Introduction

The main theory opposing the traditional views on the history of mankind is that of Evolution. When, in 1859 Charles Darwin published his book «On the origin of species by means of natural selection, or the preservation of favored races in the struggle for life» (The species is usually defined as the largest group of organisms where two hybrids are capable of reproducing fertile offspring, typically using sexual reproduction) and, in 1871, «The Descent of Man and Selection in Relation of Sex» he met an immediate success. The idea that all living beings, including man, descended from a unique source, through an evolutionary process that favors the natural selection of the best adapted has since then been received as a sort of dogma.

Darwin's ideas were based on the conceptions developed by his master and friend Lyell in the field of geology and on his own interpretation of the differentiations that he could observe between various families of birds during his famous five-year cruise aboard the Beagle between 1831 and 1836. Later on they received the support of scientists from other disciplines such as archeology, biology and astrophysics. Geology and cosmogony now postulate an age of 14 million years for the Universe, of some 4.6 billion year for the Solar system including the Earth; human fossils are reported to have an age of more than 50 000 years and are considered to be part of an evolution chain that links them to the most primitive cells at one end and to modern man at the other. In addition archeology and historical research refuse to see any correlation between the events related in the historical books of the Bible (in particular in the Pentateuch and in the Book of Joshuah) and the historic realities of ancient Egypt and Mesopotamia. The theory of evolution thus regroups today (if considered in its widest extension) a number of results of observation and hypotheses pertaining to not only geology and biology, but also cosmology and history.

Eventually, so many studies, theses and books were devoted in universities and scientific institutions to defend and develop Darwin's views that evolution is nowadays regarded as “more than a theory” - in other words, as an accurate description of nature.

In spite of the general opinion however, Evolution (in its widest extension) is and remains a hypothetical intellectual construction and, more than that, a construction that has been proven devoid of scientific value in many of its aspects, to the point that, in 1960, French biologist Jean Rostand could describe it as “a fairy tale for adults” of which one should get rid as soon as possible (“Vraiment,il serait temps de renoncer à toute illusion Lamarkienne et d'en finir, une fois pour toutes, avec ce conte de fée pour grandes personnes” Jean Rostand, L'Evolution, Delp. 1960).

In what follows, one will focus on demonstrating the scientific weakness of the supposed scientific justifications of Evolution, taking into account the most recent hypotheses developed in fields such as biology, cosmology, archeology and the dating techniques.

The word “Science” is indissociable from the word “hypothesis”. The aim of science is to present the object that it is interested in as a coherent set. The purpose is to achieve a synthetic view of what has been observed. In 1954, Einstein is reported to have said that the supreme task of the physicist is to establish universal elementary laws from which the whole cosmos can be reconstructed “by pure deduction”. This is going very far. The truth is that the universal elementary laws are not given immediately by observation. They have an hypothetical character and are valid only in the measure that they enable to justify, so to speak, the observed facts.

Besides, the term “Science” applies to three different groups of disciplines:

- that of the experimental sciences, for which hypotheses can be validated or falsified (- i.e. to be proved false, to use the vocabulary of Karl Popper) almost without delay in the laboratory (after a series of manipulations that often are far from being simple);

- those sciences are based upon the observation of phenomena that are not reproducible in the laboratory (this the case of astronomy);

- those sciences that study the past : history, paleontology, historical cosmology etc. , where direct observation is not possible and one has to base one's reasoning upon witnesses of the past : books, memoirs, epigraphy, pottery, fossils, rocks, sedimentary layers etc.

Last but not least, the development of science is a collective endeavor. The number of scientists contributing to the accumulation of knowledge can be very important. It is also a long-term endeavor – taking decades or centuries of observation and reflection – that often takes place in a context of exacerbate and sometimes ferocious competition. Suffice it to mention that Boltzman,, the genial inventor of the Boltzman constant, the author of the definition of entropy, was the target of so many mockeries from the part of his university colleagues that he finished by committing suicide...

Numerous scientists have devoted their best years to exploring nature and trying to explain its mechanisms. It is after years of intense work that they have proposed the hypothetical syntheses to which their name is attached. One does not have the pretension here to reject purely and simply those syntheses that would result in casting doubt on the traditional views of the origin of mankind. The aim pursued is purely to show that such syntheses are not the sole possible. It is also to draw the attention onto the history of the development of such syntheses and the hesitations, the errors and the conflicts that have marked this history. Scientists generally have little historical sense, so that each single generation knows little of the struggles and inner difficulties of the former generation but it is essential to take into account such struggles and difficulties in order to avoid repeating again and again the same mistakes.

The book is divided into three chapters, with a conclusion and a final remark:

• Chapter 1 gives the main scientific hypotheses of the Evolution theory (in its widest acception, i.e. with the biological, cosmological and historical arguments supporting it),

• Chapter 2 gives the counter-arguments contradicting the Evolution theory,

• Chapter 3 proposes a reconstruction of the traditional view of the beginnings of mankind,

• A General Conclusion insist that true science is the most efficient manner to fight the evolutionist propaganda.

it is followed by a reflexion addressed to the Catholic public, titled:

• Final Remark: Cowardice of the Christian exegete's and the Catholic hierarchy faced with the objections to the veracity of the Bible

Chapter 1. The main scientific hypotheses of the Evolution theory (in its widest acception)

The age of the Universe and the Big Bang theory

Tradition (i.e. the tradition based on the Bible) places the origin of mankind between approximately year 4000 (Massoretic – i.e. Hebraic version of the Bible) and year 5500 BC (Greek version of the Bible : the “Septuagint”). Saint Luke, in his genealogy (Luke 3:23-38) numbers 75 generations, which, if one counts half a century per generation, amounts to approximately 4000 years between Jesus and Adam. This was admitted till the Xviii-th century, even if Ronsard, in 1555 wrote in his Hymn to Heaven: “Seeing how beautiful you are, I could not think that four or five thousand years were sufficient to start you.("Bref, te voyant si beau, je ne saurais penser / Que quatre ou cinq mille ans te puissent commencer." Ronsard, Hymne du ciel).

The Bible provides an unbroken male lineage from Adam through to Solomon complete with the ages of the individuals involved. In his Annals of the Ancient Testament, published in 1650, James Ussher, Archbishop of Armagh and Primate of Ireland using these data as well as many others provided by other sources, came to the conclusion that Adam had been created in year 4004 BC. The full title of Ussher's work is “Annales Veteris Testamenti, a prima mundi origine deducti, una cum rerum Asiaticarum et Aegyptiacarum chronico, a temporis historici principio usque ad Maccabaicorum initia producto - Annals of the Old Testament, deduced from the first origins of the world, the chronicle of Asiatic and Egyptian matters together produced from the beginning of historical time up to the beginnings of Maccabees"). Ussher's proposed date of 4004 BC differed little from other biblically based estimates, such as those of Jose ben Halafta (3761 BC), Bede (3952 BC), Ussher's near-contemporary Scaliger (3949 BC), Johannes Kepler (3992 BC) or Sir Isaac Newton (c. 4000 BC). As a matter of fact, Ussher's chronology pretends to an exaggerated exactitude that is a little bit ridiculous, placing the creation of Adam on October 23rd 4004, the expulsion of Adam and Eve from the Garden on November 19th of the same year, the grounding of Noah's ark on Mount Ararat on May 5th, 1491 BC etc. These figures were incorporated in most versions of the Bible published from year 1701 on.

As just said, not all of the versions of the Bible provide the same ages - the Septuagint gives much longer ages, adding about 1500 years to the date of Creation. Ussher relied on the Hebrew Bible. He established an unadjusted Creation date of about 4000 BC. He moved it back to 4004 BC to take account of an error supposedly perpetrated by Dionysius Exiguus, the learned monk who was the founder of the “Anno Domini” numbering system (the system we still use today). Ussher chose 5 BC as Christ's birth year because the Hebrew historian Josephus (36-100 AD) apparently indicated that the death of Herod the Great occurred in 4 BC (Josephus' chronologies are however confused). Jesus could not, if this date is true, have been born after that date.

In the Xviii-th century, Benoît de Maillet and Buffon were the first to seriously question this chronology. Benoît de Maillet estimated (in his « Telliamed ») that the Earth was several million years old (based on the assumption of the sea level continually falling). Having meticulously observed nature and meditated about the origins of animal life, he was moreover led to adopt a conception admitting the transformation of species, and even a theory of evolution that anticipated on modern ideas. Buffon on his side, claimed having found experimental arguments favoring the thesis of an old Earth by measuring the time taken by heated cannon balls to cool down. He inferred that the age of our terrestrial globe amounted to 74 832 years.

The Xix-th century witnessed the progressive increase, in the minds of the scientists, of the age of the Earth and, more generally, of the solar system, due to reasoning based on thermodynamics associated with astronomical, geological and paleontological discoveries.

Today the « Big Bang » model proposes a certain age for the Universe, or, more precisely, a certain duration of the cosmic expansion. The true denomination of the Big Bang theory is : “theory of the expanding universe” (English astronomer Fred Hoyle is credited with coining the term "Big Bang" during a 1949 BBC radio broadcast. It is popularly reported that Hoyle intended this to be pejorative, but he explicitly denied it). The age of the Universe is defined as the time spent since an epoch called “the Planck epoch”, after which the universe can be described by known physical laws until today (the earliest phases of the Big Bang are subject to much speculation). This time span was evaluated by using the “expansion rate” of the universe, i.e. the speed with which distant galaxies are receding away one from the other. Since this expansion rate is known only approximatively, the age of the Universe is considered to be 15 billion years +/- 10%.

At the origin, one has the publication, by Albert Einstein, in 1915, of the theory of general relativity, then, in 1917, of his vision of the universe. Einstein used to describe the cosmos by a complex mathematical equation in which our universe appeared as finite, closed and static (“a finite island in the infinite ocean of space”). This vision had two drawbacks: the first , persuading the general public that the universe could now only be understood by mathematical geniuses of the Einstein type, capable of reasoning not only in three but in four dimensions (the fourth being the time); the second, the instability of Einstein's equation: it corresponded to a model that either progressively collapsed onto itself because of gravity or on the contrary grew without any limitation. To make his model stable, Einstein introduced in his equation a constant that, he admitted it himself, was fully arbitrary and that he called “cosmological constant”.

Russian mathematician Alexander Friedmann demonstrated however that this constant was not necessary, provided one adopted the hypothesis of an expanding universe. In 1927 a Belgian priest, Georges Lemaître formally proposed the hypothesis of cosmic expansion.

Then, in 1929, American astronomer Edwin Hubble observed that distant galaxies are drifting apart with an apparent velocity proportional to their distance: that is, the further they are, the faster they move away from us, regardless of direction. The parameter that he used to evaluate the velocity of this drifting was the so-called galactic “red shift”. We are familiar with the change in the apparent pitches of sirens emitted by speeding vehicles. Such changes are due to the Doppler effect. The frequency of the sound waves decreases when the source of the sound is speeding away. In the same manner, when an object emitting an electromagnetic radiation is moving away, the frequency of the radiation is decreasing, and thus its wavelength is increased , which means: shifted to the red end of the spectrum. Hubble observed that the further distant galaxies were, the higher was the redshift affecting their radiation. His conclusion was that the farther the galaxies were, the faster they moved away from us. On this basis, he calculated that the universe was some 2 to 3 billion years old. The final result of his researches were presented to the Royal Society (London) in 1929.

Everything was thus in place for enabling Lemaître to present his final version of “the expansion of the universe from a primitive atom of null dimension”. He did that in the 1931 meeting of the British Association on the Evolution of the Universe .

As a matter of fact, physics cannot describe a “primitive soup” of volume zero. The minimum that can be described by quantum physics is a universe having a diameter of 10-33 cm. When such a diameter would have been reached, the universe would have an age of 10-43 seconds and would be ready to continue its expansion following known laws of physics. Modern measurements place this moment at approximately 13.8 billion years ago, which is thus considered the age of the universe. Einstein, after some hesitation, finally adhered to the Big Bang theory, considering that his introduction of the cosmological constant in his equation had been a mistake.

The origin and age of the solar system. The Uniformitarianist hypothesis

The age of the Earth, and, more generally, of the solar system, it is estimated at approximately 4.6 billion years. One could imagine that, to evaluate the age of the earth, it would be sufficient to date the oldest rocks. It is not that simple. Observation, in particular from satellites, shows that the earth surface is continuously in the way of reshaping itself, by means of earthquakes, small or violent, so that there is practically no piece of rock that has not been subjected, more or less recently, to a process of fusion, erosion or transformation of some sort. Since the oldest rocks measured have an age of 4 billion years, it is self-evident that the Earth is at least as old. Another indication of the great age of the Earth is the fact that no radioactive isotope with a life inferior to one billion year can be found in nature. However it was possible to be more precise, thanks to the meteorites falling upon the earth surface. Most of them have the same age : 4.56 billion years. Meteorites are parts of asteroids. Based on the hypothesis that all components of the solar system have the same age, the age of the Earth is thus supposed to be also 4.6 years.

The most popular theory at present assumes that the solar system was born from the accretion of a nebula, and has remained stable in its present configuration since the beginnings until now.

The original Nebular Hypothesis was proposed by Emanuel Swedenborg (1688-1772) in 1734 in his « Prodromus Philosophiae Ratiocinantis de Infinito de Causa Finali Creationis », seven years after Newton's death (1727). Swedenborg originally was an engineer. It is thought that it was Halley (1656-1742), who gave him the first idea of the Nebular Hypothesis. Swedenborg imagined that the Sun could be a source of planetary materials. In space those materials would be distributed, would cool and condense. The mechanism for the Sun to throw out solar material to form such materials was, in Swedenborg's views, the Sun's rotation. Swedenborg's ideas spread to academic institutions and were adopted notably by Emmanuel Kant (1724-1804). Kant studied theology and the classics, but his first two loves were physical geography and mathematics. At the University of Koenigsberg, he became a semi-militant liberal, rejecting the Old Testament as bad history. He liked Swedenborg's gradualist, mechanistic approach to Solar System origin, including the mechanism of centrifugal force. In the year 1755 he published his ideas on cosmology under the title of “General History of Nature and Theory of the Heavens”. He came to the conclusion that the Long Day of Joshua was an impossibility and Noah's Flood was nonsense and that the Earth's experience had been one of stability for billions of years.

Pierre Simon Laplace (1749-1827), at the age of 24, presented a paper to the Academy of Sciences in Paris on the invariability of the planetary mean motions. He was attracted to Kant's theory of the origin of the Solar System. In 1794, he was working to develop Kant's theory in a mathematical sense. This gave his famous "Exposition du Systeme du Monde" in 1796, at the height of the French Revolution. There he proposed essentially the same theory - surprisingly, without the mathematical formulation he was capable of providing. For the next hundred years, Laplace's endorsement of Kant's hypothesis carried the aura of authenticity.

In 1881, George Darwin (1845-1912), son of Charles Darwin, proposed "The Evolutionary Tidal Theory". There he proposed that a passing star, on a near collision course with the Sun, pulled out much gaseous material from the Sun. Then, that passing star disappeared into deep space. He maintained that the Sun was the source of the materials which cooled, condensed and accreted into planets.

In 1902, Chamberlin (1843-1928) and Moulton (1872-1952) proposed their "Planetesimal Hypothesis". They revised George Darwin's idea, suggesting that an intruding star passed so close as to cause violent eruptions of matter from the Sun. That matter cooled into small "chunks" which they called "planetesimals". Small and cold, the larger planetesimals collided with yet smaller chunks but they did not ricochet. They were bound, and increased in mass. Ultimately, with enough accretions, the planets were formed and grew.

In 1904, James Jeans (1877-1946) published « The Dynamical Theory of Gases » and, in 1906, « Theoretical Mechanics ». He supposed that a large star, many times more massive than the Sun, passed within several billions of miles of the Sun, pulled material out of the Sun and stretched it as far as Uranus and Neptune (the most distant planets). He viewed it as a 3-billion mile cigar-shaped filament of solar plasma. This filament was wider and thicker in the middle, where the biggest of the planets formed. Henry N. Russell (1877-1957) introduced the hypothesis of a third star that would have approached the Sun and its Visitor star.

R. A. Lyttleton, in 1938, endeavored to improve on Russell's idea by proposing that the Sun originally had a binary partner, a small companion, which was broken up by a third body, a passing star.

In l976 Hannes Alfven (1908-1995 ) proposed an even more complicated, five-stage process of Solar System accretion. In his system, the Sun is the first primary body to accrete from a source cloud once a part of the Milky Way ; next comes the emplacement of gases and dust to form a medium around magnetized central bodies in the regions where the planet and satellite groups later accreted. During the last three to four billion years, a slow evolution of the primeval planets, satellites and asteroids would have occurred, which produced the present state of the bodies of the Solar System.

Considerable work is continuously devoted to refining the hypotheses regarding the formation of the solar system. One point however remains firm in the minds of the majority of today scientists: it is that, whatever the mechanism at the origin of the solar system, this system has been in a stable condition for some 4.6 billion years.

Geology. The Uniformitarianist hypothesis

Back in the antiquity, the formation of the earth geological configuration was attributed to discontinuous processes, catastrophes, cataclysms - among which the Deluge, the memory of which can be found in the literature of many populations in addition to Israel. This is the so-called “catastrophist” approach. Aristotle for example, considered that the present configuration of the earth had been provoked by a series of violent but short duration cataclysms. In the Xvii-th century, François Placet, published a thesis following which there had been a time when America was not separated from the rest of the world and that it is due to a series of catastrophic events that the original continental bloc had been split into two parts with an ocean in the middle (François Placet: « La corruption du grand et du petit monde », 1668). In the Xix-th century, Antonio Snider-Pelligrini reformulated the same hypothesis ( Antonio Snider-Pelligrini: « La Création et ses mystères dévoilés », 1858), insisting on the instability of the primitive bloc before the Deluge, considering that this latter had put an end to this instability by cooling down the rocks, which caused the apparition of the gigantic geological trench that separated the continents.

The most influential proponent of catastrophism in geology in the early 19th century was Jean Léopold Nicolas Frédéric Cuvier (1769-1832), known as Georges Cuvier, a French naturalist and zoologist, sometimes referred to as the "Father of paleontology". Some of Cuvier's most influential followers were Louis Agassiz in Europe and in America, and Richard Owen in England.

However in the course of the Xvii-th, Xviii-th and Xix-th centuries, the theories popularized by Georges Cuvier, which were the most accepted and circulated ideas about geology in England at the time, were challenged by the new concept of uniformitarianism - the idea that the Earth was shaped by the same processes still in operation today over very long periods of time.

En 1669, Nicolas Stenon (1638-1686), a Danish scientist, a pioneer in both anatomy and geology who, born a Lutheran, became Catholic bishop in his later years, proposed in his “Dissertationis Prodromus”, the defining principles of the science of “Stratigraphy”:

• the law of superposition: "... at the time when any given stratum was being formed, all the matter resting upon it was fluid, and, therefore, at the time when the lower stratum was being formed, none of the upper strata existed";

• the principle of original horizontality: "Strata either perpendicular to the horizon or inclined to the horizon were at one time parallel to the horizon";

• the principle of lateral continuity: "Material forming any stratum were continuous over the surface of the Earth unless some other solid bodies stood in the way"; and

• the principle of cross-cutting relationships: "If a body or discontinuity cuts across a stratum, it must have formed after that stratum."

These principles were applied and extended in 1772 by Jean-Baptiste L. Romé de l'Isle and still form the basis of stratigraphy.

Later on, James Hutton (1726-1797), a Scottish geologist, originated the principle which explains the features of the Earth's crust by means of natural processes over geologic time. He came to believe that the Earth was perpetually being formed and that the history of the Earth could be determined by understanding how processes such as erosion and sedimentation work in the present day (by infinitely repeating cycles of seabed deposition, uplifting, erosion, and submersion). His theories of geology and geologic time, also called deep time, made him one of the founders of geological uniformitarianism. He wrote in 1788 that "from what has actually been, we have data for concluding with regard to that which is to happen thereafter."

Then came Charles Lyell (1797-1875), a British lawyer, who became the foremost geologist of his day, best known as the author of “The Principles of Geology”, which popularized James Hutton's concepts of uniformitarianism. His scientific contributions included an explanation of earthquakes, the theory of gradual "backed up-building" of volcanoes, and, in stratigraphy, the division of the Tertiary period into the Pliocene, Miocene, and Eocene. He also coined the currently-used names for geological eras, Paleozoic, Mesozoic and Cenozoic. He was one of the first to believe that the world is older than 300 million years, on the basis of its geological anomalies.

“The Principles of Geology”, first published in three volumes in 1830–33, made the doctrine of uniformitarianism a dogma. Lyell saw himself as "the spiritual savior of geology, freeing the science from the “old dispensation of Moses”. "The Principles of Geology” was the most influential geological work in the middle of the 19th century.

Charles Darwin (1809-1882) was a close personal friend of Lyell, and Lyell was one of the first scientists to support “On the Origin of Species”, though he did not subscribe to all its contents. It is in his quality as geologist that Darwin took place on HMS Beagle on 27 December 1831 for a voyage during which he spent most of his time on land, investigating geology and making natural history collections, while the Beagle surveyed and charted coasts. When the Beagle came back, on 2 October 1836, Darwin was already a celebrity in scientific circles because of the publication of his geological letters and he was given the post of Secretary of the Geological Society in 1838.

Year1838 was also the year in which he found the framework of his theory of natural selection, in particular under the influence of Malthus. As he later wrote in his Autobiography:

“In October 1838 (...) I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence, which everywhere goes on, from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species. Here, then, I had at last got a theory by which to work..."

Darwin struggled for years to produce his "big book", “On the Origin of Species”. Lyell arranged to have it published in 1859. Darwin based his theory of natural selection on the supposition that very long periods were available to permit the small modifications that would lead to the generation of new species, and he recognized the influence the Lyell's Principles had exerted on his mind on that point. In the Origin of the Species, he wrote the following :

“He who can read Sir Charles Lyell's grand work on the Principles of Geology, which the future historian will recognize as having produced a revolution in natural science, yet does not admit how vast have been the past periods of time, may at once close this volume”.

In the beginning of the Xx-th century the first hypotheses concerning continental drift were proposed.

The American Frank Bursley Taylor (1860-1938) proposed to the Geological Society of America in 1908 that the continents moved on the Earth's surface, that a shallow region in the Atlantic marks where Africa and South America were once joined, and that the collisions of continents could uplift mountains. His ideas were independently discovered by Alfred Wegener in Germany three years later, in 1912. His hypothesis that the continents are slowly drifting around the Earth (Kontinentalverschiebung) was not widely accepted until the 1950s, when numerous discoveries such as palaeomagnetism provided strong support for continental drift, and thereby a substantial basis for today's model of plate tectonics. The hypothetical unique megacontinent that existed before the continental drift is called Pangaea or Pangea (from: the Greek πᾶν (« all ») and γαῖα (« earth »).

Following Snider-Pellegrini and Alfred Wegener, the locations of certain fossil plants and animals on present-day widely separated continents would form definite patterns (shown by the bands of colors), if the continents are rejoined.

Fig. Continental drift fossil evidence. (Source: Snider-Pellegrini_Wegener_fossil_map.gif . jmwatsonusgs.gov - United States Geological Survey (USGS) – http://pubs.usgs.gov/gip/dynamic/continents.html.)

The second half of the Xx th century saw the advent of Geodynamics, a subfield of geophysics dealing with dynamics of the Earth. It applies physics, chemistry and mathematics to the understanding of how mantle convection leads to plate tectonics and geologic phenomena such as seafloor spreading, mountain building, volcanoes, earthquakes, faulting and so on. It also attempts to probe the internal activity by measuring magnetic fields, gravity, and seismic waves, as well as the mineralogy of rocks and their isotopic composition.

At present, geology describes the Earth as an oblate spheroid composed of a number of different layers as determined by deep drilling and seismic evidence. These layers are:

• The core, which is approximately 7,000 kilometers in diameter and is located at the Earth's center.

• The mantle, which surrounds the core and has a thickness of 2,900 kilometers.

• The crust, which floats on top of the mantle. It is composed of the basalt rich oceanic crust and the granitic rich continental crust.

The core is a layer rich in iron and nickel that is composed of two layers: the inner and outer cores. The inner core is theorized to be solid with a density of about 13 grams per cubic centimeter and a radius of about 1,220 kilometers. The outer core is liquid and has a density of about 11 grams per cubic centimeter. It surrounds the inner core and has an average thickness of about 2,250 kilometers.

The mantle comprises about 83% of the Earth's volume. It is composed of several different layers. The upper mantle exists from the base of the crust downward to a depth of about 670 kilometers. Below the upper mantle is the lower mantle that extends from 670 to 2,900 kilometers below the Earth's surface. This layer is hot and plastic. The higher pressure in this layer causes the formation of minerals that are different from those of the upper mantle.

The top layer of the upper mantle, 100 to 200 kilometers below surface, is called the asthenosphere.

The continental crust is 20 to 70 kilometers thick and composed mainly of lighter granite. . Continental crust is thickest beneath mountain ranges and extends into the mantle. Both of these crust types are composed of numerous tectonic plates that float on top of the mantle. Convection currents within the mantle cause these plates to move slowly across the asthenosphere.

The following figures illustrate the structure of the Earth's crust and top most layer of the upper mantle. The lithosphere consists of the oceanic crust, continental crust, and uppermost mantle. Beneath the lithosphere is the asthenosphere. Sedimentary deposits are commonly found at the boundaries between the continental and oceanic crust.

Fig. Structure of the Earth (source: http://easyscienceforkids.com/all-about-earths-crust/)

 

Fig. The Earth Crust (Source: Easyscienceforkids.com)

Present scientific hypotheses consider that the temperature of the earth is due to the original heat from the primitive formation of the terrestrial globe (this heat is dissipating slowly) and the radioactive decay of different isotopes (uranium, thorium et potassium) contained in the lithosphere and in the earth core, which produces a heat flow in the direction of the surface. On average the temperature increases by 1°C every 30 m. (geothermal gradient). At the center of the earth, the temperature is approximately 5000 °C. The heat flow creates convection cells that move slowly, provoking deformations in the lithosphere in the context of plate tectonics. Due to the earth quasi-sphericity, the motions of the plates are rotations about an axis.

The present configuration of the terrestrial globe is supposed to have established itself over a time period of almost 250 million years (Ma):

• The dislocation of Pangea would have occurred around the middle of the Jurassic period (205 to 135 Ma);

• The Atlantic Ocean, between Africa and America, would have appeared during the Cretaceous (135 to 65 Ma);

• Later on, Antarctica and Australia would have drifted apart and, later still, the Indian plate would have moved to the North;

• Lastly, in the beginning of the Tertiary period, the large mountainous chains would have emerged (such as the Alps) and, at the end of the period, the collision between India and Asia would have resulted in the apparition of the Himalaya.

As a consequence of these scientific hypotheses, and in particular those due to Lyell and Darwin, the Deluge disappeared from the knowledge base of the scientific community and the story of Genesis was more and more considered as pertaining to the “literary” genre, or even to be a kind of “oriental tale”, and the idea that very long periods had been necessary to shape the configuration of the earth crust became a dogma.

Dating methodologies in archeology

Methods used

Dating is the process of estimating the age of ancient materials and remains. Dating material can be made by a direct study of an artifact (direct or absolute method), or may be deduced by association with materials found in the environment the item is extracted from (relative or indirect method).

Absolute dating methods rely on using some physical property of an object or sample to calculate its age. The main ones are:

Radiometric dating (often called radioactive dating): a technique used to date materials such as rocks or carbon, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates. Examples are:

the Radiocarbon dating – used for dating relatively young organic materials;

the Potassium–argon dating - for dating very old materials or remains.

Methods based on crystallography

• Thermoluminescence dating (for dating inorganic material including ceramics);

• Optical dating (for archaeological applications);

• Spin Resonance ;

• Fission track dating (This involves inspection of a polished slice of a material to determine the density of "track" markings left in it by the spontaneous fission of uranium-238 impurities);

• etc.

Methods based on diffusion phenomena

• Obsidian hydration dating (a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian);

• Amino acid dating;

• Lead Corrosion dating;

• Rehydroxylation dating (for dating ceramic materials).

Methods based on cyclic phenomena

• Dendrochronology (for dating trees, and objects made from wood);

• Paleomagnetism: the polarity of the Earth changes at a knowable rate. This polarity is stored within rocks; through this the rock can be dated;

• Archaeomagnetic dating (clay lined fire hearths take on a magnetic moment pointing to the North Pole each time they are fired and then cool. The position of the North Pole for the last time the fire hearth was used can be determined and compared to charts of known locations and dates);

• etc.

Relative or indirect methods tend to use associations built from the archaeological body of knowledge. The most used indirect method is the stratigraphic method, described in the next paragraph.

The Stratigraphic Method

Stratigraphy is the discipline concerned with the description of rock successions and their interpretation in terms of a general time scale that provides a basis for historical geology. Its principles and methods find their origin in the works of Stenon, Hutton and Lyell.

Stratigraphic studies deal primarily with sedimentary rocks but may also encompass layered igneous rocks (e.g., those resulting from successive lava flows) or metamorphic rocks formed either from such extrusive igneous material or from sedimentary rocks.

Most sedimentary rocks have originated in the oceans: they have been formed at the bottom of the sea, at various depths, rarely below 100 m. They have (in theory) the form of a superposition of layers, or strata, parallel one with the other. The sedimentary rocks of continental origin have been formed either underwater, at the bottom of lakes, or in rivers (by alluvions) or on the surface of the ground: sands and silt carried by the wind, glacial grinding etc. (in semi-arid environments, substantial quantities of silt are produced in such ways).

Based on the hypothesis of uniformitarianism, the whole of the geological layers, back to the formation of the Earth to the present period have been grouped into the Chronostratigraphic Chart.

The man credited as the "father of stratigraphy" was the English engineer and geologist William Smith (1769-1839). In 1815 Smith produced the first modern geologic map, showing rock strata in England and Wales. Smith's achievement influenced all of geology to the present day by introducing the idea of geologic, as opposed to geographic, mapping.

When geologists first embarked on stratigraphic studies, the only means of dating available to them were relative. Using Stenon's law of superposition, they reasoned that a deeper layer of sedimentary rock was necessarily older than a shallower layer. The stratigraphic column is the succession of rock strata laid down over the course of time, each of which supposedly correlates to specific phases in Earth's geologic history.

During the eighteenth century, scientific literature devoted to the earth sciences documented a significant increase in the study of the composition and formation of mountains and above all their stratigraphical sequence. The law of superimposition of strata was followed by most of the late eighteenth-century scholars in earth sciences, who developed subdivisions of mountains from the point of view of their formation and also included a classification of the rocks. These subdivisions supported the idea of relative chronology of the formation sequence of the studied strata: the most recent or the most ancient formation could be deduced from its position in the sequence as well as from its external lithological features.

In the second half of the eighteenth century, the work of Giovanni Arduino (1714 – 1795) contributed decisively to the development of basic lithostratigraphic classification of rocks and mountain building. His classification used four basic units called “ordini”, based only on lithology and included different rock types, which formed three kinds of mountains and one kind of plain, in a regular chronological order. Arduino's system is still regarded by the geological world as being one of the starting points for modern stratigraphy. His classification was completed by Lyell, who added a chronological reference that he considered essential : the paleontological indicators(i.e. organisms present in the various layers, the date of which is supposed to be known).

Nowadays geologic time is divided into named groupings according to six basic units, which are (in order of size from longest to shortest) eon, era, period, epoch, age, and chronology; chronostratigraphy also uses six time units: the eonothem, erathem, system, series, stage, and chronozone. The more distant in time a particular unit is, the more controversy exists regarding its boundary with preceding and successive units.

The International Union of Geological Sciences, the leading worldwide body of geologic scientists, has established an Internal Commission on Stratigraphy (ICS) to determine such boundaries. The commission selects and defines what are called Global Stratotype Sections and Points (GSSPs) (Lyell's paleontological indicators), which are typically marine fossil formations, because it is believed that life has existed longest on Earth in its oceans, and that, as a consequence, samples from the water provide the most reliable stratigraphic record.

ICS publishes the International Chronostratigraphic Chart that is the basis for the units of the International Geologic Time Scale; thus setting global standards for the fundamental scale for expressing the history of the Earth. Archaeologists investigating a site usually date the artifacts their discoveries by their position in the sequence of datable geological layers. The International Chronostratigraphic Chart is the basic instrument to achieve this.

 

Using this charts thus enables (in principle) to situate the various events that have occurred since the origin by identifying the geological layer in which they have left traces. For example the date of formation of a context totally sealed between two datable layers can, in principle, be dated with some confidence using the Chronostratigraphic Chart : it with will fall between the dates of the two layers sealing it. If the object to be dated is a fossil, the stratigraphic dating will focus on the geological layers in which the fossil is contained. This will give an approximate age. To go further, typical stratigraphic indicators are used, such as fossil vertebrates the age of extinction of which is known : these are “stratigraphic markers” Such markers facilitate the correlation of strata, and used in conjunction with fossil floral and faunal assemblages and paleomagnetism, permit dating with more accuracy.

The stratigraphic dating method is thus a relative or indirect method. It is widely used because it is rapid and relatively cheap (The dating methods based on the principle of uniformitarianism are often called, since Lyell, “actualist” - from the term actual, i.e. real).

We are living in the fourth of four eons, or eonothems, the Phanerozoic, which is divided into three eras, or erathems: Paleozoic, Mesozoic, and Cenozoic. These eras, in turn, are divided into 11 periods, or systems, whose names (except for Tertiary and Quaternary) refer to the locations in which the respective stratigraphic systems were first observed. The names of these systems, along with their dates in millions of years before the present and the origin of their names, are as follows (from the most distant to the most recent):

Periods/Systems of the Paleozoic Era/Erathem:

• Cambrian (about 545 to 495 Ma or Million years): Cambria, the Roman name for the province of Wales;

• Ordovician (about 495 to 443 Ma): Ordovices, the name of a Celtic tribe in ancient Wales;

• Silurian (about 443 to 417 Ma): Silures, another ancient Welsh Celtic tribe;

• Devonian (about 417 to 354 Ma): Devonshire, a county in southwest England;

• Mississippian (a subperiod of the Carboniferous period, about 354 to 323 Ma): the Mississippi River;

• Pennsylvanian (a subperiod of the Carboniferous, about 323 to 290 Ma): the state of Pennsylvania;

• Permian (about 290 to 248.2 Ma): Perm, a province in Russia.

Periods/Systems of the Mesozoic Era/Erathem :

• Triassic (about 248.2 to 205.7 Ma): a tripartite, or threefold, division of rocks in Germany;

• Jurassic (about 205.7 to 142 Ma): the Jura Mountains of Switzerland and France;

• Cretaceous (about 142 to 65 Ma): from a Latin word for "chalk," a reference to the chalky cliffs of southern England and France.

Within the more recent Cenozoic era, or erathem, names of epochs (or "series" in stratigraphic terminology) are derived from Greek words, whose meanings are given below:

Epochs/Series of the Cenozoic Era/Erathem:

• Paleocene (about 65 to 54.8 Ma): "early dawn of the recent";

• Eocene (about 54.8 to 33.7 Ma): "dawn of the recent";

• Oligocene (about 33.7 to 23.8 Ma): "slightly recent";

• Miocene (about 23.8 to 5.3 Ma): "less recent";

• Pliocene (about 5.3 to 1.8 Ma): "more recent";

• Pleistocene (about 1.8 to 0.01 Ma): "most recent";

• Holocene (about 0.01 Ma to present): "wholly recent";

The International Chronostratigraphic Chart presents itself as on the following figure.

 

Radiometric dating Methods

The principle of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of the Earth itself. Together with the stratigraphic principles, radiometric dating methods are used in geochronology to establish the geological time scale. By allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change.

Radiometric dating is also used to date archaeological materials, including ancient artifacts.

A particular isotope of a particular element is called a nuclide. Some nuclides are inherently unstable. That is, at some point in time, an atom of such a nuclide will undergo radioactive decay and spontaneously transform into a different nuclide. This transformation may be accomplished in a number of different ways, including alpha decay (emission of alpha particles) and beta decay (electron emission), positron emission, or electron capture.

While the moment in time at which a particular nucleus decays is unpredictable, a collection of atoms of a radioactive nuclide decays exponentially at a rate described by a parameter known as the half-life, usually given in units of years when discussing dating techniques. After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a "daughter" nuclide or decay product. In many cases, the daughter nuclide itself is radioactive, resulting in a decay chain, eventually ending with the formation of a stable (nonradioactive) daughter nuclide; each step in such a chain is characterized by a distinct half-life. In these cases, usually the half-life of interest in radiometric dating is the longest one in the chain, which is the rate-limiting factor in the ultimate transformation of the radioactive nuclide into its stable daughter. Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years (e.g., tritium) to over 100 billion years (e.g., Samarium-147).

For most radioactive nuclides, the half-life depends solely on nuclear properties and is essentially a constant. It is not affected by external factors such as temperature, pressure, chemical environment, or presence of a magnetic or electric field. The only exceptions are nuclides that decay by the process of electron capture, such as beryllium-7, strontium-85, and zirconium-89, whose decay rate may be affected by local electron density. For all other nuclides, the proportion of the original nuclide to its decay products changes in a predictable way as the original nuclide decays over time. For them, the half-life depends solely on nuclear properties and is essentially a constant. This predictability allows the relative abundances of related nuclides to be used as a clock to measure the time from the incorporation of the original nuclides into a material to the present.

The mathematical expression that relates radioactive decay to geologic time is:

D = D0 + N(t) (eλt − 1)

where

t is the age of the sample,

D is the number of atoms of the daughter isotope in the sample,

D0 is the number of atoms of the daughter isotope in the original composition,

N is the number of atoms of the parent isotope in the sample at time t (the present), given by N(t) = Noe-λt, and

λ is the decay constant of the parent isotope, equal to the inverse of the radioactive half-life of the parent isotope times the natural logarithm of 2.

Dating can now be performed on samples as small as a nanogram using a mass spectrometer. In the optimal conditions (initial conditions perfectly known, absence of perturbation during the decay process etc.), measurements permit dating with a great accuracy. For long ages, Uranium 238 (4.5 billion years half-life), Potassium 40 (1.26 billion years) or Uranium 235 (700 million years) can be used.

For shorter ages, the most used method is that of Carbon-14 (Radiocarbon dating method).

However, even in the best of conditions, the utilization of radiometric methods is complex and expensive, as shown below by the examples of the Potassium - Argon and the Radiocarbon dating method.

The Potassium-Argon methodology

This method is used in particular for the dating of volcanic rocks. Potassium can be found in abundance in the earth crust, and one of its isotopes, Potassium-40 disintegrates and gives two daughters in known proportions : Calcium 40 and Argon-40.

Unfortunately it is often difficult to evaluate the quantity of Calcium present at the origin, but Argon is a gas, that tends to escape when the rock is gaseous or in the state of magma. It seems therefore legitimate to assume that no Argon-40 was present at the origin, when the rock cooled down and took its present shape. However this is not certain, because some Argon could have stayed in bubbles imprisoned in the rock. Fortunately, Argon-40 disintegrates and gives Argon-36. Therefore by measuring Argon-40 and Argon-36 an accurate dating can be hoped for. But the method is not completely safe because the pressure of Argon-40 in the residual bubbles could be higher than the atmospheric pressure. To get rid of this difficulty, a complementary technique is used, for example, that of Argon-Argon. In this technique, the piece of rock is placed for a few hours in the center of a nuclear reactor. Under the effect of neutrons, a small quantity of Potassium-39 (A naturally stable isotope of Potassium, representing more than 93% of Potassium in its natural state) disintegrates, giving Argon-39, an isotope that does not exist in nature and that has a half-life of only 269 years. Then the piece of rock is placed into an oven, and the heat makes Argon-40 and Argon-39 escape. The dating is then possible by measuring the ratio Argon-40/Argon-39 and by taking into account the number of neutrons that have been active.

Obviously the method is complicated and requires well-equipped laboratories.

Radiocarbon dating

Carbon-14 is a radioactive isotope of carbon, with a half-life of 5,730 years, which is very short compared with other isotopes.

Carbon-14 is continuously created through collisions of neutrons generated by cosmic rays with nitrogen in the upper atmosphere and thus remains at a near-constant level on Earth. The carbon-14 ends up as a trace component in atmospheric carbon dioxide (CO2).

An organism acquires carbon during its lifetime. Plants acquire it through photosynthesis, and animals acquire it from the consumption of plants and other animals. When an organism dies, it ceases to take in new carbon-14, and the existing quantity of carbon-14 decays. The proportion of carbon-14 left when the remains of the organism are examined provides an indication of the time elapsed since its death. The carbon-14 dating limit lies around 58,000 to 62,000 years.

American physical chemist Willard Libby is credited to have been the first scientist to suggest that the unstable carbon isotope called radiocarbon or carbon 14 might exist in living matter and the first to measure radiocarbon’s rate of decay. He established 5568 years ± 30 years as its half-life.

Libby and his team initially tested the radiocarbon method on samples from prehistoric Egypt. They chose samples whose age could be independently determined. A sample of acacia wood from the tomb of the pharaoh Zoser (or Djoser, 3rd Dynasty, supposedly ca. 2700-2600 BC) was obtained and dated. Libby reasoned that, since the half-life of C14 was 5568 years, they should obtain a C14 concentration of about 50% that which was found in living wood. The results they obtained indicated this was the case.

Other analyses were conducted on samples of known age wood (dendrochronologically aged). Again, the fit was within the value predicted at some 10%. The tests suggested that the half-life they had measured was accurate, and suggested further that atmospheric radiocarbon concentration had remained constant throughout the recent past.

In 1949, Arnold and Libby published their paper "Age determinations by radiocarbon content: Checks with samples of known age" in the journal “Science”. In this paper they presented the first results of the C14 method, including the "Curve of Knowns" in which radiocarbon dates were compared with the known age historical dates. All of the points fitted within statistical range. Within a few years, other laboratories were built. By the early 1950's there were 8, and by the end of the decade there were more than 20. There are now more than 100 of them. In 1960, Libby was awarded the Nobel Prize in Chemistry in recognition of his efforts to develop radiocarbon dating.

However, if the rate of creation of carbon-14 appears to be roughly constant, researchers measuring the radioactivity of known age tree rings in the late 1950's and early 1960's found fluctuations in C14 concentration. Indeed, local eruptions of volcanoes or other events that give off large amounts of carbon dioxide can modify local concentrations of carbon-14 and give inaccurate dates. The releases of carbon dioxide into the biosphere as a consequence of industrialization have also depressed the proportion of carbon-14 by a few percent; conversely, the amount of carbon-14 was increased by above-ground nuclear bomb tests that were conducted into the early 1960s. Also, an increase in the solar wind or the Earth's magnetic field above the current value would depress the amount of carbon-14 created in the atmosphere. These temporal fluctuations in C14 concentration necessitate the calibration of radiocarbon dates to other historically aged material. Radiocarbon dates of sequential dendrochronologically aged trees primarily of US bristlecone pine and German and Irish oak have been measured over the past 10 years to produce a calendrical / radiocarbon calibration curve which now extends back over 10 000 years. This enables radiocarbon dates to be calibrated to solar or calendar dates.

There are three principal techniques used to measure carbon 14 content of any given sample: gas proportional counting, liquid scintillation counting, and accelerator mass spectrometry.

Gas proportional counting counts the beta particles that are products of radiocarbon decay emitted by a given sample. In this method, the carbon sample is first converted to carbon dioxide gas before measurement in gas proportional counters takes place.

Liquid scintillation counting is the radiocarbon dating technique that was popular in the 1960s. In this method, the sample is in liquid form and a scintillator is added. This scintillator produces a flash of light when it interacts with a beta particle. A vial with a sample is passed between two photomultipliers, and when both devices register the flash of light that a count is made.

Accelerator mass spectrometry (AMS) is the method that is considered to be the more efficient way to measure radiocarbon content of a sample. In this method, the carbon 14 content is directly measured relative to the carbon 12 and carbon 13 present. The method does not count beta particles but the number of carbon atoms present in the sample and the proportion of the isotopes.

The radiocarbon age of a certain sample of unknown age is then determined by comparing the result of the measure of the Carbon 14 content to the carbon 14 activity in modern and background samples.

Radiocarbon activity of materials in the background is also determined to remove its contribution from results obtained during a sample analysis. Background radiocarbon activity is measured, and the values obtained are deducted from the sample’s radiocarbon dating results. Background samples analyzed are usually geological in origin of infinite age such as coal, lignite, and limestone.

The principal modern standard used by radiocarbon dating labs was the Oxalic Acid I obtained from the National Institute of Standards and Technology in Maryland. This oxalic acid came from sugar beets in 1955. Around 95% of the radiocarbon activity of Oxalic Acid I is equal to the measured radiocarbon activity of the absolute radiocarbon standard - a wood in 1890 unaffected by fossil fuel effects.

When the stocks of Oxalic Acid I were almost fully consumed, another standard was made from a crop of 1977 French beet molasses. The new standard, Oxalic Acid II, was proven to have only a slight difference with Oxalic Acid I in terms of radiocarbon content. Over the years, other secondary radiocarbon standards have been made.

A radiocarbon measurement is termed a conventional radiocarbon age (CRA). The CRA conventions include (a) usage of the Libby half-life (in 1961, computations based on particles physics have given for the half life of C 14 the figure of 5734 ± 40 years . However the dating methods continue to use, by convention, the 1951 evaluation, which is 5568 ± 30 years), (b) usage of Oxalic Acid I or II or any appropriate secondary standard as the modern radiocarbon standard, (c) correction for sample isotopic fractionation to a normalized or base value of -25.0 per mille relative to the ratio of carbon 12/carbon 13 in the carbonate standard i.e. a Cretaceous belemnite formation at Peedee in South Carolina, (d) zero BP (Before Present) is defined as AD 1950, and (e) the assumption that global radiocarbon levels are constant.

Standard errors are also reported in a radiocarbon dating result, hence the “±” values. These values have been derived through statistical means.

Other dating methods

Today's archaeologists have a wide variety of dating methodologies available. In addition to

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Verlag: BookRix GmbH & Co. KG

Bildmaterialien: Cover image: Judith Beheading Holofernes, by Caravaggio, 1598-99
Tag der Veröffentlichung: 30.03.2016
ISBN: 978-3-7396-4604-6

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