Evolution -- Dating Methods

Geochronology

The new method offers greater efficiency, and access to a much more detailed geologic record than current dating methods. It is also being claimed that the standard deviations are not too large. Yes, we know that the books supporting evolution contain much more information than two pictures.

What You Will Learn

Then the partial pressure of argon 40 in the magma will never decrease below p; excess argon 40 will remain dissolved in the lava or magma as it cools. How do these dates compare to the then current geological time scale? Why K-Ar dating is inaccurate Since K-Ar potassium-argon dating is one of the most prevalent techniques, some special commentary about it is in order. Which type of fault was responsible for the devastation associated with the earthquake in San Francisco? Lubenow's work is fairly unique in characterising the normal scientific process of refining a difficult date as an arbitrary and inappropriate "game", and documenting the history of the process in some detail, as if such problems were typical. The uncertainties inherent in radiometric dating are disturbing to geologists and evolutionists It is evident to everyone, as we view our dwindling energy resources, that a lot of material was left in the ground at one time.

Which of the following makes up the sediment that forms an organic sedimentary rock? Shells and plant fibers. Which environment would be likely to produce a black shale?

Which of the following methods of transportation will result in the coarsest sorting poorest sorting? Which of the following best describes the appearance and composition of a conglomerate?

Rounded fragments; poorly sorted. Which rock is the most abundant chemical sedimentary rock? Particle size; mineral composition. Which of the following is the parent tock for quartzite? Which low-grade metamorphic rock will display fine rock cleavage and contains very fine grains of mica? Which of the following lists of metamorphic rocks places the rocks in order from lowest metamorphic grade to highest. Slate, Phyllite, Schist, Gneiss.

Which of the following rocks represents the highest grade of metamorphism? What kind of force will create foliation in metamorphic rocks? Roughly parallel layers of mineral crystals aligned perpendicular to the direction of pressure. In which geologic setting is the most widespread occurrence of hydrothermal metamorphism? Along the axis of a mid-ocean ridge system. Which tectonic boundary is associated with regional metamorphism? What is the definition of relative dating? What is a fossil?

Evidence of past life that can include skeletal as well as trace material. A worm burrow is an example of which type of fossilization? Matching up rocks of similar age in different regions. What is an index fossil? Organisms that were geographically widespread but limited to a short span of geologic time. What is an isotope? An atom that has more or fewer neutrons than it should.

If U has 92 protons, how many neutrons does it have? What is the definition of a half-life? The time it takes for half of the parent isotope to decay to the daughter.

Which era are we currently in? Which of the following is the best description for structural geology? Study of rock deformation in response to tectonic forces. Which tectonic boundary is associated with compressional stress? A rubber band being stretched in preparation to fire across the room is an example o what kind of deformation.

What is a fault? A fracture in a rock along which motion has occurred. You are sitting in class when our professor begins talking about a dome with inner layers dating back to the Tertiary and its outer layers dating back to the Permian. You immediately know this professor is wrong. What is your evidence? Domes have the oldest layers in the middle, not the youngest.

Which tectonic boundary would have many normal faults associated with it? Which type of fault was responsible for the devastation associated with the earthquake in San Francisco? Which of the following best describes the age relationship of the layers in an anticline.

Radiometric dating provides numerical values for the age of an appropriate rock, usually expressed in millions of years. Therefore, by dating a series of rocks in a vertical succession of strata previously recognized with basic geologic principles see Stratigraphic principles and relative time , it can provide a numerical calibration for what would otherwise be only an ordering of events -- i.

The integration of relative dating and radiometric dating has resulted in a series of increasingly precise "absolute" i.

Given the background above, the information used for a geologic time scale can be related like this: A continuous vertical stratigraphic section will provide the order of occurrence of events column 1 of Figure 2. These are summarized in terms of a "relative time scale" column 2 of Figure 2. Geologists can refer to intervals of time as being "pre-first appearance of species A" or "during the existence of species A", or "after volcanic eruption 1" at least six subdivisions are possible in the example in Figure 2.

For this type of "relative dating" to work it must be known that the succession of events is unique or at least that duplicate events are recognized -- e. Unique events can be biological e. Ideally, geologists are looking for events that are unmistakably unique, in a consistent order, and of global extent in order to construct a geological time scale with global significance. Some of these events do exist. For example, the boundary between the Cretaceous and Tertiary periods is recognized on the basis of the extinction of a large number of organisms globally including ammonites, dinosaurs, and others , the first appearance of new types of organisms, the presence of geochemical anomalies notably iridium , and unusual types of minerals related to meteorite impact processes impact spherules and shocked quartz.

These types of distinctive events provide confirmation that the Earth's stratigraphy is genuinely successional on a global scale. Even without that knowledge, it is still possible to construct local geologic time scales.

Although the idea that unique physical and biotic events are synchronous might sound like an "assumption", it is not. It can, and has been, tested in innumerable ways since the 19th century, in some cases by physically tracing distinct units laterally for hundreds or thousands of kilometres and looking very carefully to see if the order of events changes.

Geologists do sometimes find events that are "diachronous" i. Because any newly-studied locality will have independent fossil, superpositional, or radiometric data that have not yet been incorporated into the global geological time scale, all data types serve as both an independent test of each other on a local scale , and of the global geological time scale itself.

The test is more than just a "right" or "wrong" assessment, because there is a certain level of uncertainty in all age determinations.

For example, an inconsistency may indicate that a particular geological boundary occurred 76 million years ago, rather than 75 million years ago, which might be cause for revising the age estimate, but does not make the original estimate flagrantly "wrong". It depends upon the exact situation, and how much data are present to test hypotheses e. Whatever the situation, the current global geological time scale makes predictions about relationships between relative and absolute age-dating at a local scale, and the input of new data means the global geologic time scale is continually refined and is known with increasing precision.

This trend can be seen by looking at the history of proposed geologic time scales described in the first chapter of [Harland et al, , p. The unfortunate part of the natural process of refinement of time scales is the appearance of circularity if people do not look at the source of the data carefully enough. Most commonly, this is characterised by oversimplified statements like:.

Even some geologists have stated this misconception in slightly different words in seemingly authoritative works e. When a geologist collects a rock sample for radiometric age dating, or collects a fossil, there are independent constraints on the relative and numerical age of the resulting data. Stratigraphic position is an obvious one, but there are many others. There is no way for a geologist to choose what numerical value a radiometric date will yield, or what position a fossil will be found at in a stratigraphic section.

Every piece of data collected like this is an independent check of what has been previously studied. The data are determined by the rocks , not by preconceived notions about what will be found. Every time a rock is picked up it is a test of the predictions made by the current understanding of the geological time scale. The time scale is refined to reflect the relatively few and progressively smaller inconsistencies that are found.

This is not circularity, it is the normal scientific process of refining one's understanding with new data. It happens in all sciences. If an inconsistent data point is found, geologists ask the question: However, this statistical likelihood is not assumed, it is tested , usually by using other methods e.

Geologists search for an explanation of the inconsistency, and will not arbitrarily decide that, "because it conflicts, the data must be wrong. If it is a small but significant inconsistency, it could indicate that the geological time scale requires a small revision. The continued revision of the time scale as a result of new data demonstrates that geologists are willing to question it and change it.

The geological time scale is far from dogma. If the new data have a large inconsistency by "large" I mean orders of magnitude , it is far more likely to be a problem with the new data, but geologists are not satisfied until a specific geological explanation is found and tested.

An inconsistency often means something geologically interesting is happening, and there is always a tiny possibility that it could be the tip of a revolution in understanding about geological history.

Admittedly, this latter possibility is VERY unlikely. There is almost zero chance that the broad understanding of geological history e. The amount of data supporting that interpretation is immense, is derived from many fields and methods not only radiometric dating , and a discovery would have to be found that invalidated practically all previous data in order for the interpretation to change greatly.

So far, I know of no valid theory that explains how this could occur, let alone evidence in support of such a theory, although there have been highly fallacious attempts e. It contains a mixture of minerals from a volcanic eruption and detrital mineral grains eroded from other, older rocks.

If the age of this unit were not so crucial to important associated hominid fossils, it probably would not have been dated at all because of the potential problems. After some initial and prolonged troubles over many years, the bed was eventually dated successfully by careful sample preparation that eliminated the detrital minerals. Lubenow's work is fairly unique in characterising the normal scientific process of refining a difficult date as an arbitrary and inappropriate "game", and documenting the history of the process in some detail, as if such problems were typical.

Another example is "John Woodmorappe's" paper on radiometric dating , which adopts a "compilation" approach, and gives only superficial treatment to the individual dates. Among other problems documented in an FAQ by Steven Schimmrich , many of Woodmorappe's examples neglect the geological complexities that are expected to cause problems for some radiometrically-dated samples.

This section is important because it places a limit on the youngest age for a specific ammonite shell -- Baculites reesidei -- which is used as a zonal fossil in western North America.

It consistently occurs below the first occurrence of Bacultes jenseni and above the occurrence of Baculites cuneatus within the upper part of the Campanian, the second to last "stage" of the Cretaceous Period in the global geological time scale. The biostratigraphic situation can be summarized as a vertically-stacked sequence of "zones" defined by the first appearance of each ammonite species: About 40 of these ammonite zones are used to subdivide the upper part of the Cretaceous Period in this area.

Dinosaurs and many other types of fossils are also found in this interval, and in broad context it occurs shortly before the extinction of the dinosaurs, and the extinction of all ammonites.

The Bearpaw Formation is a marine unit that occurs over much of Alberta and Saskatchewan, and it continues into Montana and North Dakota in the United States, although it adopts a different name in the U. The numbers above are just summary values. Other examples yield similar results - i.

The results are therefore highly consistent given the analytical uncertainties in any measurement. Eberth and Braman described the vertebrate paleontology and sedimentology of the Judith River Formation, a dinosaur-bearing unit that occurs stratigraphically below the Baculites reesidei zone the Judith River Formation is below the Bearpaw Formation.

It should therefore be older than the results from Baadsgaard et al. An ash bed near the top of the Judith River Fm. Again, this is compatible with the age determined for the Baculites reesidei zone and its relative stratigraphic position, and even with the relative position of the two samples within the same formation.

How do these dates compare to the then current geological time scale? Here are the numbers they applied to the geological boundaries in this interval, compared to the numbers in the newer studies:. As you can see, the numbers in the rightmost column are basically compatible. Skeptics of radiometric dating procedures sometimes claim these techniques should not work reliably, or only infrequently, but clearly the results are similar: Most of the time, the technique works exceedingly well to a first approximation.

However, there are some smaller differences. The date for the Baculites reesidei zone is at least 0. Well, standard scientific procedure is to collect more data to test the possible explanations -- is it the time scale or the data that are incorrect?

Obradovich has measured a large number of high-quality radiometric dates from the Cretaceous Period, and has revised the geological time scale for this interval. Specifically, he proposes an age of This is completely compatible with the data in Baadsgaard et al. Skeptics of conventional geology might think scientists would expect, or at least prefer, every date to be perfectly consistent with the current geological time scale, but realistically, this is not how science works.

The age of a particular sample, and a particular geological time scale, only represents the current understanding, and science is a process of refinement of that understanding. Yes, there are many fossils lying around. That means a lot of plants and animals died and we can find their fossilized remains. Someone who believes in evolution would have you believe this happened over time. Would they stay put and untouched on the ground long enough to be covered by dirt eventually and become fossilized?

They would be eaten by other animals and blown around by the winds and rains until a complete skeleton was no longer available. The reality is that there is no evidence that fossils were formed continually or are being formed continually as the theory of evolution predicts. On the other hand, what would happen if there were a worldwide flood, causing everything to drown, including the rat and the deer?

They might float for awhile, but would eventually sink to the bottom of the water. There is no question that the large number of fossils testifies to the accuracy of the creation model rather than the theory of evolution model. The point of discussion here is whether the layers were deposited over vast geological times or over a relatively quick period. Steve Austin investigated the Mount St.

Helens eruption, which produced a small scale version of the Grand Canyon. He showed that thousands of layers were deposited over a number of days rather than being laid down gradually over long 4. We are stating that ample evidence exists that the layers of the earth could be produced quickly by a geologic catastrophe like the flood in the Bible. It includes spectacular shots taken before, during, and after the eruption of Mount St.

We are told that old fossils are found in old rock layers and recent fossils are found in recent rock layers. Yet, some fossils like clams are found in all strata, including rock layers at mountain tops.

So, learning which clam was millions of years old and which one is only a few thousand years old becomes a little tricky. Notice that although the layers of the earth were dated using index fossils, the index fossils were dated by guessing their age based on the theory of evolution.

This is not science nor a valid application of the scientific method. Suggesting a hypothetical age for a fossil based on a theory and then telling everyone it is an established fact is not the way to apply the scientific method. If you quiz paleontologists about this, many will assure you that their techniques are indeed scientific. They will tell you they accurately date the fossil using the date of the rock layer in which they found it.

Did you notice what just happened? They assigned a date to the fossil, then dated the layer of earth which contained that fossil. Then they turned around and told you they knew the age of the fossil, because they knew the date of that layer of earth. You may be wondering about radiometric radioactive dating, which we will examine next. However, you should know that scientists established the geologic time scale and assigned the ages of the fossils in those rock layers before radioactive dating was invented.

Radiometric radioactive dating does not yield results that are as consistent as many books would have you believe.

For example, a rock in Nigeria dated 95 million years old with Potassium-Argon dating, and million years old using Uranium-Helium dating measured only 30 million years old with fission track dating.

There is one documented case where a single lump of tuff a type of porous rock contained components which individually dated at 1. This dating technique does have a problem, though. It is designed to measure times on the order of a billion 1,,, years or more. Therefore everything you measure with this dating technique will seem to have great age. For example, if you wanted to measure the distance between Los Angeles and New York, you could fly a jet airplane at a constant speed and measure the time the flight takes.

Knowing the speed and time, you can calculate the distance. Now, what would happen if you used the same technique to measure the length of a house you flew over on the way to New York? It would give you bad results because you could not measure the time it took to fly over the house accurately enough to get a good answer.

The same is true if you use isochron dating to measure something that is only a few thousand years old. Another problem arises when you submit a sample for testing. This is true of both radiometric dating used for igneous rock and Carbon 14 dating used for things that were once living. Did you notice what happened? The scientist biased the results by determining the desired result before starting. Then, they chose a method that will give them the results they expect.

This is not correct scientific procedure. How would you like it if the U. A worldwide flood would kill all the animals except for some that normally live in water and most of the vegetation. Without land to break up the tides, all water movement would become very turbulent, mixing the different sizes and species together with trees and other vegetation. Whatever happened to sink to the bottom first would be covered first with the earth and silt stirred up during the flood.

Those plants and animals that sank later would be buried in the higher layers. This is an isolated incident, but the fossil discoveries in the next paragraph are very common. Fossil trees are often found in a position where a single fossil occupies many geologic layers at the same time. Are we supposed to believe these trees died and remained partly buried for thousands or millions of years until they became completely buried and fossilized? We would like someone to prove it to us by showing us a tree that was alive 10, or 20, years ago and is mostly but not completely buried in an upright position today.

A flood, which would cause massive amounts of earth movement, is a much better explanation for the unique placement of both of these fossil types. For example, a whale that died or was killed could get temporarily stuck in an upright position and quickly buried. The same thing could happen to a tree. Put simply, trees broken off during a flood would float until they became water-logged.

Then, the denser and larger diameter root end of some of the trees would sink lower in the water, putting those trees in an upright position. Later, after completely sinking, the now upright trees would be buried in sediment. This happened to many trees when Mount St. Any scuba diver in Spirit Lake next to Mount St. Helens can find many half-buried, upright trees not stumps in the bottom of the lake today. If you would like more detail, we recommend viewing the video done by Steve Austin which thoroughly, yet simply explains the mechanism that allows trees to span the geologic layers [10].

These fossils and others that span multiple layers reject and disprove the concept that geologic layers always represent long periods of time. We do not dismiss the fact that layers can be laid down over time. We are saying that the existence of layers in the earth does not prove the passage of any specific time. Further, we do know that fossils found in different layers can be deposited at essentially the same time.

Many different types of fossils are found mixed in with one another. How logical is it that animals would die in heaps, leaving their remains for a long period of time until they are eventually covered up with dust and become fossils? Does this happen anywhere today?

On the other hand, if there was a worldwide flood, causing everything to drown, you would expect the bodies of all types of unrelated animals to eventually come to rest on the bottom of the body of water, in piles. In each case the species is distinct. There are no links where one species changes into another. Yes, you can line up a dog and a cat and a person, but where is the transitional form that split into the two species?

You are only shown a gap where the change was to have taken place. It does not take a Ph. Early visitors to this page were able to use a link we provided to check it out. Unfortunately, the Webmaster of that site removed that questionable but cool feature and exchanged it with a cladogram. To see a cladogram, click here. This is such an interesting topic, we constructed two separate pages to address it.

The first examines a sequence of transitional forms. Click here to learn more about the transitional forms found. The few that exist are those from cellular and multicellular creatures such as algae or bacteria. These varied creatures include Trilobites, brachiopods, gastropods, bivalves, crinoids, graptolites, sponges, and segmented worms.

Images: principle behind radiometric dating

Smith was a creationist who believed in the old-earth view now known as progressive creationism. Each ring has its own characteristic radius in a given mineral in this case biotite. This is unstable and over time will decay back into Carbon

Put simply, trees broken off during a flood would float until they became water-logged. The path of magma also becomes longer for later flows, and the magma probably also is a little cooler, inhibiting argon flow.

The latter principle behind radiometric dating subdivisions, in an emended form, are still used today by geologists. What is the accepted age of the Earth? Since philippine online dating chat bulk of K-Ar dates are generally accepted as correct, one may say that certain minerals are reliable if they tend to give similar dates, and unreliable otherwise. It means that science continues to uphold knowledge recorded in the Bible over three thousand years ago. East African Rift Valley. This example is given to show that a mixing of three principle behind radiometric dating cannot be detected by the usual two sources test.