True polar wander during the middle Paleozoic?
نویسندگان
چکیده
منابع مشابه
True polar wander and supercontinents
I present a general model for true polar wander (TPW), in the context of supercontinents and simple modes of mantle convection. Old, mantle-stationary supercontinents shield their underlying mesosphere from the cooling effects of subduction, and an axis of mantle upwelling is established that is complementary to the downwelling girdle of subduction zones encircling the old supercontinent. The u...
متن کاملTheoretical constraints on true polar wander
[1] For the present geologic epoch, true polar wander (TPW) is relatively small, but simple theoretical considerations suggest that it could have been larger in other epochs. In this work, we use scaling arguments to assess the qualitative behavior of TPW and a simple Maxwell model to analytically describe how changes in mass anomalies translate into TPW. Unlike previous work, we derive simple ...
متن کاملLate cretaceous true polar wander: not so fast.
Using recalculated paleopoles from seamount anomaly modeling (SAM), Sager and Koppers (1) proposed an episode of rapid Late Cretaceous true polar wander (TPW). A critical review of the data used, however, suggests that Sager and Koppers have underestimated the effects that errors and data selection have on inferences of TPW and that they may not have adequately taken into account alternative ex...
متن کاملA paleomagnetic analysis of Cambrian true polar wander
The latest Neoproterozoic through Cambrian is one of the most remarkable intervals in geologic time. Tectonically, the period from 580 to 490 Ma marks a time of rapid plate reorganization following the final stages of supercontinental breakup and Gondwana assembly. The apparent speed at which this reorganization occurred led some to propose a link between tectonic events, biologic changes and c...
متن کاملMagnetization in the South Pole-Aitken basin: Implications for the lunar dynamo and true polar wander
A number of magnetic anomalies are present along the northern edge of the lunar South Pole-Aitken (SPA) basin. A variety of hypotheses for their formation have been proposed, but an in-depth study of their properties has not been performed. Here we use two different methods to invert for their source body characteristics: one that completely searches a small parameter space of less than ten uni...
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ژورنال
عنوان ژورنال: Earth and Planetary Science Letters
سال: 1994
ISSN: 0012-821X
DOI: 10.1016/0012-821x(94)90063-9