Eolian dune fields on Earth and Mars evolve as complex systems within a set of boundary conditions. A source-to-sink comparison indicates that although differences exist in sediment production and transport, the systems largely converge at the dune-flow and pattern-development levels, but again differ in modes of accumulation and preservation. On Earth, where winds frequently exceed threshold s...

Collections of gram positive bacteria from coastal sand dune vegetation, Ipomoea pes-caprae showed a predominance of orange pigmented colonies of Microbacterium arborescens-AGSB. The pigment was identified using a combination of UV/visible spectral data and HPLC retention time as a lycopene type carotenoid pigment with λmax at 468 nms. These bacteria may be accumulating carotenoids as part of t...

Sedimentation is recognized as a major factor determining the ecosystem processes of lake beaches; however, the underlying mechanisms, especially in freshwater sand dunes, have been insufficiently studied. To this end, nine belt transects from nine freshwater sand dunes, classified into low (<23.7 m), medium (25.4-26.0 m), and high-elevation groups (>28.1 m) based on their elevations in 1972, w...

Article history: Theoretical models which a Received 18 July 2008 Received in revised form 8 December 2008 Accepted 6 February 2009 Available online xxxx

Gale Crater contains Mount Sharp, a ~5km thick stratigraphic record of Mars’ early environmental history. The strata comprising Mount Sharp are believed to be sedimentary in origin, but the specific depositional environments recorded by the rocks remain speculative. We present orbital evidence for the occurrence of eolian sandstones within Gale Crater and the lower reaches of Mount Sharp, inclu...

Sand dunes can be active (mobile) or stable, mainly as a function of vegetation cover and wind power. However, there exists as yet unexplained evidence for the coexistence of bare mobile dunes and vegetated stabilized dunes under the same climatic conditions. We propose a model for dune vegetation cover driven by wind power that exhibits bistabilty and hysteresis with respect to the wind power....

Booming” sand dunes have a remarkable capacity to produce sounds that are comparable with those from a stringed instrument. This phenomenon, in which sound is generated after an avalanching of sand along the slip face of a dune, has been known for centuries and occurs in at least 40 sites around the world. A spectral analysis of the sound shows a dominant frequency between 70 and 110 Hz, as wel...

*Correspondence: Steven L. Forman, Geoluminescence Dating Research Laboratory, Department of Geology, Baylor University, One Bear Place #97354 Waco, TX 76798-7354, USA e-mail: [email protected] The eolian sand depositional record for a dune field within Cape Cod National Seashore, Massachusetts is posit as a sensitive indicator of environmental disturbances in the late Holocene from a co...

Raked linear dunes keep a constant orientation for considerable distances with a marked asymmetry between a periodic pattern of semi-crescentic structures on one side and a continuous slope on the other. Here we show that this shape is associated with a steady-state dune type arising from the coexistence of two dune growth mechanisms. Primary ridges elongate in the direction of the resultant sa...