Open-framework gravels (OFGs) form common lithofacies of alluvial fans. However, inferences their mechanisms transport and deposition, controls on distribution in alluvial-fan successions, remain difficult, limiting our ability to interpret the environmental significance such deposits predict distributions ancient successions. From an applied standpoint, predictions are important development hy...

Middle Ordovician phosphatic ironstone of the Welsh Basin provides new insight into paleoenvironmental significance and ocean chemistry. Deposition occurred in a back-arc basin along southern margin Avalonia as Rheic Ocean opened to south. Ironstone is interpreted have accumulated part an aggradational parasequence on storm-dominated shelf with coastal upwelling. This has laminated pyritic muds...

Abstract Although deltas and subaqueous fans are both formed in the same near-shore zones of basins, hydraulic conditions for their formation, development sedimentary records different. The present review discusses results previously published studies fan (Gilbert-type deltas) lacustrine glaciolacustrine environments. depositional mechanisms fans, textural structural features lithofacies associ...