ON THE QUESTION OF THE ORIGIN OF THE PACIFIC OCEAN

L. A. Pukhlyakov

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

The time and presumed cause of the origin of the Pacific Ocean. At present, the hypothesis of the extraordinary antiquity of the Pacific Ocean enjoys wide popularity [26; 17]. It should be noted, however, that this hypothesis is contradicted by abundant factual material. For example, the thickness of loose sediments on the floor of the Pacific Ocean varies within the range of 1–2 km [28]; therefore, taking into account the corresponding rate of accumulation of sediments in the open ocean, which varies within the range of 0.5–3.0 cm per 1000 years [19; 27], one may conclude that the age of this ocean should be on the order of 30–100 million years, and in no case more than 200 million years.

But this is not all, nor is it the main point. K. Burckhardt [21] showed as early as 1903 that in Upper Jurassic time, in the region of the western coast of Chile, sediments were being carried from the west; from this it follows that, in place of the southern or at least the southeastern part of the Pacific Ocean, there then existed an extensive continent. In the literature this continent has come to be called South Pacifica.

It is further known that, despite all the distinctiveness of the flora of New Zealand (its endemism amounts to 74%), there are 129 genera and no fewer than 66 species of plants there identical with those of South America [6]. Undoubtedly, among these plants there are many whose seeds were carried across the Pacific Ocean by wind, birds, or marine currents; however, among them there are also such plants—for example Nothofagus (southern beech)—whose seeds are not adapted for transport across the ocean either by wind, by birds, or by marine currents; and nevertheless Nothofagus, in addition to the land masses listed above, also inhabits Australia. But this is not all. Studies of this plant by G. Gordon [23] showed that on all three land masses the same fungus—Cyttaria—parasitizes this tree; it cannot inhabit any other plant and therefore is capable of migration only together with the living Nothofagus. Hence it follows that the migration of this plant from South America to Australia and New Zealand (or conversely) took place under conditions in which an extensive continent lay between them. Finally, on all the land masses just listed, in the mosses of Nothofagus forests there live bugs of one and the same family—Peloriidae—whose representatives are likewise found nowhere except in these forests and are completely unsuited to flight (they perish as soon as they leave the atmosphere of Nothofagus forests) [23]. This once again indicates that the migration of this tree across the space now occupied by the Pacific Ocean.

occurred under continental conditions. Thus, South Pacifica, which, according to Burckhardt’s data [21], existed in the place of the southern part of the Pacific Ocean in Late Jurassic time, according to Gordon’s data [23], continued to exist here also in the Late Cretaceous, for angiosperms and, in particular, representatives of the beech family are known only from the middle of the Cretaceous [9, p. 383].

The question arises: when, then, did this continent disappear? Proceeding from the fact that in New Zealand there are no native mammals (the exceptions are one species of rat and two species of bats), and that on the other continents representatives of this class were widely distributed from the very base of the Paleocene, it should be expected that South Pacifica disappeared before the beginning of this epoch. E. Hamilton [25], who discovered on the floor of the Pacific Ocean a shallow-water fauna of Late Cretaceous age, comes to approximately the same conclusion.

Did a similar continent exist in the place of the northern part of the Pacific Ocean? J. W. Gregory [24], V. V. Belousov [1], and many other investigators assert that it did. From what is said below it also follows that it must have existed. However, this question will not be of great importance for the subsequent arguments, and therefore there is no need to dwell on it.

Thus, in the place of the Pacific Ocean, or at least of its southern part, dry land existed almost until the end (and perhaps until the very end) of the Mesozoic. At present, however, there are no signs of this land on the floor of the Pacific Ocean. Beneath a thin layer of sediments, granites, and basalts, there are located the very same rocks that beneath the continents occur at depths of 30–50 km [28]. This is what has made the problem of the origin of the Pacific Ocean so difficult. In our work on this question [12] the following solution is given. To explain the displacement of the two Americas westward relative to Europe and Africa, it is assumed that from the Devonian to the Eocene there was an increase in the Earth’s rate of rotation; and to explain this increase it is assumed that the Earth had a second satellite—Perun—which at first approached it, and then (at the end of the Late Cretaceous) joined it. The mean density of the Moon exceeds the mean density of the sialic shell of the Earth. The same may be assumed for Perun, and from this it follows that the territory covered by its fragments must have subsided and formed a gigantic depression of the Earth’s surface. Such a depression is the Pacific Ocean. This hypothesis also satisfactorily solves other problems of the geological history of our planet, in particular the problem of the origin of the deepest depressions in the western part of the Pacific Ocean.

Approach toward the Earth’s center of accumulations of the densest rocks of Perun. As our calculations show, shortly before its accretion Perun must have possessed a certain retrograde rotation, which, at the moment of its contact with the Earth, must have sharply diminished; this must have been the cause of the breakup and final accretion of this satellite to the Earth [12]. In breaking up, Perun must have moved slowly westward relative to the Earth’s surface (relative to the Earth’s center it must have moved rapidly from west to east), and hence its densest rocks, which before the breakup were located somewhere near its center, after the breakup must have found themselves in the western part of the territory covered by it.

If several stones are placed on the surface of an asphalt lake, they will begin slowly to sink, drawing after them those substances,

which found themselves beneath them, and those that found themselves beside them. In an analogous way—as was shown in its time by O. Yu. Schmidt [20, pp. 65–69]—substances that have reached the Earth’s surface from space must behave. Otherwise, developing this thought of O. Yu. Schmidt’s, one may suppose that accumulations of heavy rocks of Perun must have acquired a tendency to move toward the center of the Earth, and that this movement must have continued until the average density of the sinking rocks became equal to the average density of the surrounding rocks.

It should be noted, however, that after sinking to a certain depth (the sinking rocks, including among them the surface rocks of our planet drawn down in the wake of the fragments of Perun) would have found themselves in a zone of higher pressure than before; from this it follows that, thereafter, chemical reactions must have begun in these rocks, accompanied by an increase in their density, and the process of their sinking and of drawing down new masses of surface rocks of the Earth after them must have resumed, or simply intensified. Thus, the process under consideration must have proceeded now stopping, now resuming, now weakening, now intensifying.

The keel-shaped form of the deepest depressions in the western part of the Pacific Ocean as evidence of their origin through the sinking of the heavy rocks of Perun into the deep zones of the Earth. A. Wegener [4] maintained that the depressions under consideration were formed as a result of the separation of surface rocks of the Earth to the sides. Hence they should have steep sides and a gently sloping bottom (this also determined their name—“trenches”). In reality, however, studies of recent years have shown that these “trenches” have nothing in common with true trenches and most closely resemble series of funnels that have joined together. In any case, the steepness of their sides not only does not decrease as one approaches their axes but, on the contrary, increases [13; 16] and, according to data of R. U. Reitt et al. [13], in individual cases reaches 24°, so that the name “keel-shaped depressions” would be far more appropriate for these depressions.

Thus, the morphology of the formations under consideration bears the best possible witness to the fact that they are foci of sinking of accumulations of the heavy rocks of Perun.

Blocks of sial torn from the continental masses owing to movement toward the foci of sinking. Obviously, the influence of the sinking masses on the surface rocks must have diminished with increasing distance of these masses from the Earth’s surface, and must have been the smaller the farther from the focus of sinking a given block of surface rocks might be situated. In other words, the horizontal stress acting on the surface rocks in the region of a focus of sinking must increase as one approaches that focus. From this, in turn, it follows that blocks of sial closer to the focus of sinking must have torn away from more distant ones and moved toward these foci at a speed on the order of 0.1–0.01 m/year. By the present time, that is, 70–100 million years after the accretion of Perun, some of such blocks, naturally, could have been completely drawn into the foci of sinking, while others could have remained partly or entirely on the Earth’s surface and risen above the level of the world ocean in the form of large islands and peninsulas.

In this respect it is interesting to note that most of the deepest depressions under consideration in the western part of the Pacific Ocean are associated with large islands and peninsulas, and the greatest distances of these from the continental mass correspond to the greatest depths of the depressions considered. For example, the northern part of the Kuril-Kam-

the Kamchatka Basin is gravitated toward by the Kamchatka Peninsula (its continuation to the south, evidently, proved to have been drawn down into the deep zones of the Earth); the Sakhalin and Japanese Islands gravitate toward the Japan Basin; the Philippine Islands gravitate toward the Philippine (Mindanao) Basin; and New Zealand gravitates toward the southern part of the Tonga Basin (the northern part of this landmass, evidently, also proved to have been drawn down into the deep zones of the Earth).

Modern volcanism in the zones adjacent to the deepest basins, as the result of the continuation of the process of subsidence at the present time. If the process of subsidence of accumulations of Perun’s heavy rocks continues at the present time, then in the zones adjacent to the basins under consideration there should even now be tensile stresses similar to those that formed the seas: the Sea of Okhotsk, the Sea of Japan, etc. And stresses of this kind, as I. V. Mushketov showed in his time [10, p. 496], must lead to the appearance of volcanoes in these regions. This expectation is confirmed as well as possible by factual data, namely: on the islands and peninsulas gravitating toward the basins under consideration there is a great multitude of active volcanoes and still more extinct ones. In fact, in Kamchatka there are 22 of them; on the Kuril Islands, 38 [5]; in Japan, 55 [2]; in the territory adjacent to the Mindanao (Philippine) Basin: on the Philippines, 10; on Sulawesi (Celebes) and the Moluccas, 25 [3]; on the islands adjacent to the Tonga and Kermadec basins there are likewise many volcanoes, namely: on the Samoa Islands, 4 active volcanoes; on the Tonga Islands, 10 [15]; on the Kermadec Islands, 3; on the North Island of New Zealand, 5.

On the Java and Aleutian basins. The Java and Aleutian basins show a great similarity to the Kuril-Kamchatka, Japan, Mindanao, and Tonga basins. First, they are strongly elongated in length; second, on the continental side they are adjoined by arcs of islands on which there are many active volcanoes. Thus, according to the data of R. van Bemmelen [3], on the Andaman Islands there is one active volcano; on Sumatra, 9; in the Sunda Strait, 1 (the famous Krakatau); on Java (that is, opposite the middle of the Java Basin), 17; on the island of Bali, 2; on Lombok, 1; on Sumbawa, 2 (including the famous Tambora); on Flores, 9; between the islands of Flores and Wetar, 5, which altogether amounts to 47 active volcanoes. On the Aleutian Islands there are 32 of them (including the famous Katmai) [15]. And this makes it possible to suppose that these basins too are foci of subsidence of accumulations of Perun’s heavy rocks.

The comparative weakness of fold-forming forces in Tertiary time in the regions adjacent to the deepest basins. In another work on this question [12] it was shown that, in the epoch of reduction of the Earth’s rotational velocity, intense compressive stresses should have arisen over its entire surface both across the equator and across the meridians in low latitudes, and on this basis Tertiary folding is explained there. Could similar compressive stresses have arisen also in the immediate vicinity of the foci of subsidence under consideration? The impression arises that they could not, for there they should have been partly or even completely neutralized by tensile stresses. This expectation is confirmed as well as possible by factual data. Namely, such powerful folded structures as the Cordilleras and the Andes are absent both along the eastern coast of Asia and along the eastern coast of Australia. Mountain structures do, of course, exist here; however, the main phases of their formation belong not to the Cenozoic but to earlier epochs. For the Cenozoic here, only rare fold-forming movements of small amplitude are characteristic. The very same picture is observed

and in Indonesia—the folding of Tertiary time there was very, very weak [3] and bears no comparison with the folding in the Himalayas.

Modern increases in the rate of rotation of the Earth as a result of the continuation of the process of approach toward its center of accumulations of heavy Perun rocks. If one proceeds from the assumption that the matter of our planet is distributed uniformly in its body, that is, its density is constant and equal to \(5.517\ \mathrm{g/cm^3}\), then the initial expression for deriving the formula for the kinetic energy of its rotation will be written in the following form:

\[ W_{\mathrm{k}}=\frac{2\pi\cdot 5.517}{9.81}\,\omega^2\,\frac{b}{a}\int_0^a r^3\cdot \sqrt{a^2-r^2}\,dr, \tag{1} \]

where

\(\omega\) is the angular velocity of the Earth’s rotation \((1/\mathrm{sec})\); \(a\) and \(b\) are, respectively, the equatorial and polar radii of the Earth (m);

\(r\) is the radius of a certain elementary cylinder singled out in the body of the Earth, the axis of which coincides with the axis of its rotation; \(dr\) is the thickness of the walls of this cylinder, and \(2\,\dfrac{b}{a}\sqrt{a^2-r^2}\) is its length.

Integrating this expression within the limits \(0<r<a\) and carrying out the corresponding transformations in it, we find the expression for the kinetic energy of the Earth’s rotation under the given conditions

\[ W_{\mathrm{k}}=\frac{4}{15}\pi\,\frac{5.517\cdot \omega^2}{9.81}\cdot b\cdot a^4,\ \mathrm{kGm}. \tag{2} \]

If, however, one proceeds from the assumption that the density of the Earth changes in accordance with Roche’s formula

\[ \delta=11.2\left[1.0-1.06\left(\frac{r}{a}\right)^2+0.30\left(\frac{r}{a}\right)^4\right]\ \mathrm{g/cm^3}, \tag{3} \]

then the kinetic energy of the Earth’s rotation will be expressed by the following relation:

\[ W_{\mathrm{k}}=\frac{4}{15}\pi\,\frac{4.587\cdot \omega^2}{9.81}\cdot b\cdot a^4,\ \mathrm{kGm}. \tag{4} \]

Comparing expressions (2) and (4) with one another, it is not difficult to see that, at one and the same rate of rotation, the energy of the Earth’s rotation will be the smaller, the greater the concentration of matter toward its center. And this, in turn, means that, at constant rotational energy, the concentration of matter toward the Earth’s center (the displacement from the deep zones of lighter rocks by heavier ones) must be accompanied by an increase in the rate of its rotation, which must either partially or completely compensate for the effect produced by tidal friction.

It turns out that this conclusion is confirmed as well as possible by astronomical observations. Namely: according to the theory of tides, the rate of rotation of the Earth at the present time should be decreasing uniformly and with a definite intensity, but, first, the actual slowing of this rotation differs greatly from that calculated theoretically. To explain this, “in 1951 Yury proposed assuming that, in addition to tidal friction, there is also a change in the moment of inertia of the Earth independent of it, corresponding to a decrease in the radius by 4.5 cm for every 100 years” [11].

In addition to the described acceleration of the Earth’s rotation, from time to time, at intervals of from 10 to 30 and more years, irregular changes in the rate of its rotation occur, alternating without any definite reg-

dependence. “Since 1820 there have apparently been four such changes—around 1864, 1876, 1898, and 1920... These changes, occurring over approximately one year, exceed the tidal changes in the angular velocity of the Earth’s rotation over 100 years. Such large and such rapidly occurring changes cannot be explained by processes taking place on the Earth’s surface, or by cosmic causes. It is enough to point out that for such a change there would have to be either the fall upon the Earth, tangentially to its surface at the equator, of more than a million meteorites each with a mass of a million tons (that is, larger than the Arizona meteorite), or a reversal in the direction of the entire system of trade winds, ... or the leveling down to sea level of a plateau 700 : 700 km² in size and 4 km high (of the Tibetan type)... One must assume that the jump-like changes in angular velocity are connected with changes in the deep zones of the Earth” [11].

Increase in the Earth’s rotation rate in the first period after the accession of Perun. If at the present time the effect caused by the approach toward the center of the Earth of Perun’s accumulations of heavy rocks sometimes exceeds the effect produced by tidal friction, then in the first period after the accession of this satellite, when the accumulations of heavy rocks under consideration were located at the very surface of the Earth and the difference in density between the sinking masses and the masses surrounding them was much greater than at present, the effect produced by tidal friction could have been completely compensated by the effect under consideration. And this means that in the first period after Perun’s accession there could have been no reduction in the Earth’s rotation rate; even more, its increase must have continued, as had occurred during the period of approach of this satellite.

It is precisely by this that one can explain the fact that the Tethys Ocean continued to exist right up to the Eocene, and that the intensive folding of Tertiary time began at the end of the Middle Eocene, whereas, judging by the absence of mammals in New Zealand and by the presence of shallow-water benthos of Upper Cretaceous age on the summits of guyots in the Pacific Ocean, the origin of this depression of the Earth’s surface, and hence the accession of Perun to the Earth, dates to the end of the Upper Cretaceous. In the irregularities of the approach toward the center of the Earth of Perun’s accumulations of heavy rocks one should also seek the cause of the fact that, as noted earlier [12], the reduction in the Earth’s rotation rate in Tertiary time was nonuniform and the folding was cyclic.

Change in the plane of the Earth’s rotation in Cenozoic time. Modern displacements of the North Pole. If the approach toward the center of the Earth of Perun’s accumulations of heavy rocks did in fact take place, and if relative to the plane of the equator it was asymmetric, then it necessarily must have been accompanied by a change in the position of this plane relative to the Earth’s surface, that is, by a displacement of its poles. The largest number of the deepest depressions is concentrated near the eastern margin of Asia, mainly between 120 and 160° E. long.; therefore there is reason to suppose that the displacement of the equator too must have occurred toward these depressions, and this means that the North Pole, during Tertiary time, must have shifted toward the Atlantic Ocean, somewhere in the sector between 20 and 65° W. long.

This expectation is confirmed as well as possible by the data of paleomagnetic studies [18], according to which in Tertiary time the North Pole wandered somewhere between the mouth of the Lena, the Beaufort Sea, and its present position, that is, almost without leaving the indicated sector.

But this is not all: as studies of the curves of the annual motion of the North Pole over the last 50 years have shown [22; 8, p. 448], at present the North Pole continues to move toward Newfoundland at a rate of approximately 6–8 cm per year. It is not difficult to see that this displacement falls within the limits of the sector established above—20–60° W. longitude. (Newfoundland is located between 53 and 59° W. longitude.)

Obviously, this displacement does not proceed uniformly, but is concentrated chiefly in those years during which the rate of the Earth’s rotation increases; however, this proposition still cannot be confirmed.

On the question of pre-Cenozoic displacements of the North Pole. The Earth’s acquisition of rotation at the expense of Perun must have led to the plane of its equator assuming the position occupied by the orbital plane of this satellite. Hence, if in Devonian time these planes did not coincide, then by the moment of Perun’s accretion the plane of the equator (and, consequently, the North Pole as well) of our planet must have changed its position substantially. But this is precisely what follows from paleomagnetic data [18], according to which, during the Upper Paleozoic and Mesozoic, the North Pole moved from the Manchuria–Japan region to the region of the mouth of the Lena–Chukotka.

A similar picture must have been observed in some more ancient period as well. In fact, in order to explain the fact that Perun was preserved as a single whole even in the immediate vicinity of the Earth and ultimately accreted to it, it was assumed above, in accordance with the development made earlier [12], that in the epoch when this satellite approached it, the Earth already had Roche rings (rings similar to the rings of Saturn). But, as modern astronomers acknowledge [14], such rings can form only as a result of the disintegration of a satellite; therefore we are compelled to make one more assumption—namely, that at some time the Earth also had a third satellite, whose approach to it ended with its transformation into Roche rings. For convenience let us give it the conventional name Lel’ (in honor of another ancient Slavic deity).

Obviously, in the epoch of Lel’s approach to the Earth, as in the epoch of Perun’s approach to it, the plane of its rotation (and the North Pole) must have noticeably changed their position. Such a conclusion is likewise confirmed by factual data. Specifically, as shown by A. N. Khramov [18] and other authors, in the early Precambrian the North Pole was located somewhere in the region of the mouth of the Colorado and by the beginning of the Devonian had moved to the Japan–Manchuria region. It is interesting to note here that two clearly expressed directions are outlined in the motion of the North Pole: a Precambrian one (west-southwest) and a Paleozoic–Mesozoic one (in general north-northwest), which corresponds to the approach of two satellites to our planet.

The andesite line, its coincidence with the axes of the foci of subsidence, as evidence of the movement of matter toward these foci along the surface. It has long been observed that volcanoes situated west of the depressions under consideration erupt acidic lavas, while volcanoes situated east of them erupt basic lavas. Proceeding from this, Marshall as early as 1911 drew a boundary separating these rocks, which is commonly called the Marshall line, or the andesite line. This line, as many authors note, coincides in an astonishing manner with the axes of the deepest depressions in the western part of the Pacific Ocean. But it turns out that there is nothing surprising in this. If the depressions under consideration are in fact foci of subsidence of accumulations of heavy rocks of Perun, then toward-

sialic rocks must move toward them from the side of the continents, and from the side of the central part of the Pacific Ocean—rocks that once formed part of Perun (its central geospheres). On the line connecting the axes of the depressions under consideration, these two “streams” must meet and pass into the deep zones of the Earth. Hence the former, which after remelting should yield lavas of acidic composition with a large amount of volatiles, must occur west of these depressions; while the latter, which after remelting should yield lavas of basic composition with a small amount of volatiles, must occur east of them.

Negative gravity anomalies in the region of the deepest depressions of the western part of the Pacific Ocean. According to the theory (hypothesis) of isostasy, all blocks of the Earth’s outer geosphere must be in a state of isostatic equilibrium, and it follows from this that gravity anomalies should not occur on the Earth’s surface. Exceptions to this rule are areas where isostatic equilibrium is constantly disturbed by some agents. For example, in regions of mountain structures, owing to the constant removal of clastic material and the insufficiently rapid isostatic rise of the unloaded blocks of sial, negative gravity anomalies arise. In zones of sediment accumulation, on the contrary, owing to insufficiently rapid isostatic subsidence, positive gravity anomalies arise.

An analogous picture should also be observed in the zones where fragments of Perun sink. In fact, here, following the denser rocks, less dense blocks of sial are constantly drawn down into the deep zones of the Earth; over a long period of time these blocks should be situated near the surface of the ocean. These blocks should likewise correspond to negative gravity anomalies, which is indeed observed. For example, as R. van Bemmelen [3] notes, in the region of the Java Trench there is a large zone of negative gravity anomalies, beginning in Burma and passing through the Andaman and Nicobar Islands, and then west of Sumatra, south of Java, Bali, and Lombok. After a break near Sumba this zone continues through Sava, Roti, Timor, Tanimbar, and Kai to Ceram. Here this zone bifurcates: one branch goes northwest toward the Molucca Sea, while the other forms a loop and, through the islands of Buru and Buton, extends to the southeastern part of Sulawesi (Celebes). According to F. Shepard [19], analogous gravity anomalies are also associated with other deepest depressions of the western part of the Pacific Ocean.

On the concentration of earthquake foci in the deepest depressions of the western part of the Pacific Ocean. At present almost nothing is known about the phenomena that accompany the processes of metamorphism of sedimentary rocks in the deep zones of the Earth. However, there is reason to expect that from time to time these processes must be accompanied by sharp shocks, felt on the surface of our planet as earthquakes. Proceeding from this, it should be expected that in zones of modern metamorphism—first of all, in the regions of the depressions under consideration and in all young mountain structures, and second, in all other regions where folded rocks have found themselves in the zone heated by the Earth’s internal heat—earthquakes must occur.

It turns out that this expectation is confirmed in the most brilliant manner, for the most frequent and strongest earthquakes are observed precisely in the regions of the depressions under consideration. Indeed, as B. Gutenberg and K. Richter [7] note, the most active seismic zones on the Earth are associated with a belt that extends from Alaska, through the Aleutian Islands, Kamchatka, and the Kuril Islands to Japan, and then bifurcates, its eastern branch passing toward

the Mariana Islands, and the western one through the Ryukyu, Taiwan, Philippine, Molucca, Sulawesi, Java, and Sumatra islands to the Andaman Islands. As a kind of branch of this belt in the Southern Hemisphere there is a zone of increased seismic activity that runs parallel to the andesite line from the Molucca Islands through New Guinea, the Solomon and New Hebrides Islands to the northern extremity of New Zealand, where it joins a second similar belt extending from the Samoa Islands west of the Tonga and Kermadec trenches. Passing through New Zealand, this belt approaches Macquarie Island, where it forms a loop and dies out. Another belt of increased seismic activity passes near the coast of the Pacific Ocean in Central and South America. Only in these zones are shocks with a focal depth of 300 to 700 km observed, and a large part of intermediate-depth shocks (with focal depths from 60 to 300 km) is concentrated there.

The Pacific coast from Alaska to Mexico possesses fairly strong seismic activity; however, this activity bears no comparison with the activity of the zones just discussed. As for the southern margin and the entire remaining territory of the Pacific Ocean, their seismic activity is negligible.

Another zone of increased seismic activity, as B. Gutenberg and C. Richter [7] note, is the so-called Trans-Asiatic zone. This zone begins at the eastern margin of the Asiatic continent and, in the form of a belt whose width at first reaches several thousand kilometers, extends westward, bounded on the south by the Himalayas. In the Pamir region this zone narrows, but farther west it again expands, bounded on the north by the Kopet-Dag and the Greater Caucasus Range, and on the south by the Indus River, the shore of the Indian Ocean, and the Tigris River. Then this zone embraces Asia Minor, the Aegean Sea, the Balkan Peninsula, and the adjoining part of the Mediterranean Sea approximately to latitude 34°, that is, including the islands of Crete and Cyprus. A kind of continuation of this zone to the west is Mediterranean Europe, including, above all, Italy and Sicily, as well as Spain, the mountainous part of North Africa, and the Alps with the Carpathians.

Characterizing the Trans-Asiatic zone as a whole, B. Gutenberg and C. Richter [7] note that it represents the only region outside the Pacific belt where the strongest shallow earthquakes (with focal depths up to 60 km) and earthquakes of intermediate depth (with focal depths from 60 to 300 km) are known. Shocks with focal depths greater than 300 km are not encountered here.

Among other seismic belts B. Gutenberg and C. Richter note, first, the Atlantic belt, connected mainly with the Mid-Atlantic Ridge; second, the Arctic belt, which, in the opinion of these authors, is a continuation of the Atlantic; then the belt of the Indian Ocean, where epicenters are confined to its most elevated parts; and, finally, the belt of the East African grabens. However, they note in the same place that the seismic activity of Africa should be considered very moderate even in comparison with the belts of the Atlantic and Indian Oceans, which, in turn, are much less active than the Pacific and Trans-Asiatic belts. In particular, catastrophic earthquakes are not known in the Atlantic and Indian belts, and strong ones are rare. The depth of the foci does not exceed 30 km.

Thus, wherever the drawing of sialic rocks into the deep zones of the Earth has occurred, we observe an increase in seismic activity; and, conversely, where there is no reason to expect that in the recent past any drawing down of sialic rocks took place, no seismic phenomena are observed. In this respect it is interesting to note that over the greater part of the Pacific Ocean, where the process of metamorphism

rocks, covered by fragments of Perun, has long since ended, seismic activity is also relatively weak.

As for the mountainous parts of Central and South America, where seismic activity reaches approximately the same value as in the regions of the basins of the western part of the Pacific Ocean, one must admit that sialic rocks are being drawn here into the deep zones not only as a result of folding, but possibly also as a result of the submergence here of accumulations of heavy rocks of Perun. In favor of such an assumption are the presence here of gigantic basins (the Atacama and Guatemalan) and intense volcanism—South America has more than 40 active volcanoes, and Central America, including Mexico, has more than 30. On the other hand, there is reason to believe that the process of submergence of Perun’s fragments here, if it is taking place, is not as intense as in the western part of the Pacific Ocean, since Tertiary folding here was quite intense. Moreover, islands similar to the Japanese and Philippine do not gravitate toward the above-mentioned basins (the Atacama and Guatemalan). Finally, the number of earthquakes with a focal depth of more than 300 km is many times smaller here than in the zones adjoining the basins of the western part of the Pacific Ocean.

There is one more fact which, from the standpoint of what has been set forth, requires some explanation. The depth of earthquake foci increases with distance from the basins of the western part of the Pacific Ocean to the west, and from the Guatemalan and Atacama basins—to the east. The impression arises that what occurred here was not simply submergence, but submergence with some displacement in the horizontal direction away from the place where Perun accreted. This is apparently connected with the fact that the rocks of Perun, as generally having had a lower temperature than the rocks of the Earth’s internal geospheres, must also have had greater strength in comparison with them. And from this it follows that they must have offered greater resistance to the masses moving downward.

On the question of the internal structure of the Earth. If one proceeds from the assumption that no accretion of Perun to the Earth took place in the recent past, then one should expect that all the components of its geospheres must be separated from one another by absolutely spherical surfaces, and that the density of these geospheres must gradually increase as they approach the center of the Earth. If, however, one proceeds from the hypothesis of the accretion of Perun to the Earth, then one should expect that in the region of the Pacific Ocean, beneath the denser rocks that once formed part of this satellite, there must be less dense rocks, which once lay on the surface of the Earth. How, then, does the matter stand in fact?

Turning to old books on geology—for example, to the fundamental work of I. V. Mushketov [10], published in 1924—one may note that in the past there was a very sharp discussion about the thickness of the Earth’s crust (the sialic shell). The point is that seismic investigations at that time were carried out mainly in the mountainous regions of Europe and the USA; on the plains they were hardly carried out at all. At the same time, every investigator who had made several measurements in one region or another believed that the data he had obtained characterized the thickness of the Earth’s crust over the entire surface of our planet, including beneath the oceans. All actually established deviations from the mean value, however, were attributed to errors of measurement. Geophysicists agreed with the fact that the thickness of the Earth’s crust is not everywhere the same only after they became convinced that the conclusions from the theory (hypothesis) of isostasy were in agreement with these data; according to this theory, mountains rise above the rest of the surface of the continents precisely because the thickness

the Earth’s crust (the sialic shell) beneath them is much greater than beneath the remaining surface of the continents; and the ocean floor lies below them because the thickness of the Earth’s crust (the sialic shell) is there much less than beneath the continents.

Thus, the nonuniformity of the thickness of the very upper geosphere of our planet was ultimately acknowledged, despite the fact that this proposition is in categorical contradiction with the hypothesis of self-development. As for existing ideas about the structure of the deeper parts of the Earth, matters are more complicated here. True, the sharp decrease in the density of rocks within the Earth that follows from the hypothesis of the accretion of Perun has in fact been proven by seismology and is recognized by geologists. It occurs at a depth of 2900 km from the surface, where the velocity of longitudinal seismic waves decreases abruptly from 13.6 km/sec to 8.1 km/sec. But, according to the hypothesis of the accretion of Perun, such a boundary of discontinuity should be traced only beneath the floor of the Pacific Ocean or not far beyond its limits; whereas, according to existing views, it is traced beneath any sector of the Earth’s surface and separates from the other geospheres of our planet the so-called Earth’s core. Thus, existing ideas about the structure of the deep zones of our planet contradict the hypothesis of the accretion to it of Perun; however, recalling how matters stood with the question of the thickness of the Earth’s crust, one may hope that, with a careful study of seismograms of earthquakes occurring in the Arctic Ocean, the Indian Ocean, and Central Asia, a gap will be found in the discontinuity at a depth of 2900 meters. It is possible that it has already been found, but that the data obtained were attributed to errors of measurement.

REFERENCES

1. Belousov V. V. On the geological structure and development of oceanic depressions. Izv. AN SSSR, ser. geol., No. 3, 1955.

2. Bemmelen R. van. Mountain Formation (trans. from English). IL, 1956.

3. Bemmelen R. van. The Geology of Indonesia (trans. from English). IL, 1957.

4. Wegener A. The Origin of Continents and Oceans (trans. from German). Vostok Publishing House, Berlin, 1923.

5. Vlodavets V. I. Volcanoes of the Soviet Union. Geografgiz, 1949.

6. Wulff E. V. Historical Geography of Plants. Publishing House of the Academy of Sciences of the USSR, 1944.

7. Gutenberg B. and Richter K. Seismicity of the Earth (trans. from English). IL, 1949.

8. Jeffreys H. The Earth, Its Origin, History, and Physical Constitution (trans. from the 4th English ed.). IL, 1960.

9. Krishtofovich A. N. Paleobotany. Gostoptekhizdat, 1957.

10. Mushketov I. V. Physical Geology, vol. 1. Gosizdat, 1924.

11. Pariiskii N. N. Nonuniformity of the Earth’s rotation. Proceedings of the Geophysical Institute, No. 26 (153), 1957.

12. Pukhlyakov L. A. On the question of the origin of mountains and oceans (Hypothesis of an increase in the Earth’s rate of rotation). Izvestiya of the Tomsk Polytechnic Institute, vol. 120, 1962.

13. Reitt R. U., Fisher R. L., Mason R. G. The Tonga Trench. In: The Earth’s Crust (trans. from English). IL, 1957.

14. Subbotin M. F. The Origin and Age of the Earth. Gostekhizdat, 1946.

15. Tyrrell G. W. Volcanoes (trans. from English). ONTI NKTP, 1934.

16. Udintsev G. B. Geological structure of the Kuril–Kamchatka depression. Priroda, No. 12, 1955.

17. Hain V. E. The Origin of Continents and Oceans. Znanie Publishing House, 1961.

18. Khramov A. N., Petrova G. N., Komarov A. G., Kochegura V. V. Methodology of Paleomagnetic Investigations. Gostoptekhizdat, 1961.

19. Shepard F. Submarine Geology (trans. from English). IL, 1951.

20. Schmidt O. Yu. Four Lectures on the Theory of the Origin of the Earth. Publishing House of the Academy of Sciences of the USSR, 1949.

21. Burckhardt C. Beiträge zur Kenntnis der Jura-und Kreideformation der Cordillere Palaeontographica. Stuttgart, 1903–1904.

1. Gold C. Instability of the Earth’s axis of rotation. Nature, vol. 175, No. 4456, 1955.

2. Gordon H. D. The problem of Sub-Antarctic plant distribution. Rep. of 27-th meet. of the Austral. and New Zealand Ass. for the Advance of Sci., 1949.

3. Gregory J. W. The geological history of the Pacific Ocean. Quart. Journ. of Geol. Soc., vol. LXXXVI, No. 342, 1930.

4. Hamilton E. L. Sunken islands of the Mid-Pacific mountains. The Geological Society of America Memoir 64, March 10, 1956.

5. Pickering W. H. The place of origin of the Moon—the volcanic problem. The Journal of Geology. A semy—Quarterly Magazine of Geology and Related Sciences, vol. XV, No. 1, 1907.

6. Piggot C. S. and Urry W. D. Time relations in ocean sediments. Bull. Geol. Soc. Amer., vol. 53, No. 8, 1942.

7. Raitt R. W. Seismic—refraction studies of the Pacific Ocean Basin. Bull. Geol. Soc. Amer., vol. 67, No. 12, 1956.