Timetable of Petrology: The beginning through 1799

Date Scientist Contribution
0007
Strabo
Recognized basalt from Etna Volcano had solidified from melt. Related earthquakes to volcanic eruptions.
1269
Peregrinus de Maricourt
Discovered magnetic polarity in lodestone (magnetite).
1560
Cooper
Age of earth deduced from biblical events by various authors as 5041-8522 years.
1540
Biringuccio
Chemical tests applied to stream waters for metal prospecting.
1546
Agricola
De Natura Fossilium; first handbook on mineralogy. Role of "mineral-bearing solutions" (succus lapidescens).
1556
Agricola
De Re Metallica; treatise on mining and metallurgy.
1600
Gilbert
Described earth as a great magnet. Observed lodestone lost magnetic properties on heating but regained them on cooling.
1619
Morin
First reference to high temperatures within the earth.
1644
Descartes
Regarded the earth as a small cooled star with chilled crust. Vein minerals, deposited in fissures, were exhalations from hot interior.
1650
Ussher
Creation of the earth, derived from biblical events, given as the "entrance of night preceding the 23rd October" 4004 BC. Adopted in subsequent authorized editions of the bible.
1669
Steno
Law of superposition of sediments. Vein fissures filled by condensation of vapors from interior. (See Descartes, 1644).
1671
Boyle
Temperature increases with depth in earth due to heat sources within the earth.
1678
Kircher
Postulates interconnected subterranean cells from which volcanic mountains arise.
1680
Leibnitz
Earth was initially molten. Scoria is a sort of glass.
1683
Lister
First map to show geologic features.
1694
Hjärne
Coined the term "rapakivi" to described an easily disintegrated granite that commonly contained ovoids of perthitic microcline mantled with oligoclase. (See Sederholm, 1891).
1715
Halley
Estimated the age of the oceans from the increase in sodium content derived from the rivers. (See Joly, 1899).
1727
Reaumur
Systematic preparation of silicate mixtures.
1739
Reaumur
Experimental devitrification of glass.
1746
Guettard
First mineralogic map.

Pott
Silica behaves as a flux in lowering the melting temperature of other minerals.
1749
Bouguer
First attempt to measure the gravity of the earth with a plumb line.
1752
Guettard
Auvergne Hills were extinct volcanoes: used modern example as clue to past.
1756
Lehmann
Considered the "father of stratigraphy." Emphasized historical sequence of strata in mountains. (see Steno, 1669).
1758
Cronstedt
Introduced technique of blowpipe analysis.
1760
Mitchell
First estimate of seismic wave velocity (0.5 km/sec). Attributed earthquakes to fire- induced explosions (volcanic). Described as "father of seismology." (publ. 1761).
1763
Desmarest
Auvergne Hills were volcanic: columnar structure due to cooling. (Publ. 1774).

Lomonosov
Physical chemist considered founder of experimental mineralogy and petrography by Ginsberg (1952). (Cf. Reaumur, 1727, 1739).
1766
d'Arcet
Mixtures of minerals melt at lower temperature than pure minerals.
1770
Delius
Lateral secretion theory of ore deposition.
1771
Desmarest
Volcanic origin of basalt. Produced by the fusion of granite.

Bergmann
Rocks are chemical precipitates from solutions. (Cf. Werner, 1787).
1775
Maskelyne
First determination of density of earth with a plumb line; density = 4.7.
1778
Faujas de Saint-Fond
Columnar lavas associated with volcanic cones.
1779
Arduino
Marble derived from limestone.

de Saussure
Partially melted granite and only quartz preserved. Basalts could not be derived by fusion of granite.
1782
Wedgwood
Estimated relative high temperatures in kiln by observing shrinkage of shaped clay body. First high-temperature pyrometer. (Cf. Seger, 1888).
1785
Hutton
Internal heat of earth caused extrusion of molten rock. Intrusive nature of granite into schist. Publ. 1788).
1786
de Launay
Classification of rocks.

de Saussure
Granite-schist relationships support transformist school.
1787
Werner
Classification of rock formations; laid foundations for descriptive petrography. Aqueous origin of igneous and metamorphic rocks. Granite crystallized from primeval ocean. "No basalt is volcanic."
1788
Hutton
"Theory of the Earth." Present is key to past.
1790
Hall
First systematic experiments on the fusion of natural granitic rocks. (Publ. 1805). (See Saussure, 1779).
1791
Dolomieu
Genetic division of rocks: precipitated sediments, transported sediments; volcanics.

Beddoes
Describes the gradual changing of basalt to granite "betraying a common origin."
1792
Spallanzani
Recrystallization of fused basalt. Lava wells out because of gas effervescence.

De Rossel
First survey of global magnetic intensity and variation with latitude. (Publ. 1808)
1794
Chladni
Meteorites are of extraterrestrial origin.
1795
Hutton
Principle of Uniformitarianism. Derived granite by complete fusion of sediments. Gneisses were semi- fused sediments.
1798
Cavendish
Density of earth determined with a torsion balance.


[Timetable of Petrology Contents] [Years 1800-1899]