- Origin
- History
- William smith
- What is studying (object of study)
- Research examples
- Study of the Colombian basin
- References
The biostratigraphy is the science that studies the distribution of fossils and the subdivision of layered materials presented on the grounds. This means that the function of this discipline is to examine the traces, products and footprints that biozones contain. Likewise, biostratigraphy tries to determine the composition and geological time of sedimentary rocks.
This field of inquiry emerged with the purpose of analyzing the characteristics and evolution of the different organisms that make up the earth. The goal of the researchers is to get away from guesswork and try to expose concrete data on the variety and age exhibited by both the fossil and the surface that surrounds it.
Biostratigraphy studies the distribution of fossils found in the land. Source: pixabay.com
For the research to become viable, it is necessary to examine whether the extension of the strata is global or local and whether its limits are lower or higher, since the density of a biozone varies from one region to another due to the modification that He experiments with the passing of the years.
Thanks to its various areas of study, biostratigraphy is linked to other sciences such as paleobiogeography and paleoecology. Regarding the first, this is related because both examine the stratigraphic distributions of fossils; Instead, the second allows you to investigate how atmospheric changes cause the evolution of rocks and strata.
In this way, it can be affirmed that biostratigraphy is an integral discipline, since through the work carried out with micros and macro-fossils, dates close to their formations and developments can be obtained. In turn, this event helps explain the geography and climate of the past.
Origin
The term biostratigraphy is made up of the prefix “bio”, which comes from the Greek and means “life”. This word is used to designate the ability of organisms and elements to develop in different environments.
On the other hand, the term “stratigraphy” is used to designate the research field that focuses on the typification and description of stratified rocks, the interpretation of the cartography and the correlation between the horizontal and vertical biozones.
For this reason, biostratigraphy is observed as the part of stratigraphy that studies historical vestiges, since, through rocks and strata, it looks for evidence of ancient life in order to explain some environmental changes of the present.
In addition, the scientists of this discipline intend to make certain hypotheses that detail the possible structural transformations of the future.
History
At the end of the seventeenth century, the Danish naturalist Nicholas Steno (1638-1686) published a work where he demonstrated that rocks were formed over the years in horizontal layers, which were worn down due to climatic changes and constant mutations that the terrain suffered.
In this way, sedimentary organisms acquired new features and proportions. These features were the ones that caused the evolution of the biozones and at the same time gave it an ancient appearance.
Sedimentary organisms acquire new traits over time. Source: pixabay.com
According to James Hutton (1726-1797), this fact occurred because the world had specific natural processes that could not be altered. This means that each territory had an immutable unification system that determined the continuous development of the strata.
These theories represented a scientific advance in the mid-1800s, allowing geologists to evaluate the many features of fossils by observation.
However, it was not yet known how to reconstruct the original order of the biozone layers using this method, and the technique for establishing a global comparison of the sediments was not known.
Such discoveries were found at the beginning of the 19th century, when William Smith (1769-1839) proposed to adapt the principle of his study of rock dating - also known as "faunal succession" - to the experiments devised by Steno and Hutton.
William smith
In order to test his hypothesis, Smith toured England for 6 years and noticed that the lithological units of the fossils used to have the same arrangement, however, the features of the layers were different from each other despite the fact that they reflected a similar distribution. Such a finding caused the birth of biostratigraphy as a scientific subject.
Consequently, it can be established that biostratigraphy forged a global path that currently allows the ages of the strata to be similar and differentiated; it also tries to build the original shape of the rocks and breaks down both the geophysical and geochemical elements of the sediments.
What is studying (object of study)
The main object of study of biostratigraphy consists of the relative dating of sedimentary rocks and the characters that a fossil contains.
The purpose of the investigation is to examine the nature, texture, size and mineralogy of the strata. It can also deal, completely or partially, with the analysis of the following elements:
- The biogenic structures of the biozones, both in their total and internal configuration.
- The active and passive investigation of the organisms that constitute the lithological surfaces.
- The characteristics and development of the sedimentation basins.
Research examples
Biostratigraphy can be seen as a tool that has innovated radioactive field studies. It is a science that enables debate in order to calculate the possible age of the earth, the volcanic rocks, the remains of animals that are categorized as prehistoric and the ruins of ancient infrastructures.
Thanks to this discipline, the geological time scale has been created and it has been theorized about the polarity of the planet and its cyclical sedimentation. Even so, it is convenient to highlight the research carried out by the Biostratigraphy Group of the Colombian Petroleum Institute (ECOPETROL).
Study of the Colombian basin
The work carried out in the Magdalena Valley basin, located in southwestern Colombia, was of great importance because it contributed to the discovery of nanofossils formed by 89 morphospecies of sedimentary layers, whose origins were between the Oligocene to Pliocene period.
That is to say, they are biozones that have undergone some transformations for 40 million years, causing a new landscape order.
References
- De Renzi, M. (2012). Biostratigraphy and Paleoecology. Retrieved on October 1, 2019 from the University of Barcelona: ub.edu
- Hecker, F. (2016). Introduction to biostratigraphy. Retrieved on October 1, 2019 from Columbia University: columbia.edu
- Intern, G. (2014). Preliminary report on biostratigraphic. Retrieved on October 1, 2019 from Princeton University: princeton.edu
- Johnson G. (2017). Models and methods for analysis of the mode of formation of fossil. Retrieved on October 1, 2019 from Cornell University: cornell.edu
- Lawrence, D. (2010). About biostratigraphy. Retrieved on October 1, 2019 from Stanford School: stanford.edu
- Meléndez, D. (2015). Towards a definition of the study of sediments. Retrieved on October 1, 2019 from the Historical Bulletin: latinoamericanarevistas.org