The 'mystic' sand dune-covered temples of Talakad, Mysore district, Karnakata: Evidence of earthquake-related destruction

Low-lying sediment mound, known as Talakad sand dunes, on the left bank of the meandering Kaveri River at Talakad, Mysore district, Karnataka, is an enigmatic geomorphic feature. Archaeological excavations in the area revealed the presence of a cluster of ancient temples, mostly in dilapidated condition, which were presumably built during the time-period dating back between 6th and 17th century AD. It is generally believed that the temples were entombed under a pile of riverine sand dunes during the 'ecodisaster' that lashed the region in the 17th century. Our field studies coupled with archaeological reports on excavations indicate that the mound is not entirely made of dune sands. Virtual absence of sand deposits over some severely damaged temples occurring near the top suggests that destruction could not have taken place only because of the load of the overlying sands. On the other hand, the scale of destruction witnessed in some of the affected temples can only be explained by the incidence of earthquakes of high magnitude. Additional proof of earthquake-related destruction comes from the occurrence of sedimentary layers (beds) containing fragmented pieces of building materials like bricks and stones in silt and clay-bearing flood plain deposits at the sites of the destructed temples and other buildings. Historical records of repeated renovation or rebuilding of temples at the same place provide further proof of recurrent incidence of earthquake-related destruction. Geomorphic changes manifested in the form of shifting of river courses consequent with the rise of the sediment mound also indicate uplift-related earth movements which must have ensued repeated earthquakes in the region

Late Archean manganese mineralization and younger supergene manganese ores in the Anmod-Bisgod région, Western Dharwar Craton, southern India: geological characterization, palaeo environmental history, and geomorphological setting

International audienc

Late Archean manganese mineralization and younger supergene manganese ores in the Anmod-Bisgod région, Western Dharwar Craton, southern India: geological characterization, palaeo environmental history, and geomorphological setting

International audienc

Geochemistry of lower jurassic sandstones of Shemshak Formation, Kerman basin, Central Iran: provenance, source weathering and tectonic setting

Lower Jurassic sandstones of Shemshak Formation of Kerman basin, central Iran were analyzed for major and select trace elements to infer their provenance, palaeoweathering of source rocks and tectonic setting. Average modal framework components (Qt: F: L= 67.25: 2.41: 30.48) and chemical composition of the sandstones classify them as litharenites. The sandstones are quartz-rich (∼ 67% quartz; 75.34 wt.% SiO2) and derived from a recycled orogen composed of quartzose sedimentary rocks. Average CIA, PIA and CIW values (69%, 76% and 80%, respectively) indicate moderate to intense chemical weathering of the source material. The inferred index of weathering/alteration is the sum total of intensities of weathering witnessed by the lithocomponents during atleast two cycles of sedimentation involving (1) chemical weathering of the source rocks («ultimate» granodiorite source and «proximal» quartzose sedimentary source), (2) chemical weathering during fluvial transport of the detritus, (3) chemical weathering of the detritus in depocenters, and (4) chemical weathering during diagenesis. Sandstones exhibit moderate maturity and were deposited under humid climatic conditions. Plots of the chemical analyses data on tectonic setting discrimination diagrams indicate active continental margin setting, which is in agreement with the tectonic evolutionary history of the Central Iran during Jurassic period

Geochemistry of lower jurassic shales of the shemshak formation, kerman province, central Iran: provenance, source weathering and tectonic setting

Lower Jurassic shales of the Shemshak Formation of Kerman Province, Central Iran, were analyzed for major and selected trace elements to infer their provenance, intensity of palaeoweathering of the source rocks and tectonic setting. Plots of shales on Al2O3 wt.% versus TiO2 wt.% diagram and Cr (ppm) versus Ni (ppm) diagram indicate that acidic (granitic) rocks constitute the source rocks in the provenance. Average CIA, PIA and CIW values (84%, 92%, 93%, respectively) imply intense weathering of the source material. Plots of shales on bivariate discriminant function diagram reveal an active continental margin setting for the provenance. The inferred tectonic setting for the Lower Jurassic shales of the Shemshak Formation of Kerman Province is in agreement with the tectonic evolutionary history of the Central Iran during the Jurassic period. (C) 2010 Elsevier GmbH. All rights reserved