Aug 27, 2004
Blueberries on Mars
And Other Spherical Rocks
The Mars rover Opportunity discovered BB-sized spheres scattered all over Meridiana Planum, as seen in the above picture taken on Sol 19 of the rover's mission. They were nicknamed "blueberries" because of their grey-blue color and the way they are embedded in the Martian rocks "like blueberries in a muffin."
After spectroscopic analysis, the Martian blueberries were identified as hematite concretions. But knowing what they are called is not the same thing as understanding how they were made. Hematite concretions are one of several types of spherical rocks that are found on Earth but are not completely understood. In the center photo above, we see the Martian blueberries. Compare these with hematite concretions from Texas (bottom right photo), and with Moqui balls from Utah (hematite spheres with sandstone cores, bottom left photo.) Other spherical formations that are difficult to explain include geodes, thunder eggs, and concretions as large as ten feet in diameter.
One problem is explaining how a spherical rock forms in the first place. This problem is compounded by the fact that many of the spheres are layered or hollow or even contain a separate "nut" rattling around inside. Theories to explain the layered interiors include multiple episodes of mineralized water "leaking in" and "leaking out." This "leaky theory" is particularly hard to imagine in the case of the oil-filled geodes found in Illinois. Many are pressurized and squirt when the shell is cut.
The speculations about the formation of Moqui balls range from meteorite impacts to underground fires. One popular idea is that they began under an inland sea as unstable limonite. Under pressure, limonite forms a gel, which might be rolled into balls, trapping sand from the seafloor inside. Later, the limonite might be converted to stable hematite by heat and gases from volcanic venting.
 Credits: LEFT, NASA/JPL/Cornell; RIGHT, NASA/JPL/Cornell/US Geological Survey |
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Mar 28, 2005 Recent discoveries by the Mars rover “Opportunity” throw new light on terrestrial “concretions”. But the strongest light may come from Dr. C J Ransom’s electrical discharge experiments. Geologists identify “concretions” as spheroidal masses usually occurring in sedimentary strata. They are often composed of minerals different from the primary constituent of the stratum in which they lie. Many concretions are formed from carbonates, but others of iron ore or silica are not uncommon, and still other varieties occur as well. Formations identified as “spherical concretions” can be as large as 10 feet in diameter. They are often layered like an onion. Inside their spherical shells, some are hollow, others contain crystals, sandstone, or even petroleum. A few examples of the different varieties can be viewed here. And some impressive links are given here. One characteristic that virtually all concretions have in common is that they are harder and more durable than their surroundings. The processes by which this is accomplished are far from clear to geologists. But that characteristic enables the concretions to survive while the surrounding materials are eroded away over time, exposing them and leaving them lying on the ground or protruding from cliffs. Another characteristic is that the concretions are confined to specific areas. Even when the same surrounding layers continue for hundreds of miles, the occurrence of concretions will be limited to a segment of the more extensive formation. The layers in which they are embedded are often level and undistorted around the concretions. The remarkable sphericity of some concretions has occasionally caused them to be mistaken for human artifacts. No known geologic or chemical process can produce sizable spheres. The kinds of geological processes commonly invoked to explain them have little or no tendency to form spheres. Sphericity is tacked on gratuitously and ad hoc. Some theoretical guesses call upon dissolved minerals to precipitate or crystallize inside spherical cavities (geodes) or around some nucleus (often a fossil). But that fails to address many of the contexts in which concretions arise, and it only sets the question of sphericity back one step: What caused the cavity to be spherical? What caused spherical layers to form around non-spherical nuclei? Of course, not all concretions are spherical, and some take very odd shapes. Examples of the famous “Pumpkin Patch” concretions can be seen here. One cluster of concretions in Southern California (now depleted by rock hounds) had long handles. S.C. Edwards reports, “We soon noticed the specimens were in regular order, all arranged with handles perfectly parallel and horizontal, points north”. Such clues are vital, but few geologists have reconsidered the larger picture. Before the discovery of the mysterious “blueberries” on Mars it was commonly assumed that concretions were unique to terrestrial geology and that complex processes contributed to the deposition of sedimentary layers over long spans of time. As the space age provided close-up views of other planets, geologists continued to work with the concepts they had synthesized from observation of earth’s present features and processes. By the time the Mars rover Opportunity sent back the stunning images of the blue-grey spherules on Mars, the geologists’ concepts had crystallized into dogma. Advocates of the Electric Universe contend that the most costly mistake in the theoretical sciences today is the ignoring of electricity. Space-age discoveries have revealed that the universe is composed almost entirely of plasma, and over a century of research into plasma has revealed its electrical properties. The refusal by the institutions of science to consider electrical explanations—even in the face of new discoveries that arepredictable electrically— can only create an environment in which prior beliefs harden into dogma, and dogma inspires new waves of pseudoscience. With the pictures of Martian blueberries before us, the question is no longer “how were the concretions formed?”. We must also ask how the layers surrounding them were formed. The picture on the left above shows the strata containing the Martian spherules imaged by the Rover Opportunity. On the right is a closer view of the fused layers of Martian soil around the spherules—looking very much like the glassy fused material of fulgurites created by lightning strikes. The images suggest possibilities never mentioned in conventional discussion of the blueberries. Could electrical arcs have created these inclusions and deposited the visible layers of soil around them? The small spheres stand out, but we also see fused globules of material where a diffuse electrical discharge lacked the intensity to create discrete spheres. Diffuse discharges are not homogeneous but consist of smaller-scale channels that vary in intensity. A regional-sized discharge that sorts and emplaces material in layers would be expected to show areas where more intense arcing formed spherules analogous to those shown in Dr. C J Ransom's laboratory experiments. In this "flash-heating" process certain minerals in the shells will be enhanced or depleted (compared to levels in the surrounding sediments). This process may also help to explain why many concretions have hollow centers, as seen in the cross section of spherules in Dr. Ransom's experiment. Trapped gases may not have time to be released before the molten surface has solidified. The electrical theorists claim that in the course of regional deposition (primarily electrostatic emplacement) electrical arcs achieved on the surface of Mars exactly what Dr. C J Ransom’s laboratory experiments have exhibited. But will geologists consider Dr Ransom’s experiment in relation to the planet Mars? As a nudge in this direction, in the coming weeks we shall devote a series of submissions to the evidence for global electrical events on Mars, the planet of a thousand mysteries. Tomorrow: “Domed Craters on Mars”. |
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Several characteristics must be addressed by any theory attempting to explain these round rocks: Most of them are clustered in zones, not randomly distributed. They are often common in one region of a particular rock formation, but absent in higher, lower, and adjacent regions of the same rock formation. In some deposits, it is obvious that there cannot have been spherical cavities while the flat surrounding sediments were being deposited. Nor could there have been spherical cavities while the sediments were being compressed into rock. Because concretions are found in the same zone, it is assumed that geodes began as concretions (or formed simultaneously with concretions.) So when did the concretions form? And why are they spherical? If they form in place from a liquid or plastic state, gravity would squash them into a dome shape. If they form while moving through a resistive medium, friction would change their shape. The forces that formed them must have been spherically symmetric. (This concern also makes one skeptical of the popular idea that hailstones, especially large ones that are spherical and radially layered, are formed in updrafts that blow the proto-stones into the cold tops of thunderheads.)
All these speculations are based on chemistry and mechanics. But there is another force that commonly produces spheres -- electric discharge. This is because the spherical focus of an electric pinch is much more powerful than gravity. In the plasma lab, tiny spheres produced by electric pinches are often hollow, like the hematite concretions seen above. Electric discharge tends to produce spherical layering and a distinct equator and pole, because the pinch "squeezes" perpendicular to the current that creates it. These characteristics are also found in the "natural" spheres. The Moqui balls pictured above have both equatorial bulges and polar markings. Rock-cutters recommend that you will get a better display from a geode if you first locate the equator and poles, then cut across the poles.
The layered crystalline look of a giant hailstone produced by a Midwestern thunderstorm (although very temporary) is also similar in form to the cauliflower-like shell and inward growing crystals of a geode.
Very little research has been done in the field of "plasma geology." But space probes since Explorers 1 and 3 in 1958 have shown us again and again that plasma plays an important role in space. We're beginning to imagine how it affects our solar system and the galaxy beyond. Perhaps the time has come to look back at our home planet and ask if plasma played an active role in Earth's geological history, too.
EXECUTIVE EDITORS: David Talbott, Wallace Thornhill
MANAGING EDITOR: Amy Acheson
CONTRIBUTING EDITORS: Mel Acheson, Michael Armstrong, Dwardu Cardona,
Ev Cochrane, Walter Radtke, C.J. Ransom, Don Scott, Rens van der Sluijs, Ian Tresman
WEBMASTER: Michael Armstrong
Copyright 2004: thunderbolts.info
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Martian "Blueberries" in the Lab Plasma physicist uses electric arcs to replicate the mysterious spherules on the Red Planet. On January 25, 2004, the Mars Rover “Opportunity” landed in a small crater on the Martian plain called Meridiani Planum. A few days later, Opportunity photographed a sight that could alter our ideas about the recent history of the solar system: Scattered around the walls of the crater were BB-sized spherules. Their blue-gray color set them apart from the reddish hue of the iron-rich Martian soil and suggested a name for them—blueberries. The left half of the picture above shows these Martian blueberries at different magnifications. They are embedded in what appears to be fused layers of soil that are exposed on the margins of the crater. As Opportunity rolled further across the Martian landscape, it found a profusion of blueberries. Investigative team members speculated that countless numbers of the spherules lie embedded in the Martian soil. Over time, erosion has exposed large numbers of them and has left many lying on the surface. After spectroscopic analysis, the Martian spherules were identified as “hematite concretions”. Hematite is an iron-rich mineral and is the primary constituent of the soil surrounding the blueberries. Geologists surmised that they are Martian counterparts of terrestrial concretions, which are commonly believed to have formed through water-induced mineral leakage. But this only widens the mystery. Theories about the formative processes of concretions are little more than untested guesses. No geologist has seen a concretion being made or has made one in a laboratory—or has disproved a competing theory. (But geologists have shown that the more a guess is repeated, the more it’s apt to be called a fact.) For many years Electric Universe theorists have proposed that concretions be examined for evidence of formation through electric discharge. In our Picture of the Day for August 27, 2004, Blueberries on Mars, we compared the Martian spherules to hematite concretions from Texas and “Moqui balls” from Utah. We gave several reasons for investigating the possible electrical origins of concretions, geodes, and other mysterious spherical geologic forms. The conventional theories, we noted, are based exclusively on chemistry and mechanics. But there is another phenomenon that produces spheres—electric discharge. In the plasma lab, electric arcs create tiny spheres that are often hollow, such as the hematite concretions seen above. Electric discharge tends to produce spherical layering and a distinct equator and pole, because the electromagnetic force "squeezes" perpendicular to the current that creates it. These characteristics are also found in the "natural" spherules. The Moqui balls pictured here (lower left) have both equatorial bulges and polar markings. Rock-cutters recommend that you will get a better display from a geode if you first locate the equator and poles, then cut across the poles. Even before this Picture of the Day was written, the plasma physicist CJ Ransom, of Vemasat Laboratories, had set up an experiment to test the electrical explanation of concretions and Martian blueberries. He obtained a quantity of hematite and blasted it with an electric arc. The results are seen in the right half of the image above. The embedded spheres created by the arc appear to replicate many of the features of the blueberries on Mars. No other laboratory process has achieved a similar result. It should encourage further experiments using higher energies. Dr. Ransom’s experimental work has laid a foundation for a radical reassessment of planetary geology. If concretions can only be replicated by electric discharge, we can no longer view them—or the strata in which they appear—through the lens of prior theory. (See tomorrow’s Picture of the Day for more on concretions.) In the matter at hand (hematite concretions), the direct evidence will be difficult to ignore. Dr C.J. Ransom's and Wallace Thornhill's paper on the laboratory-generated spherules will be presented at the national meeting of the American Physical Society, in Tampa Florida, April 17, 2005. The abstract is available at the APS web site-- |
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