[potential edits to "Geologic time scale"]
Early history
editThe most modern geological time scale was not formulated until 1911[1] by Arthur Holmes (1890 – 1965), who drew inspiration from James Hutton (1726–1797), a Scottish Geologist who presented the idea of uniformitarianism or the theory that changes to the Earth's crust resulted from continuous and uniform processes. [2] The broader concept of the relation between rocks and time are can be traced back to (at least) the philosophers of Ancient Greece from 1200 BC to 600 AD. Xenophanes of Colophon (c. 570–487 BCE) observed rock beds with fossils of seashells located above the sea-level, viewed them as once living organisms, and used this to imply an unstable relationship in which the sea had at times transgressed over the land and at other times had regressed.[3] This view was shared by a few of Xenophanes's scholars and those that followed, including Aristotle (384–322 BC) who (with additional observations) reasoned that the positions of land and sea had changed over long periods of time. The concept of deep time was also recognized by Chinese naturalist Shen Kuo[4] (1031–1095) and Islamic scientist-philosophers, notably the Brothers of Purity, who wrote on the processes of stratification over the passage of time in their treatises.[3] Their work likely inspired that of the 11th-century Persian polymath Avicenna (Ibn Sînâ, 980–1037) who wrote in The Book of Healing (1027) on the concept of stratification and superposition, pre-dating Nicolas Steno by more than six centuries.[3] Avicenna also recognized fossils as "petrifications of the bodies of plants and animals",[5] with the 13th-century Dominican bishop Albertus Magnus (c. 1200–1280), who drew from Aristotle's natural philosophy, extending this into a theory of a petrifying fluid.[6] These works appeared to have little influence on scholars in Medieval Europe who looked to the Bible to explain the origins of fossils and sea-level changes, often attributing these to the 'Deluge', including Ristoro d'Arezzo in 1282.[3] It was not until the Italian Renaissance when Leonardo da Vinci (1452–1519) would reinvigorate the relationships between stratification, relative sea-level change, and time, denouncing attribution of fossils to the 'Deluge':[7][3]
Of the stupidity and ignorance of those who imagine that these creatures were carried to such places distant from the sea by the Deluge...Why do we find so many fragments and whole shells between the different layers of stone unless they had been upon the shore and had been covered over by earth newly thrown up by the sea which then became petrified? And if the above-mentioned Deluge had carried them to these places from the sea, you would find the shells at the edge of one layer of rock only, not at the edge of many where may be counted the winters of the years during which the sea multiplied the layers of sand and mud brought down by the neighboring rivers and spread them over its shores. And if you wish to say that there must have been many deluges in order to produce these layers and the shells among them it would then become necessary for you to affirm that such a deluge took place every year.
These views of da Vinci remained unpublished, and thus lacked influence at the time; however, questions of fossils and their significance were pursued and, while views against Genesis were not readily accepted and dissent from religious doctrine was in some places unwise, scholars such as Girolamo Fracastoro shared da Vinci's views, and found the attribution of fossils to the 'Deluge' absurd.[3] Although many theories surrounding philosophy and concepts of rocks were developed in earlier years, "the first serious attempts to formulate a geological time scale that could be applied anywhere on Earth were made in the late 18th century". [6] Later, in the 19th century, academics further developed theories on stratification. William Smith, often referred to as the "Father of Geology" [8] developed theories through observations rather than drawing from the scholars that came before him. Smith's work was primarily based on his detailed study of rock layers and fossils during his time and created "the first map to depict so many rock formations over such a large area”. [9] After studying rock layers and the fossils they contained, Smith concluded that each layer of rock contained distinct material that could be used to identify and correlate rock layers across different regions of the world. [10]. Smith developed the concept of faunal succession or the idea that fossils can serve as a marker for the age of the strata they are found in and published his ideas in his 1816 book, "Strata identified by organized fossils". [10]
- ^ Holmes, Arthur (1911-06-09). "The association of lead with uranium in rock-minerals, and its application to the measurement of geological time". Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character. 85 (578): 248–256. Bibcode:1911RSPSA..85..248H. doi:10.1098/rspa.1911.0036. ISSN 0950-1207.
- ^ "James Hutton | Father of Modern Geology, Scottish Naturalist | Britannica". www.britannica.com. Retrieved 2024-12-03.
- ^ a b c d e f Fischer, Alfred G.; Garrison, Robert E. (2009). "The role of the Mediterranean region in the development of sedimentary geology: a historical overview". Sedimentology. 56 (1): 3–41. Bibcode:2009Sedim..56....3F. doi:10.1111/j.1365-3091.2008.01009.x. S2CID 128604255.
- ^ Sivin, Nathan (1995). Science in ancient China: researches and reflections. Variorum. ISBN 0-86078-492-4. OCLC 956775994.
- ^ Adams, Frank D. (1938). The Birth and Development of the Geological Sciences. Williams & Wilkins. ISBN 0-486-26372-X. OCLC 165626104.
- ^ a b Johnson, Chris; Bentley, Callan; Panchuk, Karla; Affolter, Matt; Layou, Karen; Jaye, Shelley; Kohrs, Russ; Inkenbrandt, Paul; Mosher, Cam; Ricketts, Brian; Estrada, Charlene. "Geologic Time and Relative Dating". Maricopa Open Digital Press.
- ^ McCurdy, Edward (1938). The notebooks of Leonardo da Vinci. New York: Reynal & Hitchcock. OCLC 2233803.
- ^ "William Smith (geologist)", Wikipedia, 2024-11-06, retrieved 2024-12-02
- ^ "William Smith (1769-1839)". earthobservatory.nasa.gov. 2008-05-08. Retrieved 2024-12-02.
- ^ a b Smith, William; Smith, William (1816). Strata identified by organized fossils : containing prints on colored paper of the most characteristic specimens in each stratum. London: Printed by W. Arding ..., and sold by the author ..., J. Sowerby ..., Sherwood, Neely, and Jones, and Longman, Hurst, Rees, Orme, and Brown ..., and by all booksellers. doi:10.5962/bhl.title.106808.