Home Multi-Country Search About Admin Login
Cenozoic
Mesozoic
Paleozoic
Neoproterozoic
Mesoproterozoic
Paleoproterozoic

Search by
Select Region(s) to search
Hold Ctrl (Windows/Linux) or Command (Mac) to select multiple
Janauri Gr
Click to display on map of the Ancient World at:
Janauri Gr base reconstruction

Janauri Gr

Period: 
Tonian

Age Interval: 
early Neoproterozoic


Province: 
N.India Punjab Basin

Type Locality and Naming

The name is proposed after Janauri, a village in the state of Punjab,. This group is encountered in two wells in the subsurface in Janauri -2 and Adampur-1. Drilling was not continued in other areas up to this group. Holo: Janauri-2 Latitude: 31o 38' 39" N, Longitude: 75o 58' 47" E , Drilled depth: 5027 m. The top of the group is at 4790 m. The base of the group was not penetrated in the subsurface.


Lithology and Thickness

Metamorphics. Diverse composition . In Janauri-2 it is composed of light grey to grey, crystalline, moderately hard to hard dolomitic marble. Texture is granuloblastic. Grains do not show sutured contacts. Veinlets and specks of pyrites are disseminated throughout the rock mass. In the upper part it is composed of phyllite and metaquartzite. In Adampur -1 the drilled section consists of dirty white and smoky quartzite and chloritic mica schist. Thickness: Only 237 m was drill in Janauri-2 and 25 m in Adampur-1


Lithology Pattern: 
Gneiss


Relationships and Distribution

Lower contact

This group is unconformably underlain by granitic basement

Upper contact

In the type section, this group is unconformably overlain by Lower Dharmsala Fm. The upper contact is taken at the beginning of metamorphosed rocks; therefore, this contact can be picked up easily on logs characterized by increase in resistivity and density. In the Mohand deep hole, the Mohand Fm (also Tonian) dolomitic limestone is unconformably overlying.

Regional extent


GeoJSON

{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[75.8,32.43],[74.92,32.02],[74.53,31.72],[74.61,31.39],[74.57,31.09],[73.91,30.41],[73.87,30.03],[74.75,29.95],[75.23,29.57],[75.45,29.76],[75.89,29.72],[76.5,30.06],[76.94,30.48],[76.59,31.31],[76.15,31.39],[75.89,31.95],[75.49,32.17],[75.8,32.43]]]]}}

Fossils

The palynofloral assemblage is characterized by the presence of Ellipsaletes sp., Trachysphaeridium sp., and Protoleispaeridium sp.,


Age 

Based on palynofloral assemblage a Late Riphean age is assigned to this group. "Late Riphean" = Tonian period in international usage.

Age Span: 

    Beginning stage: 
Tonian

    Fraction up in beginning stage: 
0.0

    Beginning date (Ma): 
1,000.00

    Ending stage: 
Tonian

    Fraction up in the ending stage: 
0.5

    Ending date (Ma):  
860.00

Depositional setting

This group represents the first stage of craton extension in northern India in that sediments shed off the BundelKhand areas were accumulating probably as passive margin units in the areas later to become the Himalaya.


Depositional pattern:  


Additional Information


Compiler:  

Modified from Ravi Misra (Ganga, Punjab and Purnea basins; Chap. 6; ONGC Bull 44, 2009)