what is the relationship between the mid-ocean ridge and sea floor spreading? | Yahoo Answers
A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. This uplifting of the ocean floor occurs when convection. Magnetization of the Sea Floor and Seafloor Spreading Seafloor spreading takes place at midocean ridges and produces basalt, the rock that makes up the. It occurs along ridges in the ocean floor that result from divergent boundaries. in the earth's crust allow magma to rise up and spread across the ocean floor.
This can result in an ever-widening seafloor at the expense of area lost elsewhere on the planet. Seafloor spreading ends when midocean ridges are subducted.
What is the relationship between the mid-ocean ridge and sea floor spreading?
Seafloor spreading produces major characteristics of the seafloor - 1 the age of the seafloor is progressively older away from midocean ridges, 2 the elevation of the seafloor is progressively lower away from midocean ridges, 3 the magnetic history of the seafloor bears the striped-pattern of the Earth's magnetic reversals, and 4 older parts of the seafloor have the greatest potential to have accumlated sediments over the longest time. Volcanoes and other features that grow or fall onto the seafloor move and sink with the seafloor over time.
Since the seafloor on each side of a midocean ridge moves in opposite directions, each side belongs to a different lithospheric plate.
Midocean ridges, transform faults and fracture zones are the key surface features produced by seafloor spreading.
Seafloor Spreading Animation - Earthguide Online Classroom
In detail, midocean ridges are made up of short offset segments. The curved linear features running perpendicular to midocean ridges are fracture zones and transform faults. Fracture zones and transform faults make up parts of each linear feature. The hot and partially melted mantle most of the mantle is actually solid, but soft and ductile, like clay is closer to the surface at ocean spreading centers than in any other tectonic environment on Earth.
Deep, hot mantle rises up. As the hot mantle rock gets closer to the surface, the pressure decreases, and this causes it to melt more easily. The magma melted rock has composition of basalt a rock with a lot of magnesium, iron, silicon, and aluminum more magnesium and iron, less silicon than granite.
Some of the magma cools and solidifies at the surfacein contact with seawater forming pillow basalts, but most of it cools below the surface to form gabbro same composition as basalt, but cools below the surface and peridotite more magnesium and iron than basalt. Geologists used to think that spreading centers were driving plate tectonics.
We thought that oceanic crust was being pushed out at these boundaries.
We now think that a more important driving mechanism is subduction where oceanic crust is sinking back into the mantle. The sinking crust pulls the rest of the plate along, and this causes the spreading center to spread faster. I made a very generalized sketch of whats going on at spreading center.
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For younger children, omit explanation of magnetic stripes and reversals of polarity. Use the model to show them the creation of new sea floor at spreading centers and the disappearance of old sea-floor at subduction zones.
You may wish to cut the paper model pieces for the students ahead of time, or use a model you have made as a demonstration for the class. Hydrothermal vent systems, called black and white smokers, found at oceanic spreading centers are one of the most exciting discoveries made during the last fifteen years of marine exploration. These smokers are the sites of mineral deposits and unique ecosystems that exist in total darkness. Integrate a unit on sea-floor spreading and ocean floor topography with biology by having students research the unique creatures associated with hydrothermal vent communities.
Some suggested references are given below. Research Beneath the Sea" from the United States Geological Survey provides an overview of the methods and equipment that marine geologists employ to study the ocean floor.
The pamphlet describes studies of ocean floor topography, sediments and mineral resources. The kids in Mrs. Frizzle's class take a field trip to the deep ocean floor to study animal and plant life, a hot-water vent, and a coral reef for elementary school children. About Deep Sea Hydrothermal Systems: