Pollen taphonomy and airfall sedimentation in a tropical cave: the West Mouth of The Great Cave of Niah in Sarawak, Malaysian Borneo

This paper investigates the taphonomy of predominantly biogenic sediments and pollen in the key archaeological site in the West Mouth of the Great Cave of Niah, Sarawak. Strong spatial patterning of sediments and pollen were found, with a zonation related to distance into the cave. Near the cave mouth, sedimentation is silty and derived from waters running down the cliff outside the cave, with leaves from external vegetation. Pollen assemblages are similar to forest floor samples outside the cave, and thus are of airfall or wash origin. In the interior of the West Mouth, sedimentation is highly organic and composed largely of bird droppings. Pollen assemblages in the interior are strongly but regularly biased, with 'over-representation' of mangrove and riverine taxa resulting from the recruitment of pollen by bats and swiftlets foraging preferentially in these zones, over 7 and over 2 km from the cave, respectively. The significance of these findings for the understanding of humid tropical cave sequences and particularly for the current reassessment of Niah Cave is discussed.