Geologic ages

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Geologic time scale showing ages.
Geologic time scale showing ages.

Through evidence of age attained by radiometric dating techniques evolutionary deep time is assumed and epochs of time are determined and called geologic ages. However the Earth being covered in vast layers of sedimentary rock are interpreted by most creationists as being the result of the Biblical flood of Noah. One obvious features of these rock layer is that they differ dramatically in content and consistency from one layer to the next. Early geologic investigators also noticed that the fossils contained in them also change conspicuously as one progresses from examining lower to upper layers. The fossil sorting and differences in rock types has been answered by creationists as due to a variety of mechanisms such as basic survivability due to varying environmental tolerances of organisms and hydrological sorting.

These aforementioned differences among strata have convinced geologists that a catastrophic interpretation of Earth's geology was untenable, and most now hold to an uniformitarian interpretation. The layers are believed by uniformitarian geologists to instead represent vast ages of time. Comprehensively, these geologic ages are known as the geological column. Many of the individual layers have been assigned names, which frequently describe their characteristics or location where they were first studied. Radiometric dating has also been used to assign dates to the igneous rocks associated with each layer. Their basic characterization and supposed time spans are detailed below.

Contents

Quaternary

The Quaternary Period is a subdivision of geological time scale. Evolutionists say that the Quaternary period lasted the last two million years up to the present day. The exact length of this period is a matter of debate. Many evolutionists have placed the period between 1.8 million years and 2.6 million years. You will find both dates in different published books. Together the Quaternary and the Tertiary periods form the Cenozoic Era. The Quaternary Period can be subdivided into two epochs; the Pleistocene and the Holocene. This period saw the ice age and the most climate change. It also saw the extinction of most of the prehistoric animals like the saber-tooth cat, the woolly mammoth and others.

Tertiary

Tertiary period is the name for a major portion of the Cenozoic era. It is also the most recent of the geological eras. It lasted from about 26 to 66 million years ago. The name of Tertiary was first given in about the middle of the 18th century. It was given to a layer of sediments geologically younger than other deposits know as Primary and Secondary layers. Later the Quaternary period was added around 1830 as a fourth division.

These divisions of the earth's crust seemed to be adequate for the region they were found in and were applied to. But when the same system was later found in other parts of Europe and North America, it was then realized that one scheme of classification could not be applied to every system, so the names of Primary and Secondary were abandoned. The names Tertiary and Quaternary were and still are used today. Other names also used are Palaeogene and Neogene. In the Tertiary period, Gondwanaland finally split completely apart, and India collided with the Eurasian plate. Also, the previously existing mountain ranges of North America were elevated, in Europe other mountain ranges were formed, and in Asia the Himalayas were formed. At the beginning of the Tertiary period, mammals replaced the reptiles as the dominant animal group. Modern types of animals such as birds, reptiles, fish and invertebrates were numerous at the beginning of the period or they appeared at the very beginning of the Tertiary period.

Cretaceous

The Cretaceous period is normally noted for being the last period of the dinosaurs. This period is believed by evolutionists to have lasted from about 144 to about 65 million years ago. Also, during this period a new kind of dinosaur, the ceratopsian and pachycepalosaurid appeared. We also found the first fossils of many insects and many modern mammals and bird groups, and the first flowering plant fossils. The breakup of the world-continent Pangaea, which began during the Jurassic period continued into the Cretaceous period. This continued breakup led to increased regional differences between the northern and southern continents. At the end of the Cretaceous period many types of animals and dinosaurs disappeared. Other animals that had played a secondary part in the Cretaceous period were then dominant in the next period and exist today.

Jurassic

The Jurassic period is believed by evolutionist to have began exactly 210 million years ago and lasting for 70 million years of the Mesozoic Era. In the Jurassic period the great plant eating dinosaurs walked the earth eating the growths of ferns and of palm-like cycads and bennettitaleans. The smaller but more aggressive and vicious carnivores stalked the herbivores. The oceans contained fish, squid, coiled ammonites, and the great ichthyosaurs and the long-necked plesiosaurs. The pterosaurs and the first birds were also in this period. This, the Jurassic period, was part of the Mesozoic Era. The Jurassic period was named after the Jura Mountains, which are situated on the border of France and Switzerland.

Triassic

In many different ways, the Triassic period was a time of transition. This period is said to have lasted from 248 - 206 million years ago. During this period the world continent Pangaea existed which altered global climate and ocean currents. The Triassic period was ended with a large extinction of the animals that had been living then. The Triassic period was named in 1834 by German geologist Friedrich August Von Alberti.

Permian

The Permian period lasted from around 290 to about 248 million years ago. This period was the last period of the Paleozoic Era. The major difference between the Paleozoic and the Mesozoic was one of the largest group of extinctions in recorded history. This affected many groups of animals, but it mostly affected marine life.

Some of the groups of sea life survived this mass extinction but they never recovered their large populations again. This cleared the way for new species of sea life. On land a smaller extinction was going on. This extinction led to what is known as "The Age of the Dinosaurs". The plants in this age also switched over to gymnosperms instead of being Cycads.

In the beginning of the Permian the plates of the earth brought the super-continent of Pangaea together. Most of the continents came together in Pangaea; the super-continent took up much of the area between the southern and northern poles. The rest of the Earth was covered by a single ocean know as Panthalassa with a smaller ocean to the east called Tethys.

Pennsylvanian

The Pennsylvanian started 320 million years ago and ended 286 million years ago. During this period there were low lying swamps and deltas that covered most of what is now Virginia and the western U.S. These conditions were perfect for the beginning of coal formation in the U.S. Some trees in standing position are found in surface mines. The trees are sometimes 30ft tall, suggesting a rapid burial of the tree. They age of these rocks are determined by measuring the tonstein parting in a seam. A tonstein parting is created from volcanic ash. A tonstein parting can almost always be accurately dated according to evolutionists. When Pangaea, the super-continent was beginning to be formed, newly-formed sediments pushed older sediments north. So that is why all the "older" coal seams are in northern Virginia and all the "younger" ones are in southern Virginia.

Mississippian

The Mississippian period lasted from 360 to 325 million years ago. The period was named Mississippian because the rocks were first collected in Mississippi. In Europe however, they call the period the Devonian Carboniferous. In the U.S, they split it into the Mississippian and the Pennsylvanian. Rocks are classified Mississippian based on a particular group of fossils found inside them.

Devonian

The Devonian Period lasted from 417 to 354 Million Years Ago. The Devonian was also called the Age of the Fishes. The first major plant life, like Zosterophyllophytes and Trimerophytes, two types of vascular plants, was found in the Devonian. During the Devonian, groups of animals colonized the land and different types of coral and many new types of fish colonized the sea. The major landmasses in this time period were North American and Europe, which had most of its land covered by water, which were together at the time, and were near the equator. Also another continent, consisting of South America, Africa, Antarctica, India, and Australia covered the southern part of the world.

Silurian

The Silurian lasted from 443 to 417 million years ago. In this period the first corals and jawless fish appeared. Also in this period glacial structures melted and added to the sea. This period saw many new types of sea life and animals. The end of the period saw the first jawed fish. The rest of the period was much more stable then the other time periods before it, because it didn't have dramatic environmental changes. At the end of the period, a new super-continent was formed, called Laurussia.

Ordovician

The Ordovician began about 510 Million Years ago and ended 445 Million Years Ago. All of the earth's land was in one super-continent called Gondwana (or Gondwanaland). During this period the super-continent shifted toward the south pole. This period also had much sea life. It is also suggested that plants occupied the land in great numbers. At the end of the Ordovician, Gondwana finally stopped its migration to the South Pole. This caused many small seas to drain and seas to shrink in size and in volume, causing a mass extinction at the end of the Ordovician.

Cambrian

The Cambrian Period is said to be 543 to 490 million years old. The Cambrian Period is also an important point in history of the beginning of life according to the evolutionists. During this time the major groups of animals appeared in the fossil record. In the Cambrian fossil layers there is a sudden outburst of fossils, this outburst of fossils is called the "Cambrian Explosion". The Cambrian Explosion is a fast appearance of fossils in the Cambrian fossil record. The Cambrian had been considered as the rock layer that had the first fossils of animals, but those fossils can also be found in the older Vendian strata.

Related References

Creationist References

  • Biblical Geology Tas Walker Ph.D
  • CRS Quarterly The Uniformitarian Stratigraphic Column—Shortcut or Pitfall for Creation Geology?
  • CRS Quarterly Flood Geology of the Crimean Peninsula, Part I: Tavrick Formation

Secular References


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See Also

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