Monday, June 11, 2007

Beds above the Missouri River bed

Stability in the Hinterland

All of the website investigation concerns the re-arrangement of the Earth's Crust, whenever it can be seen at the edges of uplift. This has been in areas such as the Colorado Plateau transition zone, the margins of Anatolia, and such actively uplifting islands as Java, Sumatra, and Cascadia.
How about the interior- where the continents are fairly stable and monotonous- are they as instructive as the margins? To move into this realm, I took a trip into Arkansas and Missouri with their older rocks, in June 07- which haven't been jostled (supposedly) since early Tertiary times, or more than 40 million years previous.
As shown in the above photo, sedimentary beds from this region in the Paleozoic are flat and level, and show little disturbance. Of course, I was biased, and chose a section where I had considerable previous knowledge- where I owned a farm lying astraddle the well-documented New Madrid earthquake zone. I would find that the earth is again moving about, creating some problems for man, but obscuring its' intentions with abundant surface vegetation and rubble. Man is deceived by these subterfuges, and holds the delusion that nothing bad except weather occurs in these well-SHIELDED regions.
The drastic movements of the area near New Madrid, MO indicate otherwise. A portion of my farm had sunk in the 1811-12 earthquake earth exercise, and drainage of the Great River (Mississippi) was diverted for a time, flowing southward through Arkansas creating Big Lake, Arkansas. It was caused by a graben-like sinking of the deep Paleozoic rocks below the old delta lands of the river- which extended as far north as Illinois, in early Tertiary times. Even today, this graben has continued to sink, creating abnormal pressure by the squeezing of the deep rocks on the water column (allowing artesian water wells).
This extensive earthquake zone reacted with a 7+ magnitude shaking, and the land was rearranged. The faulting at the edge of the graben created a barrier to fluid flow, and those fluids compressed to create artesian pressure. Normally, the rock frame carries the largest stress (rock pressure), and this is near 1 psi/foot of stratigraphic or vertical column. The water pressure is only about .44 psi/foot for water with some 500 ppm dissolved chemicals, so long as the water is free to move. But when the water is trapped by the rock frame and cannot readily escape, it takes on the stress of the weight of the rock column (density of 2.65 gm/cc x .433psi/foot for pure water, as much as 1.15psi/foot). This creates abnormal pressure in the fluid portion of the vertical column, and results in BLOWOUTS if a well is drilled with light weight water. Whenever abnormal pressure (sometimes named Geopressure) occurs, the earth is actively squeezing on the fluid phase, and the mere occurrence of higher than .44 psi/foot pressure is a dead-ringer for movement in the earth. It is my opinion that abnormal subsurface pressure in an otherwise flat and level region- such as Mississippi County, Arkansas- is an indicator that fluid is trapped or slowed in its movement in the deep sediments.
So if this is the hinterland, where all is flat and level, sedimentary beds are undisturbed, and the topography is monotonous (without obvious surface hills and canyons), how can there be turmoil in the Earth’s Crust?
The First Answer pertains to the portion one cannot see at the surface. In the Subsurface, there may be movement which is obscured or dampened before it can be noticed on the level ground surface. This certainly is the case in the marshes of Louisiana or Arkansas. For example, salt domes may be rising down below, creating disruption of sedimentary beds at levels which are too deep to be registered at Man’s elevation. In the case of Salt Domes (see the Blog link on Salt Dome Lore), eventually the salt does reach a proximity to the surface creating a hill where it can be seen by Man. This is immediately obvious, since there will exist a mound with a lake in the top, in an otherwise flat terrain- stagnant marsh. Do not be deceived into thinking that this was created by the Mound Dweller pre-historical culture, although the natives may have exploited it.
In the case of the St. Francis and New Madrid sunken lands, the slowly- sinking graben may not be noticed at the surface, since it is obscured by swamp or vegetation. Wells drilled into the structure will show that buried canyons or hills result, and these may hide oil or gas or high pressure water. There is an easier way to see these earth dynamics, and this is via a map of the chemical rearrangement of the ions in the water in shallow water wells. Whenever high pressure water moves upwardly to escape, it brings its chemical signature in the form of novel or rare chemicals. Examples of these include Boron, Fluoride, and Potassium.
Modern water wells drilled by knowledgeable people will measure these components, to determine the type of water encountered.
There are at least four types of water in the earth’s crust:
1. Meteoric water, extending downward into the crust as much as 1 km (3280 feet)- this is freely circulating water from rain and percolation;
2. Mineralized water (below type 1), extending into easily penetrated crustal rocks, and its location depends upon the temperature and pressure gradients moving it;
3. Chemically-reduced water (usually below type 2), such as is related to fowl-smelling compounds like oil, sulphur, and bacteria; and finally,
4. Acid waters, associated with elevated temperatures occurring with vulcanism, uplifts, and subduction.
Examples from each category include: drinkable well water, salty water, Stinking water, and mine waters (best never to drink these, since they may contain arsenic, boron, soluble irons, and fluorides.
The second Answer to monotony vs. turmoil obscurity in the Hinterlands is that of Erosion, which may occur faster than the dynamics in the subsurface. In this case, the surface features may be erased faster than they can be created. In a floodway, such as with the mighty Mississippi, the evidence is erased by the great El NiƱo floods (occurring every 7 years or so). But erosion leaves it mark, and this can be seen by the topography in the above photo, which exhibits flat and level sedimentary beds, shown in bluffs which are formed by the nearby Missouri River.
Man can leave his mark on topography also. And this is the case with my farmlands. My dad had admonished me to leave something for the wilds of Arkansas so that the local wildlife could propagate. I had left several acres of cypress and other trees for them, and this created an under story of natural lands. However, the various agencies arrived at policies which undermined my attempt to “SAVE” this habitat.1. The Fish and Wildlife Service next-door undertook to create a habitat for ducks in Big Lake lands, at the expense of beaver which were returning from the period when they were harvested for their fur. The beaver were not to be eliminated this time around, however, and they formulated various tactics.
2. The State agency wanted to form a children’s fishing lake adjacent to the lands, and they pumped fresh water above the normal lake level. This had to be circulated, so that it would remain fresh, and they created a small rock dam, north of the saved lands, so that the elevated water would flow out across my wildlife area- thereby creating a steady-state movement of water.
3. The local drainage district wanted to channel Missouri flood water through Arkansas toward the Mississippi River, far to the south, and they created a 300 foot wide ditch running through my lands- which should have drained off this fishing lake drainage. They did not allow for the far-seeing beaver- the Great Engineer, however.

Here is the natural sequence of events:
The ducks propagated, and this encouraged the beaver, which naturally moved into surrounding lands (the local people would have harvested this resource- another natural result, except that the F&W would not allow it, opting to eliminate them with their own methods).
The beaver, which were much more persistent than the government operators, loved the moving water on my lands, and exercised their teeth by cutting willows and other native trees for diet and for damming of the flow.
Consequently, the standing water behind the beaver dam stayed year-round, drowning the Black Oak, Locust, and temporarily the cypress. Only Red-ear Turtles loved the resulting marsh with no trees- sunning themselves daily for local enjoyment. Only MYSELF was discomfited by this revolting development, due to the admonishment of my Dad, from many years previously.
Knowing that Nature will have her way, and will outlive me and the seldom seen governmental operators, I relented- leaving the wild lands to express their personalities in a more timely fashion, leaving the wild lands to act in a WILD manner.

Geological Changes in the Hinterland

The largest historically-documented earthquake in USA occurred near the border of Missouri and Arkansas, in the New Madrid quake of 1811. This was documented by use of destruction of artifacts (called intensity on a numerical scale- as distinguished from Magnitude, which is used with the Richter or numerical measurement of oscillation of a pen attached to the Earth). Magnitude records occurred only in the last century, and published reports were used to document this destructive event. Since my farm borders the sunken lands created by the drop of a graben in the subsurface, this stimulated me to measure what could be found 1 ½ centuries later. The water wells told a story:
First, they yielded artesian pressure in the plantation lands near my farm. We never drilled a well on my farm, since we were always short of money, but we drove a pipe down to 20-30 feet and pumped iron-bearing water (which greatly discolored the pots, and which stunk with the iron-digesting bacteria).
Secondly, the water yielded chemical components which could be mapped as to amount (e.g. Potassium/Chloride, which can be used to find faulting or slicing in the Earth).
Thirdly, they showed that the chemical components were segregated in space- that is, they would have Bicarbonates greatly concentrated in one area, with Sulfates concentrated in another. This shows that some force is moving the components laterally, as well as vertically. Geologists don’t like to believe that fluids move significantly vertically, but there they are in unusual concentrations a few thousand feet above the depth where the exotic compounds originate. And this is what I usually find- that thousands of feet above an oilfield the water is exotic compared to that distant from the oilfield location.
There you have it- even in the marshy lands of Arkansas; Nature is working (doing its duty to offset the previous mistakes of both Man and other Life!). Nature may appear to act arbitrarily, but she will follow her Rules.