How does a slab window work?
A slab window occurs where a subducting plate tears or breaks-off, or where two plates subduct along a spreading ridge. This process alters mantle circulation and melting processes in the region, changing the chemistry of magmatism observed at the surface.
What is a slab window volcano?
Slab windows are gaps between subducted parts of oceanic plates at sites of mid-ocean spreading ridge subduction (Dickinson and Snyder, 1979; Thorkelson and Taylor, 1989).
What causes a slab window?
If plate divergence and convergence continue after the ridge intersects the subduction zone, a slab window forms between the subducted parts of the diverging oceanic plates, producing anomalous thermal, physical and chemical effects in the surrounding asthenospheric mantle.
What does a slab do at a subduction zone?
Subduction slabs drive plate tectonics by pulling along the lithosphere to which they attach in a process known as slab pull and by inducing currents in the mantle via slab suction. The slab affects the convection and evolution of the Earth’s mantle due to the insertion of the hydrous oceanic lithosphere.
How subduction zone is formed?
Where two tectonic plates converge, if one or both of the plates is oceanic lithosphere, a subduction zone will form. An oceanic plate will sink back into the mantle. But as it spreads away from the ridge and cools and contracts (becomse denser) it is able to sink into the hotter underlying mantle.
What is slab dehydration?
Subducting oceanic slabs undergo metamorphic dehydration with the increase of temperature and pressure during subduction. At fore-arc depths, slab dehydration produces aqueous fluid with dissolved salts such as NaCl. As subduction proceeds deeper, the content of silicate components increases.
What is slab melting?
Modern plate tectonic brings down oceanic crust along subduction zones where it either dehydrates or melts. Slab melts are silicic and strongly sodic (trondhjemitic). They are produced at low temperatures (< 1000 degrees C) and under water excess conditions.
Where is the Ring of Fire?
Pacific Ocean
The Ring of Fire, also referred to as the Circum-Pacific Belt, is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes. The majority of Earth’s volcanoes and earthquakes take place along the Ring of Fire.
Which plate undergoes subduction?
oceanic plate
The oceanic plate is denser, so it undergoes subduction. This means that the oceanic plate sinks beneath the continent. This occurs at an ocean trench (Figure below). Subduction zones are where subduction takes place.
What is the long deep cavity caused by the subduction of crust?
Oceanic plates are subducted creating oceanic trenches.
What is magma slab?
Magma Composition ‘ It is formed from the melting of rocks in the earth’s lithosphere, which is the outermost shell of the earth made of the earth’s crust and upper part of the mantle, and the asthenosphere, which is the layer below the lithosphere. There are also many different gases dissolved in magma.
Is magma the same as lava?
Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth’s surface.
What is slab edge insulation?
If the slab is poured separately from the exterior foundation wall and slab edge insulation is installed between the floor slab and the foundation wall, code permits that the top of the foam be cut at a 45-degree angle away from the exterior wall so that the upper edge is protected by concrete.
What is a slab door?
A slab door is a door that comes without a surrounding frame. Slab doors are commonly used when replacing an old door with the frame still intact, or when repurposing an old door, such as an antique. To hang a slab door, you will first need to fit the door to the existing doorframe.
What is slab glass?
Slag glass, also known as marble glass or malachite glass, is a type of opaque, streaked pressed glass. Production of slag glass originated in late-19th-century England, where glass manufacturers are thought to have added slag from iron-smelting works to molten glass to create a range of effects-from tortoiseshell to marbling.