5. An immense of biological and geological change
has occurred in a time span.
The age of the Earth is one-third of the age of the
universe.
The process of plate tectonics has played a major
role in the shaping the Earth’s oceans and
continents, as well as the life they harbor.
6.
7.
8.
9. The earth was formed by accretion from the solar nebula
around 4.54 Ga(billion years ago).
Volcanic outgassing created the primordial
atmosphere, but it contained almost no oxygen and
would not support life.
A very large collision tilted the earth and formed the
moon.
Much of the Earth was molten because of extreme
volcanism and frequent collisions with other bodies.
The process of plate tectonics shaped the Earth's oceans
and continents, as well as the life they harbor.
The biosphere had a significant effect on the atmosphere
and other abiotic conditions such as the formation of the
ozone layer, the proliferation of oxygen, and the creation
of soil.
10.
11. The Solar System was formed formed from a large rotating
cloud of interstellar dust and gas of hydrogen and helium
called the Solar Nebula.
It was created shortly after the Big Bang, 13.7 Ga and
heavier elements formed the supernova.
About 4.5 Ga, the nebula had a contraction that triggered
by the shock wave of the nearby supernova.
The shock wave made the nebula rotate and the cloud to
accelerate which resulted to the flattening of the nebula to
protoplanetary disk perpindicular to its axis of rotation.
Collisions of other large debris formed
Protoplanets, orbiting the nebular center.
12.
13. After more contraction, a T-Tauri star ignited and evolved
into the sun.
Protoplanitary disk began separating into rings.
The process called Runaway Accretion successively
clumped together larger fragments of dust and debris to
form Planets.
Earth formed in this way about 4.54 Ga and was completed
within 10-20 million years .
The proto-Earth grew by accretion until its interior was hot
enough to melt the heavy, siderophile metals.
These metals sank due to higher densities resulted to the
separation of a primitive mantle and a metallic core, 10
million years after the Earth’s formation.
The Earth’s first atmosphere was composed of light
elements from solar nebula, mostly H and He.
14.
15. Hadean Eon-the first eon in Earth’s History which begins
in the Earths formation.
Archean Eon-followed from Hadean Eon at 3.8 Ga.
Giant Impact Hypothesis-the moon was formed.
Late Heavy Bombardment- a period of intense meteorite
impacts that began about 4.1 -3.8 Ga, at the end of the
Hadean.
Volcanism was severe due to the large heat and geothermal
gradient.
By the beginning of the Archean, the Earth cooled
significantly.
Life couldn’t survive due to lack of Oxygen and Ozone
Layer.
16.
17. The Giant Impact Hypothesis proposes that the Moon
originated after a body the size of Mars struck the
proto-Earth a glancing blow.
Theia-a former planet which had collided with the
Earth.
The impact was enough to vaporize the Earth’s outer
layers and melt both bodies.
Under the influence of its own gravity, the ejected
material became a more spherical body: the Moon.
20. Mantle convection, the process that drives plate
tectonics today, is a result of heat flow from the Earth's
interior to the Earth's surface.
Involves the creation of rigid tectonic plates at mid-
ocean ridges.
During the early Archean (about 3.0Ga) the mantle
was 1600°C so the convection of the mantle was faster.
While a process similar to present day plate tectonics
did occur.
The initial crust, formed when the Earth's surface first
solidified.
21. However, it is thought that it was basaltic in
composition, like today's oceanic crust, because little
crustal differentiation had yet taken place.
The first larger pieces of continental crust, which is a
product of differentiation of lighter elements that
appeared at the end of the Hadean.
What is left of these first small continents are called
cratons.
These pieces of late Hadean and Archean crust form
the cores around which today’s continents grew.
22.
23. Earth is often described as having had Three
Atmospheres:
1) captured from the solar nebula, composed of
solar wind and Earth’s heatgases rele
2) volatile gases released by molten Earth, gases
ireleased by volcanoes, rich in greenhouse gases but
poor in Oxygen.
3) rich in Oxygen
The new atmoshere probably contained water vapor,
carbon dioxide, nitrogen, and smaller amounts of
pther gases.
24. The ocean and atmosphere would therefore have
started to form even as the Earth is formed.
The water must have been supplied by meteorites from
the outer asteroid belt and some large planetary
embryosfrom beyond 2.5 AU.
Comets may also have contributed.
Clouds formed as the planet cooled and rain created
the oceans as early as 4.4 Ga.
25.
26. The Proterozoic Eon lasted from 2.5 Ga – 542 Ma
(million years ago).
Cratons grew into continents with modern sizes.
The change to an oxygen-rich atmosphere was a crucial
development.
This eon saw a couple of severe ice ages called snowball
Earth.
28. It is believed that oxygen was produced by the earliest
cells.
During the Siderian Period(2500-2300 Ma), the
oxidized iron, also called banded iron
formations,formed abundantly and appeared as red as
layer in geological strata.
The released oxygen was bound up with
limestone, iron,and other minerals.
Oxygen finally began to accumulate the atmosphere.
Some oxygen was stimulated by incoming UV
radiation to form ozone.
The ozone layer absorbs a significant amount of UV
radiation that once had passed through the
atmosphere.
29. A banded iron formation from 3.15 Ga Moories
Group, Barberton Greenstone Belt, South Africa. Red layers
represent the times when oxygen was available, gray layers
were formed in anoxic circumstances.
30. Although the Sun’s luminousity increases 6% every
billion years, the Earth did not get warmer.
Instead, geological record seems to suggest it cooled
dramatically during the early Proterozoic.
The Ice Age(around 2.3 Ga) caused increased oxygen
concentration and decreased methane(CH4) in the
atmosphere.
33. Reconstruction of tectonic plate movement can be made reliably
using fitting of continental margins, ocean floor, magnetic
anomalies and magnetic poles.
Through the historyof the Earth, ther have been times when the
continents collided and formed a supercontinent with later
broke up to new continents.
Super continent RODINIA broke up and may formed
supercontinent PANNOTIA or VENDIA.
The evidence for it is a phase of continental collision known as
Pan-African Orogeny.
AFRICAN OROGENY-joined the continental masses of current-
day Africa, South America, Antarctica and Australia.
GONDWANA-included most of the landmass now in the
Southern Hemisphere, Arabian Peninsula, and the Indian
Subcontinent.
LAURENTIA-equivalent to current-day North America.
34. The end of the Proterozoic saw at least two Snowball
Earths that the oceans froze completely.
This happened about 716.5 and 635 Ma in the
Cryogenian Period. (still under investigation)
During the Snowball Earths, most of the continental
surface was covered with permafrost leading to the end
of the glaciations.
Increased volcanic activity resulted from the break-up
of Rodinia at about the same time.
35. The Phanerozoic is the major eon of life on Earth.
It consist of three eras:
PALEOZOIC
MESOZOIC
CENOZOIC
36. The Paleozoic era (meaning: era of old life forms) was
the first and longest era of the Phanerozoic
eon, lasting from 542-551 Ma.
There were unexpected changes in the environment
resulting from natural disasters.
The continents formed at the break-up of Pannotia
and Rodinia would slowly move together again.
This resulted in phases of mountain building that
created supercontinent PANGEA.
37. Pangea was a supercontinent that existed from about 300 to 180 Ma. The
outlines of the modern continents and other landmasses are indicated on this
map.
38. Pannotia had broken apart in the smaller continents:
LAURENTIA, BALTICA, SIBERIA and GONDWANA
-more oceanic crust is formed by volcanic activity
-the ocean floors and sea levels had risen
-large areas of the continents were below sea level
○ Laurentia and Baltica collided between 450-400 Ma to
form LAURUSSIA (EURAMERICA).
-traces of the mountain belt which resulted from this
collision can be found in Scandinavia, Scotland and
the Northern Appalachians
○ Gondwana and Siberia began to move towards
Laurussia.
39. Urulian Orogeny-collision of Siberia with Laurussia.
The collision of Gondwana and Siberia is called The
Variscan or Hercynian Orogeny in Europe and
Allegenian Orogeny in North America.
The Carboniferous period (359-299 Ma) the latter
phase had taken place and resulted to the formation of
the last continent.
The climates were warmer than today but at the end of
Ordovician saw a short ice age which glaciers covered
South Pole where the former Gondwana was situated.
40. Mesozoic (“middle life”) era lasted from 251-65.5 Ma.
It is sudivided into three periods: TRIASSIC, JURASSIC
and CRETACEOUS
Began with Permian-Triassic extinction event
Combination of volcanic event, an asteroid
impact, methane hydrate gasification, sea level
fluctuations, and major anoxic event
Ended with the Cretaceous-Paleogene extinction event
Wiped out dinosaurs(remains uncertain)
65 Ma, a 10 km (6.2 mi) asteroid struck the Earth just off
the Yucatán Peninsula where the Chicxulub crater is
today.
41. The Cenozoic Era began at 65.6 Ma.
It is subdivided into the PALEOGENE and NEOGENE
periods.
This is the era when they diversified into their modern
forms.
Paleogene Neogene
42.
43. Genesis 1:1: “In the beginning, God created the heavens
and the earth.
Our universe, including our planet, Earth, was in
existence for an indefinite time before the creative days
began.
Geologists estimate that the Earth is 4 billion years old.
Astronomers calculate that the universe may be as much
as 15 billion years old.
The Hebrew word translated “day” can mean various
lengths of time not just 24-hour period.
44.
45.
46. “If I as a geologist were called upon to explain briefly
our modern ideas of the origin of the earth and the
development of life on it to a simple, pastoral
people, such as the tribes to whom the Book of Genesis
was addressed, I could hardly do better than follow
rather closely much of the language of the first chapter
of Genesis.”—Geologist Wallace Pratt.
47.
48.
49. Consists of a series of constant processes through
which earth materials change from one form to
another over time.
is a model that describes the
formation, breakdown, and reformation of a rock as a
result of sedimentary, igneous, and metamorphic
processes.
is a general model that describes how various
geological processes create, modify, and influence
rocks.
50. Cementation- The process by which clastic sediment is
lithified by precipitation of mineral cement, such as calcite
cement, among the grains of the sediment.
Compaction- Tighter packing of sedimentary grains
causing weak lithification and a decrease in
porosity, usually from the weight of overlying sediment.
Deposition- The settling of materials out of a transporting
medium.
Erosion- The processes that loosen sediment and move it
from one place to another on Earth's surface. Agents of
erosion include water, ice, wind, and gravity.
Pressure- The force per unit of area exerted upon
something, such as on a surface.
51. Lithification- The processes by which sediment is
converted into sedimentary rock. These processes
include cementation and compaction.
Magma- Molten rock, generally a silicate melt with
suspended crystals and dissolved gases.
Melting- To go from a solid state to a liquid state.
Metamorphism- Alteration of the minerals and
textures of a rock by changes in temperature and
pressure, and/or by a gain or loss of chemical
components.
52. Sediment- Material (such as gravel, sand, mud, and lime)
that is transported and deposited by wind, water, ice, or
gravity; material that is precipitated from solution;
deposits of organic origin (such as coal and coral reefs).
Transportation- The processes that carry sediment or
other materials away from their point of origin.
Transporting media include wind, water and mantle
convection currents
Uplift-A structurally high area in the crust, produced by
movements that raise the rocks, as in a broad dome or arch.
Weathering- The processes by which rocks are chemically
altered or physically broken into fragments as a result of
exposure to atmospheric agents and the pressures and
temperatures at or near Earth's surface, with little or no
transportation of the loosened or altered materials.
53. This image shows how James Hutton first envisioned the
rock cycle.
James Hutton (mid-1700’s)-promoted uniformitarianism:
processes that occur today are the same ones that occurred
in the past to create the landscape and rocks as we see them
now.
He observed rocks from a nearby river from his house.
54. As shown in the diagram above, Hutton first conceived of
the rock cycle as a process driven by earth’s internal heat
engine.
Heat caused sediments deposited in basins to be converted
to rock, heat caused the uplift of mountain ranges, and
heat contributed in part to the weathering of rock.
55.
56. Magma rises from deep inside the Earth.
Some are trapped underground and hardens into intrusive
igneous rock.
Some erupts on the surface of the Earth as extrusive
igneous rock.
Pressure and heat from below cook or metamorphose the
rocks, colliding continents to push them up to the surface.
57. Wind, rain, ice and gravity erode the rock and carry away
sediment.
Rivers deposit it along their flood plains or at the bottom of
lakes and seas, where it builds up in layers and hardens
under pressure into sedimentary rocks.
These sink into the ground and are metamorphosed by
head and pressure, or folded and uplifted again by more
tectonic activity, continuing the cycle.
58. The rock cycle is powered from above and below.
Heat from within the earth ultimately derived from radioactive
decay and the slow solidification of the inner core causes the
upwelling of intrusive and extrusive rocks and produces the process
of metamorphism of rocks.
It also drives the drifting continents, uplifting mountain ranges.
The energy of the Sun heats and expands rocks at the surface and
ultimately drives the wind, waves and precipitation that cause
erosion. Gravity causes landslides which contribute to the
circulations of rocks.
59. This picture shows a basaltic eruption of Pu'u O'o, on
the flanks of the Kilauea volcano in Hawaii. The red
material is molten lava, which turns black as it cools
and crystallizes.
60. Photograph from space of the Mississippi Delta. The
brown color shows the river sediments and where they
are being deposited in the Gulf of Mexico.
61. The Grand Canyon is famous for its exposures of great
thicknesses of sedimentary rocks.
65. B.S. Environmental and Sanitary Engineering
A.Y.: 2012-2013
Second Semester
Eng’g222: Engineering Geology
Topic No.1: THE EARTH’S HISTORY AND THE ROCK CYCLE
GROUP I:
Alarcon, Arjay, BSESE 2A
Avila, Joshua, BSESE 2A
Maristela, Stephen G., BSESE 2A
Borromeo, Donna Gift C. BSSE 1-Irr.
Eng’r. Iglesia (Instructor)
November 07, 2012
Wednesday-1:00-3:00pm
GR-1
