GARHWAR SOLUTION CHANNELS

Herbert Daniel Gebauer - 06/01/2018

What engineering geologists understand to represent wide solution channels (penetrable cave passages or impenetrable conduits) in locally 80 m thick Bhander Limestone of Upper Vindhyan age noticed KRUPANIDHI (1966) in search of economically exploitable flux-grade limestone resources in parts of Rewa and Satna districts. Compare the –>Naubasta Solution Channels. SITUATION: At unspecified locations somewhere in a certain Garhwar block north-east of the village of Garhwar, Garhawar (Janardanpur) or Garnawar (note 1) which lies at estimated linear distances of 15 km ENE from Satna (N24°35': E080°50'), 30 km WNW from Rewa (N24°32': E081°18') and 35 km due south of Chitrakoot (PWD Inspection Bungalow near N25°10'25-: E080°52'10- Everest 1830). KRUPANIDHI (1966: 343): The region examined is a gently undulating country with a few hillocks and high grounds … The limestone deposits investigated lie to the north of the Rewa-Satna highway [National Highways NH7 and NH75]. The nearest ailhead at Satna on the Katni-Allahabad section of Central Railway is about 23 to 50 km from the deposits. (note 2) KRUPANIDHI (1966 location map opp. page 344) shows Garhwar Block south-east of Tons River and north-west of the Dehi nala in the area between N24°36'30” to N24°37' and E081°05'00” to E081°06'30” (unspecified geodetic datum probably Everest 1830), north-east of the village of Garhawar (Janardanpur) and adjacent south-west of the village of Bela. CAVE DESCRIPTION: KRUPANIDHI (1966: 345): Joints are not common in the Bhander Limestone. The few available joints are either strike or dip joints and are always vertical. Wide solution channels are developed along a few of these joint planes in Naubasta and Garhwar blocks. GEOLOGY: KRUPANIDHI (1966: 344) gives a stratigraphic table listing (from top to bottom) 12m buff to gray shale and impura limestone 13-17m Upper Grey Limestone: Grey limestone with papery or thin, commonly irregular shaly laminae and a few beds of darkgrey limestone) 0-3m buff or grey shale and shaly limestone 1-2m grey limestone with many shaly laminae, small pockets of greenish grey limestone and tiny specks of pyrite 12m buff or grey shale and shaly limestone 3-6m purple to grey limestone with many shaly laminae and associated greenish grey shale 0-5m shaly or dolomitic limestone 8-11m Lower Grey Limestone: Dark grey to grey limestone 0.5-1.5 siliceous or cherty limestone 18-21m impure limestone and shale. KRUPANIDHI (1966: 345): The Bhander limestone has a thickness of about 80 m … The shale and shaly limestone occurring immediately below the Upper grey limestone locally disappears in a few localities with a corresponding increase in the thickness of the limestone underlying it. The shaly or dolomitic limestone overlying the Lower grey limestone band is seen only in Bela Block and in its neighbourhood. The Bhander limestone formation as a whole, however, shows a remarkable uniformity in the region in its thickness and in the pesistance of the marker horizons … The principal marker horizons are the purple to grey limestone characterised by conspicuous circular to semi-circular laminated structures and a siliceous or cherty limestone. […] The rocks of the Bhander Limestone, which occupy the largest portion of the region [note 3] are generally nearly horizontal with gentle rolls. They have an ENE-WSW strike with a low southerly dip rarely exceeding 5°. However, in the westernmost portion, the general strike of the formation trends NNW-SSE with a low dip towards WSW. The area between Baijnath and Dadar (N24°38': E081°12') [note 4] and west of Sejahata [N24°34': E081°02'] show gentle folding. The most prominent among these folds is an anticline with a low plunge towards WSW in Bela block [24°30'05- to 24°32' and E081°09'30” to 81°12']. Small outliers of buff to grey shaly limestone overlying the Upper grey limestone are present in Bela Garhwar and Sejahata blocks. An outlier of shale exists on th hillock 1088 Dadar []. hillock 1088 Dadar [].