Monday, May 14, 2007

How Life (including grains) helped form the Crust

Glacial National Park Elderhostel (June 27, 04)

Flathead Musings

My wife and I thought ‘twould be nice
If we reflected on the ice,
Which was reputed to occur
In the mountains of the chain
That stretched abruptly from the plain
And the wilds of the island, where we were.

However, we soon found to our dismay
That global warming has had its say
And the Glaciers which had beckoned
Were long gone, so some had reckoned,
So that we were soon chagrined
That we had missed our goal, tho’ had not sinned.

Nevertheless we remained undaunted,
Since the mountains and rocks soon flaunted
Sufficient scenes and colors just along the way,
That we felt inspired to write
Phrase and sonnet which sound jus-trite,
And non-fiction which was most appropriate for the day.

Now in the ultimate scheme of things
We rely on Fate which shortly brings
More of Serendipity and Chance for us to ponder;
We will in future leave to ‘Hostel
Further programs- so to jostle-
And to vagaries of raw Chance, for Trips out Yonder.

OBSERVATIONS MADE WHILE TREKKING THE ANCIENT ROCKS

We did not find the blue Ice which we desired but we did make several forays into the faulted and upthrown Precambrian outcrops which were scheduled for the trip, in Glacial Natinal Park.
I noticed that the Proterozoic had few shales in the beds, but they did have many siltstones and fine-grained metamorphic sediments. There were some organic remains such as stromatolites, and this indicated that the algae and bacteria were at work in those 0.6- 1.6 billion year age rocks. The siltstones also had much calcitic cementation, indicating that limestones were beginning to form; in this age of silicic rocks, carbonates were beginning to take their place. I had already noticed the following features in previous excursions:
1. The incidence of bedded limestones increases as organic remains- mainly algae- increase with time (observing the sediments from Precambrian to late Paleozoic); that is, life in the ancient seas incorporates CO2 from the atmosphere and incorporates it into the seafloor- the end result of which becomes CaCO3 or calcareous cement;
2. Oxygen is given off by this process- especially after trees proliferated- and therefore the atmosphere would increase in O2 composition with time (all the way through the Paleozoic into the Mesozoic where silicates again predominate);
3. Life would have to accommodate this process, and would adjust to increasing oxygen gradually; this would involve oxygen-using invertebrates in the Cambrian and later.

An example of limestone being formed by LIFE (even though outwardly it appears to be a result of inorganic processes) is as follows, for the Gulf of Mexico:
a. Rivers- which are dominant in calcium ion at the expense of sodium and potassium- bring di-valent ions of Ca and Mg to the sea;
b. These ions are grabbed by living organisms, which convert them to shells, carapaces, and slightly soluble solid materials in the seawater (with the addition of CO2 from the air);
c. As the organisms die, the hard parts sink to the bottom of the Gulf, where the pressure is higher and the temperature is colder;
e. For both colder and high pressure conditions, the solubility of CaCO3 and MgCO3 is increased- hence the ionic concentration of both increase in seawater;
f Currents incorporate this saturated solution (with respect to the alkaline earth cations) of brine and force it over the shallow ridges at the south of Florida, thereby elevating its T and decreasing the P;
g. The limestone drops out of solution for these changed T and P and forms oolites in the Bahamas. NOTICE that a key to this whole sequence is LIFE- without which the process would not occur (or as easily).
Dr Beus, a paleontologist, took issue with all this, stating from his life study of the Grand Canyon, that there was indeed limestone in the Proterozoic, e.g. in the Bass limestone. My rejoinder is that these limestones are a result of stromatolites, again a result of life processes. Others may want to challenge the idea that most limestones are created by life and that lifeless planets can have none.

I theorize that soil and organic compounds are also directly involved in this conversion of the atmosphere into organic sediments (clay and shale) in the following way:
a. As the seafloor rises with all of its attendant organic deposition, it becomes mulch for life, when the seafloor is raised with subduction or other thermal expansion. This creates soil, as the mulch, organic remains and living creatures, oxygen, and mineralized waters create a regime in which vegetation can live, in the land elevated above the sea (distant from the salt water);
b. This soil, with its organic components and gases and water, is converted to shale when it is buried throughout time. Shales are created as the carbonate cycle is replaced by the silicate cycle at the end of the Paleozoic (they are more like the obsolete marls until the occurrence of redbeds in the Permian and later Mesozoic). The organic contents are buried in the Crust either continuing to live or as dead remains;
c. By the time of the Carboniferous, the oxygenating influence is dominant, resulting in overkill- by Permian time, the atmospheric oxygen is toxic (the air has excessive oxygen, killing off most of the life which cannot accommodate this process). By Jurassic time, the survivors have adjusted, the atmosphere has decreased in oxygen fraction, and finally the carbonates begin to re-form limestones in the Cretaceous (man may be able to restart this process, with his release of CO2 from coals and hydrocarbons). Evidently the Cretaceous has a buildup of carbonates from the increasing CO2 in the atmosphere (at least until the beginning of the Tertiary).
d. So long as life remains in terrestrial soil, shales will accompany the burial of organic sediments, and carbonates will not be the dominant deposition. The decreased formation of carbonates is an indicator of the health of the life-sustaining atmosphere and water system. Whenever CO2 builds up from combustion of carbon compounds (or from a paucity of trees), there is a decrease of the oxygen fraction. This helps dissolve the exposed carbonates with the increase of acidity in the air and moves the earth towards a new life mix (water-dwelling creatures, at the expense of land dwellers). This is evidently an evolutionary process, since immediately the seas become more acidic as carbon dioxide increases. Limestones would not precipitate in acidic conditions, and for an alkaline condition to occur, Life must adjust to the new conditions for the theorized sequence to occur.
This sequence had been introduced to me whenever I arranged several patents for processes noticed in oilwell cuttings, converted into slurries of shale fines and distilled water in my oil patch days. Here is what I observed:
A.A handful of cuttings were rapidly heated in an ordinary skillet (all of these measurements were made using common kitchen and drilling mud monitoring equipment used on the oil platform) to remove all but the capillary water. These dry cuttings were sieved with 50 mesh screens, so that 50 grams of fines could be mixed with 50 cc. of distilled water to make a clay slurry.
B. This slurry was measured for electrical resistivity, so that it could be compared to the shale baseline on the Electrical Log. Only 5 cc was necessary for a reading;
C. The cooled slurry was then filtered through a standard filter press, using 100 psi pressure and 100 Whatman filter paper- timing the process in minutes/10 cubic centimeters;
D. The time of filtration was inversely proportional to the hydration of water- well-hydrated clays containing potassium, nitrate, and phosphate compounds would release the water with difficulty;
E. The color of the effluent, filtrate, varied inversely with the Time of filtration; for very slow filtration, the color was gold to amber- indicating hydrated ions. For fast filtration, color was clear. Five visual color changes were used: clear, slightly yellow, yellow, gold and amber;
F. The filtrate was then measured using ion-selective membranes- for Na, K, and resistivity.
A Log could then be made showing resistivity and Sodium Potential versus depth. This was somewhat similar to the ordinarily electric log for shales. Unusual high pressure in the shale would be noticed for low resistivity cuttings and a sodium high would occur for a high sand content with its accompanying NaCl.
The preceding process was much later performed for garden soils, and it took me a lengthy period to realize that the results were similar, indicating that what occurred in a garden soil was also occurring deep in the earth’s Crust. Living organisms were interacting with the clay fines and aqueous solutions to produce some important processes;
1. Gas was being produced by the organisms, producing Geopressure deep in the earth or gasified soil in the garden;
2. Life was being sustained by the action of sunlight on carbon compounds in water (electrons are freed by low energy light), while evolved life in the subsurface was being assisted by natural radioactivity in shales to propagate itself (electrons are knocked off by energetic gamma rays); and,
3. Simple fine particles, assisted by Life, are converted into shale as it is buried in the subsurface, and finally into slate. Without the Life partnership, the fines would remain as silts or non-living rock dust, which is what was noticed in the Glacial Park rock (few shales or slates, but many siltstones) Soil, shale, slate and the crust are being created by Life Processes. The crust is being thickened with Geologic Time, while Life is making a nest for itself!