Basin Introduction :. Geographic Location of the basin Rajasthan Basin forms the eastern ank of Indus geosyncline and comprises the sedimentary tract to the west and northwest of Aravallis upto Indo-Pakistan border !his pericratonic basin also forms a part of the great !har "esert Category of the basin !he Rajasthan Rajasthan Basin Basin comes under the #ategory $ I basin %onland& %onland& with established established commercial production Area of the Basin !otal ! otal Basinal Basinal area' area' ()*+),,, . km km %/nland& ub-basin wise distribution' Barmer-sanchor' ((),,, s. km Bikaner-0agaur ' 1,),,, s. km 2aisalmer ' 34),,, s. km km Age of the Basin Age ranges from #ambrian !o Recent Barmer-sanchor' !ertiary !ertiary basin Bikaner-0agaur ' Paleo5oic basin 2aisalmer ' 6eso5oic 7 #eno5oic basin basin Sedimentary thickness Average thickness of sediments in Rajasthan basin is 8 4,,, m Top
Tectonic History :. Type of Basin 2aisalmer sub-basin - Peri Pericratonic cratonic Basin Basin Bikaner- 0agaur 7 Barmer-sanchor $ Intracratonic Basins !ectonic 9ones within !ectonic within the Basin Basin Rajasthan Basin has been divided into three ub-basins separated from each other by basement ridges:faults !hese ub-basins are' - 2aisalmer 2aisalmer ub-basin ub-basin which is further divided into ; depres depressions sions 8 hahgarh "epression 8
-Barmer-sanchor ub-basin Prominent tectonic elements in this subbasin are ' "evikot-0achna ?plift with @atehgarh @ault which marks the northern limit and an east-west trending !harad Ridge marks the southern limit while separating it from #ambay Basin Another cross trend along arnu ill @ault divides Barmer-anchor ub-basin into Barmer "epression in the north and anchor "epression "epress ion in the south !he Pokhran Pokhran igh separates separates the Bikaner Bikaner-0agaur -0agaur ub-basin ub-basin from from 2aisalmer ub-basin "evikot-0achna uplift separates 2aisalmer ub-basin from Barmer-anchor ub-basin !he tectonic evolution evolution of Rajasthan Rajasthan Basin Basin took place place in four distinct distinct phases corr corresponding esponding to
- Precambrian - !riassic plate movement - Breaking of Indian plate from southern continent during 2urassic - #ollision of Indian plate with the Asian plate from ocene onwards - ?plift of ind-Baluchistan fold belt resulting in Clling up of the Indus shelf a!or Lineaments !hree major trends along 8 0-D %Aravallis& direction 8 0-DD or D direction 8 0D- %"harwarian& direction !he 0-D trending lineament %Aravallis& being the oldest is oEset by late sublatitudinal lineaments Both 0-D and 0-DD or -D trends are aEected by younger 0D- "harwarian lineament) which resulted in the formation of Barmer-anchor ub-basin Top
Stratigraphy :. Fenerali5ed 7 subsurface stratigraphy of 2aisalmer sub-basin Fenerali5ed 7 subsurface stratigraphy of Bikaner $ 0agaur sub-basin Fenerali5ed 7 subsurface stratigraphy of Barmer - anchor sub-basin Interbasinal tratigraphic Relationship Sedimentation History !he Destern Rajasthan helf which forms an integral part of Indus Basin) originated during Pre-#ambrian period !he sediments range in age from Gate Protero5oic to Recent with intermittent transgressions and regressions 8 !he Crst cycle of sedimentation corresponding to Protero5oic-arly Palaeo5oic is designated as Birmania:Randha @ormation representing deeper water sediments 8 A prominent orogeny) probably resulting from the collision of older plates led to a major uplift and hiatus in this region /n the peneplained Birmania-Randha topography) the
@ormation in 2aisalmer ub-basin which continued during !uronian and ended in #oniacian times with the development of predominantly marine marls and carbonates with clastic interbeds 8 A major uplift of the aHial belt gave rise to a prominent hiatus ranging in age from 6aestrichitian to "anian and brought an end to this marine cycle "uring this interval there was a major volcanic eruption in anchor "epression) which obliterated the pre-eHisting topography !he volcanic activity was more intense south of anchor 8 !he neHt cycle of sedimentation began with the deposition of clastic se.uence of anu:Akli:Balutri @ormation representing brackish to shallow marine environment probably during early Paleocene and arly ocene 8 !he
&ormation Age
"epositiona# $n%ironment
humar
@luvial:lacustrine:eolian 6arine shelf environment ranging from inner to middle shelf regime
Bandah
Aptian
*,,
Pariwar
0eocomian
+1,
BaisakhiBhadasar 2aisalmer
?pper 2urassic 1;, to #retaceous 6id 2urassic ((;K
helf:shallow 0eretic sea #ontinental to marine:inner to middle shelf /pen marine environment ranging from middle to outer shelf regime /verall transgressive shallow marine with short regressive cycle 0earshore environment with occasional eEect of storm surges /verall regressive phase with intermittent marine incursion 0ear shore to shallow marine Gow energy environment over a
Gathi Bhuana Birmania Randha
Gower 2urassic Permo-!riassic Protero5oic to Gower cambrian Protero5oic to Gower cambrian
+,, 1,1 *,,, *,,
stable shelf with occasional intertidal eEects #ontinental $ @luvial:uvio-deltaic @luvial to shallow marine 6arine reducing environment with restricted circulation #ontinental to nearshore
Bikaner-0agaur sub-basin ' &ormatio Age n 6ar 2ogira 6arh Palana
uaternary
Sedimentary Thickness'a(.) 4, to 1,
Gower to middle +, ocene Paleocen to Gower *(, ocene Paleocene
(*, %M&
Badhaura Gower Permian ;4, PermoBap 4, to (+, #arboniferous Protero5oic to 0agaur (K, Gower #ambrian Protero5oic to Bilara ;, to (,,, Gower #ambrian Protero5oic to 2odhpur (,, to *,, Gower #ambrian
"epositiona# $n%ironment @luvial environment showing changes from arid to eolian condition hallow marine %inner to middle 0eretic& @luvial to shallow marine Reducing parallic:swampy environment hallow marine:intertidal @luvio-glacial condition hallow water high condition Restricted shallow condition
energy marine
hallow water uvial environment Top
*etro#eum System :. Source Source +aisa#mer Bikaner, -agaur Barmer, Sanchor
eser%oir eser%oir
Gower Foru) Pariwar) embar : Bedesir - Baisakhi hales )
+aisa#mer Bikaner, -agaur Barmer, Sanchor
#lastic' Baisakhi-Bedesir) Pariwar) Foru) anu and
Trap Trap +aisa#mer
Anticlinal closures) @ault related closure:traps) ?nconCrmity related traps vi5) Dedge outs) Githostratigraphic traps
Bikaner, -agaur
6oderate to high basement-controlled anticlinal structures and fault closures
Barmer, Sanchor
Roll over anticlines developed on the previously planer boundary faults and fault closures against the transverse faults
Top
*etro#rum *#ays :. 2aisalmer sub-basin 8 Paleocene eHtensional fault blocks with #retaceous age reservoirs 8 arly !ertiary stratigraphic subcrop closure of anu clastics beneath the shales of the lower
high Bikaner-0agaur subbasin 8 arly #ambrian !ranspressional fault-blocks 8 arly #ambrian !ranspressional reactivation combined with salt swells 8 ands developed at the toe-set end of =clinoform se.uence> 8 ands developing structure within prograding clinoform 8 !ertiary reactivated fault-blocks) eHtensional movement along eHisting faults 8 Gate !ertiary transpression of pre-eHisting faults , Cambrain p#ays Available evidence indicates that the #ambrian sediments have gererated both oil and gas /il is discovered in #ambrain dolomites in the well
