Bhima Basins Research Articles

Tectonic setting of Kaladgi-Badami basin and its possible connection with adjacent Proterozoic basins, Karnataka, India

Sedimentary rock types and basin geometries are interrelated with characteristic tectonic settings. In fact, sedimentation pattern at central stable cratonic areas are not same as that on continental margins. Kaladgi-Badami (KB) basinal feldspathic arenite (i.e., arkose) dominated rocks contain more plagioclase than potassium feldspar unlike the opposite scenario of Phanerozoic sandstones. Tectonic history of the KB basin has been interpreted since basin development, sedimentation through interrupting hiatus, tectonic reworking, redeposition at later developed depocenters and later exhumation, erosion, tectonism till Deccan volcanism and finally latest configuration. As per the International commission of Stratigraphy (ICS), principles of stratigraphic classification and usages of terminology of fundamental lithostratigraphic unit ‘Formation’ is reexamined in this paper. The definition of Formation as “smallest mappable rock unit with a definite lithologic characteristic that allow it to be distinguished from other such units” is improperly used because without mentioning a specific scale every unit is mappable or traceable. Therefore, the minimum mappable unit means the unit which can be at least visible in a scale in which entire basin can be seen. Based on this slight modification is proposed in the stratigraphy of KB basin. Geochronology based radiometric stratigraphy is best tool for determination of time sequence of geological events. However, it is always a matter of concern that dating methods and materials are often not suitable in sedimentary geology. In case of passive rifted sedimentary basins like Kaladgi, Badami and Bhima of the Dharwar Craton, there is negligible igneous events and indirect dating methods are mostly available. Detrital zircon dating can give maximum age or provenance age, which cannot be of much use. However, there are other indirect tools, which are already utilized by several workers earlier and based on the reviews and present observation and mapping compilation it is proposed that KB and Bhima basins used to be a single basin, and later tectonism followed by Deccan volcanism affected the present geographic continuity. Since the distance between westernmost Bhima basinal rocks and easternmost KB basinal rocks near Mudhebihal is nearly around 15km, it is logical to consider that these were geographically connected, because there is an intense faulting near to these basin margins.

Palaeomagnetism of the uppermost carbonate units of the Purana basins in southern India: new demagnetization results from the Kaladgi and Bhima basins, Karnataka

AbstractFour unconformity-bound sequences can be identified in the Purana successions in southern India, of which the third sequence (Sequence III) has the widest distribution. Sequence III contains deep-water carbonate units with consistent sedimentological characteristics across the subcontinent. The current extent of field relationships and existing ages has not allowed the correlation and chronology of these carbonates to be established conclusively. Palaeomagnetism may help resolve this essential question for the Purana sedimentation. Here, we report new palaeomagnetic results (HIG+/– pole: 21.7° N, 81.1° E, radius of cone of 95% confidence A95 = 15.9°) from Sequence III carbonates in the Kaladgi (Badami Group) and Bhima (Bhima Group) basins. The HIG+/– magnetization, revealed after the removal of secondary magnetizations that include a present-day field and an Ediacaran–Cambrian overprint, is interpreted to be primary based on its dissimilarity to known younger magnetizations, the presence of distinctly different magnetic components in sites and a positive reversal test. Our HIG+/– pole differs from the c. 1.4 Ga pole and various c. 1.1 Ga and younger poles. Instead, it overlaps with the Harohalli dyke pole that was long considered to be c. 823 Ma in age, but has recently been suggested to be much older with an age of c. 1192 Ma. We therefore consider the uppermost carbonate beds of Badami and Bhima groups to have been deposited during late Mesoproterozoic times. A critical evaluation of parameters from which an earlier Neoproterozoic age for these carbonates was established indicates that the available 40Ar/39Ar, Rb–Sr and U–Pb ages in the Kaladgi and Bhima basins could reflect the timing of post-depositional alteration events.

A status report on age, depositional motif and stratigraphy of Chhattisgarh, Indravati, Kurnool and Bhima basins, Peninsular India

A status report on age, depositional motif and stratigraphy of Chhattisgarh, Indravati, Kurnool and Bhima basins, Peninsular India

Comments on Paper: “Depositional history and provenance of cratonic ‘Purana’ basins in southern India: A multipronged geochronology approach to the Proterozoic Kaladgi and Bhima basins” by Joy et al., 2018. Geological Journal, https://doi.org/10.1002/gj.3415

The paper by Joy et al. (2018) contains several generalizations and appears to have followed a flawed analytical technique. We seek clarifications from the authors on specific points to ensure the credibility of the conclusions drawn by them.

Reply to the comments by Pillai, S. P., George, B. G., Ray, J. S., and Kale, V. S., (GJ‐19‐0112) on Paper: “Depositional history and provenance of cratonic “Purana” basins in southern India: A multipronged geochronology approach to the Proterozoic Kaladgi and Bhima basins” by Joy et al., 2018

We thank Patil Pillai et al. for preparing a critique on our article (Joy et al., 2018). Patil Pillai et al. contest the analytical procedure utilized for the carbonates and “geological information” documented in our research article and raise concerns on our conclusions. We hereby provide our reply to each of their comments.

Depositional history and provenance of cratonic “Purana” basins in southern India: A multipronged geochronology approach to the Proterozoic Kaladgi and Bhima basins

Peninsular India is a collage of Archaean cratonic domains separated by Proterozoic mobile belts. A number of cratonic basins, known as “Purana basins” in the Indian literature, formed in different parts of the Indian Peninsula during extensional tectonic events, from Paleoproterozoic through Neoproterozoic times. In this contribution, we present a diversity of new geochronological data for different units within the Kaladgi and the Bhima basins, which overlie the western and eastern Dharwar cratons, respectively. The new geochronology data are discussed in terms of depositional history and provenance of these poorly understood Proterozoic intracratonic basins. For the Kaladgi Group, a U–Pb baddeleyite age of 1,861 ± 4 Ma obtained for a dolerite dyke intruding the Yendigere Formation is used to constrain the minimum age of deposition of the lower Kaladgi Group. This result demonstrates that this part of the succession is comparable in age to the Papaghni Group of the Cuddapah Basin, heralding onset of Purana sedimentation at ~1,900 Ma. The detrital zircon populations from the clastic rocks of the Kaladgi and Bhima basins show unique and distinct age patterns indicating different source of sediments for these two basins. Palaeocurrent analysis indicates a change in provenance from south or southeast to west or northwest between the Kaladgi and Bhima clastic sedimentation. New U–Th–Pb and Rb–Sr radiometric dates of limestones and glauconite‐bearing sandstones of the Bhima Group (Bhima Basin) and the Badami Group (Kaladgi Basin) indicate deposition at around 800–900 Ma, suggesting contemporaneity for the two successions. Thus, the unconformity between the Kaladgi Group and the overlying Badami Group represents a time gap of up to 1,000 Myr. These new results demonstrate the complex multistage burial and unroofing history of the Archaean Dharwar Craton throughout the Proterozoic, with important implications for exploration of metal deposits and diamonds in Peninsular India.

Chapter 19 Geological history of the Kaladgi–Badami and Bhima basins, south India: sedimentation in a Proterozoic intracratonic setup

Abstract The Proterozoic Kaladgi–Badami and Bhima basins are intracratonic basins occurring over the Archaean Dharwar craton. The Kaladgi–Badami Basin contains arenites, shales and carbonates with minor cherts and conglomerates deposited in continental, transitional and shallow-marine environments presumably during the late Palaeoproterozoic/Mesoproterozoic to Neoproterozoic. The lower part of the succession (Bagalkot Group) is deformed into east–west-trending elongated doubly plunging synclines and anticlines. The upper part of the succession (Badami Group) is undeformed and unconformably overlies the lower part. The evolution of the Kaladgi–Badami Basin was controlled by movements along east–west-trending normal faults under an extensional stress regime. The Bhima Basin hosts mainly limestones with subordinate arenites and shales deposited in fluvial, deltaic and tidal flat environments possibly during the Neoproterozoic. These sediments are undeformed except along faults with significant strike-slip components. The basin is exposed in narrow strips arranged in an en echelon pattern and appears to be a pull-apart basin. Inadequate data exist on the age of the basin fills, the deep basinal architecture, subsidence history and tectonic controls for both of the basins. Future research may be directed towards these aspects which will have wide implications for understanding intracratonic basin formation, reconstructing Proterozoic supercontinents and studying the evolution of the atmosphere and primitive life forms.

Felsic Volcanic Rocks, a Potential Source of Uranium - An Indian Overview

Abstract Felsic volcanics constitute a primary source of uranium for forming an economic deposit. All over the world, volcanic rocks have not received due attention they deserve in uranium exploration. The volcanogenic deposits have been grouped with “other deposits”, as they constitute a meager In India the uranium exploration activities in the early 50 s till the 90 s were mainly confined to the Singhbhum Shear Zones, the Himalayas,Meghalaya plateau, parts of Central India and the geological environs of the Dharwar Craton. The granitic rocks, especially the peraluminous biotite – granite was always considered as a potential source for uranium and the geological environs closer to these granites always remained the first order targets. A number of small to medium size uranium deposits have been identified in Singhbhum Shear Zone, parts of Cuddappah, Bhima Basins and in Meghalaya. Now since the significance of the volcanic rocks, especially the felsic volcanics as a potential source of uranium has been clearly understood, it is imperative to reorient our exploration strategy to tap the potential of these volcanic rocks. The Malani Magmatic Province (MMP) in the northwestern part is the largest suite of an -orogenic acid volcanics in India occupying an area of 50000 sqkm. The Proterozoic Basins of India are replete with volcanic activity, mainly acid volcanism. In the southern and Central India, Dharwar and parts of Central Indian Craton also witnessed significant acidic igneous activities. The Cuddapah and the Vindhyan Basins have also recorded extensive acidic volcanic activity in the Papaghni, Chitrvati, Nallamalai Groups and Semri and Kaimur Groups respectively. In view of this the Proterozoic Basins mentioned above and the geological environs adjacent to the MMP deserve a re -look to have a proper assessment of their uranium potential, using integrated exploration inputs.

Assessing Genetic Differentiation in Geographic Populations of Labeo calbasu Using Allozyme Markers

The population structure of Labeo calbasu from 11 rivers belonging to the Indus, Ganges, Bhima, Mahanadi, and Godavari basins was investigated using allozyme marker systems. Seven out of 20 allozyme loci (35%) were polymorphic (P < 0.99). Both probability and score tests indicated significant deviation of genotype proportions from Hardy-Weinberg expectations at two loci, XDH* (Mahanadi, Bhima, and Godavari) and G6PDH* (Mahanadi). A pairwise genetic homogeneity test and F (ST) values indicated a low-to-moderate level (0.0515) of genetic structuring in the wild population of L. calbasu. AMOVA analysis also indicated moderate differentiation among the samples from different river basins. Analysis for genetic bottleneck was performed under the infinite allele model. The study revealed nine genetic stocks of L. calbasu from the natural population across Indian rivers. Evidence of genetic bottlenecks in some rivers was also revealed.

Late quaternary palaeoclimates of western India : A geoarchaeological approach

Western India comprises parts of the states of Rajasthan, Gujarat and Maharashtra. This region has varied climate and landscape. Northwestern Rajasthan is an area of internal drainage, with dunes, playas and rocky pediments. The Luni, Sabarmati and Mahi basins to the south of this zone show the influence of both aeolian and fluvial processes. Aeolian landforms are absent in the Nrmada, Tapi, Godavari and Bhima basins and fluvial aggradation has alternated with erosion in response to climatic change. Dominance of semi-arid to arid climate throughtout the Quaternary in the entire region has ment that Quaternary geological processes have been weak, preserving many features of the Tertiary in the present landscape. The variation in the geomorphic processes shaping the landscape and the complex links between geomorphic proceses and climate mean that our understanding of palaeoclimates in western India in far from complete. This paper gives an overview of the Late Quaternary palaeoclimate of western India, based primarily on recent work by the authors in Rajasthan and Maharashtra. Some issues in the palaeoclimatic interpretation of the geological record are discussed. Signatures of Late Pleistocene aridity, fluctuating climate during the Pleistocene Holocene transitional period, early Holocene humid climate and increased aridity from the middle Holocene onwards are reflected in different ways in the different landscape settings.

Craft specialization and social organization in the Chalcolithic Deccan, India

The Deccan Chalcolithic and its sitesSystematic archaeological research began in the Deccan after 1950 when a Chalcolithic settlement was discovered at Jorwe near Sangamner in Ahmednagar district, Maharashtra state. The Deccan, which includes the present states of Maharashtra, (except for the western coast and some parts of Vidarbha in the east) and northern Karnataka, falls in a semi-arid zone with a precipitation ranging between 400 and 900 mm. There are three major river valleys in the Deccan, the Tapi in the north, the Godavari in the centre and the Bhima in the south. Microecological variations in each valley have considerably affected the settlement patterns of the early farmers. Altogether 150 Chalcolithic settlements have so far been discovered in this part of India. The Tapi valley in the north, considered to be one of the most fertile tracts in the country and well watered by the Tapi and several of its perennial tributaries, was extensively occupied, for over 100 Chalcolithic settlements have so far been discovered there (Shinde in press). It was also observed that there was a general tendency to locate a settlement away from the main river because of the danger posed by the severe monsoon floodings. Most of the settlements were located along the banks of its tributaries, which are safe. In the Godavari and Bhima basins, on the other hand, because of the inadequate perennial water supply and limited availability of fertile soil, there were sporadic settlements (Shinde 1989) (FIGURE1 ). On the basis of environmental studies, surface finds, site location, the extent and thickness of habitation deposits, the Chalcolithic sites in the Deccan have been divided into different categories such as a regional centre, a farming village, a farmstead, a herding unit, and a camp to exploit localized resources (Shinde in press).

Purana basins of peninsular India: a review

AbstractSeven supracratonic, Proterozoic basins, occupying more than a fifth of the Precambrian exposures in the Indian Peninsula, comprise the Purana basins. A comprehensive review of the current status of knowledge of these voluminous orthoquartzite‐carbonate‐shale suites in the context of their contemporary lithostratigraphy, depositional environments and structural disposition is presented. Stromatolite biostratigraphy and available geochronological data are compared, to discern their age limits.These basins contain perhaps one of the most elaborate records of Middle to Late Proterozoic (Riphean‐Vendian) sedimentation preserved in an unmetamorphosed and only slightly deformed state. Further sedimentological and structural studies could lead to a better understanding of the Proterozoic craton‐margin processes. Their close association with the Middle Proterozoic Mobile Belt of peninsular India is that of two contrasting tectonic regimes, contemporaneously adjoining each other. The existing lithostratigraphic classifications of many of these sequences may not stand the test of process ‐ response considerations as demonstrated by the recent revisions in the stratigraphy of the Cuddapah and Bhima basins. The prolific stromatolitic, micro‐organic and trace‐fossil communities preserved in them require much more detailed, but cautious study, and may yield information on the Riphean‐Vendian biota. However, these studies must be undertaken in association with elaborate geochronological determinations which are sparse at present.Inadequacy of the existing knowledge of these basins is highlighted, with the view of inviting the attention of the geological community to these unique basins from peninsular India.