Timeline Of Geology

Timeline of geology

## 16th and 17th centuries

Portuguese and Spanish explorers systematically measure magnetic declination to estimate the geographical longitude [4][5]

## 18th century

• 1701 - Edmund Halley suggests using the salinity and evaporation of the Mediterranean to determine the age of the Earth
• 1743 - Dr Christopher Packe produces a geological map of south-east England
• 1746 - Jean-Étienne Guettard presents the first mineralogical map of France to the French Academy of Sciences.
• 1760 - John Michell suggests earthquakes are caused by one layer of rocks rubbing against another
• 1776 - James Keir suggests that some rocks, such as those at the Giant's Causeway, might have been formed by the crystallisation of molten lava
• 1779 - Comte de Buffon speculates that the Earth is older than the 6,000 years suggested by the Bible
• 1785 - James Hutton presents paper entitled Theory of the Earth - earth must be old
• 1799 - William Smith produces the first large scale geological map, of the area around Bath