On the Origin of Mountains and Oceans

(The Hypothesis of an Increase in the Earth’s Rate of Rotation¹)

L. A. Pukhlyakov

(Presented by the interdepartmental seminar of the Geological Prospecting Faculty)

The permanence hypothesis. Until comparatively recently, the hypothesis of the permanence (constancy) of the oceans enjoyed wide currency; according to it, these forms of the Earth’s surface have existed for exactly as long as the Earth itself has existed. This hypothesis was created chiefly to explain the absence of a normal sialic shell in the region of the oceans; however, it is precisely this question that it does not solve, but merely postpones its solution to an infinitely remote past, for the mechanism of the concentration of sial into continental masses in the descriptions of this hypothesis is too schematic. In addition, this hypothesis is contradicted by such facts as the strengthening of land connections between the existing continents—for example, between Europe and North America—in the Carboniferous, in the Jurassic [5], and especially in the Lower Eocene [24]; the presence of signs of subaerial weathering at depths reaching 3000–3500 m [23]; and other facts. Finally, this hypothesis may be said to ignore the processes of denudation of the continents and sediment accumulation in the oceans. In fact, if one proceeds from the fact that the rate of accumulation of sediments in the oceans lies within the range from 0.5 to 3.0 cm per 1000 years [16, 20], and takes into account that the thickness of loose deposits in the Pacific Ocean averages 1.0 km and nowhere exceeds 2.0 km [21], while in the Atlantic it ranges from 0.8 km south of the Bermuda Islands [19] to 5.0 km in the region of the Mid-Atlantic Ridge [23], it follows that the age of the Pacific Ocean is approximately 30–100 million years, and that of the most ancient parts of the Atlantic is 200–250 million years. In an analogous way, proceeding from the fact that the volume of solid material annually carried from the continents into the oceans is 13.6 km³, D. Gilluly [6] comes to the conclusion that approximately 225 million years will be required for the complete reworking of the existing continents. Thus, they acquired their present outlines comparatively recently.

The hypothesis of the submergence of the continents. To explain the facts that led to the crisis of the permanence hypothesis, many tectonists—for example, V. V. Belousov [1, 2], O. K. Leont’ev [10], M. V. Muratov [12], P. F. Zhirov [7], and others—return to the ideas of the ancient Greek philosopher-idealist Plato, according to which continents can pro—

could arbitrarily turn into oceans, just as, in epeirogenic movements of the Earth’s crust, continental plains turn into epicontinental seas. In this connection some of them, for example N. F. Zhirov [7], refer to this author’s report on the submergence of Atlantis as one of the proofs of their hypothesis. It is appropriate here to point out that as early as the end of the last century A. N. Karnozhitskii [8], analyzing Plato’s dialogues Critias and Timaeus, came to the conclusion that Plato’s Atlantis must have been situated in the eastern part of the Mediterranean Sea; and at the beginning of the present century the English archaeologist K. T. Frost [17], on the basis of excavations on Crete, proved that this island in particular is Plato’s Atlantis, so that the report of its submergence is an invention of ancient Egyptian priests.

The impossibility of arbitrary submergences of continents to depths of several kilometers follows, first, from the hypothesis of isostasy, which the followers of Plato unlawfully ignore, but which enjoys absolute recognition among geophysicists and astronomers [11; 4; 13]. Secondly, if, contrary to this hypothesis, the oceans had formed as a result of a simple subsidence of the Earth’s surface, then their territory would be covered by a normal sialic shell. In fact, the thickness of the sialic shell in the oceans is far smaller than on the continents [19; 21], which follows from the hypothesis of isostasy.

The only facts that the hypothesis of arbitrary submergences explains satisfactorily, and which for this reason underlie it, are the above-mentioned signs of subaerial weathering on the ocean floor and the strengthening of land connections between separate continents. However, all these facts are also satisfactorily explained if one assumes major falls in the level of the world ocean. Incidentally, the confinement of signs of subaerial weathering to the shallowest parts of the oceans (down to a depth of 3500 m) argues in favor of the second of these hypotheses.

Submarine canyons. It is interesting to note that one of the signs of subaerial weathering (submarine canyons) categorically contradicts the hypothesis of continental submergence. These formations, as F. Shepard [16; 22] has shown, are submerged river channels. And if this is so, then along the lines where the submergence of the continents occurred there should be sharp bends in these channels, which in fact do not exist. Hence, there have been no submergences of continents in the territory of the modern oceans.

In this connection the followers of Plato make every effort to refute the erosional hypothesis of the origin of submarine canyons; however, in the end, even the most consistent of them, for example O. K. Leontiev [10, p. 331], are forced to agree with it. Thus, the hypothesis of continental submergence proves to be completely refuted.

Wegener’s hypothesis. Obviously, the oceans formed over the course of the geological history of our planet; however, this occurred not as a result of the submergence of continents, but as a result of certain processes that removed the sialic shell from particular areas. It is interesting to note that individual researchers, proceeding from entirely different premises, arrive at the same conclusion. For example, A. Wegener [5], proceeding from the parallelism of the coasts of the southern part of the Atlantic Ocean, the identical sequence of deposits in certain Carboniferous and Devonian series of South America and Africa, and certain other data, asserts that this ocean formed as a result of the displacement of the continents of America westward relative to the Old World, that is, that these continents were in contact with one another in the past.

It should be noted, however, that A. Wegener was unable to substantiate the forces that could have moved the continents apart. At any rate, the pole-fleeing force he assumed and the force due to the braking of the Earth’s rotation by tidal friction amount to no more than one millionth of the force of gravity and are therefore regarded by most researchers as insufficient.

Nor did this author determine the time of the process quite satisfactorily. Namely, according to Wegener, the separation of America from the Old World began in the Lower Cretaceous and continues to the present time. However, if one proceeds from the table he gives of the number of identical forms of reptiles in North America and Europe [5, p. 56], then one must agree with his opponents, who maintain that these continents apparently constituted a single whole only in the Carboniferous, or even earlier. Other weak points of Wegener’s hypothesis have also come to light, as a result of which geologists at present have abandoned it completely.

E. V. Bykhanov’s hypothesis on an increase in the speed of the Earth’s rotation. Can the crisis of Wegener’s hypothesis mean that in nature there could never have been forces capable of moving the continents apart? Obviously not. In 1877, that is, more than thirty years before the appearance of Wegener’s first book, the Russian amateur astronomer E. V. Bykhanov, in the book Astronomical Prejudices, suggested that the aforementioned parallelism of the shores of the Atlantic Ocean can be explained if it is assumed that in the past there occurred not only a decrease in the speed of the Earth’s rotation, but also an increase in it, and one cannot but agree with this. In fact, an increase in the speed of the Earth’s rotation should have led to a lengthening of the equatorial radius and a shortening of its polar radii, and thus to the formation of cracks in the Earth’s crust across the equator. The rocks that protruded at the bottom of such cracks could not rise to the upper level of the sialic shell because of their greater density. Consequently, the territory covered by them must have formed a depression of the Earth’s surface—a water basin. Obviously, one such fissure-basin is the Atlantic Ocean. A series of other similar fissures formed the Indian Ocean.

Calculations show that, simultaneously with the lengthening of the equator, there should have occurred an increase in the length of meridians in low latitudes and a shortening of it in high latitudes. This, in turn, should have led to the formation of fissure-basins along the equator. Such fissure-basins may be considered the Mediterranean Sea, the Black Sea, etc. In another place, stresses of this kind led to a northward displacement of the block of Hindustan relative to Africa and Australia, that is, to an additional expansion of the Indian Ocean.

When the increase in the speed of the Earth’s rotation was replaced by the reverse process (and this must be assumed, since the speed of the Earth’s rotation at present is comparatively small), intense compressive stresses must have arisen on its surface. In other words, processes of ocean formation must have been replaced by processes of fold formation. Especially intense fold formation occurs in post-Paleocene time (the Alpine cycle of tectogenesis); therefore one may say that, beginning with the Eocene, a decrease in the speed of the Earth’s rotation was taking place.

The Tethys Ocean as an indication of an increase in the speed of the Earth’s rotation. If one proceeds from the assumption that the Earth’s inner geospheres are not in a liquid state but in a solid one, then it is not difficult to understand that the deformations occurring in them will proceed only in the presence of a certain excess pressure from the poles in the epoch of increasing rotational speed, or from the equator in the epoch of decreasing rotational speed—

tions. And this means that in the first case a concentration of water toward the equator should be observed, and in the second toward the poles.

Such an expectation is confirmed in the best possible way by the data of historical geology, which indicate that in the past, at the Earth’s equator, there in fact existed a stable water basin—the Tethys Ocean—which divided the land of that time into two parts isolated from one another. One of them (the southern) is usually called Gondwana, and the other—Laurasia [9]. R. van Bemmelen [3] dates the emergence of this ocean to the Devonian, and its dismemberment to the beginning of the Eocene. Such facts as the presence of Eocene-age coral limestone at the base of the Eniwetok Atoll at a depth of 1200–900 m [18], and the absence, beginning with the middle Eocene, of a connection between North America and Asia [14], although the depth of the Bering Strait at the present time does not exceed 200 m, testify to a concentration of water toward the poles in post-Paleocene time.

Cyclicity in the increase of the Earth’s rate of rotation. On the floor of the Atlantic Ocean there is a series of extensive ledges, greatly elongated in length, which I. Tolstoy and M. Ewing [23] call terraces. This fact compels one to suppose that the increase in the Earth’s rate of rotation took place in several cycles, separated from one another by epochs of stabilization and even of some reduction in it. And from this it follows that those processes of folding which manifested themselves with such intensity in post-Paleocene time must, to some degree, have manifested themselves in earlier epochs as well. Thus, the hypothesis of an increase in the Earth’s rate of rotation explains the origin not only of certain oceans, but also of many phases of folding.

Emerging on the floor of fissure-basins, strongly heated magma must have caused intensive evaporation of water. Therefore epochs of increase in the Earth’s rate of rotation must have corresponded to epochs of warming and humidification of the climate, and epochs of stabilization—to a certain aridization and cooling of it. In this connection it is interesting to note that in the Lower Carboniferous the climate was unusually warm and humid, and a thalassocratic regime prevailed on the present-day land. An analogous situation is recorded also for such periods as the Jurassic, Cretaceous, and Paleocene. In Permo-Triassic time the climate was dry and cold; on the present-day continents a geocratic regime prevailed.

Evidently, in the Lower Carboniferous the first cycle of increase in the Earth’s rate of rotation occurred, and then there came an epoch of prolonged stabilization, which ended only by the beginning of Jurassic time. After this, cycles of increase in the rate of rotation apparently followed one another so rapidly, and the epochs of stabilization were so short, that exposures of magma in different basins did not have time to cool sufficiently.

From the point of view of the proposed scheme, intensifications of the thalassocratic regime on the existing continents must correspond to intensifications of land connections between them, and, conversely, intensifications of the geocratic regime on the existing continents must correspond to weakenings of land connections between them, which in fact has been recorded by historical geology. For example, according to A. Wegener, citing Arldt [5], the number of identical reptile forms in North America and Europe for Carboniferous time is equal to 64%; for the Permian it decreases to 12% (evidently, the water level in the Atlantic Ocean rose somewhat); for the Triassic it remains relatively small—32%; while in the Jurassic, which, like the Carboniferous, is characterized by an intensification of the thalassocratic regime on the existing continents, it rises sharply (to 48%). Evidently, the water level in the Atlantic Ocean fell again.

The cause of the increase in the Earth’s rotational speed. The most probable cause of the increase in the Earth’s rotational speed in pre-Eocene time may have been the approach to it of a second satellite, which, for brevity, it is proposed to call Perun. Apparently, this approach began as early as Devonian time; beginning with the Carboniferous, it began to affect the Earth’s rotational speed, and at the end of the Cretaceous it ended with the attachment of this satellite to the Earth.

The mechanism of such an approach may be imagined in the following form. At that time the Earth apparently had two satellites, the Moon and Perun, and rings similar to the rings of Saturn. Owing to intense tidal friction, Perun, which was closer to the Earth, ultimately had to equalize its angular velocity of revolution with the angular velocity of rotation of our planet. After this, the tidal bulges caused by it on the Earth’s surface should no longer have moved, and, consequently, their velocities should have become stabilized.

But the Moon, situated at a greater distance from the Earth, moved more slowly and therefore had to retard the Earth’s rotation. In the end this should have led to Perun beginning to overtake the Earth’s surface and to increase the speed of its rotation. For this it had to expend its energy of motion and thus approach the Earth. But the more strongly it approached it, the greater its velocity had to become, and the more intensely the process of transfer of energy and of approach to the Earth of this satellite had to continue.

But then it approached so closely that individual fragments of the rings began to fall onto its surface. They were situated still closer to the Earth and possessed still greater velocity, and therefore, striking the surface of Perun, they had to increase its store of energy. This, in turn, should have led to its moving somewhat away from the Earth and decreasing its velocity. Thanks to this it could equalize itself with the rotational speed of the Earth and again become stabilized.

After this there again had to come an epoch of slow braking of the Earth’s rotation by the Moon, during which small folded structures had to form. This epoch had to continue until the difference between the angular velocities of the Earth’s rotation and Perun’s revolution reached a significant magnitude and the process of Perun’s approach resumed.

The fall of fragments of the rings onto the surface of Perun should have led to its acquiring a certain retrograde rotation, and this should have allowed it to remain as a single whole (that is, not turn into rings similar to the rings of Saturn) even in the immediate proximity of the Earth (inside the Roche zone).

Apparently, by the middle of the Upper Cretaceous all the fragments of the Earth’s rings had been gathered on the surface of Perun, and it began to approach the Earth rapidly. This event corresponds to the formation on the floor of the Atlantic Ocean of extensive plains situated between the above-mentioned terraces, and to the cutting of submarine canyons down to the present depth of 2200 m. At the end of the Upper Cretaceous Perun came into contact with the Earth’s surface, as a result of which its retrograde rotation was sharply slowed and its disintegration began, which ended with the attachment of this satellite to our planet.

The origin of the Pacific Ocean. The mean density of Perun, like the mean density of the Moon, must have exceeded the mean density of the Earth’s surface geospheres, and therefore the territory covered by its

with debris, should have turned into a gigantic depression of the earth’s surface. Such a depression may be regarded as the Pacific Ocean.

The appearance of a new water basin should have led to a lowering of the water level in the other water basins, in particular in the Atlantic Ocean. This event may be connected with the establishment of land connections between Europe and North America, which occurred in the Lower Paleogene, and with the cutting of submarine canyons to a present-day depth of 3500 m.

The rise of the level of the world ocean in the Middle Eocene. It is known that, under the conditions at the earth’s surface, erupted rocks undergo weathering—being transformed into new rocks containing bound water in their composition. Accumulating in large quantities, these rocks bury enormous amounts of water with them; therefore one cannot agree with those who assert that in the future the entire surface of the Earth will turn into a waterless desert. According to V. A. Sulin [15], the amount of bound water in the earth’s crust at the present time down to a depth of 20 km does not fall below 8% by weight, which is equivalent to 20% by volume.

Having become covered by the debris of Perun, such rocks should have been heated under the action of radioactive decay and released the bound water contained in them into the hydrosphere of our planet. As a result, the level of the world ocean should have risen by approximately 2.5 km.

In this connection it is interesting to note that the level of the world ocean was unusually low only during the Lower Paleogene, that is, for approximately 10–15 million years. In the Middle Eocene, in polar latitudes, it already reached the present level, as a result of which the land between Alaska and Chukotka was flooded; while under the equator it did not reach the present level by 900–1200 m, as was stated above.

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1. Published as a contribution to discussion. ↩