Permian Triassic Boundary (PTB) is the most important transitional succession in Geological events. The great mass extinction events, called the Permian Mass extinction happened in this boundary, 251.94 Million years ago. The most devastation past event in which more 90% of marine species and 70% of terrestrial vertebrate families died out (Erwin, 1994). These great dying events occurred across the Permian Triassic Boundary. The Permian Triassic Boundary is most important to correlate and establish the great dying event globally. Now, Meishan Section (GSSP), South China (Global Stratotype Point and Section) is used to correlate the other Permian Triassic Boundary to identify the exact event horizon globally.
|Geologist collecting rocks|
Problems of GSSP Concepts as a FAD to Identify the PTB;
Some Geologist uses Lowest Observed Occurrence Point in the replacements of the FAD (First Appearance of the Datum) to identify and correlate with the established GSSP. This concept is a misunderstanding from the geologist or scientist. The GSSP concept is the use of the Conodont Fossil named Hindadus Parvus and based on the First Appearance of this Fossil is determined as a Global Stratotype Point and Section) for the GSSP section like Meishan Section, South China. The first Conodont Fossil, Hindadus Parvus has been found at 251.88 Ma at the Meishan Section.
Here are some other misunderstandings of using rightly of the GSSP concept which makes the geologist a wrong correlation of the PTB for a new Stratigraphic section.
Understanding the Misunderstanding of the GSSP Concept to use;
|Time-distance diagram modified from Eicher (1968)|
Graphic Correlation Model;
Graphic Correlation Model is a very simple model and widely used in the oil exploration expert, or other geologists. The model has two successions in X and Y-axis as a Hypothetical Reference Section and a Hypothetical Comparison Section. Using this model is very accurate to identify and establish a correlated section. Here, the Hypothetical Reference Section indicates the established GSSP section data and the Hypothetical Comparison Section include all the data from the new section to be compared. Then, we have to compare both the LOOP and HOOP data for both sections. Then we will get a Line of Correlation Curve (LOC). This line of correlation curve will be projected in the established GSSP section and we can get the exact PTB of a new stratigraphic section.
|Graphic Correlation Model|