What defined the Ordovician period?
Thanks DrBob222 :) That is the link my school gave me, but I read over it again and understand it now.
This isn't cheating, but I did follow the link my lesson provided. It has a lot of events, but I don't really get which are the most important.
https://ucmp.berkeley.edu/ordovician/ordovician.php
The Ordovician period was defined by a combination of geological and biological factors. To understand how this period was defined, we first need to know the methods scientists use to determine and characterize geological periods.
1. Stratigraphy: Stratigraphy is the study of rock layers, or strata, in the Earth's crust. By examining the different layers and their characteristics, scientists can determine the relative ages of the rocks and the order in which they were formed. This helps in dividing Earth's history into various geological periods.
2. Fossils: Fossils are the remains or traces of ancient organisms preserved in rocks. The presence and types of fossils found in specific rock formations can provide vital information about the age and environmental conditions during a particular period.
Now, let's look specifically at the characteristics that defined the Ordovician period:
1. Rock Formation: The boundaries of the Ordovician period were determined by studying the distinctive rock formations found around the world. The rocks from this period are typically sedimentary and can be identified based on certain features like composition, texture, and the presence of specific minerals.
2. Fossil Record: Fossils found in the rocks from the Ordovician period played a crucial role in defining this period. Paleontologists have studied a wide range of fossilized organisms from this time, including marine invertebrates like trilobites, brachiopods, cephalopods, and early fish. These fossils provided valuable insights into the diversity and evolution of life during the Ordovician period.
3. Chronological Placement: By dating the rock layers using radiometric dating techniques, scientists have determined that the Ordovician period lasted from approximately 485.4 to 443.8 million years ago. This chronological information, along with the distinctive rock formations and fossil assemblages, allows scientists to identify and define the specific period.
In conclusion, the Ordovician period was defined based on the analysis of rock formations, examination of fossils, and determining the chronological position of the rock layers. Through these methods, scientists have been able to characterize this period as a significant chapter in Earth's history marked by distinct geological and biological features.