Evidence for eastward mantle flow beneath the Caribbean plate
... tractions and low fault friction coefficient are still required. The best models with these lateral boundary conditions underestimate fault slip rates along the Caribbean-North America boundary and the seafloor spreading rate on the Cayman trough, and a better joint fit of datasets is obtained for m ...
... tractions and low fault friction coefficient are still required. The best models with these lateral boundary conditions underestimate fault slip rates along the Caribbean-North America boundary and the seafloor spreading rate on the Cayman trough, and a better joint fit of datasets is obtained for m ...
T2 Precambrian Geology Homework KEY
... 14) The largest belt of folded rocks indicating Proterozoic continental collisions is called the: a) Grenville Orogen. b) Trans-Hudson Orogen.. c) Mazatal Orogen. d) Wopmay Orogen 15) The last major Proterozoic collision before assembly of Rodinia is recorded by rocks in the: a) Grenville Orogen.. ...
... 14) The largest belt of folded rocks indicating Proterozoic continental collisions is called the: a) Grenville Orogen. b) Trans-Hudson Orogen.. c) Mazatal Orogen. d) Wopmay Orogen 15) The last major Proterozoic collision before assembly of Rodinia is recorded by rocks in the: a) Grenville Orogen.. ...
The plates consist of an outer layer of the Earth, the lithosphere
... of the mid-ocean ridges? These questions could not be answered without also knowing the significance of these ridges. In 1961, scientists began to theorize that mid-ocean ridges mark structurally weak zones where the ocean floor was being ripped in two lengthwise along the ridge crest. New magma fro ...
... of the mid-ocean ridges? These questions could not be answered without also knowing the significance of these ridges. In 1961, scientists began to theorize that mid-ocean ridges mark structurally weak zones where the ocean floor was being ripped in two lengthwise along the ridge crest. New magma fro ...
Earth,Notes,RevQs,Ch13
... Answers to the Review Questions 1. The echo sounder pulse travels a distance equal to twice the water depth. In 6 seconds the pulse travels 9000 meters (1500 m/sec X 6 sec = 9000 m); thus the depth (1/2 of 9000 m) is 4500 meters. 2. Satellites equipped with radar altimeters are able to determine fea ...
... Answers to the Review Questions 1. The echo sounder pulse travels a distance equal to twice the water depth. In 6 seconds the pulse travels 9000 meters (1500 m/sec X 6 sec = 9000 m); thus the depth (1/2 of 9000 m) is 4500 meters. 2. Satellites equipped with radar altimeters are able to determine fea ...
Lecture 47
... The lithosphere is the part of the Earth through which heat is conducted rather than convected. Mantle lithosphere (the subcontinental lithospheric mantle: SCLM) tends to have fast seismic velocities, suggesting is cold compared with the convective mantle. Xenoliths derived from these regions) are o ...
... The lithosphere is the part of the Earth through which heat is conducted rather than convected. Mantle lithosphere (the subcontinental lithospheric mantle: SCLM) tends to have fast seismic velocities, suggesting is cold compared with the convective mantle. Xenoliths derived from these regions) are o ...
Earth`s Layered Structure
... in California or Italy. However, it was observed that P waves were bent around the liquid outer core beyond about 100 degrees away from an earthquake. The outer core also causes P waves that travel through the core to arrive several minutes later than expected. This region, where bent P waves arrive ...
... in California or Italy. However, it was observed that P waves were bent around the liquid outer core beyond about 100 degrees away from an earthquake. The outer core also causes P waves that travel through the core to arrive several minutes later than expected. This region, where bent P waves arrive ...
Spreading Continents Kick-Started Plate Tectonics Plate tectonics
... comparable to that of present-day tectonic forces driving orogenesis1. To explore the tectonic impact ...
... comparable to that of present-day tectonic forces driving orogenesis1. To explore the tectonic impact ...
Mountains Without Collision: Orogenic Activity in Accretionary
... explain the geological history of a significant number of orogenic belts throughout the world in which deformation, metamorphism and crustal growth took place in an environment of continual convergence between oceanic and continental plates. These belts are termed accretionary orogens. ...
... explain the geological history of a significant number of orogenic belts throughout the world in which deformation, metamorphism and crustal growth took place in an environment of continual convergence between oceanic and continental plates. These belts are termed accretionary orogens. ...
Plate Tectonics: This works as a result of hot mantle asthenosphere
... mantle, that have been kept separated for many hundreds of millions of years. They have distinct trace element and isotopic characteristics. (You may come across references to them as DMM, HIMU, EM1, EM2 and PREMA), but there is uncertainty as to where they are located. ...
... mantle, that have been kept separated for many hundreds of millions of years. They have distinct trace element and isotopic characteristics. (You may come across references to them as DMM, HIMU, EM1, EM2 and PREMA), but there is uncertainty as to where they are located. ...
Mantle-drip magmatism beneath the Altiplano
... in thickness at convergent margins, but this is not observed seismically (Wernicke et al., 1996). Similarly, continental crust generated at orogenic margins needs a complementary ultramafic (but not peridotitic) lithospheric reservoir (Lee et al., 2006), which is not known to exist under most contin ...
... in thickness at convergent margins, but this is not observed seismically (Wernicke et al., 1996). Similarly, continental crust generated at orogenic margins needs a complementary ultramafic (but not peridotitic) lithospheric reservoir (Lee et al., 2006), which is not known to exist under most contin ...
Main Seismic Phases: Seismic Phases and 3D Seismic Waves
... means paths that are not “great-circle” are slower than the center point (geometrical prediction). The story is much less obvious in the case of a minimax pattern, a case of a reflected wave where interference is weird. Blue represents a faster reflection path than ...
... means paths that are not “great-circle” are slower than the center point (geometrical prediction). The story is much less obvious in the case of a minimax pattern, a case of a reflected wave where interference is weird. Blue represents a faster reflection path than ...
1. Define habitat and describe how geologic processes influence habitats. Habitats
... Earthquakes and volcanoes that rise from the sea floor to create chains of volcanic islands are common. The Aleutian, Japanese, Philippine, and Mariana island chains are examples. 28. Describe the collision between two continental plates. Because both plates are of relatively low density, neither pl ...
... Earthquakes and volcanoes that rise from the sea floor to create chains of volcanic islands are common. The Aleutian, Japanese, Philippine, and Mariana island chains are examples. 28. Describe the collision between two continental plates. Because both plates are of relatively low density, neither pl ...
Chapter 32: Plate Tectonics: A Working Model for the Earth
... appears that the same heat source has produced all the volcanoes in the chain either by migrating to the southeast or—more likely, given the several parallel island chains on the Pacific plate—by remaining stationary while the plate rode over it. The nature of such heat sources is not well understoo ...
... appears that the same heat source has produced all the volcanoes in the chain either by migrating to the southeast or—more likely, given the several parallel island chains on the Pacific plate—by remaining stationary while the plate rode over it. The nature of such heat sources is not well understoo ...
Evolution of magma-poor continental margins from rifting to sea¯oor
... apparently representing successive stages of margin evolution, that is, thinned continental crust dissected by low-angle detachment faults succeeded by exhumed sub-continental mantle, with oceanward-increasing ma®c melt volumes, that merges into oceanic crust3,6,13,14. We describe each zone in turn, ...
... apparently representing successive stages of margin evolution, that is, thinned continental crust dissected by low-angle detachment faults succeeded by exhumed sub-continental mantle, with oceanward-increasing ma®c melt volumes, that merges into oceanic crust3,6,13,14. We describe each zone in turn, ...
Mantle detachment faults and the breakup of cold continental
... core complex, facilitated by channel flow and necking of the feldspar layer. Channel flow in this case is driven by shear related to mantle upwelling. The mantle core complex lacks the typical asymmetry expected for core complexes, characterized by the dominance of a single major detachment dipping ...
... core complex, facilitated by channel flow and necking of the feldspar layer. Channel flow in this case is driven by shear related to mantle upwelling. The mantle core complex lacks the typical asymmetry expected for core complexes, characterized by the dominance of a single major detachment dipping ...
Intra-Panthalassa Ocean subduction zones revealed by fossil arcs
... associated with Mesozoic intra-oceanic subduction west of North America7 , associated with the Wrangellia and Stikinia terranes (Fig. 1). Previously, the presence of seismic scatterers (Fig. 2) in the deep mantle below the central Pacific was interpreted to be caused by remnants of subducted and fol ...
... associated with Mesozoic intra-oceanic subduction west of North America7 , associated with the Wrangellia and Stikinia terranes (Fig. 1). Previously, the presence of seismic scatterers (Fig. 2) in the deep mantle below the central Pacific was interpreted to be caused by remnants of subducted and fol ...
Convection and the Mantle
... The transfer of heat by the movement of a heated fluid is called convection. Fluids include liquids and gases. During convection, heated particles of a fluid begin to flow, transferring heat energy from one part of the fluid to another. Heat transfer by convection is caused by differences in tempera ...
... The transfer of heat by the movement of a heated fluid is called convection. Fluids include liquids and gases. During convection, heated particles of a fluid begin to flow, transferring heat energy from one part of the fluid to another. Heat transfer by convection is caused by differences in tempera ...
Mantle plume
A mantle plume is a mechanism proposed in 1971 to explain volcanic regions of the earth that were not thought to be explicable by the then-new theory of plate tectonics. Some such volcanic regions lie far from tectonic plate boundaries, for example, Hawaii. Others represent unusually large-volume volcanism, whether on plate boundaries, e.g. Iceland, or basalt floods such as the Deccan or Siberian traps.A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. The currently active volcanic centers are known as ""hot spots"". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. Another hypothesis for unusual volcanic regions is the ""Plate model"". This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension.