http://www.grisda.org/origins/51006.htm
W.
I took a look at the article.
The first third of it examines the ramifications for radiocarbon dating based on a global flood. There is absolutely no evidence for a global flood. There is a tremendous amount of evidence that there was no global flood.
The next major section deals with the absolute upper limits of the radiocarbon method. This is the area where contamination from any source will yield measurable results. I find this argument to be unconvincing. If you want radiometric results in that age span you use other methods than radiocarbon, and they work quite well. But the article ignores all other methods of radiometric dating.
In essence, the article is saying that at the extreme upper limits of the radiocarbon method you start to get flaky results, so we have evidence of a young earth. This is absolutely false. Any method has its limits, and trying to extend the radiocarbon method to 100,000-300,000 years is way beyond the limits any scientist would currently propose for radiocarbon.
This article conveniently ignores several other radiometric methods which work very well in that age range and provide evidence that the early really is billions of years old.
All in all, I find that this article contains dishonest research. It misinterprets several well established scientific methods, includes the entirely unsubstantiated global flood as a correction mechanism, and ignores evidence which disproves its main point. Thats about as dishonest as you can get. I suppose that is par for the course in apologetics, but it is not acceptable in science.
I have not studied the Turin Shroud articles so I have no clue yet on that one.
Please read the links I posted earlier.