Earth From the Inside Out
Yosemite’s Half Dome, part of the Sierra Nevada mountain chain.
,• Geomorphology: study of the shape of the
Earth’s features and how they change over time
• Uniformitarianism: James Hutton, 1795: the
same geologic processes observable today have
operated since the beginning of Earth’s history,
the present is the key to the past
• Catastrophism—previous theory that argued
change came through sudden upheavals
, The geologic timescale: 4.5 billion years
Priscoan Eon (Hadean)—earliest known rocks on Earth, 4.3 billion years old, Northwest
Territories, Canada.
Proterozoic Eon—oxygen added to atmosphere, 2.8-2.4 billion years ago, through
photosynthetic bacteria.
Ordovician Period (Paleozoic Era, Phanerozoic Eon)—480 mya Appalachians form, Pangea
Triassic Period (Mesozoic Era, Phanerozoic Eon)—Sierra Nevadas form
Quaternary Period (Mesozoic Era, Phanerozoic Eon)—glaciers, 2.5mya – 10,000 years ago. Ice
Age climate variability meant proliferation of plants and animals and rise of Homo sapiens.
, The Earth’s history in a 24 hour day or a 12 month year
The Earth in 1 Year:
1 cell by May-Nov
Multi-cell in Nov.
Nov.21—fish, vertebrates
Nov. 27—plants
Dec. 7—reptiles
Dec. 14—mammals, birds
Dec. 21—flowers
Dec. 24—grass, primates
Dec. 31—upright walking
12am, Jan.1—Homo Sapiens
Modern humans appear
about 200,000 years ago…in
Earth’s 4.6 billion year
history.
Life emerges in the last 2 hours & 50 minutes.
Yosemite’s Half Dome, part of the Sierra Nevada mountain chain.
,• Geomorphology: study of the shape of the
Earth’s features and how they change over time
• Uniformitarianism: James Hutton, 1795: the
same geologic processes observable today have
operated since the beginning of Earth’s history,
the present is the key to the past
• Catastrophism—previous theory that argued
change came through sudden upheavals
, The geologic timescale: 4.5 billion years
Priscoan Eon (Hadean)—earliest known rocks on Earth, 4.3 billion years old, Northwest
Territories, Canada.
Proterozoic Eon—oxygen added to atmosphere, 2.8-2.4 billion years ago, through
photosynthetic bacteria.
Ordovician Period (Paleozoic Era, Phanerozoic Eon)—480 mya Appalachians form, Pangea
Triassic Period (Mesozoic Era, Phanerozoic Eon)—Sierra Nevadas form
Quaternary Period (Mesozoic Era, Phanerozoic Eon)—glaciers, 2.5mya – 10,000 years ago. Ice
Age climate variability meant proliferation of plants and animals and rise of Homo sapiens.
, The Earth’s history in a 24 hour day or a 12 month year
The Earth in 1 Year:
1 cell by May-Nov
Multi-cell in Nov.
Nov.21—fish, vertebrates
Nov. 27—plants
Dec. 7—reptiles
Dec. 14—mammals, birds
Dec. 21—flowers
Dec. 24—grass, primates
Dec. 31—upright walking
12am, Jan.1—Homo Sapiens
Modern humans appear
about 200,000 years ago…in
Earth’s 4.6 billion year
history.
Life emerges in the last 2 hours & 50 minutes.
