A detailed and comprehensive study that covers the aspects of facies and palinology has been carried out on the Nenering bed to determine its depositional history and age. Field evidence based on sedimentary logs of outcrop shows that the sediments have been deposited in a limited intermontane basin. Its sedimentary facies reveal that the sediments were derived from the adjacent older sedimentary rocks. The sediments were transported and deposited in the basin by ephemeral streams. Coarse-Âgrained facies are more dominant in the basin margin area whereby finer-grained facies are more concentrated along the basin axis. Vertical facies changes reveal that in the earlier stage of deposition the basin axis was dominated by finer-grained facies which was then succeeded by the coarserÂgrained sediments brought-in by ephemeral streams. Palynological avidence reveals that the deposition in the basin took place during the Late Cretaceous (? Aptian-Albian).
Lapisan Nenering yang dilaporkan sebelum ini telah dikaji dari aspek sedimentologi don polinologi secara menyelurnh. Bukti-bukti lapangan berdasarkan log turus sedimen pada keseluruhan singkapan mendapati unit batuan sedimen ini telah dimendapkan di dalam lembangan yang kecil yang wujud di antara pergunungan. Fasies sedimennya menunjukkan punca sedimen telah diterbitkan daripada batuan tua di sekitarya. Sedimen dimendapkan di dalam lembangan secara bermusim oleh sungai-sungai efemeral. Fasies berbutir kasar tertumpu ke bahagian tepian lembangan sementara bahagian tengah didominasi oleh sedimen butiran halus. Perubahan fasies secara menegak pula menunjukkan, pada awal pemendapan bahagian tengah lembangan dinominasi oleh sedimen berbutir halus dan kemudian berlaku kemasukan sedimen butiran kasar yang dibawa oleh sungai-sungai berkala. Bukti-bukti palinologi menunjukkan pemendapan sedimen di dalam Lembangan Nenering berlaku paling mungkin semasa Kapur Akhir (? Aptian-Albian).