Monday, November 14, 2011

The geology of Uluru and Kata Tjuta

One of the most distinctive and well-known geological features in Australia -- and in fact the world -- is the massive sandstone mound known as Ayers Rock, now more often referred to by its name in the Western Desert Language of the Anangu, Uluru. The formation rises to heights of over 1,100 feet, and its perimeter is more than five and half miles.

It is sacred to the aboriginal people of the land and they request that visitors do not climb it, remove rocks from it, or photograph certain portions of it.

Conventional geologists account for this impressive massif by describing waters flowing off of the granite mountains to the south and depositing eroded arkose sand in a mighty alluvial fan, which later tipped due to the upward-thrusting tectonic forces which they believe created most of the mountains and basins of central Australia, between roughly 450 million and 300 million years ago. A typical description of the alleged forces which shaped Uluru -- and the related formation about twenty miles away known as Kata Tjuta in the langauge of the Anangu, which is similarly sacred -- can be found at this website, along with an amazing aerial photo.

There are some problems with this conventional explanation, however. Chief among the problems would seem to be a clear mechanism to explain why these mighty formations (Uluru and the multiple "heads" of Kata Tjuta) resisted erosion when all around them did not -- in other words, what could explain why these incredible geological features rise up so abruptly from the Amadeus Basin when everything else around them was apparently carried away by erosion over millions of years?

Another problem, as Dr. Walt Brown points out in the section of his online book which discusses these majestic Australian landmarks, is the composition of the sand grains which comprise Uluru. He points out that they are very angular, which is a characteristic not consistent with being washed down by rivers and deposited into alluvial fans, nor with being eroded for thousands of years:
The sand grains comprising Ayers Rock are jagged but, if exposed to rapid currents, would have become rounded. Had the grains been weathered for thousands of years, they would have become clay. Instead, these grain characteristics are consistent with the gentle currents produced by liquefaction and the rapid cementing in the years after the flood.
The angular nature of these coarse-grained arkose sand particles are noted in the Wikipedia entry discussing Uluru as well.

Dr. Brown's hydroplate theory, however, proposes a very different explanation for the formation of both Uluru and Kata Tjuta, and one which is consistent with geological evidence around the world. He explains that the liquefaction which created the layered strata during the global flood would have sorted the sediments into layers. During the compression event in which the massive plates carrying the continents drifted and then ground to a halt due to friction, these layers, still infused with water, would have experienced massive compression and deceleration, much the way a human body strains forward against the seatbelt of a car when it decelerates rapidly.

The sand layers in the strata, Dr. Brown explains, would have had the greatest water content, with up to 40% of their mass being water. This high water content would have made this layer extremely bouyant, and during the violent compression event the lighter liquified sand would have erupted upwards through heavier overlying layers in many places, resulting in sand plumes which can still be seen in many places on earth, such as the one shown in the photograph below from Kodachrome Basin State Park in Utah, in the US.

This tendency for the lighter layer to spill upwards, Dr. Brown explains, can be understood by filling a jar with a lighter liquid and then pouring a heavier liquid on top of it (such as water over oil). If the jar is given a jolt, the lighter liquid "will float up in plumes through the denser fluid."

Dr. Brown calls these remnants of the plumes that penetrated up through overlying layers "liquefaction plumes." In places where conditions were right, the same phenomenon created more massive and bowl-shaped "liquefaction mounds" -- and the enormous geological features discussed above are two of the most prominent examples remaining on the surface of the earth today. He describes the formation of liquefaction mounds in this way:
Some plumes, especially those rising from thick, laterally extensive sand layers, spilled onto the earth’s surface. This spilling-out resembled volcanic action, except water-saturated sand erupted, not lava. Small liquefaction mounds, as they will be called, appear when liquefaction occurs during earthquakes. Hundreds of liquefaction mounds are found in basins in the southwestern United States.
Dr. Brown explains that most of these mounds did not survive for long, but that those which formed in basins which were filled with water that did not drain away (carrying the mounds with them) after the flood would have had the chance to survive. Notably, both Uluru and Kata Tjuta are found in an enormous basin in Central Australia. Dr. Brown explains:
Why basins? During the compression event, liquefied water-sand mixtures in many places erupted like small volcanoes. Being surrounded and permeated by water, they would have quickly slumped into the shape of an upside-down bowl—a liquefaction mound. As the flood waters drained at the end of the flood, most liquefaction mounds were swept away, because they did not have time to be cemented. However, mounds inside postflood lakes (basins) were cemented as each lake cooled and its dissolved silica and calcium carbonate were forced out of solution. If a lake later breached and dumped its water, the larger cemented mounds could resist the torrent of rushing water and retain their shapes.
Note that the liquefaction mounds which remain in the US are also found in basins that were filled with water after the flood, perhaps for centuries, during which time the water cooled, the mounds hardened, and they were able to survive when those lakes breached (many of them are found on the floors of the two enormous post-flood of dissolved silica in the standing post-flood water basins in conjunction with the flakes that breached to form the Grand Canyon). We have discussed previously the concept of dissolved silica in an examination of the formation of petrified wood, which is also found today primarily where water was trapped after the flood, cooled, and the silica precipitated out.

Regarding Uluru or Ayers Rock, and the neighboring formation of the Olgas or Kata Tjuta, Dr. Brown says:
Ayers Rock has characteristics of both a broad liquefaction plume and a liquefaction mound. Its surface layers (bedding) are nearly vertical, and they connect to a horizontal sandstone layer underground. It formed in the Amadeus Basin, whose contained waters covered and protected it while the flood waters drained from the earth. Probably most soft sediments, through which the plume rose, were swept away when the basin’s lake finally discharged. The many large holes in the sides of Ayers Rock show where water drained out. (Almost 20 miles away, this same, deep horizontal sandstone layer also connects to a series of liquefaction eruptions called the Olgas.)
Note that his explanation also takes into account the characteristic holes in the side of true liquefaction mounds, which he refers to as "water vents" because they were formed by internal water escaping (just as water drains from a heavy sponge when it is lifted from a lake, he says). Most conventional explanations (including the web page linked above) attribute these caves to "rainstorm after rainstorm" for "millions of years," but Dr. Brown notes that wind and rain would tend to smooth out holes rather than make them, and that these holes are typically found on the sides of liquefaction mounds, not their tops, where external water would be most expected to create bowls or caves.

Those interested can examine Dr. Brown's discussion of the important phenomenon of liquefaction in greater detail on his website, and compare the strengths of the different explanations for the origin of Uluru and Kata Tjuta for themselves. The theory of rising liquefaction plumes and liquefaction mounds appears to be far more satisfactory than the mechanisms offered by conventional explanations (note as well that Dr. Brown elsewhere discusses a similar phenomenon which produced salt domes and noted that the sedimentary layers next to the upward-rising dome can be prime places where oil is trapped -- the Amadeus Basin where these enormous Australian liquefaction formations are found happens to be a major oil and natural gas producing region of Australia, which tends to support Dr. Brown's explanation).

The very comprehensive nature of Dr. Brown's theory is an extremely powerful and compelling aspect of his overall thesis. The fact that the catastrophic events he describes would explain geological phenomena around the world that are so varied and so far apart lends tremendous force to his analysis. For a list of other features on our planet -- and into the solar system beyond -- which all appear to be better explained by the hydroplate theory than by conventional tectonic or uniformitarian explanations, see the lists of links in this previous post and this previous post, as well as his book itself, which he graciously makes available to anyone for free online.