Abstract We review and compare morphologies from continental basaltic lavas, using examples from the Deccan Volcanic Province to compile their internal configurations and mutual associations and compare them. The mechanism of endogenous transfer of lava within an insulating (rapidly developed) crust provides an efficient mode of dispersal of the molten lava in flood basalts. The growth of the lava flow can be achieved by a single extrusion or by multiple pulses of endogenous emplacement that enable the lava to efficiently spread over large areas and thicken. We show that the morphology of a lobe manifests the response of the molten lava to several parameters (including volumetric rate of emplacement, substrate topography, viscosity, vapour loss, etc.) that govern the dynamics and cooling history of basaltic lava after it starts to spread on the surface. The lateral transition from one morphology to another within lobes of a lava flow is a testimony to the interactive response of the lava dynamics and rheology to variation in the local systems in which they were emplaced. The morphologies do not evolve as rigid partitioned categories from ‘áā and pāhoehoe lava types' but as parametric progression of interactive variations in the spreading and cooling lava. A hierarchical recognition of lobes, flows and flow fields and mapping of the morphology (and their lateral transition or continuity) combined with the stacking patterns provides the volcanological framework for a sound stratigraphic mapping of flood basalts. Such an architectural documentation of flood basalt provinces will lead to robust models of their eruptive histories.

Abstract The western edge of the Deccan Plateau (=Western Uplands) has been depicted in its evolutionary models to be a contiguous crustal block exposing structurally undisturbed subhorizontal stacks of Deccan Trap basalts. The geomorphological and morphometric characteristics of this terrain, Quaternary fluvial sediments capping the Deccan Traps in some river basins, compounded with deformation features in the basalts, and in the overlying sediments, are compiled here. They demonstrate that the Western Upland region of the Deccan Plateau may be constituted of no less than three blocks with differential Quaternary uplift histories, rather than the entire region experiencing a unified uplift.