View
215
Download
0
Tags:
Embed Size (px)
Citation preview
Founders of Historical Geology
Can be traced back to classical Greece
Nicolaus Steno (Neils Stensen) 1638-1687
Originally a Danish physicianAn expert in anatomy
(Public Dissections)Developed the fundamental
principles of historicalgeology
Physician to the de Medicifamily in Florence
Nicolaus Steno (Neils Stensen) 1638-1687
In 1669, Steno wrote De solido intra solidum naturaliter
contento dissertationis prodromusProdromus to a dissertation on Solids
Naturally Enclosed in Solidsonly 78 pages long
Founders of Historical Geology
Founders of Historical Geology
Superposition - The scientific law stating that in any unaltered sequence of rock strata, each stratum is younger than the one beneath it and older than the one above it, so that the youngest stratum will be at the top of the sequence and the oldest at the bottom.
Founders of Historical Geology
Superposition, con’t.
With tilted beds, we needto consider othersedimentarystructures, like ripple marks,mudcracks,graded bedding, geopetal structuresor cross-bedding to help determineup direction.
Can also use vesicles inlava flows.
Founders of Historical Geology
Principle of Original Horizontality - The scientific law stating that sediments settling out of a fluid (air and water) are deposited horizontally or nearly horizontally in layers that lie parallel or nearly parallel to the Earth’s surface.
Founders of Historical Geology
Principle of Lateral Continuity - The scientific law stating thatas originally deposited, strata extend in all directions until theyterminate by thinning at the margins of the basin, endabruptly against some former barrier to deposition, or gradelaterally into a different kind of sediment.
Founders of Historical Geology
John Strachey 1671-1743
Used superposition and original lateral continuityDetermined the stratigraphic succession of coals in EnglandRecognized what would later be termed unconformities
Performed local-scale observations.
Founders of Historical Geology
Giovanni Arduino 1714-1795
Had a broader global view of sedimentary layersDeveloped the first classification of rocks and relative ages
Primary Mountains crystalline rocksoldest rocks on Earthlater became igneous/metamorph.
Secondary Mountains layeredfossiliferous rockslater sedimentary rocks
Tertiary unconsolidated sedimentslava flows
Founders of Historical Geology
Johann Lehmann 1719-1767Georg Füchsel 1722-1776
Came up with classification similar to that of ArduinoDeveloped stratigraphic successions of rocks in Thuringia,
and the Hartz and Ertz Mountains.Began to understand the events that lead
to mountain building
Lehmann
Founders of Historical Geology
Peter Simon Pallas 1741-1811
Improved geologic history of the mountains of EuropeDeveloped the general geologic history of the UralsObserved changes in rock assemblages going from margins to
the core of mountains.
Reise durch verschiedene Provinzen des Russischen Reiches 1771-1776Journey Through Several Provinces of the Russian Empire
Founders of Historical Geology
Abraham Gottlieb Werner 1749-1817
Most influential geologist of the late 18th centuryStudied at the Freiburg Mining AcademyTaught mineralogy at Freiburg.Developed the “Neptunian”
classification of rocksAll rocks of the crust were deposited
or precipitated from sea waterA universal ocean once covered the
EarthFollowers called “Neptunists”
Founders of Historical Geology
Abraham Gottlieb Werner 1749-1817
Primitive Rocks Deposited firstCame from hot, steamy fluid with many
dissolved mineralsCoarse grained igneous and metamorphic
Transition Rocks Ocean basins formed, waters cooledFossiliferous, stratified rocksDeformed rocksOcean resembled modern oceans
Founders of Historical Geology
Flötzgebirge Flat lying sedimentary rocksContained lava flows
Alluvium All unconsolidated material
Founders of Historical Geology
James Hutton 1726-1797
Father of Modern Geology
Edinburgh physician & geologist?Opponent to Neptunism
Believed fire was the answer.
Recognized change on the Earth’ssurface
(Surficial processes were active)
Developed cyclic view of Earth
“No vestige of a beginning, noprospect of an end”.
Laid foundation for uniformitarianism“The past history of our globe must be explained by what
can be seen to be happening now”.
By observing geologic processes in operation around him,Hutton could infer the origin of features observed in rocks.
“Present is the key to the past”.Archibald Geike 1835-1924
Founders of Historical Geology
Founders of Historical Geology
Geologic past has been different than today:
AtmosphereLifeMeteorite ImpactsElevation of ContinentsClimate
Rate of change and intensity varied, butprocesses are the same.
Founders of Historical Geology
Actualism Natural laws governing both past and present processes on Earth have been the same.
Hutton observed that for all the processes to be active, immense time was needed.
Exploration of Siccar Pointrecognized the vastness of time
recognized unconformable relationships in the rocks
unable to determine the age relationships.