Physical and chemical properties of sound-producing and soundless sand particles from booming sand dunes, northern China
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ORIGINAL PAPER
Physical and chemical properties of sound-producing and soundless sand particles from booming sand dunes, northern China Fei Han 1 & Mingzhong Tian 1 & Fadong Wu 1 & Jianping Zhang 1 & Siwen Liu 2 & Lulin Wang 1
Received: 27 October 2016 / Accepted: 19 May 2017 # Saudi Society for Geosciences 2017
Abstract This study here is the result of a comparative study of the geomorphic features, grain size distribution, major mineral components, and micro-textures of sound-producing and soundless sands from three geoparks in north China, and discusses the possible causes of this naturally occurring, physical phenomenon. The sound-producing sand dunes we have investigated are situated along a curvilinear belt of deserts and experience variable precipitation–evaporation rates on a yearly basis. BSinging sands^ occur mainly on barchan-type dunes and adjacent to lakes or springs, whereas soundless sands are mainly located in desert areas where there is no nearby surface or groundwater sources. We have analyzed samples from nine sound-producing and two soundless sand dunes using grain size, X-ray diffraction and fluorescence, and SEM analyses. All sand types are composed largely of quartz and feldspar, but sound-producing sands also contain secondary minerals such as kaolinite (3–5%), albite (2–6%), microcline (2–5%), and calcite (5%) that are lacking in the soundless sand samples. Sound-producing sands are generally fine-grained whereas soundless sands are coarse-grained, and all sand types are generally sub-rounded to rounded indicating long transport distance from their provenance. Sphericity values of both sand types are nearly identical with predominantly oblate shapes. Surface pitting is not a unique feature of either sand types, and hence can be ruled out as a major cause of the acoustic properties of sound-producing sands. Densely
* Fei Han [email protected]
1
Faculty of Earth Science and Resources, China University of Geosciences, Beijing, China
2
Faculty of National Center for Geoanalysis, Chinese Academy of Geological Sciences, Beijing, China
distributed dissolution features such as scale-like upturned plates and silica scales on grain surfaces contribute significantly to the sound emission of singing sands. Thus, the physical–climatic conditions in deserts such as the presence of surface water and groundwater and precipitation–evaporation rates, which collectively control the formation and distribution of dissolution features on sand surfaces, have a first-order control on the production of sound-producing sands. Keywords Sound-producing sands . Geomorphic features . Grain size components . Mineral components . Micro-textures . Comparative analysis
Introduction When wind-swept sand particles pile up on the top of certain large dunes and then avalanche, a loud booming acoustic emission can occur with a dominant frequency in the range 50– 200 Hz (Haff 1986; Nori et al. 1997; Sholtz et al. 1997). This sound emission is a naturally occurring phenomenon and an important geo-heritage attraction (T
