Abstract

The Kendeng zone is an anticlinorium situated between the NE Java hinge belt and the axis of the central trough of Java. It appears to be a distinct geological unit from the standpoints of structure, lithostratigraphy and tectonics.

From late Oligocene to Holocene, sediments were deposited within this area under dominant regressive conditions which prevailed at first in the West then progressively extended eastwards and finally resulted in the emersion of the entire Kendeng zone. Volcanoes were almost permanently active in the western and southern adjacent areas during this period.

A first uplift of the Kendeng anticlinorium occurred in late Pliocene time. The major tectonic phase took place at the end of the Pliocene, and epirogenic movements went on during the Quaternary.

Phases of orogenesis and periods of volcanic activity were closely related. Epidermal folding and faults were due to a northwards compression originating from the Plio-Pleistocene uplift of the spine of Java. Horizontal displacement of basement blocks along deep-seated wrench faults likely occurred at that time at both extremities of the Kendeng zone.