G-16 Formasi Kalibeng Sambongrejo
Kalibeng Formation is characterized by a thick sequence of white tuffaceous conchoidal fractured marl, which is cut by both reverse and normal faults. This formation is dated from Late Miocene to Early Pliocene. In some locations, this formation is interbedded with thin layers of calcarenite
Formasi Kalibeng dicirikan oleh sekuens tebal napal putih tufan dengan rekahan konkoidal (conchoidal fracture), yang dipotong oleh sesar naik maupun sesar normal. Formasi ini berumur Miosen Akhir hingga Pliosen Awal. Di beberapa lokasi, formasi ini berselang-seling (interbedded) dengan lapisan tipis kalkarenit.
