Seismic stratigraphy of Chinese loess

A loess section near Lanzhou, China, has been investigated using the seismic refraction technique. The results show that the method is able to discriminate four distinct seismic boundaries within the section as well as indicating that the loess-bedrock contact occurs at a depth of more than 200 m. A 30 m deep pit was subsequently dug and revealed that the first two seismic boundaries correspond to soil units Sa (an intermediate soil within loess unit L1) and S1 (the last interglacial soil at the base of L1). These results, though preliminary, indicate the potential of the technique not only for mapping loess-bedrock contacts but also for determining the finer subsurface detail of the loess-palaeosol stratigraphy.