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Ocean and ice core records of the intensity of the South‐west Indian Monsoon (SwIM) show rapid shifts in most proxy indicators of climate over the past 125 kyr on decadal to millenial scales. However, the responses of continental environments to such perturbations remain unknown due to the absence of a suitable long‐term continental record. The stratigraphic record from Gujarat, western India, an area where all sedimentological processes are governed by the vagaries of the SwIM, reveals three aggradation phases that represent deposits of seasonal rivers (AP1), ephemeral rivers (AP2) and dust storms (AP3). Based on a review of available dates and new ESR dates on the oldest exposed calcretes from palaeovertisols these phases are assigned the time brackets 135–100 kyr bp (AP1), 100–20 kyr bp (AP2) and 20–6 kyr bp (AP3). These results suggest that continental depositional environments respond in a subdued manner and are separated by thresholds. For climate shifts to effect durable changes in the continental depositional environment, a period between > 5 kyr and 16 kyr is the minimum time required to permanently change the landscape of an area. Alternatively, catastrophic changes in terrestrial depositional environments may also be effected by abrupt climatic shifts that are beyond the tolerance limits of the depositional systems.

SYNOPSISSeven distinct sets of fold structures have been recognised within 450 square kilometres of Moinian and Lewisian rocks. The earliest structures are only locally preserved, and are deformed by major folds which originally had approximately NE.-SW. axial traces and very variable axial directions. The formation of these folds was associated with high-grade Barrovian metamorphism and with the development of major slides. A pair of large N . -S . folds subsequently deformed this major fold pattern, apparently under conditions of fairly low metamorphic grade.High-grade metamorphism persisted or was re-established in part of the region during the formation of later structures oblique to the dominant regional trend. Subsequently a widespread set of folds whose style and orientation vary with varying metamorphic grade was superposed. In the area of higher grade these have approximately NE.-SW. axial traces, but their attitude in rocks of lower grade is more variable. Formation of another locally-developed set intervened between this widespread folding and the development of the last structures, which are mainly small NE.-SW. folds formed under low-grade conditions. Possible correlations with events in other parts of the Northern Highlands are discussed.

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Rubidium and strontium determinations are reported for Godhra and geographically related granites from central Gujarat. The whole rock data define a Rb-Sr isochron corresponding to a common age of 955 • 20 m.y. and initial Sr ratio of 0.7130• This age is distinctly older than the age of 735 m.y. reported for the Erinpura suite of rocks from Mount Abu in western Rajasthan and from Idar in northern Gujarat: There are at least two generations of post-Delhi intrusive rocks in the Gujarat precambrian. Biotites associated with these granites have the same age as the whole-rocks within experimental error indicating the absence of significant metamorphic heating since the time of emplacement. It is significant that rocks of similar age occur in the Rajasthan Precambrian mainly in the axial zone of the Aravalli Mountains.