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Late Quaternary vadose carbonate diagenesis in coastal and desert dune and beach sands: is there a palaeoclimatic signal?
Author(s) -
McLaren Sue,
Gardner Rita
Publication year - 2004
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.1132
Subject(s) - diagenesis , geology , vadose zone , interglacial , quaternary , paleontology , mediterranean climate , carbonate , paleoclimatology , climate change , paleosol , arid , phreatic , holocene , aquifer , oceanography , groundwater , ecology , materials science , geotechnical engineering , loess , metallurgy , biology
A study of the variation in cement amounts in aeolianite and sandy beach calcarenites that range in age from Holocene to Last Interglacial is used to assess whether a palaeoclimatic control on vadose diagenesis can be identied. Examples are taken from modern‐day arid to subhumid settings and represent a geographical distribution ranging from Libya and Oman, to the Mediterranean, the Caribbean and Mexico. The results indicate that a palaeoclimatic signal can be identied in some deposits. However, in other sediments there is substantial variability in mean cement abundance within deposits as well as between these sand bodies. Moreover, many of the better cemented sediments are located in areas where there is accelerated diagenesis, such as in the sea spray zone, close to the groundwater table or near to a palaeosurface, rather than in climatically wet regions. The inference is that palaeoclimatic interpretations are substantially complicated by other factors that affect diagenetic processes and change. Therefore caution is needed when studying the role of climate in vadose diagenesis in the light of the effects of other intrinsic and extrinsic controls. This paper does not aim to provide a denitive comparison of sites from different climatic zones. The approach taken here is: (a) to see if there is an overall palaeoclimatic signal in the samples studied; (b) to use examples to illustrate how explanations/controls other than those relating to climate can account for the variabilities observed; and (c) if there is a climatic effect, to see if it is the main over‐riding control on vadose diagenesis. The conclusions drawn from this research highlight that it is possible to misinterpret evidence if the study is approached with preconceived notions of simplistic relationships between diagenesis and climate. Copyright © 2004 John Wiley & Sons, Ltd.