Tsunami deposit

As Tsunamite sedimentary rocks are called, which are composed of the deposits that are made ​​during a tsunami. These deposits are characterized by a sharply demarcated, usually several meters thick sediment layer with embedded chaotic breccias and lithoclasts ( rock fragments and blocks) that can be derived from the shallow marine area and the adjacent beach area. An influx in tsunami wave leads to the destruction of rocks and coral reef in shallow marine area and the entire beach area. The tsunami that followed the back wave eroded large areas of beach and shallow sea area in part several meters deep and takes the sediments in coastal areas with more distant.

Depending on the morphology of the sea basin, the intensity of the wave motion and the size of the entrained objects are found Tsunamite in the shelf zone, on the continental slope and in the deep sea. With the distance from the coast, the grain size and the thickness of the deposits generally decrease. In the hinterland of the beach tsunami -induced sediment can be deposited in the wake of widespread flooding also in shallow lagoons. Go to the hanging wall Tsunamite due to several days of persistent, highly turbulent water movement over sediments with storm surge Character ( Tempestit ) gradually returned to the normal sedimentation of the respective deposition chamber above.

Individual blocks of Paläotsunamiten (which are Tsunamite that were deposited in the past) can weigh up to 200 tons and are preferred to find in the Indian Ocean and Mediterranean Sea.

The term was introduced in the late 1980s and took place in the following years, the entrance to the geological terminology.

Tsunamite can be used to allostratigaphischen classification of sediments due to the sharp temporal limitation of the deposition events.