Tree Ring Dating

Most everyone knows that trees have rings. Each year, a tree grows a new ring. The age of a tree typically can be determined by counting the rings. I bring this up because counting tree rings proves that the earth must be more than 11,000 years old.

Now it’s a little more complicated than I have implied (but only a little). The oldest known living tree is 5065 years old. This fact alone places into question the young-earth chronology in which a global flood devastated the earth only 4360 years ago.

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Each ring consists of both light and dark wood and corresponds to one year of growth.

Tree rings carry information. Each ring contains two types of wood. The first type, which forms at the beginning of the growing season, is called the early wood. It is less dense and is lighter in color. The second type, which forms at the end of the growing season, is called the late wood. It is denser and is darker in color. The thickness of the early wood and the late wood formed in a given year is an indication of the nature of the growing season in that year. A long, warm growing season with plenty of rainfall produces a wide ring. A cold growing season or one with little rainfall produces a narrow ring.

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Bristlecone pines such as this one include the oldest known living trees.

Now a warm year for one tree is also a warm year for other trees in the same area. As a result, one would expect a correspondence between the widths of the rings of different trees in the same area. This is, in fact, the case. Trees of the same type living in the same area at the same time show the same pattern of wide and narrow rings.

Suppose that one were to find a piece of fossilized wood of unknown age. It may be possible to match the rings of that wood to the rings of living trees of the same type in the same area and hence to determine the age of the wood. Now suppose that a reliable match is determined but that the fossilized wood also has rings that were formed before the earliest ring of the living tree. The record of tree rings then encompasses a span of time longer than the age of the oldest living tree.

This process has been carried out by scientists many times, resulting in continuous tree ring records that, in some cases, stretch much farther back through time than the age of the oldest living tree. The longest continuous tree ring record of this sort spans more than 11,000 years.

At this point, I might typically answer some objections or address opposing arguments. However, there really is nothing in that respect to be done because Answers in Genesis has already done it. They have analyzed this issue and have affirmed that the rings are indeed correctly cross-matched and that the bristlecone pines are not capable of producing more than one ring per year.

So not only do we have direct evidence that trees have been growing on the earth for more than 11,000 years, but we also have evidence concerning the nature of those years and even the amount of carbon-14 present in the atmosphere in each year—which will be the subject of the next post.