How The Mountains Grew, John Dvorak, c. 2021

Excerpts at these links:
February 12, 2022;
February 9, 2022;
February 5, 2022;
February 1, 2022;
February 1, 2022;
January 31, 2022;
January 29, 2022;
August 18, 2022;

A New Geological History Of North America

There are probably no less than 3,000 geographic locations mentioned in this book. The prologue begins with Mount Rushmore, South Dakota. The epilogue ends with Rugby, North Dakota.

 

Four geologic eons:

• Hadean: 4.566 billion years ago
• Acasta Gneiss: 4.030
• Archean:
• First Snowball Earth: 2.420
• Proterozoic
• Boring Billion
• Second Snowball Earth -- Great Unconformity: 541 million years ago
• All of the previous: PRE-CAMBRIAN
• Gardens of Ediacaran 
  
• Phanerzoic eon - first period: CAMBRIAN
  
• Now

 

Proterozoic (eon)

***********************************
Ediacaran: that time between the second snowball earth
and
the burst of life in the Cambrian Period

************************************
Phanerzoic (eon)
Cambrian Period

• Paleozoic (era)
• Cambrian period
  
• Ordovician
• Silurian
• Devonian
• Carboniferous
• Permian
• Siberian Traps
• Mesozoic
• Triassic
• Jurassic
• Cretaceous
• Chicxulub impact
• Deccan Traps
• Cenozoic
• Paleogene
• Neogene Period
  
• Miocene Epoch: 23 to 5.333 million years ago
• used to model CO2 levels and global warming
  
• Quaternary

    
***********************************

Prologue: Mount Rushmore, South Dakota

Chapter 1: The Relics of Hell -- The Hadean Eon -- 4.568 bya - 4.030 bya

 

Chapter 2: Bombardment and Bottleneck -- The Archean Eon -- 4.030 bya - 4.020 bya

 

 

Chapter 3: The Children of Ur -- Early and Middle Proterozoic Eon -- 4.020 bya - 0.72 bya

 

Chapter 4: Gardens of Ediacaran -- Late Proterozoic Eon -- 720 mya - 541 mya

Cryogenian and Ediacaran Periods

 

Vendian:

• the Vendian period immediately preceded the Cambrian
• during the Vendian Period, Rodinia, supercontinent

Chapter 5: The Great Unconformity -- Early Paleozoic Era -- 541 mya - 443.8 mya
Cambrian and Ordovician Periods

As the Cambrian age began, Rodinia began to fragment

• concentrated in the southern hemisphere
• Gondwana: largest landmass
• Laurentia: second largest landmass; straddled the equator;
• Siberia and Baltica: landmass just south of the equator wedged between Gondwana and Laurentia
• rest, in bits and pieces, along the north coast of Gondwana
• Climate: Cambrian bracketed between two ice ages
• one during the late Late Proterozoic
• the other during the Ordovician
• these ice ages led to mass extinctions
• so mass extinction just before the Cambrian explosion
• and, a mass extinction ending the Cambrian, called the Orduvician
• melting of ice caps; seas rose; marine invertebrates, such as trilobites, thrived
• plants had not yet evolved
• photosynthesis: bacteria and algal protists
• oxygen-depleting bacteria significantly decrease --> much more oxygen available
• excess oxygen may have been the reason for the "Cambrian explosion"

Orduvician: first major extinction; ice age, Gondwana south pole, first plants (marine):

• Gondwana: south pole; ice
• "modern" continents along the equator; but most of land below sea level, initially;
  
• then, glaciers on Gondwana; sea levels dropped; most of land above sea level
• changes led to mass extinction (remember, most of life was marine)
• marine life
  
• trilobites did not die out with the mass extinction
• cephalopods become dominant life form: molluscs related to octopus and squid
• brachiopods: look like clams but not of same family
• crinoids: attached to sea floor
• sponges, corals, fish
• first plants: because they had chlorophyll, but needed to live in water; no vascular system

Chapter 6: An Ancient Forest At Gilboa -- Middle Paleozoic Era
443.8 mya - 358.9 mya
Silurian and Devonian Periods

Remember, during the Orduvician, glaciers on Gondwana --> sea levels falling
now, in the Silurian, just the opposite, sea levels rising

• rich marine life
• extensive reef building
• first signs that life began to colonize the new estuary, fresh water and terrestrial ecosystems
• Gondwana: still south pole
• two smaller continents along equator
• Laurentia
• Baltica
• these three continents start to move / collide
• Orduvician: start to move
• Silurian: movement continues
• Devonian: movement complete -- large continent, Euroamerica
• Caledonian Orogency: mountains of northern latitude: British Isles, Scandinavia; and, Appalachia

Silurian:

• most of North American under shallow watrer
• first jawless fish: jawless, Agnatha
• Romundina, a placoderm; armored; cartilage skeleton; earliest fish known to have developed jaws

Devonian: Age of Fishes

• Laurussia or Euroamerica: Laurentia + Baltica
• Gondwana: still to the south; much of it the South Pole
• sea water covered 85% of the globe
• oxygen decreased significantly: led to extinctions, but then also new life forms

Chapter 7: Fires, Forests, and Coal -- Middle Paleozoic Era -- 358.9 mya - 298.9 mya
Carboniferous Period

Beginning:

End: the Carboniferous Rainforest Collapse -- only one of two plant mass extinctions in all history of the earth; the other only 50 million years later, end of the Permian

• climate change: suddenly from hot and humid to cold and dry
• think, from Amazon rain forest to Arctic ice
• collision of Euramerica and Gondwana was ending and Pangea was forming (this is interesting, because the Permian Basin, in the next period, was the direct result of collision of Euramerica and Condwana
• three things:
• massive continent: monsoons could not reach the interior (but why cool?)
• relatively less coastline -- less coastal biome for marine lief to migrate to
• also, huge shadow from Alleghenian Orogeny down cent of the continent --> dried the land
• Lepidodendron became extinct

• Amphibians: many extinct -- needed water; think, again, loss of frog species in Amazon rainforest
• dry conditions favored those who found new type of egg: amniotes; among the first -- Hylonomus 
• Hylonomus: link here. 
• 312 mya, during the Late Carboniferous
• earliest unquestionable reptile (Westlothiana is older, but in fact may have been an amphibian, and Casineria is rather fragmentary)
  
• the only species is the type species, Hylonomus lyelli
  
• looks like the Geico gecko 
• found in the Joggins Formation, Nova Scotia
• named the Provincial Fossil of Nova Scotia in 2002
  
• reptiles: hard-shelled eggs
• hard-shelled eggs: reptiles, dinosaurs, and birds (dinosaurs)
  

 

Chapter 8: The Great Dying -- Late Paleozoic Era -- 298.9 mya - 251.902 mya
Permian Period

Permian: the Great Dying -- Trilobites die during the great Permian extinction.

Reminder, another way to look at this, to remember eons and eras

• if life was present, the eon had to be the Phanerzoic (some minor exceptions)
• if life was present:
• before dinosaurs, predominantly sea life, early amphibians, early reptiles: Proterozoic Era
• with dinosaurs, also came more reptiles, early mammals: Mesozoic Era
  
• after the dinosaurs, rise of mammals: Cenozoic Era
  
• then, one can go back to each of the periods of the Proterozoic
• Cambrian: burst of life
• Ordovician:
• Silurian:
• Devonian:
• Carboniferous:
• Permian:

Euramerica <-->Gondwana -------> Pangea (west Texas oil)

All geology is local ... as well as global.

 

Chapter 9: A Grand Staircase --Early and Middle Mesozoic -- 251.902 mya - 145.7 mya

Triassic and Jurassic Periods

Dinosaurs, p. 181.

Pangea begins breaking apart; megamonsoons -- some, hemi-spherical in extent.

As Panagea broke up, storms became smaller in size.

When Triassic began, storms were at their height -- so -- Triassic / Pangea --

Jurassic Period: much of the central and western Pangea extremely arid --> Navajo Sandstone (Zion National Park)

As the Jurassic Park continued, the Atlantic widened. North America separated from Europe / Africa.

Jurassic: dense forests -- mostly conifers -- lush forests -- far extent from the equator. Atmospheric CO2 at least 4x what it is today; lots of rain but western half of Pangea still aria.

Abundant life, especially dinosaurs filling every niche. 

Morrison Formation: soon thereafter Jurassic Period came to an end. 

Jurassic / Cretaceous boundary: what is the exact boundary? p. 184.

Wow: experts abandoned fossils defining the boundary -- p. 184.

Jurassic --> Cretaceous -- boundary now, temporarily, defined by earth's magnetic polarity, M19n, p 184.

Coincides with miroorganism: Calpioella alpine.

But Jurassic / Cretaceous --

Cretaceous:

• first flowers;
• first broad-leaf trees;
• new types of animals;
• including new types of dinosaurs

Cretaceous, p. 186 -- Western Interior Seaway

Chapter 10: Western Interior Seaway -- Late Mesozoic Era 145.7 mya - 66.043 mya
Cretaceous Period

 

 

Chapter 11: A Calamitous Event -- Chicxulub Meteor Impact -- 66.043 mya

 Along with dinosaurs, the ammonites go extinct

 

Chapter 12: Extinction -- Deccan Traps -- 66.4 mya - 65.6 mya

 

 

Chapter 13: How The Mountains Grew -- An Orogenic Interlude

 

Chapter 14: The Great Lakes of Wyoming -- Early and Middle Cenozoic Eras -- 66.043 mya - 2.58 mya

Paleogene and Neogene Periods

 

Chapter 15: A Drowned River at Poughkeepsie -- Late Cenozoic Era -- 2.58 myka to the Present

Quarternary Period

 

Chapter 16: A World Bequeathed and the Great Acceleration

The Anthropocene

 

Epilogue: Rugby,  North Dakota

The Future