Evolution is an interpretation of the fossil record. The YEC position interprets the fossil record differently.
Some interpretations follow the data, while others, such as YEC, are absolutely contradicted by the data. To claim that each is a valid interpretation is complete nonsense. You should know better than to try to palm this off here.
Therefore, it is begging the question when you use evolutionnary presuppositions in order to derive an age, and then use this age as proof YEC is wrong, since you had already assumed it was wrong when you based your estimate on evolution.
Ages are derived from a wide variety of sources, from nuclear chemistry to stratigraphy, to geology, to archaeology, and more.
The fact is, all of the evidence points to an old earth. Your YEC belief has been contradicted and disproved time and time again. You can "interpret" the evidence all you want, but you can't hide from the facts, and the facts show the earth is old and that the YEC belief is wrong.
Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.