ESS102H1 Lecture Notes - Neptunism, James Hutton, Plutonism
Questions on class 2:
- list differences between
Leonardo da Vinci and Georg Agricola
Vinci: work not distributed. Fields: Erosion and sedimentation. Accurate observer. Others not aware
of his works.
Agricola: wrote the book De Re Metallica. Limited by what he could see. Field: Mining. Classified
minerals and explained how these unfolded. Latin = language of science, his works widely read
- Why did science change during the
The printing of books made ideas & information disseminate. Ideas could circulate. Museums:
People put together collections that one person could not do himself in his lifetime.
Neptunists vs. Plutonists
an early controversy on the origin of rocks related to the questions of earths origin.
Viewed from a quarter millennium later, this controversy is often portrayed as a battle between two
eminent scientists and their schools of thought. These 2 were the most prominent ones, either
wrote widely read books. People travelled to listen to them. Easier for us to link this idea to 2 people
though there was more to it.
But: scientific controversy should not be primarily a battle between people, but between ideas.
However: battle between 2 titanic personalities is easier to report & remember
Neptunists[ - watermen
- rocks originated by sedimenting or precipitation out of a primeval ocean.
One ocean was the origin: rocks formed early in history.
Abraham Werner t Freiberg, Saxonia
- rocks we see originated from heat. By cooling of molten magma or by other action of heat.
James Hutton t Edinburgh, Scotland
Werner t 1749 - 1817. Eastern Germany - Silesia. Studied law and mining in Freiberg and Leipzig.
Professor in 1775 at Bergakademie Freiberg. A mining school.
Proposed that all rocks had precipitated out of a single enormous flood.
Werner proposed that Earth was originally an irregular solid body covered completely with a heavily
saturated fluid. Over time, solids precipitated from this fluid in a regular succession: first the primitive
rocks, such as granite and gneiss; then the transition rocks, such as slates and some limestones; and
finally, recent rocks, such as sandstone and other types of limestone. As the fluid lost its chemical
content, it gradually became the salty oceans that we know today.
Harz and Freiberg key mining areas in Europe at the time. Silver was discovered here in 1180.
Bergakademie founded in 1765. 10 yrs later Werner joined as a faculty member. Well known
through Europe. Inspirational teacher. The great oracle of geology t Lyell on Werner
Another difference on Werner and Hutton: Werner very easy going and eloquence. Hutton was very
different, shy, withdrawn, and not so public. Werner had many students who continued to well
Gebirgsarten - 1786 published. Short classification and description of the various types of
Classified rocks in 4 types linked to Neptunists[XdZ]o](]]}v]o]vl}Z}Ç}(Z]}]P]vX
1 hot (turbulent) primeval ocean
2 ocean cooled and calmed rocks precipitated out
3 ocean drained and sediments were formed
(1 to 3 compromises one global flood event)
4 volcanic activity
Resulting rocks, new to old. These 4 stages related to a type of mountain, each are related to certain
types of rocks.
4. Volcanic rocks, lava generated by burning of coal lava and ash, hot springs deposits
3. ^µ(PZÁu']P_~Á-together mountains) unconsolidated sands, clays, during final
draining of continents
2 ^&o}ÌP]P_~](]]uvÇ}l~]voµ]vPoand coal), also basalt from
erosion of emerging mountains. As the ocean drains some sediments come above water
1. ^hP]P_~]u]]ÀWPv]te, gneiss, schist first material to precipitate. A ocean still
turbulent, like a flood, wave action, sediment in there
Theory linked to observation around Freiberg, ex: layered rocks in Erzgebirge (Saechsische Schweiz)
The saxonian Switzerland, limestones and sedimentary rocks form nicely. The theory he developed,
he travelled these areas and saw these sedimentary rocks.
Block diagram to show geology of Germany
the pink rocks (sedimentary) blue (transitional) rocks sheets of paper, draped over the pink ones.
These are rocks the edge of a prominent layers. Yellow colours (swept together materials) related to
glaciers, red blocks volcanoes.
Southern Ontario t similar thing
red and grey t very old material, number 1. Layers that form the blue stuff, number 2. Yellow stuff -
the glaciers, the number 3. Volcanic stuff on top not here.
Wrong to say it all developed from an original ocean
some theory problems: where did the water go? No evidence so no testable hypothesis
tilted layers (or strata)? In their original position according to neptunists, believable for chemical
Although Werner's ideas had many attractive features, especially in explaining the sequences of rock
strata, they suffered several fatal flaws. One was that Werner never offered an explanation of where
the rest of the fluid had gone. Even more alarming was the implication from his theory that all the
rock that ever would exist had formed already. It was clear that the continents were gradually being
washed into the oceans. If no new rock were formed, the continents would eventually disappear.
Siccar point, Hutton described this are first.
Cross cutting granites: granites classified with "primitive" strata but found to cross-cut and intrude
rocks of younger classification.
if it all formed in same ocean, why do some rocks cut through other rocks. And if their classified as
primary why would they cross cut younger rocks?
2. the plutonists and James Hutton
1726 t 1797.
English lawyer and doctor.
Thesis on circulation of blood in the "microcosm" of the body.
Gentleman farmer t studied farming.
Interest in geosciences started in 1752.
Moved to Edinburgh
Sparked interest in geosciences
Hutton gave great importance to the interior heat of Earth, which was well known from mines.
Edinburgh in late 1700s buzzing city. Major intellectual centre.
(Economist Adam Smith, philosopher David Hume,
Engineer James Watt, inventor Benjamin Franklin,
Poet Robert Burns)
Huttinsection t series of rocks
ancient volcano that overlooks the city influenced ,µ}v[ thinking
1795 published ^theory of the earth_XdZoµ}v][À]Á}(}l(}u]}vX
Magma freezes to become rock.
Heat deep within Earth is primary driving force
- heat formed igneous rocks
- Sedimentary rocks are consolidated sediments formed by later processes
- Heat could consolidate sediments and elevate layers of rock
Hutton proposed that the interior of the Earth was hot, and that this heat was the engine which
drove the creation of new rock: land was eroded by air and water and deposited as layers in the sea;
heat then consolidated the sediment into stone, and uplifted it into new lands. This theory was
dubbed "Plutonist" in contrast to the flood-oriented theory.
presented his thoughts. James Hutton read the paper, very shy, criticism, went back and did a lot of
1785 t granite near Aberdeen contains quartz within feldspar within quartz could not form from
aqueous solution but from magma:
the feldspar the first one to crystallise. Quarts typically do not show its crystal faces, ][ the last to
crystallise to fill ÁZÀ[ left.