All of the pages within this page are linked-to in AGE OF THE EARTH - SCIENTIFIC EVIDENCE where you can find longer pages with more in-depth treatments, and many additional resources about age-science. This page, assembled by Craig Rusbult, is an "overflow" from a collection of pages with Examples of Old-Earth Evidence.
• Coral Reefs: Indicators of an Old Earth
by Perry G. Phillips
Viewed from the air, Pacific coral reefs generally appear as circular islands called atolls. They
have a shallow lagoon in the middle and the open ocean lies toward the outside. Other features
include: (1) a steep slope towards the ocean outside that descends into the depths; (2) a flat reef-platform between the island and the steep slope; (3) faster-growing corals on the windward, outer
side; (4) storm-broken pieces of coral on th e windward side, many of which have fallen partway
down the slope and become fused to the reef; (5) slower-growing corals on the leeward (down-wind) side of the island.
The reefs are built by living organisms, primarily corals. The corals contain green algae in their
interiors that provide oxygen the corals need to live. The corals, in turn, provide protection for
the algae - a mutually supportive relationship that is called a symbiosis. The algae produce the
oxygen by photosynthesis, so they need sunlight. This requirement limits reef-building coral to
the upper 65 feet or so of water where sufficient light exists for photosynthesis. Of course, the
dead carbonate "skeletons" of the coral can continue to exist at much greater depths.
The most reasonable explanation for coral growth begins with a volcano. Volcanoes can build
themselves thousands of feet upward from the ocean floor, and some of them will grow tall
enough to break through the surface of the water. During periods of volcanic inactivity, corals
and lime-secreting algae colonize the areas just below the shoreline around the volcano. The
corals and algae cement themselves together with lime as they grow, thereby constructing a
circular reef around the volcano. Eventually the volcanic peak erodes to sea level. Further, as a
result of tectonic activity, the volcano slowly sinks into the ocean depths. If the rate of sinking is
slow enough, the reef-building can keep pace and continue constructing the reef. In this way a
reef can be built that is several thousand feet tall, even though living corals can only survive in the
upper layers of the ocean. Deep sea drilling at several atolls in the Pacific has confirmed this
theory of reef growth, revealing volcanic rock below the corals.
We will here concentrate on one atoll - Eniwetok - as an example of how we can determine the
age of a reef. This reef was thoroughly investigated by deep core drillings in preparation for its
use as a test-site for a hydrogen bomb explosion. This atoll is roughly circular with all the
standard characteristics of a growing reef. It rests upon an extinct volcano, as expected, and the
volcano rises about two miles above the ocean floor. The reef itself is 4,610 feet tall.
Examination of the material from the bore holes reveals that this is a normal reef that formed from
the cementing together of corals and lime-secreting algae. (This algae is different from the kind
that lives within the corals.) In addition, three unconformities (discontinuities in the growth of the
reef) were located at depths of 300, 1000, and 2780 feet. These unconformities contain pollen
from seed-bearing shrubs and trees, which indicates there were periods when the reef surface was
above sea level (and so no coral growth at the surface) which lasted long enough for land plants
to colonize the surface.
With this information we are ready to calculate the age of the Eniwetok reef. All we need to do
is divide the height of the reef by the rate at which it grew. This calculation is rather like finding
how long it would take to travel a certain distance. The time is calculated by dividing the distance
to be travelled by the speed or rate of travel. For example, if one is to travel 150 miles and one's
average rate of speed is 50 miles per hour, then the trip will take 150/50 = 3 hours to make the
trip, not allowing for stops along the way. Just think of the height of the coral as the distance
travelled and the rate of coral growth as the speed.
Research indicates that maximum rates of reef growth are about 8 millimeters per year,
determined by examining the present growth rates of numerous reefs in the vicinity of Eniwetok.
Admittedly, one may question whether the growth rate wasn't perhaps faster for this particular
reef, but there are limits to how fast corals can grow. Growing biological systems obey strict
physical and chemical laws relating to metabolism, reproduction, and intake of nutrients. This last
item is particularly important because the rate of growth of coral depends on the amount of
dissolved calcium carbonate it can extract from the seawater. Calcium carbonate, though, is
rather insoluble, so there is not a large concentration of it in ocean water. Thereby reef growth is
limited to a fraction of an inch per year.
Thus 8 millimeters per year cannot be far from the actual growth rate of the Eniwetok corals.
Using this value, the age of the reef is calculated by dividing 4,610 feet by 8 millimeters (about .3
inch) per year, which is about 175,000 years. But this is a minimum age since we have not taken
into account the time periods (represented by the unconformities mentioned above) when the reef
was not growing. Nor have we taken into account the time necessary to form the volcanic base
on which the reef grew.
Recently, further calculations for the rate of reef growth have been based on the concentration of
dissolved calcium carbonate in seawater and upon the rate at which corals can absorb it and
manufacture their shells. This rate turns out to be only about 5 millimeters per year, which means
that the Eniwetok reef is more like 280,000 years old, not counting pauses in growth. A similar
analysis for the much larger Grand Bahama Reef reveals an age of 790,000 years. And again, this
is a minimum age, since that reef also contains numerous unconformities.
Young-earth creationists, of course, object to these great ages. They attempt to find alternative
explanations for the formation of reefs. One idea is that the reefs formed as calcium carbonate
precipitated out of the waters of Noah's Flood. This is nonsense, however, because precipitation
involves dissolved calcium carbonate. How can one explain that the calcium carbonate managed
to precipitate in the form of a reef, complete with the five characteristic features mentioned above,
and the presence of corals that look just like those that were once alive? Besides, the insolubility
of calcium carbonate is such that all the ocean waters of the world could not hold enough to
construct past and present reefs in a one-year flood.
Another young-earth proposal is that reefs were formed by the piling up of lime during the time
of Noah's Flood. But if this were true, how did the raging flood waters just happen to pile up the
lime in a structure that has all the appearance of having been a growing entity? And why are the
reefs free from the mud, clay, and other debris invariably present in flood waters? Finally, how
were the waters able to pile up the reef material only on the upper slopes of ancient volcanoes?
This would be the last place we would expect waters to deposit their debris, especially on those
that are thousands of feet tall. For all these reasons, the proposal that reefs were piled up by flood
waters lacks any credibility.
Finally, one can find statements in young-earth literature that corals can grow as fast as five
centimeters per year. This is true for unusual and isolated corals, not the ones that construct large
reefs. One also needs to keep in mind that although some individual corals may grow this quickly,
the reef as a whole grows much more slowly because such faster growing corals are easily broken
by storm waves. In addition, reefs are constantly being degraded by storm breakage, weathering,
and dissolution of calcium carbonate back into the ocean water. These competitive processes
prevent the reef from growing faster than the rates cited earlier.
In conclusion, the only rational interpretation for the presence of very tall reefs in deep ocean
water is that these reefs grew over long periods of time by the natural processes discussed above.
As such, reefs are indicators of ages on earth that are far greater than the 10,000 or so years
allowed by young-earth creationists.
• Tidal Slowdown, Coral Growth, and the Age of the Earth
by Perry G. Phillips
• Coral and the Moon
by Don Lindsay
The Moon causes tides. Tides make the Earth slightly asymmetrical,
and one result is that the Earth's rotational energy is slowly being
stolen by the Moon. We spin more slowly: and the Moon rises to a
higher, slower orbit.
This was worked out mathematically in the 1800's. Today, however,
it has been measured.
One consequence is that in the future, there will be fewer days in
a year. And in the past, there would have been more.
Modern corals deposit a single, very thin layer of lime once a
day. It is possible to count these diurnal (day-night)
growth lines. You can also count annual growth. So, given the right
piece of coral, you can measure how many days there are in a year.
These measures can equally well be done on fossilized coral. For
example, coral from the Pennsylvanian rockbeds have about 387 daily
layers per year. Coral from the Devonian rockbeds have about 400
daily layers per year. In the Cambrian, a year was 412 days. One
Precambrian stromatolite gave 435 days per year.
With bivalves, you can count days and lunar months. Recent
bivalves give 29.5 days per lunar month; Pennsylvanian give 30.2;
Devonian give 30.5.
If you care, there ore a lot more details about coral. There's a reading list at the rear
of that, and the topic is covered in Strahler, and the Creationist Daniel Wonderly has written about
it. But there are also some broader issues.
For one, do all these numbers increase, as one goes to supposedly
older and older layers of the "geologic column"? The answer is yes.
For another, are these numbers the same, if one takes corals from
different continents, but in the "same" rock layer? The answer is yes.
For a third, do these numbers agree with the theoretical numbers
that the astronomers had in hand? In order to tell, we need to use
radioactive dating techniques, to get dates for the various rocks.
So, the comparison is somewhat a test of
radioactive dating.
• How long does a coral reef take to grow?
by Answers in Genesis (? - no author is listed), paper in Creation 14(1):14–15, December 1991
Australia’s beautiful Great Barrier Reef is the world’s longest coral reef. It extends from near Papua New Guinea down Australia’s east coast for about 2,000 kilometres.
In a previous Creation magazine (Vol. 8 No. 1), we showed that using measured growth rates at the mouth of the Burdekin River, the Great Barrier Reef could have formed in the time since Abraham lived.
However,
the Great Barrier Reef, in spite of its huge area, is not the thickest known reef. This distinction probably belongs to Eniwetok Atoll in the Marshall
Islands. This is a living reef resting on an extinct volcano cone which comes
up about three kilometres (two miles) from the ocean floor. Drilling revealed
about 1,400 metres (4,600 feet) of reef material. At least two writers have
attacked the young age position using the argument that this coral atoll must
have taken a very long time to form—they estimate 138,000
and 176,000 years respectively as the minimum age for Eniwetok.
Ariel Roth of the Geoscience Research Institute has commented on the fact that estimates of
net reef growth rates vary from 0.8 millimetres per year to 80 millimetres per year, whereas
actual measurements based on soundings at depth are many times these estimates. Roth suggests a number of reasons for this difference.
The main one is that measurements made at the surface will show lower rates of growth
because of exposure to air at low tides and intense ultraviolet light. Lack of light will of
course kill a reef—no live coral growth takes place below about 50 metres under the surface.
Hence thick atolls such as Eniwetok require the ocean floor to sink as the coral builds.
As the coral is lowered, faster growth is possible than that which we measure at the surface.
There are complex factors which both add to the growth
of a reef and take away from it. For instance, attack by certain organisms
and wave destruction will contribute to a decline in reef size. On the
other hand, a growing reef can trap sediments as they are moved along
by currents, thus adding to its thickness. Storms can dramatically add
to the thickness of a reef by bringing in coral from other areas.
For example, in 1972, Cyclone Bebe ‘constructed’ a rampart of coral rubble 3.5 metres high,
37 metres wide and 18 kilometres long in a few hours.
Given all the above, it seems reasonable to rely on the actual figures reported from
depth-sounding measurements for coral reef growth rates, rather than calculations trying to
take all these other factors into account. Such reef growth rates have been reported as high
as 414 millimetres per year in the Celebes. At such a rate, the entire thickness of the
Eniwetok Atoll could have been formed in less than 3,500 years.
In addition, actual experiments indicate that the rate of coral growth can be nearly doubled
by increasing the temperature five degrees Celsius (remember that Eniwetok sits on a
now-extinct volcano), or increasing the carbonate content of sea water.
To maintain that Eniwetok Atoll could have formed in the time-span since the Flood recorded
in Genesis is not at all inconsistent with real-world evidence.
• Reefs and Young-Earth
Creationism
by EarthHistory.org
Eniwetok Atoll as a Post-Flood
Reef
The Eniwetok atoll is a reef in the Marshall
Islands. The US detonated hydrogen bombs there in the 1960's.
Drill cores show that this reef is about 4600ft thick, and rests
atop the surface of a submerged volcanic seamount. The entire
thing is composed of corals, calcerous algae, foraminifera,
echinoderms, oysters and so forth, which are cemented together.
In terms of texture and composition, this reefs is very similar
to buried reef strucures in the fossil record. How quickly could
it form? Could it form in the 4500 year post-flood period?
Doing research on the Eniwetok atoll, I decided
to visit some creationist websites and see how they explained
these structures in terms of an earth less than 10,000 years old.
According to the "Stand for Jesus" web page, the oldest
living coral reef is only 4200 years old. This claim can be found
on dozens of creationist web pages, and is evidently widely
accepted as an accurate estimate. Answers in Genesis makes the same claim: ". . . reef growth rates have been
reported as high as 414 millimetres per year in the Celebes. At
such a rate, the entire thickness of the Eniwetok Atoll could
have been formed in less than 3,500 years. To maintain that
Eniwetok Atoll could have formed in the time-span since the Flood
recorded in Genesis is not at all inconsistent with real-world
evidence." I could not find any articles at ICR
addressing the issue.
The Evidence for Rapid Reef-Building
Let's examine the "real-world evidence"
cited for this conclusion. Every one of the creationist web pages
I found seem to be relying, directly or indirectly, on two
papers, one by Arthur Chadwick, and an Origins paper by A. A.
Roth. These papers list various estimates of reef growth rates
from a variety of methods. Most of the estimates cited by
Chadwick and Roth give long ages for the growth of a 1,400m coral
reef. However, both authors include a single anamalously high
estimate rate of 414mm(!)/yr. These estimates
were based on "soundings" done in the early 1930's.
They cite only a single source for this astounding rate, a 1932
paper by J. Verstelle, 'The Growth Rate at Various Depths of
Coral Reefs in the Dutch East-Indian Archipelago', Treubia 14:117-126,
1932.
Virtually all of the other estimates in
Chadwick's paper yielded rates of reef growth of 0.8-30mm or so,
requiring many thousands or even millions of years to form a reef
1400m thick. For instance, Hubbard et al. (1990), estimated
growth rates of 0.7 tp 3.3mm per year. Davies and Hopley (1983)
estimated a *maximum* of 20mm/yr. Smith and Kinsey (1976) listed
rates of 2-5mm/yr. Smith and Harrison (1977) listed rates of 0.8-1.1mm/yr,
and so on. Many additional studies indicate Holocene reef growth
histories on the order of 1-15mm/yr, with the upper range only
being attained in reefs dominated by the fast-growing Acropora corals (e.g. Aronson et al., 1998; Hubbard, 2001). While
Chadwick's paper included many reasonable estimates, his readers
predictably siezed upon the one rate reported by Verstelle over
60(!) years ago, ignoring a massive body of more
recent research on the subject.
Another odd thing is that both Roth and
Chadwick's papers also included estimates of the growth rates of
*individual corals,* and they showed that even most individual
corals cannot grow nearly that fast (i.e. ~400mm/yr)! Most
studies document maximum *coral* growth rates of only 10-50mm per
year.
How Fast Can Reefs Really Grow?
By far the most contentious isse here is the
rate at which reefs can grow. Studies of reef growth in the
modern Pacific show that even under ideal conditions, the growth
of the actual reefs is only on the order of 8-10mm a year (see
below). Note that individual corals can grow a bit faster than
this, but this cannot be used to estimate the growth rate of the
*reef* itself, since the reef is not one giant coral, but is
largely composed of billions of coral fragments that are broken
by waves and cemented to the growing mass (see below).
So, assuming an average 10mm per yr growth
rate, the Eniwetok Reef would require 140,000 years to grow to
its present thickness. And this assumes no compaction, no
destruction by storms, no temporal breaks in growth, continuous
optimal growth rates, and adequate subsidence rates. All of these
assumptions are entirely unreasonable, and thus any estimate
based on extrapolation of optimal reef growth rates is clearly a
minimum.
For instance, we know that there are at least 3
major weathered unconformities within the Eniwetok, at 300ft,
1000ft, and 2,800ft depth. These unconformities not only show the
type calcite cementation which develops on exposed reef surfaces,
they are also extremely enriched in pollen, most of which appears
to be from Mangrove trees. Mangrove trees are growing on many
exposed reefs in the Pacific today. In some cases, the pollen is
so abundant that there are an estimated 10,000 or more pollen
grains per gram (Leopold, E. B., 1969, "Bikini and Nearby
Atolls, Marshall Islands, Miocene Pollen and Spore Flora of
Eniwetok Atoll, Marshall Islands," U. S. Geological Survey
Professional Paper 260-II , U. S. Government Printing Office, 53
pp). This shows that at each of these unconformities, the reef
surface remained exposed for an extended period of time, although
exactly how long is not known.
Subsidence as a Limiting Factor of Reef
Growth
And there is one more simple reason why such
high estimates assumed by AIG and others are entirely
unreasonable. The reason is this -- the net growth of the reef
can only be as fast as the net subsidence of the seamount or
platform on which it is growing. This is a limiting factor. Thus,
even if a reef could grow at, say, 3cm per year rather than
around 1cm or less as virtually all of the empirical estimates
show, the reef can still only grow to the surface of the water.
Where rates of subsidence of seamounts can be measured, it is
only a few mm per year. Subsidence rates have been estimated with
high precision for the Hawaiian Islands, which are similar in
most respects to the submerged seamount atop which the Eniwetok
atoll rests. These islands are subsiding at only a few mm per
year.
Carbon dating of drowned reefs on the side of
Hawaii show that it has subsided at this slow rate for hundreds
of thousands of years. In fact, its a little more interesting
than that. You can actually predict the radiometric ages of a
drowned coral reef, with considerable accuracy, simply by
dividing the depth in mm by the observed subsidence rates in mm
per year.
Radiometric ages of Hawaiian corals compared to
ages predicted by extrapolating observed subsidence rate of 2.7mm
per year. Judging by the close correlation between predicted age
and actual age, the rate of subsidence for the island of Hawaii
has remained very close to 2.7mm per year throughout at least the
last half-million years.
But for agument's sake, let's disregard the
radiometric dates. Do any YECs have a plausible explanation for
the growth of a 4600ft thick reef in 4500 years of post-flood
time? And if YECs really think reefs can grow at rates of 100-400mm
per year or more, when can we expect to see the research
documenting this, and the evidence showing that the required
conditions for this were somehow satisfied throughout post-flood
times, while not being satisfied anywhere today? Remember, even
if we multiply the fastest observed reef growth rates by a factor
or 10, and assume *continuous* maximum growth rates, and assumed
*no* erosional breaks or storm damage, and assumed that
subsidence was somehow *greatly* accelerated, we would *still*
need 14,000 years for the growth of Eniwetok.