CHAPTER TWENTY-FIVE
We have entertained the possibility that till might have originated from the tail of a comet or cyclonically (tempestites). Using the typical approach of an intruder with an unwelcome hypothesis, I introduced statements of anomaly and bafflement. Thus, where is the till of the seas? Why is the correlation between till fields and glaciated areas not strong? If tektites can be exoterrestrial, why not till -remember that the feather and cannonball of Galileo fall at the same speed? And so on.
Dreimanis could be quoted: "Most of North America, particularly Canada, the entire northern part of Europe and considerable portions of other continents have been glaciated several times during the last two million years, and covered by various thicknesses of till and other glacigenic deposits... It sounds like a paradox, but till appears to have become more complicated with time, in spite of detailed and extensive investigation... " [1] And Kujansuu showed that "the flow directions of the ice sheet in Central Lapland," as indicated by five beds of till, followed five largely different directions [2] . And G. W. White: "In almost any excavation in the glaciated northwestern Allegheny Plateau, a till different from the surface till will be encountered, and in an excavation of 15 feet or more, several till sheets of different ages are to be expected... The tills vary in texture, composition, compactness, permeability and in joint spacing... the till sheets may be separated by a sand layer or a silt layer of varying thickness... unweathered till may lie upon weathered till, or a paleosol, or another unweathered till." [3] As with till, so with all sediments: none is perfectly simple, or, if so, can be proved to be. Sand occurs as 10% or less of deep ocean sediments. Basalt does not give up sand; sand is continental. Is this fall-out, turbidity currents of unobserved ferocity coming off the slopes, early winds over empty beds? Shelton ends his book on geology much as I end this chapter, musing about hypothetical studies, "and finally, before we can do any of these things, we must be able to tell one rock from another -which is just about where we started." [4]
About 5% of all crustal rock is composed of sediments that remain in something approaching their state after deposition. They veneer about three-quarters of the continental surface to thicknesses ranging from the merely visible to a dozen kilometers in height, with the average for the globe at over two kilometers. Sediments have been classified by priority of deposition and anywhere from ten to hundreds of major and minor strata have been allocated positions, sometimes only after prolonged controversy, some only among certain believers. Besides containing chemical and mineral traces and distinguishable fossil remains, an estimated 80% of sedimentary rock are shales composed of mud or clay, 10% are of sandstone and 10% are of limestone.
The old problem of sediments missing from the geological column became more worrisome with the discovery that the ocean bottoms do not carry their proportionate burden of sediments, much less the extra quantity to fill the gap in the geological column. The continental slopes are formed of shaken down, wasted down, and blown down debris from the shelves of the continents; but they would constitute only a small part of the supposed accumulation. The composition of the slope deposits is unknown. Perhaps half was carried off the shelves in the continental movements and orogeny following lunagenesis. A fifth may have descended from the sky preceding and accompanying the event. A tenth might have been washed in during the Noachian deluge. The small balance may be divided between river run-off into the oceans and cosmic and volcanic fall-out. Ager reports that "... chaotic deposits and slump topography have now been found at the foot of many present-day continental slopes." [5] The continental shelves and the abysses carry clay. The polar regions and half the remainder of the basins carry ooze. Sand and boulder are confined largely to occasional polar sediments. However, sand composes 10% of the ocean bottoms, too much for long-term sedimentation to have occurred. Carbonates, suggesting organic detritus, are common in the shelf and ooze sediments. Little suggests the continental rock in the oceanic sediments; it is a different world of unconsolidated material.
Perhaps the granite that forms the massive substructure of the continents down to about ten miles is composed of melted sediments, making the original crust out to be a thin basalt covering where the upper mantle has cooled. The chemical composition of granite would deny this idea, however. Nor does the location of the granites or sediments suggest that granitization has consumed sediments. Granite is found below, and intrusively, among sediments, not apparently where it might have been transforming them by conveying some special electrical or thermal force.
Old sediments do not appear to be far less common than new sediments, which they would be if they had been formed and consumed in a special earlier time on Earth. Granites can be formed by subjecting a mixture of albite, orthoclase and quartz minerals to high pressure (30,000 lbs/ in 2 ) and melting temperatures, and then allowing cooling. Hence it was surmised by O. F. Tuttle that the origin of granites was in hot magma of the mantle [6] . This idea may be the best of the three considered by him (the others being the metamorphosis of mostly sedimentary rock through hot chemical solutions, as above, and metamorphosis of proto-granites from ion exchanges causing crystal changes even while in a solid state); but he does not consider, nor do others, the possibilities of an accumulation of granite from atmospheric (plenum) deposits in an earlier state of the solar system, or of a massive electrical discharge between Earth and external bodies, or of a melt of an earlier crust by an exoterrestrial encounter.
In this book, granite is presumed to be the creation of a period during which the Earth gained dust, charge, water, and heat from the gaseous tube extending between the Sun and its binary partner. We suppose that granite is an exoterrestrial electric welding of a crustal covering for the Earth. It lay under such sediments as have formed out of largely 'cool' fall-out and heavy erosion.
That granite and basalt, both with the hardness of steel, can be quickly reduced to debris is attested by the well-defined Washington scablands; there closely-spaced rushes of water cut many channels of many meters of depth through hundreds of kilometers of basalt plains, before dumping some of their debris in hills, and more debris into the Pacific Ocean basin, where perhaps it was overrun by the continent. It may be added that most of the granite once possessed by Earth was ripped off and exists in a reconsolidated state on the Moon.
With the granite went half of the sedimentary rock as well. Still, much sedimentary rock is found in a largely disarranged condition on Earth, in some places being miles thick, in other places scanty or even nil. And the geological ages of the Earth, largely founded upon the layerings of sedimentary rock of the continents, have long been suspect simply because of the disarrangement and, indeed, chaos of the sediments. Geologists customarily still speak of erosion as the source of all sedimentary rock [7] , following a process of weathering of source material, transportation, deposition, and lithification which compacts and cements the material into a coherent rock. But to address such rocks with the fixed idea of gradual erosion is inappropriate.
Geologists, writes Ager, generally act on the belief that "the stratigraphical column in any one place is a long record of sedimentation with occasional gaps... But I maintain that a far more accurate picture of the stratigraphical record is of one long gap with only very occasional sedimentation... The gaps predominate .... the lithologies are all diachronous and the fossils migrate into the area from elsewhere and then migrate out again." [8] Ager does not presume to measure gaps of time, perhaps because if nothing happens, there can be no measure of it. Therefore the gap may be long or short. Here we prefer the brief gap to the long. Indeed, often it can be argued that no gap exists.
In a remarkable survey, Woodmorappe has denoted the presence or absence of the ten conventional geological periods on a sample of 967 equal square areas of 406 square kilometers of the continental lands [9] . Ideally, every square on Earth should exhibit some rocks of all ten periods. Natural history assumes that all areas have undergone similar weathering experiences during any given long period of time; if, as is known, rocks of all ten periods are not found, it is because field surveys have not been competent or complete, or because the weathered debris of given age has been transported as such or as rock later on to somewhere outside the 406 square kilometer area (a journey of a maximum of a dozen kilometers), or because the rock did actually form but was eroded and carried off, or because the rock once formed was later subjected to metamorphosis. Some credence can be given to all these explanations, but, too, it is noteworthy that the "presence" of period rocks in Woodmorappe's study often refers to a minor outcropping within the area and not to full coverage of the area.
The departure of reality from the myth is impressive. In no more than one per cent of this sample of the areas of the world are all ten periods of natural history represented. Some of these widely scattered areas are doubtfully complete (in the Himalayas, Bolivian Andes, Indonesia, South Central Asia, and Cuba). Rarely does one find even three of the ten geological periods in their expected consecutive order. Moreover, "42% of earth's land surface has 3 or less geologic periods present at all; 66% has 5 or less of the 10 present; and only 14% has 8 or more geologic periods represented..."
Individual geologic periods' coverage of the earth's land surface range from a high of just over 51% for Cretaceous ... to a low of only 33% for Triassic. Only 21% of the Lower Paleozoic is represented in 3 or more of its periods; the complete Upper Paleozoic is found in 17% of the areas; the Mesozoic is complete in 16% of the areas. A complete Paleozoic record is found in 5.7% of the areas, and a complete Upper Paleozoic plus Mesozoic in 4.0%. Some percentage of every geologic period rests directly upon Precambrian 'basement', especially high percentages of Ordovician (23.2%) and Devonian (18.6%) doing so.
The data confirm the belief of those who argue, with Ager, that there are more gaps than record. Too, the chances are painfully high that one stands upon a seriously incomplete geological column wherever one may be on Earth.
Although the statistics will not suffice to show causation, they support the line of thought here: the Earth's surface has been reconstituted; the reconstitution has camouflaged the earlier surface and the earlier surface has disguised the reconstruction. Many of the "gaps" in the record are illusions. Fossils are probably as often the perpetrators of unconformities as the indicators of them; they must often have gathered where "they didn't belong" in the course of catastrophes.
The strata of all periods prefer to rest directly upon their prior strata, showing a tendency towards a time-consistency in superpositioning, as conventionally believed; that is, each era tends to be more on its preceding era than on any other era. There is one important exception: all have a greater chance of resting on pre-cambrian than on the last post-cambrian eras. Except for the two periods just prior to it, a period has a better chance of resting directly on pre-cambrian than on any other stratum; the correlation except for two directly preceding periods must be nil. This indicates a pre-cambrian basement preference of all strata. It also suggests a simultaneity for deposits that have previously been assigned as successions [10] .
So what Price once called the "onion skin theory" of sedimentation is untenable, if it is indeed still retained by many. The essential principle of sedimentation should probably be called "quantavolution." Actually the idea has many antecedents and precedents: this we now well understand. Specifically applied to sedimentation, it means that the rocks of the phanerozoic era convey by their composition, strata, geography, quantities, and geological columns a patterning that suggests intensive, large-scale sudden and brief events, that is, a lately tortured Earth.
Derek Ager takes the position of a macrochronic quantavolutionist. "Changes, cyclic or otherwise, within the solar system or within our galaxy, would seem to be the easy and incontrovertible solution for everything that I have found remarkable in the stratigraphical record." [11] The secondary mechanism, which he employs repeatedly but without criticism of its fundamental origins, is plate tectonics. "The theory of plate tectonics now provides us with a modus operandi." [12]
He sees a distinction between the exoterrestrial cause and the drifting continents as cause; thus, "we come to one of the great anomalies of the stratigraphical record, with the widespread extinctions of the Frasnian/ Fammenian junction" of the Devonian. There is no evident explanation to be found in drifting continents or colliding plates. It seems that here, at least, we must appeal to an exoterrestrial cause. He has several additional preferred temporal locations for exoterrestrial interventions in geology.
He can use plate tectonics to discover and discuss numerous "periodic" and "episodic" catastrophes around the world. This enables him to be macrochronic: "the history of any one part of the Earth, like the life of a soldier, consists of long periods of boredom and short periods of terror."
He offers a wide range of examples, from numerous eras, of the worldwide distribution of various rock-types and fossils; this leads us to the supposition not only of a Pangea in which sediments and life forms might readily become worldwide but also, and perhaps more important, of species that never reached their potential limits, suggesting forceful interruptions of their spreading. Further, it implies worldwide equal conditions for even very special kinds of sedimentation and rocks to form.
He illustrates the bizarre differences in depth of the deposits of the same age in separate regions both near and distant, pointing out, for example, the one foot of Jurassic sediment in Sicily in contrast to the 15,000 feet of one Jurassic zone's sediment in Oregon [13] . Since they do not form on mountains, sediments, which can fill basins to a depth of up to 20,000 meters, would have been below sea level if the oceans existed when they grew.
He alludes to numerous wide differences in rates of sedimentation: a 38-foot fossil tree stands amidst the late Carboniferous Coal Measures of Lancaster; but for the flow of sediments from rivers into the seas he quotes Holmes' measure of only one centimeter per millennium. He estimates the Grand Canyon at under 10 million years; the gorge, that is, provides a case of rapid erosion. "The periodic catastrophic event may have more effect than vast periods of gradual evolution:" this he calls "the phenomenon of quantum sedimentation." [14]
As there are more gaps than record, it is also true that there are more rapid deposits than slow ones, and the two facts may be connected in quantavolution. Rapid rates are easy to discover; Vita-Finzi cites a mid-Atlantic rate of clay deposit that increased suddenly from 0.22 to 0.82 grams/ centimeter 2 /year about 11,000 years ago (conventional dating), along with a drop in total carbonate deposition from 2.80 to 1.34 g/ cm 2 /y [15] . Nearly a 400% increase over an immense area; was it a type of Worzel ash fall-out? Or another case of rapid sedimentation?
At Nampa, Idaho, a well-carved human image in soft stone was recovered at 300 feet depth during well-boring [16] . The drill had penetrated 60 feet of alluvium, 15-20 feet of lava, and 200 feet of quicksand beds and clay, coming upon the sculpture in coarse sand, just below which was vegetable soil, followed by sandstone. One recognizes here a probable catastrophic sequence; the statue's presence, if admitted, wreaks havoc upon anthropology or geology or both.
Doeko Goosen has developed a wealth of related material, yet unpublished [17] :
Two of my students collected undisturbed samples of a transition zone between a soil of less than 1 m thick and the underlying shale. My hunch was that the soil had not developed from the shale, and minerological analysis proved me right. Within cracks of the shale multi-layer cutans were found. Traditionally such is explained by the one-layer per season theory, but when I looked through the microscope I saw oddities not compatible with that theory. [An expert on micromorphology confirmed his conclusions.] The phenomenon must have been caused by very strong tectonic vibrations, causing cracking of the slate and a sudden influx of clay and lime. At the same time fragments of the slate must have been projected upwards violently, passing through the soil, and now found on the surface.
Such tectonic miscibilation must be worldwide and visible under examination according to the quantavolution hypothesis in ground not believed to have experienced tectonism historically. Furthermore, a probable catastrophic cause may be assignable to soil processes that are considered ordinary and gradual. Goosen writes:
The formation of a laminated deposit via the season after season theory occurs only in highly exceptional circumstances. Wherever flooding occurs, there is also biological activity. The Rhine in the Netherlands each year floods pastures within the zone between the dikes, and leaves a thin deposit of clay. In the thus accumulated soil there is absolutely no lamination. The growing grass plus organisms like worms lead to homogenization. Indeed, it will be difficult to find on earth an environment where the season after season theory could be demonstrated. And then, upon seeing a laminated sediment, the inevitable conclusion must be that it is a catastrophic sediment, including the famous Scandinavian varves.
"Sedimentation goes on all the time, for ever moving from place to place, for ever cannibalizing itself." [18] It accumulates also from erosion of igneous and metamorphic rock. All sedimentary bodies, other than deep sea oozes and volcanic ash deposits, are likely to be diachronous. They stretch and spread out from a node over a small or large region, so that the elapsed time from the center outwards may be considerable. Two contrasting illusions, we note, can be created if the same sediment is thinly spread over a large area, first that the sediment is all of the same time, whereas it is not, second that the time itself must be long because of ambiant indicators applying to some central segment. That is, dating the indicator, one applies it to the whole, which brings about an illusory dating of adjacent rocks, too.
Rejecting the "layer cake" and "gentle rain from heaven" images as explanations of sedimentations, Ager introduces a rolled carpet that is gradually unrolled with time. We can extend the analogy. A producer of carpets lays down his roll and rolls it out before a salesman; the salesman rolls it up and carries it away to sell to buyers. Sometimes the producer has no carpets; at other times he brings only part of his collection; sometimes he brings in many rolls. The salesman sometimes rejects carpets and they are not sold; sometimes he buys one, or several, or all. A pile of rugs accumulates in the producer's showroom. Piles grow elsewhere. The salesman may even return his defective carpets. He may decide to deal with several producers, even as the producers may deal with different salesmen. Some buyers save carpets as a form of money; others wear them out quickly. In critical times for the economy, heaps of unsold carpets are laid out and accumulate, or are desperately sold in heaps; in inflationary periods, carpets become quickly and widely distributed. These last time periods would quantavolutionize the rug business.
When he is not imagining rugs, Ager's picture of the stratigraphical record is "of one long gap with only occasional sedimentation." [19] But his "occasional" sometimes is rare and sometimes frequent. I have noted this earlier in his view of tsunamis. Also now avalanches: "the frequency of landslides is quite enough to account for a major part of the wearing down of new mountain chains." Three cubic miles dropped in one slide at Flims, Switzerland; 40 million cubic meters of mountains fell into Lituya Bay, Alaska, in 1958. Still, a single earthquake of 10 or more on the Richter scale (and what was the number of the rising of the Sierra Nevadas?) would shake a new mountain range into well-worn shapes with garlands of debris all about below, and enough detritus to provide many moraines; the rise of a mountain range, indeed, may be its own heaviest eroder, then and there. The more rapid its rise, the more eroded it will be when it ceases to rise.
Ager argues convincingly the origin of deep sediments. The production of sediments is independent of subsidence. "It is only when sedimentation and subsidence coincide that the conditions will be right for the preservation of the vast thicknesses that constitute the stratigraphic record." [20] Again, we encounter a falling back upon the old notions of subsidence and uplifting. The phenomena are not mistaken; they are only insufficiently explanatory.
Ager partly realizes this, and sets up a very busy plate welding shop operating episodically over vast periods of time. A number of plates (and he seems to accept many major fractures everywhere as plate boundaries) spend history in roughly their original geographical locations, jostling heavily against one another periodically, episodically, spasmodically. "The continental plates, rather than sailing about the earth until they met in catastrophic collisions, separated and came together again repeatedly along the same general lines. In other words, there were many catastrophes and certain parts of each plate were particularly accident prone." [21] He would better have taken up the simple concept of ocean basins being created before the oceans and filled by debris washed down and fallen out of the catastrophic deluges.
We should not diminish one whit or alienate so expert and staunch an ally. We may, as mildly as we can, offer a suggestion. Let us give one more turn to the screws on the lately tortured Earth by computerizing its morphology. Suppose only one index to be composed for a sample of, say, 5 100 sedimentary sequences chosen at random from the 510 million square kilometers of the Earth's surface (one in 100,000; this ratio and size of sample is typical for discovering the political opinions and predicting the voting behavior of the American population).
Call it an Index of Quantavolution "Q/ a" (actually this could be a composite of a set of indices). It should contain and combine the number of distinguishable strata; an index of conformity to the ideal sequence of geological ages; the number of discontinuities that might be of diastrophic origin; the proportion of igneous and metamorphic intrusions; the proportion of the square kilometers (as judged by a hexagonal reading from drilling or otherwise) occupied by the central sequence of strata; and a total of the estimate of the lowest possible elapsed time for the deposit of each stratum to the column. Determine the usual statistical parameters of the sample, the sums, means, modes, quartiles, standard deviations etc. of the 5100 sedimentary sequences, and perform the obvious analysis and comparisons.
Some will say that the general information sought here is already known and taken into account, others that it is largely unknown and impossible to achieve, and many (rightly) that it is a caricature of a carefully drawn index. Many will comment that if the MOHOLE could not be financed to drill into the underseas mantle at an especially flushed period of American government finances, this project could never be funded. Many would want "add-ons": for example, "why not get samples of all strata in every sequence while we are at it?" We would eagerly agree. However, plausible conjectures and semi-data might be developed for all aspects of the index by library research and questionnaires addressed to many experts. Substitute sampling could be extensively employed.
Ultimately I would suppose refined summations to emerge such as the following: that the number of strata increase with recency; that superposition is 90% or better, but less than 50% of the recognized sequence is present; that 95% of the discontinuities might conceivably indicate diastrophism; that possible intrusions occupy over 50% of 80% of the sequences; that few sequences preserve their integrity over a square kilometer; that 80% of all sequences might conceivably have been laid down in their totality within 1000 (sic) years and that individual sequences would never exceed 10,000 years using conceivable assumptions.
The report would be entitled, Reductio ad absurdum, Part II. Perhaps one of the more entertaining aspects of such a study would be the objections that it is too literally empirical, and that the "total picture" is needed to disprove it and set it aright; the "total picture" is, however, what hitherto has given rise to the cosmogonies and science fiction that have commonly caused distress among geologists.
It would be possible to elaborate the hypothetical findings of such a study and to explain their heuristic and substantial utility, but not here. Thus, if the data is rotated topographically, significant summaries of continental and regional data would be generated. Moreover, as characterizes discussion of empirical data, no matter how crude, the air would be cleansed of some of the purely terminological pockets and gusts that cause turbulence and mental cloudiness. I see in such a project, also, a confrontation of the facts and their consequences that even a most learned and iconoclastic scientist does not consistently afford himself. He may come to realize that microchronism must be employed as a hypothetical model if a catastrophist is ever to integrate his facts.
Notes (Chapter Twenty-five: Sediments)
1. "Tills: Their Origins and Properties," in Legget, ed., op. cit., 11.
6. O. F. Tuttle, "The Origin of Granite," 192 Sci Amer. (Apr. 1955), 81.
7. As for example, W. G. Ernst, Earth Materials (Englewood Cliffs, N. J.: Prentice Hall, 1969), 111.
16. G. Frederick Wright, 11 Amer. Antiquarian (1889), 379-81.
17. From letter to author, 15 Oct. 1982, Enschede (The Netherlands).