Late?Syn? to Post?Rift Salt Tectonics on Wide Rifted Margins—Insights From Geodynamic Modeling

Tectonics of early Earth: Some geodynamic considerations

Today, plate tectonics is the dominant tectonic style on Earth, but in a hotter Earth tectonics may have looked different due to the presence of more melting and associated compositional buoyancy as well as the presence of a weaker mantle and lithosphere. Here we review the geodynamic constraints on plate tectonics and proposed alternatives throughout Earth’s history. Observations suggest a 100...

Numerical Geodynamic Modeling of Continental Convergent Margins

From Continental Drift to Plate Tectonics

SINCE THE l6TH CENTURY, CARTOGRAPHERS HAVE NOTICED THE jigsaw-puzzle fit of the continental edges. Since the 19th century, geologists have known that some fossil plants and animals are extraordinarily similar across the globe, and some sequences of rock formations in distant continents are also strikingly alike. At the turn of the 20th century, Austrian geologist Eduard Suess proposed the theor...

Salt tectonics and collapse of Hebes Chasma, Valles Marineris, Mars

A photogeologic and physical modeling study indicates that Hebes Chasma, Mars, formed by collapse of the megaregolith. Local heating facilitated drainage of ~105 km3 of brines and entrained particulates through fractures in the chasma fl oor and into a regional aquifer. A megaregolith rich in salts and water is implied by massive, low-gradient allochthonous fl ows that terminate in deep pits an...

Response to Comment on “ Intermittent Plate Tectonics ? ”

The realization that Earth may have lost heat more slowly in the past than at present has motivated the search for mechanisms to reduce the efficiency of plate tectonics in the past. Several mechanisms have been proposed, such as the resistance to subduction of thick plates (1) produced by deeper melting at higher mantle temperatures (2). We (3) proposed an alternative mechanism, namely subduct...