Q. 74: How do you respond to Ollier and Pain’s 17 objections to the concepts of plate tectonics?

CPT Q. #74 – 101 Q&A on Catastrophic Plate Tectonics

Question: 74. Cliff Ollier and Colin Pain, certainly world authorities on the origin of mountains, threw down the gauntlet regarding plate tectonics, bringing up dozens of major problems with plate tectonics theory. In fact a major thrust on page 323 of their exhaustive book, The Origin of Mountains, Routledge, London, 2000, is that mountain formation just simply does not fit with the plate tectonics theory. I do realize that some of these points may not apply to CPT, but many do. I bring the whole list and invite your commentary though, as I’m sure I won’t be the first or the last to bring up these points. Then your response can be on record as well, and you can even clarify what applies, and what does not apply to your model.

Response: I will insert my responses following each individual difficulty/ objection below.

Difficulties with and objections to plate tectonics

(a) The total length of spreading versus subduction sites

The total length of spreading sites is three times longer than that of subduction sites.

This claim is simply not true. One can refer to their map of plate boundaries in Figure 1.7 and observe by eye that the total length of spreading ridges shown in their map is close to being equal to the total length of the zones of plate convergence also shown in the map (which includes convergence in the Himalayas, south of the Zagros Mountains, through Turkey, and in the Mediterranean Sea. As I pointed out in my response to question 15, detailed estimates of plate convergence and divergence is provided in a 2003 paper by Peter Bird entitled “An updated digital model of plate boundaries,” Geochem., Geophys, Geosys., 4(3) and posted at http://peterbird.name/publications/2003_PB2002/2001GC000252.pdf. Below is a table that summarizes the results.

Table: Collective Properties of Plate Boundaries by Class

Class	Total length (km)	Mean velocity (mm/yr)	Area production (m2/s)
Continental Convergent	23,003	26.2	-0.013616 (-12.6%)
Continental Transform	26,132	24.7	-0.000599 ( -0.5%)
Continental Rift	27,472	17.6	+0.011502 (+10.7%)
Oceanic Ridge	67,338	46.6	+0.095348 (+88.4%)
Oceanic Transform	47,783	40.5	+0.001022 ( +1.0%)
Oceanic Convergent	17,449	17.6	-0.007141 ( -6.7%)
Subduction Zone	51,310	62.3	-0.086516 ( -80.1%)
Totals	260,487	39.6	0

The total length of convergent boundaries is 91,762 km, while the total length of divergent boundaries is 94,810. If we neglect the continental convergent and rift boundaries and consider only convergent and divergent boundaries in the ocean basins, the total length of subduction zones and other convergent segments is 68,759 km, while the total length of oceanic ridges is 67,338 km, again very similar. The current rate of area increase along the oceanic ridges is 0.095 m2/s is very close to the current rate of area loss along convergent boundaries in the oceans, 0.094 m2/s. While there is no logical or geometrical requirement for the total lengths of convergent and divergent boundaries to be identical, they are amazingly similar.

(b) Why subduction is concentrated around the Pacific

Plate tectonic theory does not explain why subduction is located almost entirely around the Pacific, while spreading is present in all oceans.

Actually, the explanation is simple. It is that most of the recent plate motion history is associated with the breakup of the Pangean supercontinent and the opening of the present day Atlantic and Indian Oceans. This plate motion history can be inferred from, among other types of observational data, the patterns of mid-ocean ridges and fracture zones and radioisotope dates of the ocean floor basalts from the world’s seafloors.

(c) Spreading sites that migrate and grow longer

The spreading sites are not static, but move away from continents. The circum-Antarctic spreading site is the best example. It was once just bounding Antarctica, but has moved away in all directions to its present position. Spreading is also symmetrical around most of Africa. As it moved towards the equator, the circum-Antarctic ridge also grew longer. Plate tectonics has not provided any mechanism for spreading sites to grow longer. As a geometric consequence of the mobility of spreading sites, subduction sites are also mobile.

That is correct—a spreading ridge generally does not remain in a fixed location but tends to move with the average velocity of the two plates between which it lies. In so doing, seafloor spreading is very close to symmetrical across the ridge, and ridge location coincides with the line of zero plate thickness. In the case of Antarctica, the African plate, Australian plate, and Pacific plate have all migrated in northward directions, away from Antarctica. The mid-ocean ridges which lie between Antarctica and these other plates have therefore all migrated away from Antarctica. The ridge migration velocity is very close to one-half the separation velocity of these other plates relative to Antarctica. It is also true that subduction zones migrate.

(d) North America overriding the North Pacific plates

The North America plate rides indiscriminately over the North Pacific (and other) plates with no regard to spreading sites, plate margins, or transform faults.

Again, that is true. What is known as the Farallon Plate, an oceanic plate which once spanned much of the oceanic region west of North America, has been almost entire subducted beneath it. Only small remnants of it still exist at the earth’s surface today. These include the tiny Juan de Fuca plate off the coasts of Washington and Oregon and the Cocos plate off the Pacific coasts of Mexico and Central America. Indeed, North America did migrate westward and did override most of this plate as well as most of the spreading ridge that lay between it and the Pacific plate. Seismic methods are now able to image much of the portions of this plate that still reside beneath North America. What were the forces driving this remarkable behavior? In short, it was primarily the negative buoyancy of this plate but in the context of the other catastrophic forces that were unleashed during the Flood cataclysm.

(e) The chemistry of subduction, batholiths, and andesitic magmas

The chemical and petrological work allegedly achieved by subduction is quite remarkable. Subduction sediments are presumed to mix, melt and contaminate basalt to produce granite batholiths and andesitic magmas that are common in collision sites (andesite and granite do not have the same composition). The proportions added from various sources should be quite variable, and the possibilities of reaction numerous.

Again, that is true. In the framework of catastrophic plate tectonics a much larger fraction of sediment that finds its way to a subduction zone gets entrained by the downgoing plate and is carried to depths where it comes into contact with extremely hot mantle wedge rock beneath the overriding plate. In this environment it readily melts, with the resulting sialic magma together with water also carried down in the subduction process rising through the mantle wedge and penetrating upward into the overriding plate. The water tends to lower the melting points of minerals in the mantle wedge rock, and consequent partial melting generally produces varying amounts of basaltic magma. However, these two types of magma do not tend to mix very well and tend to result in separate magmatic expressions as they penetrate toward the surface.

(f) The uniform composition of MORB

After subduction, the descending slab is supposed to return to the mid-ocean ridge as part of the convection cell. Mid-Ocean Ridge Basalt (MORB) has a very consistent and rather odd composition. How can MORB, with such a complicated history, be so uniform in composition? Also eruptions at the mid-ocean ridge erupt helium, which is so light that it escapes from the Earth and is not recycled, and juvenile (new) water.

No, seismic evidence is compelling that subducted slabs eventually penetrate into the lower mantle and sink to the bottom and so their graveyard is at the bottom of the mantle and not in the upper mantle. The chemical composition of MORB shows it to be strongly depleted in the elements that appear to be concentrated in the granitic rocks of the continental crust. Because of this complementary chemistry of the upper mantle relative to the continental crust, one might speculate that, in the processes God used in fashioning the earth in the very brief period of Day 1 and Day 2 of Creation Week, He may well have melted the upper portion of the earth’s mantle to extract and form the continental crust. But regardless of how this chemistry came to be, the distinctive chemistry is genuine. Seafloor spreading simply taps this reservoir of depleted upper mantle rock which seems to be remarkably uniform in its chemical composition. There is no major issue here relative to plate tectonics, catastrophic or otherwise.

(g) Sediments deposited on passive margins

Most of the world’s great rivers drain to passive margins and most sediment is deposited there (Potter, 1978). How do sediments deposited on passive margins ever get back into the rock cycle or the plate tectonic cycle?

The reason most (but certainly not all) major rivers drain to passive margins is that active margins, such as the west coasts of South and Central America, often contain uplifted mountain belts. Especially when prevailing winds bring moisture dominantly from the passive margin side of one of these mountain belts, it is natural for the rivers draining these regions to flow to the passive margin. If one views earth history as spanning some 4.6 billion years, this might be somewhat of an issue. However, in the reliable summary of earth history that God has provided in Scripture—a summary that indicates that earth structure was largely determined at creation and then modified somewhat during a catastrophic year-long Flood only a few thousand years ago—there is no real need to think in terms of rock cycles or plate tectonic cycles.

(h) Back-arc basins and ‘subduction roll-over’

Island arcs in the western Pacific are explained as the result of subduction of the Pacific plate. The collision might be expected to cause compression, but instead of compression we find further seafloor spreading on the other side of the arc, the back-arc basin. ‘Subduction roll-over’ is the special pleading in this case, but it is hard to apply in three dimensions.

The term ‘subduction roll-over’ is not a standard term in the geosciences. However, there is a term that is commonly applied in this context, which is ‘trench rollback’ (or sometimes ‘hinge rollback’). Trench (or hinge) rollback tends to occur for a very simple geometrical/physical reason. The reason is that gravity acts in a vertical direction on the subducting plate as it bends along the hinge line and plunges into the mantle at a trench. Not only is there the ‘slab pull’ force acting in the direction in which the slab is moving, but there is also locally the downward force of gravity, a component of which is not in the plane of the downgoing slab. It is this vertical component of force that has the tendency to cause the hinge line to migrate backwards, in the direction away from the trench. Trench rollback, in turn, leads to what is called ‘back-arc spreading’, which corresponds to extension and plate failure and even a new line of seafloor spreading behind the volcanic arc that results from magma production at depth due to water being carried down on the subducting plate. This is a common and observable phenomenon, especially when one oceanic plate subducts beneath another, as occurs in many settings in the western Pacific.

(i) Subduction at an island arc

Subduction at an island arc. Island arcs are conical surfaces intersecting the Earth’s surface. If the direction of plate movement is constant, as seems to be the case, how can it give rise to a conical surface? Alternatively, if the subduction is perpendicular to the arc, as suggested by most cross-sections, all the subducted streams must be meeting at the point of the cone, which gives a space problem as material piles up. But we do not find uplift in such places, but more sea-floor spreading.

This objection is not well worded. This issue is discussed in an article by Brian Bayly entitled “Geometry of subducted plates and island arcs viewed as a buckling problem,” Geology 10(12), 629-632, 1982. Bayly describes the problem and its consequences in his abstract as follows:

During subduction, a plate’s leading edge is forced to squeeze into a smaller total width than it occupied at the surface, yet the plate resists change of dimension in its own plane. A possible outcome is that the plate buckles as it descends… Before being subducted a lithosphere plate is convex upward at all points, whereas, to buckle, it must become convex downward in a series of plunging synclines.

In many studies undertaken during the almost 30 years since this paper, there is abundant documentation that slabs indeed to in fact deform in dramatic ways after they subduct, including tearing.

(j) Subduction around curved mountain ranges

Subduction around curved mountain ranges. Subduction is invoked to explain curved mountain ranges such as the Apennines and the Carpathians. But if subduction is perpendicular to the mountain range, the subducted slabs must be converging at some place within the arc, which should cause accumulation of material and presumably uplift, but this area is always a relative lowland.

The geology and tectonics of that part of Europe is extremely complex. Here is the abstract of a paper reporting work to try to resolve some of these issues by C. Chiarabba, P. De Gori, and F. Speranza entitled “The southern Tyrrhenian subduction zone: Deep geometry, magmatism and Plio-Pleistocene evolution,” Earth and Planetary Science Letters 268, 408-423, 2008.

We report on a high-resolution V_p, V_p/V_s and Q_p model of the southern Tyrrhenian subduction zone, obtained by the inversion of P- and S-wave arrival times and t* values from intraslab seismicity. The arcuate shape of the southern Apennines–Calabrian arc-Sicilian Maghrebides is perfectly mirrored by two rather continuous low and high V_p bands lying beneath the belt system at ca. 25 and 100 km, respectively. Between 100 and 300 km, two independent high V_p slabs lie beneath the Neapolitan region and the southern Tyrrhenian Sea, separated by unperturbed mantle. We suggest that the ca. 150 km-wide slab window beneath the southern Apennines opened after a tear occurring within a composite subduction system, formed by the Apulian continental lithosphere and the Ionian oceanic slab. The abrupt slab rupture induced ultrafast southeastward retreat of the Ionian slab, and the 19 cm/yr spreading of the back-arc oceanic Marsili basin between ca. 2.1 and 1.6 Ma ago. The 25 km low V_p zone beneath the arc denotes continental upper crustal rocks below the chain. Its striking continuity requires a unique orogenic wedge at 25 km depth below the southern Apennines, the Calabrian arc, and the Sicilian Maghrebides. The alternative explanation would imply the ubiquitous occurrence of autochthonous lower plate rocks at 25 km depth, i.e. a puzzling autochthonous continental Calabria. The Ionian slab beneath Calabria shows high V_p, high Q_p and low V_p/V_s anomalies, typical of old oceanic lithosphere. Intermediate depth seismicity is concentrated within its thin oceanic crust, suggesting the occurrence of vigorous metamorphism. The slab dehydration promotes the melting of the overlying mantle, as testified by high V_p/V_s and low Q_p anomalies between the slab and the Aeolian magmatic arc.

Part of the basic message here is that careful seismic work looking at the seismic velocity structure in the upper mantle beneath this region reveals the presence of two slabs of mature oceanic lithosphere separated by what the authors infer to be a tear in the original ocean plate. This work implies that subduction was indeed involved and that the dynamics were dramatic.

(k) Rock masses subducted in opposite directions

A rock mass cannot move simultaneously in opposite directions. But the Po Plain appears to be subducted under both the Southern Alps to the north, and the northern Apennines to the south. The Pelvoux Massif appears to be subducted to the north, south and west.

Again, the tectonic processes responsible for this region were so complex that researchers have as yet hardly scratched the surface in identifying all the important pieces of the puzzle, much less putting the pieces together in a correct manner.

(l) Why mountain uplift occurred so recently

If subduction is the cause of mountain building, why did mountain uplift occur mainly in the last 5 million years, while subduction is supposedly a continuous process that worked over the past 50 to 200 Ma in different parts of the world?

Please read my March 2005 ICR Impact article entitled “Recent rapid uplift of today’s mountains,” (http://www.logosresearchassociates.org/Documents/Baumgardner/Rapid-Uplift-of-Today’s-Mountains.pdf) where I describe much of Ollier and Pain’s evidence in a very favorable way and also provide the obvious answer to their dilemma expressed here. That obvious answer is that the 50-200 million years they believe in is an illusion! On the other hand, if this tectonic work occurred, not over tens or hundreds of millions of years, but only within a few weeks’ time just a few thousand years ago, the uplift of the mountains during the decades to centuries following this cataclysm corresponds to the reasonable amount of time for isostatic rebound to occur. In other words, in the CPT framework the isostatic response time, instead of being tens of millions of years or more as in the uniformitarian framework, is now plausible, and the puzzle pieces fit together.

To reiterate, the problem of why there was 50-200 million years delay between the time subduction processes dramatically increased crustal thickness in the tectonic belts around the earth and the time when isostatic adjustment kicked in to uplift the mountains in these belts is a non-problem if all the subduction occurred as part of a year-long cataclysm and the uplift followed in the century or two following. The problem is the assumption these authors have adopted that the uniformitarian/radioisotope time scale is true, when it is not. To me the evidence these authors have assembled supporting the recent uplift of all the major young mountain belts in the world is some of the clearest available that the uniformitarian time scale is wrong.

(m) Planation before the period of uplift

Subduction fails to explain where there is a period of still-stand, when land was extensively planated before the period of mountain uplift on a global scale.

Again, in the framework of CPT and the Flood, the answer is obvious. The planation is caused by the waters of the Flood, most likely, by the waters retreating rapidly from the flooded continents, before isostatic adjustment has had time to uplift the mountains.

(n) The symmetry of many mountain ranges

The symmetry of many mountain ranges, discussed in the last section, presents a further problem. Some advocates of subduction have the same process of subduction causing underthrust on the near side and overthrust on the distal side, with remarkably similar results. Others subduct Brazil, Russia or other continental masses - which is a huge leap from subduction as originally conceived, and for which there is scant evidence.

Ollier and Pain seem to be only vaguely aware that the primary way in which subduction generates continental mountain ranges is by adding buoyant rock from below to increase the overall crustal thickness. Isostasy then operates to uplift the resulting zones of thickened crust. This process often, if not most of the time, generates relatively symmetric mountain belts.

(o) Crustal expansion and the vanished Tethys Ocean

Stocklin (1989) pointed out that subduction and spreading had to be equal at the same time, and objected to the plate tectonic concept of subduction of the Indian Plate under Tibet because of the lack of geological evidence for the existence of the vast Late Paleozoic Tethys Ocean supposed to have been available for Mesozoic subduction. He concludes, rather, that the excess of crustal expansion in the Indian Ocean over crustal shortening in the orogenic belt is evidence for expansion of the Earth.

To me the evidence is close to overwhelming for the formation of the Indian Ocean by the process of seafloor spreading, for the collision of the Indian Plate with the continent regions to the north, and for the disappearance of the Tethys Ocean in that process. There is no need to invoke earth expansion.

(p) Does subduction have “too many degrees of freedom”?

The real problem with subduction is that it can do everything. Plate collision may be invoked ‘to explain uplift (making mountains), or subsidence (making deep trenches). It may make folds by compression, but makes backarc basins by tension. The fact that the subduction hypothesis can account for both uplift and subsidence, compression and tension, means that it has too many degrees of freedom. It can account for opposite effects and it is not testable’ (Ollier and Pain, 1988).

The physics involved in all these diverse processes is well understood and well tested.

(q) Geomorphology and the recent origin of mountains

Plate tectonics as a general principle has been enormously helpful in many aspects of geology, but its practitioners have neglected the ground surface, and have often been uncritical in their time scales. The geomorphology of mountains and their recent origin make plate tectonics an improbable mechanism for mountain building.

I have already pointed out that the root cause of their confusion is the long uniformitarian time scale which they are assuming.