account in easy-to-understand terms, using evidence from the fields of paleontology, geology, biology, and provide links and a bibliography for those who want to study both sides of the issue.
One of the very foundations of evolution and popular science today is the “geologic column. Although not found in all locations and although it varies in thickness as well as the numbers of layers present, this column can be found generally over the entire globe. Many of its layers can even be found on top of great mountains – such as Mt. Everest and the American Rockies.
In some places, such as the mile deep Grand Canyon, the layers of the column have been revealed in dramatic display. Certainly the existence of the column and its layered nature is quite clear, but what does it mean? Is it really a record of millions and even billions of years of Earth’s history? Or, viewed from a different perspective perhaps, does it say something else entirely? As one looks at the geologic column, it is obvious that the contact zones, between the various layers, are generally very flat and smooth relative to each other though the layers may be tilted relative to what is currently horizontal or even warped since their original “flat” formation.
Tiny pores on plant leaves and needles called stomata regulate carbon dioxide absorption and water vapor release. Stomata numbers decrease during times of high atmospheric CO2, and increase when atmospheric CO2 is low. The SI-CO2 relationship varies according to plant species, habitat altitude, and other factors. Correlation charts are constructed using modern plant specimens by determining their SI numbers and corresponding CO2 concentrations.
When SI and CO2 ranges are fully characterized for a plant species, the charts are used as to estimate CO2 levels for related species in the geologic past.
Absolute dating is used to determine a precise age of a rock or fossil through radiometric dating methods. This uses radioactive minerals that occur in rocks and fossils almost like a geological clock.
Primary source references As a preface to this document, I want to point out that it is a shame that we have to continue to refute the same arguments that evolutionists keep bringing up over and over again in their attempts to argue against the fact of creation, which fact has been well established since the day the earth was created ex nihilo several thousand years ago. It is also a shame that the masses have bought all this based on some circular reasoning about fossils, where fossils tend to be found buried, similarities between various life forms, the presence of certain decay products in rocks, and other inherently speculative arguments about the past, based on phenomena that exist in the present.
If I hope to accomplish anything, it will be to simply encourage critical thinking. One must get past the arguments ad populum that its popularity counts for something , ad hominem that if you attack the person making the argument, this counts for something , and especially ad baculum that there are people who have the clout to decree it as true , to ask the key questions and challenge the unsubstantiated assumptions and thinking of those who would hold to the evolution position.
Today there are an increasing number of anti-creationist authors who are producing books and periodicals that make this relatively brief presentation insufficient to deal with all the points in dispute. Those defending creation today who don’t have the time to devote their life’s study to gaining expertise in all fields of inquiry must principally be prepared to think critically, logically, and challenge unsubstantiated assumptions made by these people.