线形沙丘成因不能排除被风侵蚀

Linear dunes¹, widespread on Earth and Saturn's moon, Titan, are generally considered to have been formed by deposits of windblown sand. It has been speculated for some time that some linear dunes may have formed by "wind-rift" erosion, but this model has commonly been rejected due to lack of sufficient evidence. Now, new research supported by China's NSF and published this week in GSA BULLETIN indicates that erosional origin models should not be ruled out. The linear dunes in China's Qaidam Basin have been proposed to have formed as self-extending lee dunes（背风沙丘） under a unidirectional wind regime owing to a high level of total silt²（淤泥，泥沙） , clay, and salt content or cohesiveness³ of sediments⁴, and they have undergone southward lateral⁵ migration⁶ at rates of up to 3 m/yr.

New GSA BULLETIN research examines the sediments, internal structures, and optically stimulated⁷ luminescence ages of the linear dunes in the central Qaidam Basin approximately 80 km north of the city Golmud. The study's findings suggest that the linear dunes are most likely of erosional origin similar to yardangs（风蚀土脊） with orientations⁸ controlled by strikes of joints¹⁰.

According to the study's lead author, Jianxun Zhou of the China University of Petroleum¹¹'s State Key Laboratory of Petroleum Resource & Prospecting¹², "If the control of tectonic（建筑的） structures on the orientation⁹ of wind-eroded ridges¹³ is taken into account, morphodynamic interpretations¹⁴ for the wind-rift model may become much simpler. No one has considered the possibility of erosional origin for the linear dunes on Titan. Nearly all researchers consider the linear dunes on Titan to be of depositional origin, but their morphodynamic interpretations are complicated and their relationships to wind directions are in dispute. If an erosional origin is considered, the morphodynamic interpretations of the linear dunes on Titan can also be greatly simplified."