Dynamic model of turbidite erosion and deposition in three dimensions

Turbidites often makeup a considerable fraction of observed stratigraphic s equences and, even when they do not, turbidite sands within a stratigraphic sequence are often highly petroliferous. MOSED3D is a turbidite flow model and has been used to examine the turbidite flow problem. Modelling of turbidite flow and deposition in three dimensions is accomplis hed by taking quanta of sediments, released at different locations on a bas inal slope, and allowing the sediments to flow constrained by the existing topography of the basin slope, and previously modified by the passage of ea rlier turbidites. Sediments released in each quanta are transported downslo pe and deposited when their flow energy drops below a critical value. The t urbidite flow can also cause erosion of the existing basin slope, and the t otal mass of sediments then follows the transport rules. Each quantum of se diment can be composed of variable fractions of up to ten lithologic types, ranging from very fine-grained material to coarse-grained sediments. Depos ition takes place dependent upon the parameter values assigned to each lith ologic type; default values are arranged so that coarse-grained material is deposited first and fine-grained material last. The MOSED3D (MOdel of SEdiment Deposition in 3 Dimensions) computer program is written in C with an X Window System Toolkits, which provides a user-fr iendly interface for MOSED3D. Model results can be displayed in contour map form, as isopachs, and also as 2-D cross sections drawn in arbitrary, user -defined, directions across the system. The code is fast, requiring about 2 min cpu time on a SUN SPARC for a typical run. Thus many different geologi cal scenarios with multiple parameter assignments can be investigated quick ly for accordance with either required behaviours or with observed patterns of deposition. This paper describes some test cases designed to illuminate individual fact ors the code is capable of handling.