Philippine Trench

The trench is located in the Philippine sea of the western North Pacific Ocean and continues NNW-SSE.

The central part of the Philippine fault formed during the Plio-Pleistocene times[15] is considered to be an active depression of the Earth's crust.

This caused a change in geological processes creating a subduction zone, that is dropping the ocean floor deeper.

[2] Sedimentation of the Philippine trench contains slightly metamorphosed, calc-alkalic, basic, ultrabasic rock and sand grains.

[16] The southern area of the trench contains homogeneous blue clay silt and is poor in lime.

The Philippine Trench, in the middle of the picture.
The Philippine Trench in the east which continues downward, and the Philippine Mobile Belt .