Abstract Orientated carbonate (calcite twinning strains; n = 78 with 2414 twin measurements) and quartzites (finite strains; n = 15) were collected around Gondwana to study the deformational history associated with the amalgamation of the supercontinent. The Buzios orogen (545–500 Ma), within interior Gondwana, records the high-grade collisional orogen between the São Francisco Craton (Brazil) and the Congo–Angola Craton (Angola and Namibia), and twinning strains in calc-silicates record a SE–NW shortening fabric parallel to the thrust transport. Along Gondwana's southern margin, the Saldanian–Ross–Delamerian orogen (590–480 Ma) is marked by a regional unconformity that cuts into deformed Neoproterozoic–Ordovician sedimentary rocks and associated intrusions. Cambrian carbonate is preserved in the central part of the southern Gondwana margin, namely in the Kango Inlier of the Cape Fold Belt and the Ellsworth, Pensacola and Transantarctic mountains. Paleozoic carbonate is not preserved in the Ventana Mountains in Argentina, in the Falkland Islands/Islas Malvinas or in Tasmania. Twinning strains in these Cambrian carbonate strata and synorogenic veins record a complex, overprinted deformation history with no stable foreland strain reference. The Kurgiakh orogen (490 Ma) along Gondwana's northern margin is also defined by a regional Ordovician unconformity throughout the Himalaya; these rocks record a mix of layer-parallel and layer-normal twinning strains with a likely Himalayan (40 Ma) strain overprint and no autochthonous foreland strain site. Conversely, the Gondwanide orogen (250 Ma) along Gondwana's southern margin has three foreland (autochthonous) sites for comparison with 59 allochthonous thrust-belt strain analyses. From west to east, these include: finite strains from Devonian quartzite preserve a layer-parallel shortening (LPS) strain rotated clockwise in the Ventana Mountains of Argentina; frontal (calcite twins) and internal (quartzite strains) samples in the Cape Fold Belt preserve a LPS fabric that is rotated clockwise from the autochthonous north–south horizontal shortening in the foreland strain site; Falkland Devonian quartzite shows the same clockwise rotation of the LPS fabric; and Permian limestone and veins in Tasmania record a thrust transport-parallel LPS fabric. Early amalgamation of Gondwana (Ordovician) is preserved by local layer-parallel and layer-normal strain without evidence of far-field deformation, whereas the Gondwanide orogen (Permian) is dominated by layer-parallel shortening, locally rotated by dextral shear along the margin, that propagated across the supercontinent.

Two thick sequences of ancient glacial and glacial marine rocks, the late Proterozoic Mineral Fork Formation of Utah and the Late Paleozoic Whiteout Conglomerate of West Antarctica, reflect similarities and differences in temperature regimes of the glacial delivery systems, climatic settings in the zones of ablation, and nature of the glacier interfaces with the depositional environments. Both units attain thicknesses of about 1,000 m and both are segments of widely distributed glacigenic deposits covering thousands of km 2 . They appear to represent significant erosion of platformal areas beneath basal ice at or near its melting point. In the Mineral Fork Formation, facies patterns indicate supraglacial melt-out, sediment gravity flow, and deposition from meltwater streams, all characteristic of glacier ice where the climate is subpolar or temperate in the zone of ablation. The vertical sequence, which includes subglacial tills, supraglacial melt-out facies, and a complex glacial marine facies, indicates multiple advances of a grounded ice sheet along the margin of a craton, and final retreat accompanied by a marine transgression. In contrast, the Whiteout Conglomerate lacks facies indicative of supraglacial melting; the absence of meltwater-generated fluvial and plume deposits is especially striking. Rather, subglacial melt-out from grounded ice and basal melting of ice shelves and perhaps icebergs, all accompanied by vertical settling, are indicated. Lateral changes represent a regional transition from grounded marine-based glaciers at the pressure melting point in the basal zone to a shelf of polar ice warmed sufficiently at the base to release sediment there by melting as well as by iceberg calving. The study of thick ancient glacigenic sequences accumulated on subsiding continental margins provides information not yet obtainable from sedimentary piles of Quaternary age.