1. Founders of Historical Geology
Can be traced back to classical Greece
Nicolaus Steno (Neils Stensen)
Originally a Danish physician
An expert in anatomy
(Public Dissections)
Developed the fundamental
principles of historical
geology
Physician to the de Medici
family in Florence

2. Founders of Historical Geology
Nicolaus Steno (Neils Stensen)
In 1669, Steno wrote
De solido intra solidum naturaliter
contento dissertationis prodromus
Prodromus to a dissertation on Solids
Naturally Enclosed in Solids
only 78 pages long

3. 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.

4. Founders of Historical Geology
With tilted beds, we need
to consider other
sedimentary
structures, like
ripple marks,
mudcracks,
graded bedding,
geopetal structures
or cross-bedding
to help determine
up direction.
Can also use vesicles in
lava flows.
Superposition, con’t.

5. 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.

6. Founders of Historical Geology
Principle of Lateral Continuity - The scientific law stating that
as originally deposited, strata extend in all directions until they
terminate by thinning at the margins of the basin, end
abruptly against some former barrier to deposition, or grade
laterally into a different kind of sediment.

7. Founders of Historical Geology
John Strachey
Used superposition and original lateral continuity
Determined the stratigraphic succession of coals in England
Recognized what would later be termed unconformities
Performed local-scale observations.

8. Founders of Historical Geology
Giovanni Arduino
Had a broader global view of sedimentary layers
Developed the first classification of rocks and relative ages
Primary Mountains crystalline rocks
oldest rocks on Earth
later became igneous/metamorph.
Secondary Mountains layered
fossiliferous rocks
later sedimentary
rocks
Tertiary unconsolidated sediments
lava flows

9. Founders of Historical Geology
Johann Lehmann
Georg Füchsel
Came up with classification similar to that of Arduino
Developed stratigraphic successions of rocks in Thuringia,
and the Hartz and Ertz Mountains.
Began to understand the events that lead
to mountain building
Lehmann

10. Founders of Historical Geology
Peter Simon Pallas
Improved geologic history of the mountains of Europe
Developed the general geologic history of the Urals
Observed changes in rock assemblages going from margins to
the core of mountains.
Reise durch
verschiedene Provinzen
des Russischen Reiches
Journey Through
Several Provinces
of the Russian Empire

11. Founders of Historical Geology
Abraham Gottlieb Werner
Most influential geologist of the late 18th century
Studied at the Freiburg Mining Academy
Taught mineralogy at Freiburg.
Developed the “Neptunian”
classification of rocks
All rocks of the crust were deposited
or precipitated from sea water
A universal ocean once covered the
Earth
Followers called “Neptunists”

12. Founders of Historical Geology
Abraham Gottlieb Werner
Primitive Rocks Deposited first
Came from hot, steamy fluid with many
dissolved minerals
Coarse grained igneous and metamorphic
Transition Rocks Ocean basins formed, waters cooled
Fossiliferous, stratified rocks
Deformed rocks
Ocean resembled modern oceans

13. Founders of Historical Geology
Flötzgebirge Flat lying sedimentary rocks
Contained lava flows
Alluvium All unconsolidated material

14. Where did all the water go?
Founders of Historical Geology
Where did all the water go?

15. Founders of Historical Geology
James Hutton
Father of Modern Geology
Edinburgh physician & geologist?
Opponent to Neptunism
Believed fire was the answer.
Recognized change on the Earth’s
surface
(Surficial processes were active)
Developed cyclic view of Earth
“No vestige of a beginning, no
prospect of an end”.

16. Founders of Historical Geology
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

19. Founders of Historical Geology
Geologic past has been different than today:
Atmosphere
Life
Meteorite Impacts
Elevation of Continents
Climate
Rate of change and intensity varied, but
processes are the same.

20. 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 Point
recognized the vastness of time
recognized unconformable relationships in the rocks
unable to determine the age relationships.

21. "The mind seemed to grow giddy by looking so far into the abyss of time.".