The Basement of the Deccan Traps and Its Madagascar Connection: Constraints from Xenoliths

Paleogeographic reconstructions of India and Madagascar before their late Cretaceous rifting juxtapose the Antongil Block of Madagascar against the Deccan Traps of India, indicating that the Western Dharwar Craton extends below the Deccan lavas. Some recent studies have suggested that the South Maharashtra Shear Zone along the northern Konkan coast of India limits the northern extent of the Western Dharwar Craton, implying that the craton does not extend below the Deccan Traps, raising a question mark on paleogeographic reconstructions of India and Madagascar. The continuity of the Western Dharwar Craton north of the South Maharashtra Shear Zone below the Deccan Traps—or its lack thereof—is critical for validating tectonic models correlating Madagascar with India. In this study, zircons in tonalitic basement xenoliths hosted in Deccan Trap dykes were dated in situ, using the U-Pb isotope system. The data furnish U-Pb ages that define three populations at 2527 ± 6, 2456 ± 6, and 2379 ± 9 Ma. The 2527 ± 6 Ma ages correspond to the igneous crystallization of the tonalites, whereas the 2456 ± 6 and 2379 ± 9 Ma ages date metamorphic overprints. The results help to establish for the first time that the basement is a part of the Neoarchean granitoid suite of the Western Dharwar Craton, which extends northward up to at least Talvade in central and Kihim beach in the western Deccan. By implication, the South Maharashtra Shear Zone cannot be the northern limit of the Western Dharwar Craton. The granitoids are correlated with the Neoarchean felsic intrusions (2.57–2.49) of the Masaola suite in the Antongil Block of Madagascar, supporting the existence of a Neoarchean Greater Dharwar Craton comprising the Western Dharwar Craton and the Antongil-Masora Block.

Ancient History as a Means of Transforming Colonial India in the Late-Eighteenth and Early-Nineteenth Centuries

This article focuses on the studies and discourses of mostly British scholars of the early colonial period belonging to two schools of thought. It shows how the studies of both schools – European orientalism and utilitarianism – were intricately connected to the political development of the emerging British paramountcy over the South Asian sub-continent, as both were looking for means of establishing and/or strengthening colonial rule. Nevertheless, the debate was not just a continuation of discussions in Europe. Whereas the ideas of the European Enlightenment had some influence, the transformation of the Mughal Empire and especially the idea of a decline of Muslim rule offered ample opportunities for understanding the early history of India either as some sort of “Golden Age,” as the orientalists and their indigenous supporters did, or as something static and degenerate, as the utilitarians did, and from which the population of sub-continent had to be saved by colonial rule and colonial values. Fearing the spread of the ideas of the French Revolution, the first group of British scholars sought to persuade the native elites of South Asia to take the lessons of their past for the future development of their homeland. Just as the classicists back in Europe, these scholars were convinced that large-scale explanations of the past could also teach political and moral lessons for the present although it was important to deal with the distant past in an empirical manner. The utilitarians on the other hand believed that India had to be saved from its own depravity through the English language and Western values, which amounted to nothing less than the modern transformation of the true Classical Age.