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Zorluk: KolayEarth's Interior and Plate Tectonics

When continental crust begins to pull apart at a divergent boundary, a sequence of geological events eventually creates an ocean basin. In what chronological order do these developmental stages occur from first to last?

  1. 1Continental crust stretches, thins, and fractures to form a central rift valley.
  2. 2The widening rift valley subsides below sea level and floods, creating a narrow, linear sea.
  3. 3Continuous seafloor spreading produces new oceanic crust, developing a wide, mature ocean basin.

Cevap

The correct chronological sequence begins with continental crust stretching and fracturing to form a rift valley, followed by flooding to form a narrow linear sea, and concludes with long-term seafloor spreading forming a mature ocean basin.
Divergent boundary evolution begins when upwelling thermal currents pull continental crust in opposite directions, causing normal faulting and a rift valley (such as the East African Rift). As divergence widens the gap and lowers the elevation, seawater floods the valley to form a long, narrow linear sea (such as the Red Sea). Continued seafloor spreading along a central mid-ocean ridge continuously adds basaltic crust, eventually forming an expansive, mature ocean basin (such as the Atlantic Ocean).

Adım Adım Çözüm

1
Identify the initial continental splitting stage
Formation of a continental rift valley
Tensional stress first thins and pulls the continental lithosphere apart, dropping the central block to form a valley.
2
Identify the intermediate marine inundation stage
Creation of a narrow linear sea
As the rift expands and sinks below sea level, ocean water enters and inundates the depression.
3
Identify the long-term mature basin stage
Development of a mature ocean basin
Persistent magma upwelling at the central spreading center generates oceanic crust, widening the basin into a full ocean.

Anahtar Kavram

Evolutionary sequence of divergent plate boundaries from continental rifting to mature ocean basin development
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