Thanks for sharing; a bit of hefty duty reading; but even from a "christian perspective", if it goes against the Bible timeline, then it is not a christian perspective, but I digress.
Let's address one key point in the article for assessing the age of anything past 6,000 years:
That's an assumption that it is a yearly layering.
Follow if you will that the Bible account of the world wide flood is true and Peter did referenced that the world was covered by water in 2 Peter 3.
From the report in the Bible and what we see in nature without reading the evolutionary perspective into it:
The moon is slowly moving away from the earth; of which I say started at the time of the global flood as that moon did not have any impact craters when it was created, thus pointing to the cause of it moving away from the earth.
There are impact craters on the earth, one big one off of the coast of Nova Scotia: they too all happened at the time of the global flood as the impact would result in the fountain of the deep rising up, forming the mid-Atlantic ridge mountain, which in the time of Peleg did sink as the water that was all in one place when the world was created began filling parts of the one land that sank below sea level, dividing the land.
All of these impact craters would cause a plate shift.
The supervolcanoes and other volcanos as a result would be spewing volcanic debris into the air adding to the debris from the impact craters.
The moon known now for creating the rise & fall of tides and moving away from the earth would have an effect on the mist that God provided to water the earth and thus causing that list to rise & condense to form clouds and thereby rain has come for the first time.
We see how water reservoir as discovered by science can give fossils an older dating than it actually is. That would also apply to fossils as found buried in sentiments.
Now out of all of that chaos, how can science expect to get an accurate dating on anything when the global flood has dramatically changed the rate of decay in everything?
Now in relations to the ice core samplings: I say it is assuming it is a yearly layering only when things has settled down enough from that global flood for a regular pattern to develop. Imagine a greenhouse planet going through dramatic changes, starting off with an instant freeze as one can attest to the frozen mammoths found with greeneries still in its mouth.
Now having been a greenhouse planet, would there not be a flashes of heat and cold happening as the chaotic weather that has developed would hardly relate to normalcy to what our yearly weather for a pattern to discern?
The same goes for tree rings.
Genesis 7:24 And the waters prevailed upon the earth an hundred and fifty days.
Genesis 8:1And God remembered Noah, and every living thing, and all the cattle that was with him in the ark: and God made a wind to pass over the earth, and the waters assuaged; 2 The fountains also of the deep and the windows of heaven were stopped, and the rain from heaven was restrained; 3 And the waters returned from off the earth continually: and after the end of the hundred and fifty days the waters were abated.
So the ice shelf was formed, but no one can say if it had started forming by "yearly layering" out of all that mess from the global flood event any more than those tree rings going beyond the 6,000 years Biblical marker was a yearly ring.
And I do point out that global warming may just be the earth getting back to what it used to be before the flood, but without that mist covering the whole earth like a protective blanket, I can see how fervent heat will be coming on the earth soon, albeit, I am sure there is more to that than just that when the supervolcano at Yellowstone erupts and a great earthquake will occur wherein the world responds to the Bridegroom when He visits.
Luke 12:49 I am come to send fire on the earth; and what will I, if it be already kindled?
Luke 21:25 And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring; 26 Men's hearts failing them for fear, and for looking after those things which are coming on the earth: for the powers of heaven shall be shaken. 27 And then shall they see the Son of man coming in a cloud with power and great glory. 28 And when these things begin to come to pass, then look up, and lift up your heads; for your redemption draweth nigh. 29 And he spake to them a parable; Behold the fig tree, and all the trees; 30 When they now shoot forth, ye see and know of your own selves that summer is now nigh at hand. 31 So likewise ye, when ye see these things come to pass, know ye that the kingdom of God is nigh at hand. 32 Verily I say unto you, This generation shall not pass away, till all be fulfilled. 33 Heaven and earth shall pass away: but my words shall not pass away. 34 And take heed to yourselves, lest at any time your hearts be overcharged with surfeiting, and drunkenness, and cares of this life, and so that day come upon you unawares. 35 For as a snare shall it come on all them that dwell on the face of the whole earth. 36 Watch ye therefore, and pray always, that ye may be accounted worthy to escape all these things that shall come to pass, and to stand before the Son of man.
2 Peter 3:5 For this they willingly are ignorant of, that by the word of God the heavens were of old, and the earth standing out of the water and in the water: 6 Whereby the world that then was, being overflowed with water, perished: 7 But the heavens and the earth, which are now, by the same word are kept in store, reserved unto fire against the day of judgment and perdition of ungodly men. 8 But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day. 9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. 10 But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up. 11 Seeing then that all these things shall be dissolved, what manner of persons ought ye to be in all holy conversation and godliness, 12 Looking for and hasting unto the coming of the day of God, wherein the heavens being on fire shall be dissolved, and the elements shall melt with fervent heat? 13 Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness.
I do thank you for sharing, brother, but I point out that because of the global flood, no science can account for the decay rate of anything, let alone date anything when they are not taking the chaotic event of the global flood in account. So therefore I take the word of God over men's even whne they try to do science from a "christian" perspective.