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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 56 (1972)

Issue: 2. (February)

First Page: 269

Last Page: 336

Title: "The New Global Tectonics": Major Inconsistencies

Author(s): A. A. Meyerhoff (2), Howard A. Meyerhoff (3)


Geologic and geophysical data, from the ocean basins and the continents, are now sufficiently abundant to demonstrate that all proposed models for "the new global tectonics" are seriously in error. For example, several sets of paleoclimatic data--specifically, the distribution on the continents and shelves of ancient evaporites, carbonate rocks, coals, and tillites--can be explained only if the present positions of the rotational axis, continents, and ocean basins have been constant for at least 1,600 m.y. The distributions of fossil invertebrate and tetrapod faunas and floras likewise indicate the constancy of position of the rotational axis, continents, and ocean basins for at least 570 m.y. Faunal realm studies are proving to be extremely useful, because they are unamb guous in demonstrating the relations among continents since Proterozoic time.

A truly devastating fact is that the topological requirements for moving the Americas away from Eurafrica eliminate any possibility of such movement unless the earth has expanded greatly during the last 150-200 m.y. Other space requirements for the continents do not permit east-west movements since Archean time of more than 100-200 km in the Northern Hemisphere. North-south movements of individual continents are limited to a few hundred kilometers--on the basis of paleoclimatic and paleontologic data. Movements involving the "opening" and "closing" of Tethys--from present-day Spain to New Guinea--are restricted by detailed field geologic studies to distances of less than 300 km. Geologic mapping during the past 100 years proves that north-south movements since Proterozoic time in the resent Mediterranean Sea region of Tethys have involved horizontal translations of less than 200 km. If sea-floor spreading is taking place in the Tethyan belt, lateral movements have been--and are--restricted to mantle movements and the overlying lithosphere has been detached from the mantle.

Ocean-basin studies show that island-arc trench fills, where "subduction" supposedly takes place, are undeformed. The volumes of undeformed sedimentary rocks in layer 1 indicate (1) that sea-floor spreading has not taken place since Mesozoic or earlier time; or (2) that "subduction" must take place seaward from the island-arc trenches; or (3) that there is no such process as "subduction." Detailed studies of the Lesser Antilles and Tonga-New Zealand arcs prove that aseismic island chains seaward from both arcs have been in their same relative positions since mid-Mesozoic and late Paleozoic times, respectively. Preliminary studies of several other island-arc systems lead to similar conclusions.

Sediment fills in fracture zones crossing midocean ridges also are undeformed--a remarkable fact if sea-floor spreading is taking place. Many of these fractures continue onshore into the continents, where the proved senses of movement are the opposite of those predicted by "transform-fault" solutions.

JOIDES drilling results have been hailed as a "remarkable confirmation" of "plate tectonics" predictions. The first dating of the "basement" basalts of JOIDES coreholes indicates that the "basement" beneath Mesozoic rocks is late Tertiary or younger. Thus another prop of "the new global tectonics" begins to crumble.

The points listed in the preceding paragraphs have been termed "minor details." Are they?

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