Composition and development of the continental tectosphere

  title={Composition and development of the continental tectosphere},
  author={Thomas H. Jordan},
  • T. Jordan
  • Published 1 August 1978
  • Geology
  • Nature
Beneath the old continental nuclei are thick root zones which translate coherently during plate motions. These zones are apparently stabilised against convective disruption by the depletion of the continental upper mantle in a basalt-like component. Construction of this delicately balanced tectosphere is accomplished by the dynamic and magmatic processes of the Wilson cycle. 

Basalt magma sources during the opening of the North Atlantic

The mantle that supplied basalts to the North Atlantic Tertiary province at the time of continental breakup was isotopically similar to the present-day sub-oceanic mantle. There is no evidence for

Deep Seismic Expression of an Ancient Plate Boundary in Europe

The transition to low seismic velocities below Phanerozoic Europe coincides with the crustal boundary zone of the craton and exists to depths of at least 140 kilometers, which rules out any significant lateral transport of asthenospheric material across the suture zone.

Seismic evidence for a fossil mantle plume beneath South America and implications for plate driving forces

A teleseismic travel-time study reveals the presence of a fossil plume in the deep upper mantle beneath Brazil, which has apparently remained geographically fixed with respect to the overly-ing

Section 6. Siderophile Elements in Subcontinental Lithospheric Mantle

Sub-continental lithospheric mantle (SCLM) is interpreted by many to be mantle that began life as DMM, then melted in a plume or subduction zone environment, and finally became emplaced under

The tectosphere and postglacial rebound

Large lateral variations in the thickness of the lithosphere and viscosity of the mantle may be associated with continental roots. The effects of continental roots, or the tectosphere, on postglacial

Geodynamic evidence for a chemically depleted continental tectosphere.

Inversions of a large set of geodynamic data related to mantle convection, using tomography-based mantle flow models, indicate that the tectosphere is chemically depleted and relatively cold to 250 kilometers depth below Earth's surface.

Some Speculations on Continental Evolution

There appears to exist a thick (>300 km) thermal boundary layer (TBL), or tectosphere, beneath the ancient cratonic nuclei that is stabilized against convective disruption by a buoyant, viscous,

Subduction zone backarcs, mobile belts, and orogenic heat

Two important problems of continental tectonics may be resolved by recognizing that most subduction zone backarcs have hot, thin, and weak lithospheres over considerable widths. These are (1) the

Thermal aspects of komatiite generation and greenstone belt models

Thermal modelling suggests that the problems posed by the high liquid temperatures (∼1,650 °C) of peridotitic lavas in Archaean greenstone belts, and the implied high degree of mantle melting (∼70%),

The case for accretion of the tectosphere by buoyant subduction

This paper tests three hypotheses for the origin of the tectosphere. Continental collision cannot explain the low metamorphic grade of crust that predates the tectosphere. Halfspace cooling and



Plate Tectonics and Crustal Evolution

Preface Plate tectonics The Earth's crust Tectonic settings Crustal evolution The core and mantel Supercontinents Atmosphere, oceans and climate Life and mass extinctions The origin of the solar

Is there an Icelandic mantle plume?

SCHILLING1 has interpreted the chemistry of basalt lavas from the Reykjanes Ridge and Iceland, identifying two distinct upper mantle sources for these lavas, one of which rises in a primordial hot

Lateral heterogeneity and mantle dynamics

Recent work on the nature of the Earth's lateral heterogeneities yields two conclusions with implications for mantle dynamics: seismic velocity differences between continents and oceans extend to

A Model for Plate Tectonic Evolution of Mantle Layers

Calculations of mass transfer with time demonstrate that the entire mass of the present mesosphere could have been produced in geologically reasonable times (3 x 109 to 4.5 x 109 years).

Tibetan, Variscan, and Precambrian Basement Reactivation: Products of Continental Collision

Extensive terranes of basement reactivation are interpreted as resulting from crustal thickening following continental collision. It is suggested that terranes, such as the Grenville Province and

St. Peter and St. Paul Rocks: A High-Temperature, Mantle-Derived Intrusion

St. Paul's Rocks, often postulated to be an exposure of the suboceanic mantle, consists of a wider variety of rocks than previously recognized. These perhaps crystallized at different mantle levels,

Thermal model of continental lithosphere

The predictions of a simple model based on the concept that the lithosphere is a thermal boundary layer, somewhat analogous to a layer of ice on a pond, are in agreement with the relevant data from

The continental tectosphere

Studies of free oscillations and body wave travel times have established that the one-way vertical S wave travel times through the upper mantle average about 5 s greater for oceans than for stable

A Discussion on the evolution of the Precambrian crust - Crustal development in the Precambrian

  • B. Windley
  • Geology
    Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
  • 1973
The oldest Archaean rocks in most shield regions are largely granulites and gneisses, and in west Greenland there is evidence of 1000 Ma of crustal history before the final high-grade metamorphism.