Sediments and stratigraphy in rockshelters and caves: A personal perspective on principles and pragmatics

Abstract

Over the last half century the study of rockshelter and cave sediments has evolved from straightforward descriptive analysis to sophisticated examination on several scales-from field observations to bulk laboratory analyses to microscopic examination. Still an integrated theory to guide the interpretation of these analyses does not exist, in part because of the idiosyncratic nature of individual caves and rockshelters. This paper reviews studies that couple field observations with laboratory analyses including particle size, pebble morphology, chemical, and mineralogical studies to provide, first, the necessary basic description of the sediments and, second, an interpretation of the environment of sedimentation. These studies can lead to an understanding of site-formation processes during human occupation, and eventually to a reconstruction of local and, in some cases, regional paleoclimates. Furthermore, sediment study is essential for intrasite correlation, independent of artifact, faunal, floral, and radiometric techniques. Finally, it is emphasized that close cooperation among sedimentologists, archaeologists, and biological specialists during planning, excavation, and interpretative stages is crucial to a successfully integrated study. ᭧

Differential preservation of vertebrates in Southeast Asian caves

“…The introduction of sediment from people, either from adhering mud, vegetation, refuse, and animal matter, and/or fires can significantly increase sedimentation rates. For example, Farrand (2001) reported sedimentary accumulation at a rate of as high as 250 cm per 100 years in Mesolithic deposits in Franchthi Cave, Greece. Human activity was identified as a major driver and contributor of sediment accumulation at the cave entrances of both Lene Hara and Laili, significantly impacting local slope stability and dominating the allochthonous sedimentary input ; a process similarly observed in Jerimalai, MK1, 2, Tron Bon Lei, Makpan, and Fatu Aki Anik Knua.…”

Bayesian age-depth modelling of Late Quaternary deposits from Wet and Blanche Caves, Naracoorte, South Australia: A framework for comparative faunal analyses

“…Deposition of sediments into caves is controlled by a range of interacting factors including cave entrance type, prevailing climatic conditions, proximal vegetation cover and local sediments and their transport (e.g., Farrand, 2001;Hearty et al, 2004;White, 2007). These factors are expected to have affected the mechanisms of sediment deposition into Wet and Blanche Caves, primarily aeolian (dust) and water transportation (Darrénougué et al 2009;.…”

Excavations at Mlambalasi Rockshelter: a Terminal Pleistocene to Recent Iron Age Record in Southern Tanzania

“…This combination of attraction and preservation renders caves and rockshelters a major source of archaeological deposits in many parts of the world. Some insist that, because of this, caves and rockshelters represent the best opportunity for archaeology in circumstances where sites are rare (Farrand 1985(Farrand , 2001aStraus 1979). However, these environments also possess their own complex suite of postdepositional taphonomic agents, including human occupants who would have modified and transformed the spaces in which they were living.…”

“…However, these environments also possess their own complex suite of postdepositional taphonomic agents, including human occupants who would have modified and transformed the spaces in which they were living. Farrand (2001a) and Goldberg and Sherwood (2006) emphasize the importance of understanding cave sediments not just as anthropogenic sediments but as parts of larger stratigraphic frameworks that also include the deposits outside of the cave proper. Goldberg and Sherwood (2006, p. 20) also stress that the depositional and postdepositional processes in rockshelters are Bdifferent from those in caves, more akin-to open-air sites.^Rockshelters have much greater connection with the outside environment, are illuminated by daylight, and have less structural stability than caves (Farrand 2001b).…”