Comparative Study On The Characteristics And Cause Of The Resonance Of Sound-producing Sands In North China

Sound-producing sand is a universal natural phenomenon,but the cause for its resonance has remained undiscovered.Most sound-producing sand dunes in China are distributed along curvilinear belt of deserts in thenorh,but there is still short of scientific and systematic comparatie studies on the sound-producing and soundless sands.In this paper,sound-producing sand samples were obtained from the Yulong Shahu Singing sand in Bo Longke Sand lake in Ongniud Banner,Inner Mongolia,the Yin Ken Sound-Producing Sand Bay in the Kubuqi Desert,the Mount Mingshashan in Dun Huang in the Gansu Provinceand the Baran Baori Taolegai Sand dune in the Badan Jaran Desert of Inner Mongolia,and the soundless sand samples were from the Kumtag Desert between Gansu and Xinjiang Autonomous Region,and the the sand dune on the northeastern edge of Mount Minshashan.This paper provides new data and interpretations based on a comparative study of the geomorphic features and distributions,grain-size compositions,mineralogical components and grain micro-textures of sound-producing and soundless sands in order to better quantify the causes of the acoustic features of these sound-producing sand dunes.Sound-producing sands can also develop on the windward slope of sand duens,such as the sand samples of Yulong Shahu Singing sand in Bo Longke Sand lake in Ongniud Banner were collected from the windward slope,which refutes the “Resonance Box” theory proposed by Ma Yuming(2000)that all sound-producing sands develop on the sunny side of the leeward slope.All the four sound-producing sand dunes are near lakes or spring underneath,while there are not any water sources around the two soundless sand dunes.The sand particles of Baran Baori Taolegai Sand Dune is the most coarse one among all the sand samples,with medium-size and coarse sand particles reaching over 93%,while that of the Yin Ken Sound-Producing Sand Bay of Erdos is the finest one of all,with the very fine and fine sand particles reaching over 77%.All the sound-producing sand particles are positively biased,and all the soundless sand particles are negatively biased.The sound-producing sand samles from Mount Mingshashan of Dunhuang is the best-sorted,less than 0.4,while those soundless sand samples from the west-east of Mount Mingshashan of Dunhuang is the worst-sorted,over 0.55.The kurtosis of all sand samples is around 0.95,yet that from the Baran Baori Taolegai Sand dune is lower than that.All the sound-producing and soundless sand samples consist mainly of quartz and potassium feldspar,respectively reaching over 70% and 95%.Kaolinite,albite,microcline and calcite occur as secondary minerals in the sound-producing sand samples,around 1%-10%,but they are lacking in the two soundless sand samples.The sphericity values?roundness values and standard deviation of all the sound-producing and soundless sand samples are similar.And pits appear on both of the sound-producing and soundless sand particles and they are not just exclusive to the sound-producing sand surface.And more scale-like upturned plates,silica scale and fractures,the maximum content reaching 55%,35% and 40% respectively,which might be one of the reasons contributing to the resonance of the sound-producing sands.