The deep Earth origin of the Iceland plume and
... large ice sheets over Greenland currently mask geological evidence that could potentially resolve this debate (Rogozhina et al., 2016). Endmember plume motion paths have been proposed (see Rogozhina et al., 2016 for a discussion) based on a moving hotspot reference frame constrained by the hotspots ...
... large ice sheets over Greenland currently mask geological evidence that could potentially resolve this debate (Rogozhina et al., 2016). Endmember plume motion paths have been proposed (see Rogozhina et al., 2016 for a discussion) based on a moving hotspot reference frame constrained by the hotspots ...
Advances in Environmental Biology
... Fig. 5: Chondrite-normalized REE plot of the South Ardestan rocks. Normalization Irvine and Baragar, 1971 factors from Taylor and McLennan, 1985. The South Ardestan rocks normalized with primitive mantle (normalized data from [35] and McLennan. Tectonic setting: Trace element discrimination diagrams ...
... Fig. 5: Chondrite-normalized REE plot of the South Ardestan rocks. Normalization Irvine and Baragar, 1971 factors from Taylor and McLennan, 1985. The South Ardestan rocks normalized with primitive mantle (normalized data from [35] and McLennan. Tectonic setting: Trace element discrimination diagrams ...
Subducting slabs: Jellyfishes in the Earth`s mantle
... the slab where the resolution is increased to level 8, i.e., the element size is 1/256 of the size of the unit cube. Free slip is assumed on all boundaries. The experiment is initiated by placing a vertical (unless otherwise specified) plate of length, l = 0.066 (∼182 km) and thickness h = 0.03 (∼83 ...
... the slab where the resolution is increased to level 8, i.e., the element size is 1/256 of the size of the unit cube. Free slip is assumed on all boundaries. The experiment is initiated by placing a vertical (unless otherwise specified) plate of length, l = 0.066 (∼182 km) and thickness h = 0.03 (∼83 ...
23. Petrology and K-Ar Age of Basaltic Rocks, Sites 353, 354, and
... transverse valley filled with up to a kilometer of Pleistocene and Recent sediments, with a transverse ridge adjacent to the southern segment of the MidAtlantic Ridge (Figure 1, inset). Dredge hauls from the northern wall of the valley show it to consist in its upper part primarily of basalts, while ...
... transverse valley filled with up to a kilometer of Pleistocene and Recent sediments, with a transverse ridge adjacent to the southern segment of the MidAtlantic Ridge (Figure 1, inset). Dredge hauls from the northern wall of the valley show it to consist in its upper part primarily of basalts, while ...
Viscosity of the asthenosphere from glacial isostatic adjustment and
... [20] Predicted sea level curves are compared to observations in Figure 4 for Earth models with different asthenospheric thicknesses and the asthenospheric viscosity chosen to optimize the fit to the observations. The predictions agree well with the observations. They feature a very similar rapid fal ...
... [20] Predicted sea level curves are compared to observations in Figure 4 for Earth models with different asthenospheric thicknesses and the asthenospheric viscosity chosen to optimize the fit to the observations. The predictions agree well with the observations. They feature a very similar rapid fal ...
Metamorphism and tectonics
... b) Cloos's model: Cloos (1982) suggested that during B-type subduction, accretionary wedge pelitic material moving down the subduction zone will tend to flow back upwards by the forces of buoyancy, when it can then carry bits and pieces of the subducted slab (now metamorphosed under blueschist and e ...
... b) Cloos's model: Cloos (1982) suggested that during B-type subduction, accretionary wedge pelitic material moving down the subduction zone will tend to flow back upwards by the forces of buoyancy, when it can then carry bits and pieces of the subducted slab (now metamorphosed under blueschist and e ...
Upper mantle flow in the western Mediterranean
... 120 mGal or more [35]) and very high heat flow values (up to 140 mW/m2 or more [36]) along the Tyrrhenian margin and in the adjacent Tyrrhenian Sea. Moreover, the occurrence of hot asthenospheric material at relatively shallow depth below the western portion of the Southern Apennines is consistent w ...
... 120 mGal or more [35]) and very high heat flow values (up to 140 mW/m2 or more [36]) along the Tyrrhenian margin and in the adjacent Tyrrhenian Sea. Moreover, the occurrence of hot asthenospheric material at relatively shallow depth below the western portion of the Southern Apennines is consistent w ...
What moves slabs - Dipartimento di Scienze della Terra
... (a), and by a much smaller, single vergent accretionary prism, and the occurrence of a backarc basin (b). It is easy to apply these different kinematics to the Alps and the Apennines, or to the eastern and western Pacific subduction zones. Therefore, the behaviour of the subduction hinge that can de ...
... (a), and by a much smaller, single vergent accretionary prism, and the occurrence of a backarc basin (b). It is easy to apply these different kinematics to the Alps and the Apennines, or to the eastern and western Pacific subduction zones. Therefore, the behaviour of the subduction hinge that can de ...
CHAPTER 7 - SYNTHESIS
... Although these general patterns can be distinguished, the local state of stress is strongly dependent on time and place and changes gradually from one stress regime to the other (see e.g. Simón-Gómez [1986]). A concept of different and subsequent ‘tectonic phases’ seems not to be valid over the enti ...
... Although these general patterns can be distinguished, the local state of stress is strongly dependent on time and place and changes gradually from one stress regime to the other (see e.g. Simón-Gómez [1986]). A concept of different and subsequent ‘tectonic phases’ seems not to be valid over the enti ...
- White Rose Research Online
... The latest major tectonic events in the late Cenozoic geologic evolution of Anatolia are the development of the North Anatolian fault, the East Anatolian fault and the Dead Sea fault. The resulting northward relative differential plate motion between Arabia and Africa has accelerated the convergence ...
... The latest major tectonic events in the late Cenozoic geologic evolution of Anatolia are the development of the North Anatolian fault, the East Anatolian fault and the Dead Sea fault. The resulting northward relative differential plate motion between Arabia and Africa has accelerated the convergence ...
BEHAVIOR OF STORED MAGMA IN ARC CRUST
... and because, once breached, they provide an easier path for magma flow than continued dike propagation. It is suggested that large polygenetic cones normally have pods as their immediate sources. If so, such pods can persist for 104 to 106 years. Chemically, they tend to remain in the andesite/dacit ...
... and because, once breached, they provide an easier path for magma flow than continued dike propagation. It is suggested that large polygenetic cones normally have pods as their immediate sources. If so, such pods can persist for 104 to 106 years. Chemically, they tend to remain in the andesite/dacit ...
Do faults trigger folding in the lithosphere
... that both processes may develop concurrently, so that faulting may serve as a mechanism of folding in the brittle domain. We support this hypothesis by direct numerical modeling. The results are compared with the data on three most prominent and well-known cases of the oceanic and continental foldin ...
... that both processes may develop concurrently, so that faulting may serve as a mechanism of folding in the brittle domain. We support this hypothesis by direct numerical modeling. The results are compared with the data on three most prominent and well-known cases of the oceanic and continental foldin ...
riDge-HotSpot iNteractioNS what mid-ocean ridges tell us
... The causes of hotspots and their depths of origin are the focus of an intense debate in the scientific community. The “plume” model hypothesizes rising of buoyant mantle plumes as the primary cause of prominent hotspots such as Iceland and Hawaii (Morgan, 1971). In contrast, the “anti-plume” school ...
... The causes of hotspots and their depths of origin are the focus of an intense debate in the scientific community. The “plume” model hypothesizes rising of buoyant mantle plumes as the primary cause of prominent hotspots such as Iceland and Hawaii (Morgan, 1971). In contrast, the “anti-plume” school ...
Some remarks on subduction zones - Dipartimento di Scienze della
... m-1 (e.g., Turcotte and Schubert, 2002). This is a force per unit length parallel to the trench. However this value is very small when compared to other energetic sources for Earth, such the energy dissipated by tidal friction, heat flow emission, and Earth’s rotation (e.g., Denis et al., 2002). Mor ...
... m-1 (e.g., Turcotte and Schubert, 2002). This is a force per unit length parallel to the trench. However this value is very small when compared to other energetic sources for Earth, such the energy dissipated by tidal friction, heat flow emission, and Earth’s rotation (e.g., Denis et al., 2002). Mor ...
Mechanisms of crustal growth in large igneous
... complex and gabbros postulated for the VPM crust is strongly analogous with the structure of oceanic crust (Fig. 2). From the surface down to the Moho, the VPM crust (Fig. 1) is composed of (i) several wedges of seaward-dipping volcanic rocks (otherwise known as seismic ‘SDR’), (ii) intensively intr ...
... complex and gabbros postulated for the VPM crust is strongly analogous with the structure of oceanic crust (Fig. 2). From the surface down to the Moho, the VPM crust (Fig. 1) is composed of (i) several wedges of seaward-dipping volcanic rocks (otherwise known as seismic ‘SDR’), (ii) intensively intr ...
Crustal Deformation
... How Geologists Use These Clues • We can mentally fill out the sketch to get an idea of the shape of the fold. • Note that we still have no idea how big the fold is, only what kind it is. 3. Small structures provide clues to much larger structures ...
... How Geologists Use These Clues • We can mentally fill out the sketch to get an idea of the shape of the fold. • Note that we still have no idea how big the fold is, only what kind it is. 3. Small structures provide clues to much larger structures ...
Topic The IASPEI standard nomenclature of seismic
... relationship of the language elements. One should be aware, however, that the seismological nomenclature will inevitably develop exceptions to the rules, as any historically developed language, and also depending on the context in which it is used. Although not fully documented below, some exception ...
... relationship of the language elements. One should be aware, however, that the seismological nomenclature will inevitably develop exceptions to the rules, as any historically developed language, and also depending on the context in which it is used. Although not fully documented below, some exception ...
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.