Heisenberg-Uncertainty-Principle.pptx.pdf

In this document, we will understand the birth of geology including the several method of dating the Earth.

1. PhSc 115
Earth Science

17. The Birth of
Modern Geology

18. GEOLOGY?

19. What is Geology?
the scientific study of
the Earth's physical
structure, its
composition, the
processes that have
shaped it, and the
history of the planet
and its inhabitants.

20. The Birth of Modern Geology
Late 18th century marked the beginning of
modern geology
James Hutton suggested
Uniformitarianism - “The present is
the key to the past”
Lyell emphasized geology as a
foundation of Earth studies

21. Early Methods of Dating
the Earth:
Finding the rate at which sediments
where deposited
Determining the salinity of the
oceans
Computing the Heat lost by the Earth

22. 1. Finding the rate at which
sediments were deposited
Measured rate of sediment accumulation
Divided by total sediment thickness to
estimate Earth’s age
3 million – 1,500 million years

23. 2. Determining the Salinity of the
oceans
believe that oceans started
as fresh water
measured the quantity of salt
added each year vs. total salt
in oceans
calculated the age of the
earth is 90 million year old
John Joly

24. 3. Computing the heat loss by earth
Lord Kelvin estimated
based of precise
measurements
required few assumptions
widely accepted

25. Earth has originally molten and cooled to
present state
age could not exceed 100 million years
the sun in the past had been much hooter
and the future will become much cooler
he believe that the earth become
habitable only for around 20-40 million
years
Key Assumptions:

26. RADIOACTIVITY AND
RADIOMETRIC DATING

27. Radioactivity Dating
The spontaneous decay of unstable atomic nuclei,
releasing energy in the form of radiation.
A radioactive decay is natural process that happens
inside atoms or the process that happens when a
radioactive isotope changes into a stable atom.
A radioactive isotopes an unstable form of an
element (an atom with too many or too few neutrons
in its nucleus)

28. Isotopes

29. Two common types​ of Radio-active
•Alpha (α) decay: Emission of alpha particle (2
protons, 2 neutrons).Reduces atomic number b
mass number by 4.
•Beta (β) decay: Emission of beta particle (elec
Neutron converts to proton + electron; electron
emitted.
​Increases atomic number by 1, mass number st
same.

31. The radioactive isotope is called parent
while the elements resulting from its decay
are termed daughter product's.
-Example: Uranium (atomic number 92,
mass number 238) decays into Lead
(atomic number 82, mass number 206).

32. Two common types​ of Radio-active
•Alpha (α) decay: Emission of alpha particle
protons, 2 neutrons).Reduces atomic number
mass number by 4.
•Beta (β) decay: Emission of beta particle (el
Neutron converts to proton + electron; electro
emitted.
​Increases atomic number by 1, mass number
the same.

34. Radioactive Decay Series
The process that measures the
radioactive decay of radioactive elemen
is called Radiometric dating
A Half-Life is the time it takes for one h
of the radioactive material to decay.
Half-lives are computed from laboratory
analysis of radioactive elements.

38. Radiometric Dating Range: The rang
limited by the precision of lab equipme
Amount of Radioactive Element: Mo
minerals contain a small amount of
radioactive element, and this amount
decreases over time.

39. Carbon-14 Dating Limitations:
Cannot date very old tree trunk
the radioactive carbon is too
small.
Cannot be used if the tree trunk
lessthan100yearsold

40. Closed System Assumption:
Scientists assume a "closed system"
where nothing is added or lost.
Error Minimization: Scientists
minimize errors by carefully selecting
samples analysis of radioactive
elements.

41. Modern geology began in the la
18th century with James Hutton
concept of Uniformitarianism.
Uniformitarianism posits that
geological processes observed
today are the same as those in
past.Summary

42. Early methods to date Earth
included assessing sediment
deposition rates, ocean salinity,
and Earth's heat loss.
Radioactivity, the decay of
unstable elements, continuously
releases heat, which Kelvin
misinterpreted as Earth's cooling

43. Atoms comprise a nucleus wit
protons and neutrons, and
electrons orbiting it.
Radioactivity is the
spontaneous break-up or deca
of unstable atomic nuclei.

44. Alpha decay involves the
emission of an alpha particle,
reducing atomic number by 2
and mass number by 4.
Beta decay involves the emissio
of an electron, increasing atomi
number by 1 while maintaining
massnumber

45. The original radioactive elemen
is called the "parent," and the
new element formed is the
"daughter product."
Radiometric dating measures t
decay of radioactive elements t
determine the age of materials.

46. A key assumption of radiometric
dating is that the rate of
radioactive decay is constant ove
time.
Half-life is the time it takes for
half of a radioactive material to
decay, crucial for age
calculations.

47. The useful range of radiometri
dating is limited by laboratory
precision and the amount of
radioactive element present.
Carbon-14 dating cannot be
used for samples less than 10
years old or very old samples
with insufficient carbon-14.

48. Accurate radiometric dating
requires a "closed system" where
no radioactive elements or
daughter products are added or
lost.
Commonly used radioactive
elements like Uranium-238 and
Carbon-14 have specific half-
lives and dating applications.

49. THANKYOU and
GOD BLESS!