History of geology 1

History of geologyThe history of geology is concerned with the development of the natural science of geology. Geology is thescientific study of the origin, history, and structure of the Earth.[1] Throughout the ages geology provides essentialtheories and data that shape how society conceptualizes the Earth.

Antiquity

A mosquito and a fly in this Baltic amber necklace arebetween 40 and 60 million years old

The slightly misshapen octahedral shapeof this rough diamond crystal in matrix istypical of the mineral. Its lustrous facesalso indicate that this crystal is from a

primary deposit.

Some of the first geological thoughts were about the origin of theEarth. Ancient Greece developed some primary geologicalconcepts concerning the origin of the Earth. Additionally, in the4th century BC Aristotle made critical observations of the slowrate of geological change. He observed the composition of the landand formulated a theory where the Earth changes at a slow rateand that these changes cannot be observed during one person’slifetime. Aristotle developed one of the first evidentially basedconcepts connected to the geological realm regarding the rate atwhich the Earth physically changes.[2]

However, it was his successor at the Lyceum, the philosopherTheophrastus, who made the greatest progress in antiquity in hiswork On Stones. He described many minerals and ores both fromlocal mines such as those at Laurium near Athens, and furtherafield. He also quite naturally discussed types of marble andbuilding materials like limestones, and attempted a primitiveclassification of the properties of minerals by their properties suchas hardness.

Much later in the Roman period, Pliny the Elder produced a veryextensive discussion of many more minerals and metals thenwidely used for practical ends. He was among the first to correctlyidentify the origin of amber as a fossilized resin from trees by theobservation of insects trapped within some pieces. He also laid the basis of crystallography by recognising theoctahedral habit of diamond.

Middle Ages

Abu al-Rayhan al-Biruni (973-1048 AD) was one of the earliest Muslim geologists, whose works included theearliest writings on the geology of India, hypothesizing that the Indian subcontinent was once a sea:[3]

Ibn Sina (Avicenna, 981-1037), a Persian polymath, made significant contributions to geology and the natural sciences (which he called Attabieyat) along with other natural philosophers such as Ikhwan AI-Safa and many others. Ibn Sina wrote an encyclopaedic work entitled “Kitab al-Shifa” (the Book of Cure, Healing or Remedy from ignorance), in which Part 2, Section 5, contains his commentary on Aristotle's Mineralogy and Meteorology, in six chapters: Formation of mountains, The advantages of mountains in the formation of clouds; Sources of water; Origin of earthquakes; Formation of minerals; The diversity of earth’s terrain. In medieval China, one of the most intriguing naturalists was Shen Kuo (1031-1095), a polymath personality who dabbled in many fields of study in his age. In terms of geology, Shen Kuo is one of the first naturalists to have formulated a theory of geomorphology. This was based on his observations of sedimentary uplift, soil erosion, deposition of silt, and marine fossils found in the

History of geology 2

Taihang Mountains, located hundreds of miles from the Pacific Ocean. He also formulated a theory of gradualclimate change, after his observation of ancient petrified bamboos found in a preserved state underground nearYanzhou (modern Yan'an), in the dry northern climate of Shaanxi province. He formulated a hypothesis for theprocess of land formation: based on his observation of fossil shells in a geological stratum in a mountain hundreds ofmiles from the ocean, he inferred that the land was formed by erosion of the mountains and by deposition of silt.

Industrial RevolutionDuring the 17th century the heated debate between religion and science over the Earth’s origin further propelledinterest in the Earth and brought about more systematic identification techniques of the Earth’s strata.[4] The Earth’sstrata can be defined as horizontal layers of rock having approximately the same composition throughout.[5]

Bust of William Smith, in the OxfordUniversity Museum of Natural History.

The popular mining industry during the 18th century both increased socialinterest and drove scientists to form more systematic and detailed studies ofthe composition of the Earth’s strata. From the increased societal interest ofgeology, in 1741 it became a specific field of study to be taught at theNational Museum of Natural History in France.[6] The controversial topic ofthe Earth’s origin continued to circulate between religious and scientificcircles. Two feuding theories developed to explain the Earth’s origin withdesignated followers: the Neptunists whose theory supported that of theBible’s Great Flood and the Plutonists who believed the Earth graduallyformed over an immeasurable amount of time.[7]

The dialogue about the creation of the Earth occurring within the scientificcommunity and the evidence being uncovered in Civil Engineering worksduring the 19th century drove the development of the stratigraphical column;many of the concepts behind this invention can be attributed to WilliamSmith, Georges Cuvier and Alexander Broignart.[8] Also in this period,imperialism motivated countries to sponsor voyages of exploration to distantlands. Charles Darwin made geological observations on such a voyage,providing evidential support of his revolutionary theory of evolution.[9] Again a religious debate ensued; twoconflicting groups, uniformitarians and catastrophists, argued over the age of the Earth.[10] Charles Lyell, aninfluential uniformitarian, published his book in 1830 the “Principles of Geology” which proposed that the Earthchanges very gradually and is immeasurably old.[11]

The theory of Continental Drift was proposed in 1912 by Alfred Wegener.[12] This idea, unaccepted at the time,suggested a method of continental movement that occurred throughout history.[13] Supporting evidence ofContinental Drift, including seafloor spreading and paleomagnetism, justified the theory of Continental Drift, whichin the late 1960s was replaced and encompassed by Plate Tectonics.[14] In the latter half of the 20th century theapproach to the study of geology changed to evaluating the Earth in a broader perspective.[15] To coincide with thisperspective, satellites were first used in the 1970s and are still currently in use by the Landsat Program to produceimages of the Earth that can be geologically studied.[16]

History of geology 3

17th century

A portrait of Whiston with a diagram demonstrating his theories ofcometary catastrophism best described in A New Theory of the Earth

It was not until the 17th century that geology madegreat strides in its development. At this time, geologybecame its own entity in the world of natural science. Itwas discovered by the Christian world that differenttranslations of the Bible contained different versions ofthe biblical text. The one entity that remainedconsistent through all of the interpretations was that theDeluge had formed the world’s geology andgeography.[17] To prove the Bible’s authenticity,individuals felt the need to demonstrate with scientificevidence that the Great Flood had in fact occurred.With this enhanced desire for data came an increase inobservations of the Earth’s composition, which in turnled to the discovery of fossils. Although theories thatresulted from the heightened interest in the Earth’scomposition were often manipulated to support theconcept of the Deluge, a genuine outcome was a greaterinterest in the makeup of the Earth. Due to the strengthof Christian beliefs during the 17th century, the theoryof the origin of the Earth that was most widely acceptedwas A New Theory of the Earth published in 1696, by

William Whiston.[4] Whiston used Christian reasoning to “prove” that the Great Flood had occurred and that theflood had formed the rock strata of the Earth.

18th centuryFrom this increased interest in the nature of the Earth and its origin, came a rise in the interest of minerals and othercomponents of the Earth’s crust. Moreover, the increasing commercial importance of mining in Europe during themid to late 18th century made the possession of accurate knowledge about ores and their natural distributionessential.[18] Scholars began to study the makeup of the Earth in a systematic manner, with detailed comparisons anddescriptions not only of the land itself, but of the semi-precious metals that had such great value. For example, in1774 Abraham Gottlob Werner published the book “Von den äusserlichen Kennzeichen der Fossilien” (On theExternal Characters of Minerals), which brought him widespread recognition because he presented a detailed systemfor identifying specific minerals based on external characteristics.[19] The more efficiently that productive land formining could be found and that the semi-precious metals could be identified, the more money that could be made.This drive for economic success fueled geology into the limelight and made it a popular subject to pursue. With anincreased number of people studying it, came more detailed observations and more information about the Earth.During the eighteenth century, the story of the history of the Earth; namely the religious concept versus factual evidence once again became a popular discussion in society. In 1749 the French naturalist Georges-Louis Leclerc, Comte de Buffon published his Histoire Naturelle in which he attacked the popular Christian concepts of Whiston and other Christian theorists on the topic of the history of Earth.[20] From experimentation with cooling globes, he found that the age of the Earth was not only 4,000 or 5,500 years as inferred from the Bible, but rather 75,000 years.[21] Another individual who attributed the history of the Earth to neither God nor the Bible was the philosopher Immanuel Kant who published this concept in 1755 in his “Allgemeine Naturgeschichte und Theories des Himmels.”[22] From the works of these educated men, as well as others, it became acceptable by the mid eighteenth

History of geology 4

century to question the age of the Earth. This questioning represented a turning point in the study of the Earth. It wasnow possible to study the history of the Earth from a scientific perspective rather than a religious one.With science as a driving force behind the investigation of the Earth's history, the study of geology could nowbecome a distinct field of science. First, the terminology and definition of what geological study consisted of had tobe determined. The term geology was first used professionally in publications by two Genevian naturalists,Jean-André Deluc and Horace-Bénédict de Saussure.[23] Geology was not well received as a term until it was used inthe very popular encyclopedia, the Encyclopédie, published in 1751 by Denis Diderot.[24] Once the term was coinedas the study of the Earth and its history, geology slowly became a more prevalent and recognized science of its ownstanding that could be taught as a field of study at educational institutions. In 1741 the most well-known institutionin the field of natural history, the National Museum of Natural History in France designated the first teachingposition specifically for geology.[25] This was an important step in the further development of geology as a scienceand in the recognition of the importance of widely distributing this knowledge.After the designation of geology as a specific field of study in an institution, this subject flourished in educatedsociety. By the 1770s two feuding theories with designated followers were established. These contrasting theoriesexplained how the rock layers of the Earth’s surface had formed. The German geologist, Abraham Werner proposedthe theory that the Earth’s layers, including basalt and granite, had formed as a precipitate from an ocean that coveredthe entire Earth, referring to the Deluge. Werner’s system was influential and those that believed his theory wereknown as Neptunists.[26] The Scottish naturalist, James Hutton, argued against the theory of Neptunism. Huttonproposed the theory of Plutonism; the Earth formed through the gradual solidification of a molten mass at a slow rateby the same processes that occurred throughout history and continues in present day. This led him to the conclusionthat the Earth was immeasurably old and could not possibly fit within the limits of the inferences from the Bible.Plutonists believed that volcanic processes were the chief agent in rock formation, not water from a Great Flood.[27]

19th century

Engraving from William Smith's 1815monograph on identifying strata by fossils

The Neptunists and Plutonists supplied necessary data to help completethe stratigraphical column in the early 19th century. The stratigraphicalcolumn can be defined as “the sequence of rock formations arrangedaccording to their order of formation in time.”[28] William Smith,Georges Cuvier and Alexander Broignart can all be recognized fortheir roles during this century in furthering the concept of fossil-basedstratigraphy. The English mineral surveyor William Smith foundempirically that fossils were a highly effective means of distinguishingbetween otherwise similar formations of the landscape. At about thesame time, the French comparative anatomist Georges Cuvier realizedthat the relative ages of fossils could be determined from a geologicalstandpoint; in terms of what layer of rock the fossils are located and the distance these layers of rock are from thesurface of the Earth. Cuvier’s mineralogist colleague Alexandre Brogniart augmented Cuvier’s practices. Through thesynthesis of these findings, Brogniart and Cuvier realized that different strata could be identified by fossil contentsand thus each stratum could be assigned to a unique position in a sequence.[8] After the publication of Cuvier andBroignart’s book, “Description Geologiques des Environs de Paris” in 1811, which outlined the concept ofstratigraphy, came a great interest in this new method.[29] Stratigraphy became very popular amongst geologists;many hoped to apply this concept to all the rocks of the Earth. During this century various geologists further refinedthe stratigraphical column to completion. For instance, in 1833 while Adam Sedgwick was mapping rocks that hehad established were from the Cambrian Period, Charles Lyell was elsewhere suggesting a subdivision of the

History of geology 5

Tertiary Period;[30] whilst Roderick Murchison, mapping into Wales from a different direction, was assigning theupper parts of Sedgewick's Cambrian to the lower parts of his own Silurian Period.[31] The stratigraphical columnwas significant because it now supplied a method to assign a relative age of these rocks by slotting them intodifferent positions in their stratigraphical sequence. This created a global approach to dating the age of the Earth andallowed for further correlations to be drawn from similarities found in the makeup of the Earth’s crust in variouscountries.

Geological map of Great Britain by WilliamSmith, published 1815.

In early nineteenth-century Britain, catastrophism was adapted with theaim of reconciling geological science with religious traditions of thebiblical Great Flood. In the early 1820s English geologists includingWilliam Buckland and Adam Sedgwick interpreted "diluvial" depositsas the outcome of Noah's flood, but by the end of the decade theyrevised their opinions in favour of local inundations.[10] [32] CharlesLyell challenged catastrophism with the publication in 1830 of the firstvolume of his book Principles of Geology which presented a variety ofgeological evidence from England, France, Italy and Spain to proveHutton’s ideas of gradualism correct.[8] He argued that most geologicalchange had been very gradual in human history. Lyell providedevidence for Uniformitarianism; a geological doctrine that processesoccur at the same rates in the present as they did in the past andaccount for all of the Earth’s geological features.[33] Lyell’s works werepopular and widely read, the concept of Uniformitarianism had taken astrong hold in geological society.[8]

During the same time that the stratigraphical column was beingcompleted, imperialism drove several countries in the early to mid 19thcentury to explore distant lands to expand their empires. This gave

naturalists the opportunity to collect data on these voyages. In 1831 Captain Robert FitzRoy, given charge of thecoastal survey expedition of HMS Beagle, sought a suitable naturalist to examine the land and give geologicaladvice. This fell to Charles Darwin, who had just completed his BA degree and had accompanied Sedgwick on a twoweek Welsh mapping expedition after taking his Spring course on geology. Fitzroy gave Darwin Lyell’s Principlesof Geology, and Darwin became Lyell's first disciple, inventively theorising on uniformitarian principles about thegeological processes he saw, and challenging some of Lyell's ideas. He speculated about the Earth expanding toexplain uplift, then on the basis of the idea that ocean areas sank as land was uplifted, theorised that coral atolls grewfrom fringing coral reefs round sinking volcanic islands. This idea was confirmed when the Beagle surveyed theCocos (Keeling) Islands. Darwin's discovery of giant fossils helped to establish his reputation as a geologist, and histheorising about the causes of their extinction led to his theory of evolution by natural selection published in On theOrigin of Species in 1859.[11] [32] [34]

Economic motivations for the practical use of geological data caused governments to support geological research.During the 19th century the governments of several countries including Canada, Australia, Great Britain and theUnited States funded geological surveying that would produce geological maps of vast areas of the countries.Geological surveying provides the location of useful minerals and such information could be used to benefit thecountry’s mining industry. With the government funding of geological research, more individuals could studygeology with better technology and techniques, leading to the expansion of the field of geology.[18]

In the 19th century, scientific realms established the age of the Earth in terms of millions of years. By the early 20th century the Earth’s estimated age was 2 billion years. Radiometric dating determined the age of minerals and rocks, which provided necessary data to help determine the Earth’s age.[35] With this new discovery based on verifiable scientific data and the possible age of the Earth extending billions of years, the dates of the geological time scale

History of geology 6

could now be refined. Theories that did not comply with the scientific evidence that established the age of the Earthcould no longer be accepted.

20th century

Alfred Wegener, around 1925

The determined age of the Earth as 2 billion years opened doors fortheories of continental movement during this vast amount of time.[35]

In 1912 Alfred Wegener proposed the theory of Continental Drift.[12]

This theory suggests that the continents were joined together at acertain time in the past and formed a single landmass known asPangaea; thereafter they drifted like rafts over the ocean floor, finallyreaching their present position. The shapes of continents and matchingcoastline geology between some continents indicated they were onceattached together as Pangea. Additionally, the theory of continentaldrift offered a possible explanation as to the formation of mountains.From this, different theories developed as to how mountains were built.Unfortunately, Wegner’s ideas were not accepted during his lifetimeand his theory of Continental Drift was not accepted until the1960s.[10]

In the 1960s new found evidence supported the theory of ContinentalDrift. The term Continental Drift was no longer used but was replacedby the concept of Plate Tectonics that was well supported and acceptedby almost all geologists by the end of the decade. Geophysical evidence suggested lateral motion of continents andthat oceanic crust is younger than continental crust. This geophysical evidence also spurred the hypotheses ofseafloor spreading and paleomagnetism. The hypothesis of seafloor spreading, proposed by Robert S. Dietz andHarry H. Hess, holds that the oceanic crust forms as the seafloor spreads apart along mid-ocean ridges.Paleomagnetism is the record of the orientation of the Earth’s magnetic field recorded in magnetic minerals. Britishgeophysicist S. K. Runcorn suggested the concept of paleomagnetism from his finding that the continents had movedrelative to the Earth’s magnetic poles.[36]

Modern geologyBy applying sound stratigraphic principles to the distribution of craters on the Moon, it can be argued that almostovernight, Gene Shoemaker took the study of the Moon away from Lunar astronomers and gave it to Lunargeologists.In recent years, geology has continued its tradition as the study of the character and origin of the Earth, its surfacefeatures and internal structure. What changed in the later 20th century is the perspective of geological study.Geology was now studied using a more integrative approach, considering the Earth in a broader contextencompassing the atmosphere, biosphere and hydrosphere.[37] Satellites located in space that take wide scopephotographs of the Earth provide such a perspective. In 1972, The Landsat Program, a series of satellite missionsjointly managed by NASA and the U.S. Geological Survey, began supplying satellite images that can be geologicallyanalyzed. These images can be used to map major geological units, recognize and correlate rock types for vastregions and track the movements of Plate Tectonics. A few applications of this data include the ability to producegeologically detailed maps, locate sources of natural energy and predict possible natural disasters caused by plateshifts.[38]

History of geology 7

Notes and references[1] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 7[2] Moore, Ruth. The Earth We Live On. New York: Alfred A. Knopf, 1956. p. 13[3] Abdus Salam (1984), "Islam and Science". In C. H. Lai (1987), Ideals and Realities: Selected Essays of Abdus Salam, 2nd ed., World

Scientific, Singapore, p. 179-213.[4] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 118[5] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 114[6] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 219[7] Frank, Adams Dawson. The Birth and Development of the Geological Sciences. Baltimore: The Williams & Wilkins Company, 1938. p. 209,

239[8] Albritton, Claude C. The Abyss of Time. San Francisco: Freeman, Cooper & Company, 1980. p. 104-107[9] Frank, Adams Dawson. The Birth and Development of the Geological Sciences. Baltimore: The Williams & Wilkins Company, 1938. 226.[10] Peter, Bowler J. The Earth Encompassed. New York: W.W. Norton & Company, 1992. p. 404-405[11] Frank, Adams Dawson. The Birth and Development of the Geological Sciences. Baltimore: The Williams & Wilkins Company, 1938. p. 226[12] Charles, Drake L. The Geological Revolution. Eugene : Oregon State System of Higher Education, 1970. p. 11[13] Charles, Drake L. The Geological Revolution. Eugene : Oregon State System of Higher Education, 1970. 11.[14] Charles, Drake L. The Geological Revolution. Eugene : Oregon State System of Higher Education, 1970. p. 13[15] "Studying Earth Sciences." British Geological Survey. 2006. Natural Environment Research Council. http:/ / www. bgs. ac. uk/ vacancies/

studying. htm , accessed 29 November 2006.[16] Rocchio, Laura. "The Landsat Program." National Aeronautics and Space Administration. http:/ / landsat. gsfc. nasa. gov , accessed 4

December 2006[17] Frank, Adams Dawson. The Birth and Development of the Geological Sciences. Baltimore: The Williams & Wilkins Company, 1938. p. 96[18] Jardine, N., F. A. Secord, and E. C. Spary. Cultures of Natural History. Cambridge: Cambridge University Press, 1996. p. 212-214[19] Jardine, N., F. A. Secord, and E. C. Spary. Cultures of Natural History. Cambridge: Cambridge University Press, 1996. p. 212[20] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 88[21] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 92[22] Jardine, N., F. A. Secord, and E. C. Spary. Cultures of Natural History. Cambridge: Cambridge University Press, 1996. p. 232[23] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press. 1990. p. 8[24] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 8[25] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 219[26] Frank, Adams Dawson. The Birth and Development of the Geological Sciences. Baltimore: The Williams & Wilkins Company, 1938. p. 209[27] Albritton, Claude C. The Abyss of Time. San Francisco: Freeman, Cooper & Company, 1980. p. 95-96[28] Frank, Adams Dawson. The Birth and Development of the Geological Sciences. Baltimore: The Williams & Wilkins Company, 1938. p. 239[29] Peter, Bowler J. The Earth Encompassed. New York: W.W. Norton & Company, 1992. p. 216[30] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 144[31] Second J A (1986) Controversy in Victorian Geology: The Cambrian-Silurian Dispute Princeton University Press, 301pp, ISBN

0-691-0244-13[32] Herbert, Sandra. Charles Darwin as a prospective geological author, British Journal for the History of Science 24. 1991. p. 159–192 (http:/ /

darwin-online. org. uk/ content/ frameset?viewtype=text& itemID=A342& pageseq=1)[33] Gohau, Gabriel. A History of Geology. New Brunswick: Rutgers University Press, 1990. p. 145[34] Keynes, Richard ed.. Charles Darwin's zoology notes & specimen lists from H.M.S. Beagle, Cambridge University Press, 2000. p. ix (http:/ /

darwin-online. org. uk/ content/ frameset?viewtype=text& itemID=F1840& pageseq=12)[35] Jardine, N., F. A. Secord, and E. C. Spary. Cultures of Natural History. Cambridge: Cambridge University Press, 1996. p. 227[36] Peter, Bowler J. The Earth Encompassed. New York: W.W. Norton & Company, 1992. p. 405-415[37] "Studying Earth Sciences." British Geological Survey. 2006. Natural Environment Research Council. http:/ / www. bgs. ac. uk/ vacancies/

studying. htm , accessed 29 November 2006[38] Rocchio, Laura. "The Landsat Program." National Aeronautics and Space Administration. http:/ / landsat. gsfc. nasa. gov , accessed 4

December 2006

History of geology 8

External links• http:/ / geology. com• http:/ / landsat. gsfc. nasa. gov

Article Sources and Contributors 9

Article Sources and ContributorsHistory of geology  Source: http://en.wikipedia.org/w/index.php?oldid=460506673  Contributors: Aggierockhunter, Agüeybaná, Aidanmckinlay, Andycjp, Ashmoo, Bluezy, Captainm,Carboxen, CarolGray, ChildofMidnight, Chris.urs-o, Colonies Chris, CommonsDelinker, Dave souza, Dyvroeth, Extremophile, Generalboss3, Geologyguy, Geoz, GreenEco, Gump Stump,J8079s, Jagged 85, Joostvandeputte, KConWiki, Kaiser matias, Kww, Look2See1, Mbz1, Mikenorton, Miquonranger03, NatureA16, Ospalh, Ozcep, PericlesofAthens, Peterlewis, Phe,Pinethicket, Professor marginalia, Qwyrxian, Ragesoss, Rich Farmbrough, Rjd0060, Rkolste, RockMagnetist, Rusty Cashman, Skarebo, Stwalkerster, Sushant gupta, Tabletop, TimVickers,Tobby72, Tranletuhan, Visite fortuitement prolongée, Vsmith, Wavelength, Zimbres, 37 ,דקי anonymous edits

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