Nonradioactive absolute chronometers may conveniently be classified in terms of the broad areas in which changes occur—namely, geologic and biological processes, which will be treated here. During the first third of the 20th century, several presently obsolete weathering chronometers were explored.
Most famous was the attempt to estimate the duration of Pleistocene interglacial intervals through depths of soil development.
In the American Midwest, thicknesses of gumbotil and carbonate-leached zones were measured in the glacial deposits tills laid down during each of the four glacial stages. Based on a direct proportion between thickness and time, the three interglacial intervals were determined to be longer than postglacial time by factors of 3, 6, and 8. To convert these relative factors into absolute ages required an estimate in years of the length of postglacial time. When certain evidence suggested 25, years to be an appropriate figure, factors became years—namely, 75,, ,, and , years.
And, if glacial time and nonglacial time are assumed approximately equal, the Pleistocene Epoch lasted about 1,, years. Only one weathering chronometer is employed widely at the present time.
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Its record of time is the thin hydration layer at the surface of obsidian artifacts. Although no hydration layer appears on artifacts of the more common flint and chalcedony, obsidian is sufficiently widespread that the method has broad application.
Practical experience indicates that the constant K is almost totally dependent on temperature and that humidity is apparently of no significance. Whether in a dry Egyptian tomb or buried in wet tropical soil, a piece of obsidian seemingly has a surface that is saturated with a molecular film of water. Consequently, the key to absolute dating of obsidian is to evaluate K for different temperatures. Even without such knowledge, hydration rims are useful for relative dating within a region of uniform climate.
Like most absolute chronometers, obsidian dating has its problems and limitations. Specimens that have been exposed to fire or to severe abrasion must be avoided. Furthermore, artifacts reused repeatedly do not give ages corresponding to the culture layer in which they were found but instead to an earlier time, when they were fashioned.
Finally, there is the problem that layers may flake off beyond 40 micrometres 0. Measuring several slices from the same specimen is wise in this regard, and such a procedure is recommended regardless of age. Sediment in former or present water bodies, salt dissolved in the ocean , and fluorine in bones are three kinds of natural accumulations and possible time indicators. To serve as geochronometers, the records must be complete and the accumulation rates known.
The fossiliferous part of the geologic column includes perhaps , metres of sedimentary rock if maximum thicknesses are selected from throughout the world. During the late s, attempts were made to estimate the time over which it formed by assuming an average rate of sedimentation.
Because there was great diversity among the rates assumed, the range of estimates was also large—from a high of 2. In spite of this tremendous spread, most geologists felt that time in the hundreds of millions of years was necessary to explain the sedimentary record. If the geologic column see below were made up entirely of annual layers, its duration would be easy to determine.
Varves arise in response to seasonal changes. In moist, temperate climates, lake sediments collecting in the summer are richer in organic matter than those that settle during winter. This feature is beautifully seen in the seasonal progression of plant microfossils found in shales at Oensingen, Switz. In the thick oil shales of Wyoming and Colorado in the United States, the flora is not so well defined, but layers alternating in organic richness seem to communicate the same seasonal cycle. These so-called Green River Shales also contain abundant freshwater-fish fossils that confirm deposition in a lake.
At their thickest, they span vertical metres.
Geochronology - Nonradiometric dating | hirnakrobat.de
Because the average thickness of a varve is about 0. Each of the examples cited above is of a floating chronology— i. In Sweden , by contrast, it has been possible to tie a glacial varve chronology to present time, and so create a truly absolute dating technique.
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Where comparisons with radiocarbon dating are possible, there is general agreement. As early as , an English chemist named Middleton claimed that fossil bones contain fluorine in proportion to their antiquity.
This idea is sound in principle, provided that all the other natural variables remain constant. Thus, determining the age of the Earth with alternative techniques could serve to strengthen the conclusions that have been reached with radioisotope dating methods. In this paper, a different approach to solving the problem is proposed. As is known from studies of million year old fossil corals, Earth years were days in duration in distant times because the Earth rotated faster than it does today.
According to calculations based on the fundamental law of rotational motion dynamics involving the moment of inertia of a body, the radius of the ancient Earth million years ago was Let us call this the evolutionary Earth growth constant; it does not take into account the effect of lunar tidal friction. If the present day Earth radius of km is divided by 1. One of the key goals has been to not only determine the conditions surrounding the formation of Earth, but also the whole evolutionary sequence of Earth and periodization of all major geological events.
Our attention here is focused on the characterization of geological time that encompasses the evolutionary sequence of the material geological environment, or more accurately, the stratigraphic divisions. We call time geological due to specifics regarding the fixation of geological events over billions of years. Stratigraphic divisions are associated with certain development stages, and then they disappear as they are replaced by other divisions i.
Exhaustive knowledge on methodological aspects of geological theories and isotope time sequences has been demonstrated in many works, for example, the work by Wells [ 1 ]. Studies of geological time typically begin with event relation determinations early—late events, ancient—recent events and finish with continuity determinations and positioning on the modern geochronological scale. These studies may involve both qualitative and quantitative observations. Qualitative topological treatments of geological time are ultimately connected to quantitative metric treatments.
Specifically, topological characteristics are often used for determining the relative age and order of discreet geological events, whereas metric characteristics are used to determine the specific ages and lengths of geological events. Specific geological ages, which can be referred to as absolute times versus relative times, are determined conventionally by radiometric methods. Such estimates can span from the modern era into the deep geological past and are presented in descending order i. The estimates are derived from isotope data, which are converted into radiological ages.
These times are determined based on corresponding positions of ground layers, i. Organic fossil remains contained in older geological layers provide important insight into the stratigraphic scale. What relation exists between absolute and relative geological times? For example, are the data complementary or incongruent?
The goal of this work is to find the answer to this question.
To begin, let us refer to following facts, whose truths remain undisputable among many researchers: However, some of these numbers are not constants. Growth data from million year old fossil corals indicate that Earth years were days in duration in distant times, i.
This is an unusual conclusion that is difficult to accept using common sense. Let us name the value of 1. The abovementioned results complement, and thus strengthen the truth of, estimates of the absolute age of the Earth that were determined by radiometric methods.
Non-Radiometric Dating Methods
Along with this conclusion, the evolutionary Earth growth constant of 1. According to the Kant-Laplace hypothesis, Earth was formed via accretionary processes involving gases and dust masses that remained after the formation of the Sun. These processes were largely completed over a time span of 10—20 million years.
We do not share this point of view given that our research suggests that Earth has been growing gradually by 1. The Earth growth hypothesis suggested here is not new; it was first suggested at the beginning of the twentieth century.
Non-Radiometric Dating of the Age of the Earth: Implications From Fossil Coral Evidence
Since that time, this hypothesis has been actively developing and has modern supporters. However, much of this research was treated as obsolete after the development of plate tectonics theory. The evolutionary Earth growth constant found by us can serve as solid ground to revive the expanding Earth hypothesis. The greatest thinkers of our planet have been fascinated by questions about the origin and evolution of the planetary system and the Sun. Philosopher Kant and mathematician Laplace along with many astronomers and physicists of the nineteenth and twentieth centuries tackled this problem.
Although much understanding has been gained over the past two centuries, conclusive answers to questions pertaining to the origin and evolution of our solar system are still not clear. In the classical Kant-Laplace hypothesis, angular momentum is the most important characteristic of an isolated mechanical system, which our Sun and its surrounding planets are. The whole process of planetary evolution, from the initial stage of cosmic nebula to the formation of the Sun and the eight planets, was in strict accordance with angular momentum.