ESC 102 Evolution of Earth and Life Historical Geology Spring 2011. Earth Systems can you identify them?. When we view the Earth from space what Earth systems are observable? What is most obvious? Are these systems independent or do they interact with one another ?.
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Evolution of Earth and Life
Solid Earth is composed of plates that move over Earth’s surface.
Earth’s biota – all living things – has evolved or changed through history.
Geologic processes take place within extensive geologic time -~ 4.6 billion years of Earth’s history.
James Hutton observed tilted sedimentary layers overlain by near-horizontal layers.He realized that whatever processes created this rock outcrop must have taken millions of years.In 1785, published his Theory of the Earth and is considered founder of modern geology.
He furthered the work of James Hutton: concept ofUniformitarianism
Rock layers reveal sequences of events based on processes that occur today.
Smith’s map took many years to complete and helped establish the geologic time scale.
above absolute zero is observed in space(-273o C or -460o F)
“Afterglow” of the Big Bang discovered in 1965 As predicted, it was cosmic microwave radiation from .space
Imagine the surfaceof a balloon as itis inflated. Locations
on the surface move
away from one another.ther.
Determine the Age of the Universe
Determine rate of expansion“Back-model” to a time when the galaxies would be together in the same space
--very dense matter came into existence
--The four basic forces separated:
gravityelectromagnetic force strong nuclear and weak nuclear forces
Enormous expansion occurred
The formation of the solar system
Solar nebula theory
The planets formed with distinctorbits around the sun.Some planets have satellites which orbit individual planets.
The Hubble Telescope image shows a solar nebula as a protoplanetary disk or “proplyd” located in Orion Nebula with dozens of others. The proto star is the bright glow; dark area is a dense molecular cloud.
Small in size
Composed of rock
Large in size.
Composed of hydrogen, helium, ammonia, methane
Small rocky cores
Kuiper Belt Pluto: no longer has planet statusThe Planets
The earth and moon were heavily bombarded in Earth’s early history.
4.6 to 4.4 billion years ago
Ejected a large quantity of hot material that cooled and coalesced to form the moon
came from the mantle of the colliding planetesimal
The material cooled and
crystallized into lunar layers
Moon is smaller than Earth and cooled quickly.Light colored surface areas are lunar
Highlands – heavily cratered.
evidence of massive meteorite
Mare: areas of lava flows more likely due to impact than tectonics
Top 4 most abundant elements:OxygenSiliconaluminum
After decades of puzzling evidence, the theory was developed in the1960s
Mechanism: Plate tectonics is driven by convection in the mantle
and in turn drives mountain building
and associated igneous and metamorphic activity
seconds, hours, days, years
hundreds or even thousands of years
millions, hundreds of millions, billions of years
Resulted from the work of many 19th century geologists who