Geology of the area around Jhalawar
The western part of India displays well developed geosynclinal and intracratonic proterozoic basins, among which the Vindhyan Basin, which concentrically envelopes the Bundelkhand massif follows the pattern of intra cratonic rhythm of sedimentation and deformation. The Basin holds a repetitive sequence of shales, limestones and sandstones, having a cumulative thickness of 2900 m. This sedimentary pile exhibits negligible deformation in the axial portion and intense deformation in the form of regional anticlines and synclines all along the basin margins with their axial traces trending parallel to the basin margins in the Vindhyans of Rajasthan, which forms the Western part of the Vidhyan basin of Central India.
Jhalawar district is an expanse of fertile, undulating plains having rich black-cotton soil. Geologically, the district is occupied by the Vindhyan Supergroup, represented by the Semri, Kaimur, Rewa and Bhander Groups which consist of sandstones, shales and limestones. The Deccan traps, which lie unconformably over the Vindhyans, cover almost 70% area in the southern part of the district. The Vidhyan sandstone and shales form linear hills trending NW-SE. They are exposed around Jhalawar town and to its northeast and northwest. The Jhalawar area forms the south western peripheral part of the Vindhyans of Rajasthan. In this area, an interlayered sequence of shales, limestones and sandstones of the Lower and Upper Vindhyans forms a major anticlinal structure (see the geological map) with its axial trace trending in NW-SE direction. Erosion of the crestal part of the anticline has given rise to the older formations being exposed in the central part of the Jhalawar Anticline, with successively younger horizons occurring on either sides of the anticlinal axis. The features observed in the anticline include a parallel geometry of the fold, uniform orthogonal thickness, absence of axial plane cleavage, development of coaxial folds on bedding surfaces, rounded hinges of the fold and wider spacing between the glide surfaces. All these features suggest that the regional structure followed the pattern of flexural slip fold mechanism operating in a strongly isotropic medium.
The topography of the Vindhyan and Deccan Trap terrain around Jhalawar is in general mature, in parts undulating to rugged, consisting of linear ridges and valleys, plateaus, arcuate to rounded and conical hills, and broad rolling plains. Landforms are mainly controlled by lithology and structure. Satellite imagery of the area shows the presence of three major geomorphic units with their characteristic features recognizable on the scale of the imagery. Three board geomorphic units can be delineated by image interpretation technique. These units with their characteristic details are given below. (Rakshit, 1983)
1. Structural Hills: Linear ridges parallel to the regional strike of rock formations with alternating ridges of sandstones and intervening valleys of shale and limestones. These are carved by a parallel and rectangular drainage pattern. Low mounds, hummocks and arcuate hills of folded sandstone beds are characteristic. Occasionally, plateaus of horizontally disposed sandstones with cuesta, mesa and butte forms can be seen.
2. Denudational Hills: Comprising plateaus, benches and steps of horizontal Deccan Trap flows characterized by escarpments and dendritic drainage. Conical and rounded hills of vesicular lavas with contour like forms and sometimes flat tops occur in the southwestern part of the area.
3. Low-lying Surfaces: Undulatory plains with shallow depressions on sedimentary rocks with gently rolling topography, moderate to high dissection, dendritic drainage and extensive cultivation with sporadic rock exposures. Such plains are quite common over the Deccan Traps with more or less dendritic drainage and cultivated dark soil. Fluvial depositional surfaces comprise flood plains of rivers, slope wash deposits, sand bars and channel-fill deposits, containing gravel, sand, silt and clay materials.
Jhalawar is watered by several rivers, making it a forested tract at the southern extremity of the desert state of Rajasthan. Rivers and streams draining the Jhalawar district belong to the Chambal system. The general ﬂow is from south to north. The rivers of Jhalawar may be divided into two groups: the western group and eastern group. The western rivers are Ahu, Piplaj, Kyasri, Kantli, Rawa, Kali Sindh and Chandrabhaga. The eastern rivers are Parwan, Andheri, Newaj, Ghar and Ujar. There are artiﬁcial lakes Kadila and Mansarovar. Generally speaking, rivers have deep beds, with the result that the water level in channels is below that of the surrounding areas. Drainage density in most part of the district varies from 0.5 to 0.7 km/km2. Drainage density is from 0.7 to more than l km/km2 in the southeastern and southwestern parts of the district. In the north central part of the district, it is low and ranges between 0.3 to 0.5 km/km2. The largest river flowing through Jhalawar town is Kali Sindh which flows northwards through the town to join the Chambal – the largest river in Rajasthan. Just north of Jhalawar town, the Kali Sindh is joined by the Ahu River which drains the western part of the district.
Rakshit, A.M. 1983. Capability of photointerpretation methods for mapping Vindhyan and Deccan Trap terrain – a case study from Jhalawar area, Rajasthan. Photonirvachak, 11(2), pp 76-70.
This website is hosted by
Department of Geology
Aligarh Muslim University, Aligarh - 202 002 (India)