My presentation about the geology of Saudi Arabia According to Lithology and Stratigraphic sequence through geologic time .

1. GEOLOGY
OF
SAUDI ARABIA

2. INRTODUCTION :
•The geology of the
•kingdom of Saudi Arabia
•divided in two major geologic
features :
•The Arabian shield .
•The Arabian shelf .

3. ARABIAN SHIELD :
•The Arabian shield rocks are mostly volcanic and
metamorphic rocks .
•- the Arabian shield importance :
•Represents of its being the number one destination
for mineral explorations .
- Volcanic environments (Arabian shield) are always
considered the place for mineralization processes
and mineral deposits .

4. ARABIAN SHELF :
•The Arabian shelf are mostly sedimentary
rocks that indicate many different
environments .
The Arabian shelf importance :
-concerned with the hydrocarbon
accumulations.
- Ground water aquifers.

5. Tectonism plays a very important role of forming both
The arabian shield
And
The arabian shelf
Through geologic time .

6. PROTEROZOIC:
- Formation of the Arabian –Nubian Shield .
- Hijaz tectonic movements :
- Stabilization of the shield .
- Accretion of island arches ,micro continents and terranes .
- Extensional trends and syn-rift depositions .
- compressional N-S faults.
- Shear N-W faults.
- Shear N-E faults.

7. PROTEROZOIC:
•- pacific type collision leading edge the Arabian plate .
-- Convergence activities between N/E Africa and W Arabian plate .
-Neo-Proterozoic:
-Gaskers , Marinoan and Sturtian glaciations.

8. INFRACAMBRIAN
•- development of Hormuz salt baisn .
:- Najd – fault system
-- Separated basins filled with : clastic , carbonates , evaporites ,volcanic rocks.
-- Deposition of Jabalah group .

9. INFRACAMBRIAN:
Najd tectonic movements :
-- Onset tilting.
-- Regional S/E shear faults .
-- Development of pull-a- part basins N/W .
- Unmetamorphosed deformations with period of erosion .

10. INFRACAMBRIAN:
Assyntic time-equivelant movements :
-- Regional uplift .
- Strong folding and faulting N/S .

11. CAMBRIAN :
- Regional strong folding , deformation ,erosion and tilting .
- Peneplanation of the Arabian shield and the overlying sediments .
- Subsidence and deposition of Ash-Shiq formation .
- First marine invasion :
- Deposition of the first carbonate rocks north of Saudi Arabia subsurface :
- Farwan formation .

12. CAMBRIAN :
-- Continental and shallow marine deposition of : Al-ula and Saq (risha member)
formations.
- regional subsidence of the continental Gondwana including the Arabian plate :
-- Gondwana continent assembled and Panthalassa ocean established .
-- stable Gondwana shelf margin post-rift .
--Late –syn rift continental and marine depositions .

13. ORDOVICIAN
-Plate divergence :
- Regional extensional stress.
-- Continental spreading and faulting .
- regional marine invasion :
- Deposition of regional shale beds ( Hanader formation ) .

14. ORDOVICIAN:
-Cyclic transgression and regression :
-- deposition of continental , deltaic ,shallow
marine sandstone and shale :
Ra’an ,Khafah and Quwarah members .

15. ORDOVICIAN:
-Late Ordovician Taconic time equivalent :
--Regional sea level drop .
- development of paleo valleys .
-- Uplift , tilt and deep erosion .
-- Deposition of :
Qassim and Saq formations.
- Sepreation of Gondwana and Avalonia .

16. ORDOVICIAN:
-- Late Ordovician glaciations :
--Deposition of Sanamah formation S/W the Arabian plate .
--Short lived transgression in central Arabia : deposition of Hawban formation.
--Polar glaciation in west Arabia .
-deposition of : Saqiyah and Sarah formations in central and N/W Arabia .

17. SILURIAN :
-deglaciation:
-wide spread (Tethys) marine invasion.
-deposition of Baq’a sandstones .
- Deposition of regional organic shale Qusayba.
--Deposition of deltaic sandstone :
-( Sharawra formation )

18. SILURIAN :
-- Acadian time-equivalent movement:
- uplift (structural growth )
--Tilting N/W and S/E .
-- Folding E/W.
-Erosion of Sharawra , Qusayba , Baq’a , Hawban , Sarah and Saqiyah formations
eastward .
-continental sandstones :
Deposition of coarse grained sandstone ( Tawil formation ) .

19. DEVONIAN :
- Subsidence of N/W Arabian plate :
-deposition of carbonate and shale units:
( Jawf formation members ):
Shua’ibah , Qasr , Sabbat , Hamamiyat and Murayr members .
- Limited short lived transgressions and regressions in N/W Saudi Arabia .

20. DEVONIAN
-magma intrusions :
Dykes intruded the Jawf formation in Domat al-Jandal ( Jawf
region ).

21. DEVONIAN :
--Early Hercynian time-equivalent movements :
--Collision between Gondwana and Laurussia .
- short periods of non deposition and / or erosion .
--Deposition of continental shallow marine siliciclastics:
Jawbah and Aba ar-Ruwath formations.
- Deposition of Jawf sandstone (Murayr member ) which considered as a reservoir
rocks in the subsurface of the eastern province .

22. CARBONIFEROUS :
-- Structure growth :
-- development of infracambrian Hormuz salt domes.
-- rejuvenation of basement faults .
-- E-W arching :
-Central Arabia , Qatar and Hadramaut arches.

23. CARBONIFEROUS:
-maximum hercynian time-equivalent movement :
-Collision between Gondwana and Euramerica .
--Plate convergence between Europe and Africa ( Appalachian collision ).
- Regional uplift , tilt and erosion of carboniferous and Cambrian deposits .

24. CARBONIFEROUS
-Regional uplift , tilt and erosion of deposits from
Precambrian to carboniferous .
--Continental siliciclastic north of the central arabian arch :
Shjara formation .
- Deposition S/E Arabia of subsurface Juawyl formation .

25. CARBONIFEROUS
•Perom-Carboniferous glaciation :
Glaciation south of the central Arabian arch .

26. PERMIAN :
Drop o the sea level :
- Subsidence and onset of the neo-Tethys .
- Regional deposition of continental , shallow
marine, siliciclastic carbonates and evaporites :
(Safra member ) Unayzah formation.
_________________________
-divergence between the Arabian plate and the
Iranian plate .

27. PERMIAN
Deglaciation – major regional marine invasion :
-(Neo-Tethys ) in the arabian plate :
Deposition of carbonates shale and evaporites (Khuff formation) .
_________________________
Neo-Tethys :
-Opining of the neo-Tethys ocean .
- Subsidence of the north and east Arabian plate .

28. TRIASSIC :
-Restricted shallow marine :
- Deposition of continental regressive clastic beds (Sudayer formation).
-- Deposition of carbonates , evaporites and siliciclastic rocks (Jilah formation).
- Regional extension and continental spreading and faulting .
- Movement of the Arabian plate into equatorial latitude .

29. TRIASSIC :
Plates collision :
- Uplift , tilt and structure growth :
- Deposition of (Manjur formation) sandstone – ground water aquifer .
______________
Early Kimmerian time-equivalent movements:
- The end of Triassic time.
- Closing of the Hercynian ocean .
- Leading edge : plate convergence :
- Collision between the Arabian plate and the Eurasian plate .

30. JURASSIC :
-Onset of marine invasion :
-- Deposition of carbonates and shales :
-(Marat and Duruma formations )
-outline of the Tethys basin .
-- Rift between east and west Gondwana .
-- onset of break up of super-plate Pangea.
-- arching and faulting along Zagros suture .

31. JURASSIC
•- expansion of Neo-Tethys (Alpine ocean )
•- opening of Neo-Tethys along Zagros suture .
-Deposition of thick carbonates :
-(Tuwayq , Hanifah and Jubaylah formations) .
-widespread marine invasion and deposition of carbonate and shale.
-plate subsidence and tilt northward .

32. JURASSIC :
-- Intial faulting in the Arabian plate related to the collapse of Gulf of Aden .
- uplift in the S/W of the Arabian plate resulting : Yemen rifts , Indian ocean
rifting and intrashelf basins.
-- Cyclic deposition of carbonate and Anhydrite (Arab and Heet formations ) .
- Alternating shallow platform .
- The Jurassic maximum evaporate phase of Gotnia basin .

33. CRETACEOUS
End of evaporates phase :
- Central Arabia paleo-high .
- Erosion and / or non deposition periods .
- Deposition of Thamamah group :
( Sulay , Yamamah and Buwayb) formations.

34. CRETACEOUS
Opening of the Mediterranean sea :
-- Movements of Hormuz salt in the Zagros belt .
- Closing of the Alpine ocean (Neo-Tethys) .
-- Development of sub-basins in the Arabian plate.

35. CRETACEOUS
•- uplift of western Arabian plate (shield area)
•- depositions of Bayad group :
(Zubair , shuaybah ,khafji and Saffaniyah formations )
And Wasi’ group :
( Maudwd , Warah , Ahmadi , Rumaylah and Mushrif formations)
Subsurface formations

36. CRETACEOUS
•- accelerated structural growth : series of N-S linear uplifs
- Infracambrian salt movements .
Leading edge : Oman >< Zagros.
Closure of Neo-Tethys .
-Collision : Arabian plate ><Eurasian plate .
--Uplift .
-- late cretaceous pre-rift growth (red sea)

37. TERTIARY :
•A - Paleogene:
•- local slumps and collapses .
•-widespread eveporites phase (Umm er Rus)
•-a marine invasion and deposition of carbonates and
shale Dammam Formation.
•-end of middle Eocene structural development with the rising
of the Arabian plate .
•- Red sea rifting

38. TERTIARY
•B-Neogene:
•Meocene :
•- After the pyrenean activities depositional of Hayrduk formation calcareous sand stone .
•-final phase of the red sea rifting .
•- deposition that indicates transitional environment : (deposition of marl , shale and
calcareous sandstone ) .
•Lidam , Hafuf ,
Medyan BASINArabian Shelf

39. TERTIARY:
•- the Arabian plate had a marine flooding after that depositing carbonates , marl and
shale that indicate (transitional environment ) .
•- Suez Gulf subsidence continued .
•- deformations : uplifting , thrusting 'folding and tilting .

40. TERTIARY
•Pliocene :
•-Formation of Zagros and Taurus belts , before that the main Zagros basin
hydrocarbons had axis to migrate to the Arabian gulf position .
•- alpine tectonic activities :
•Collision between the Arabian and the Turkish plates causing some volcanic eruptions
.

41. QUARERNATY:
•- Harrat formations
•-forming of springs karsts and subsurface cavities
•- deposition of umm shi’al and Ruf'a formations .
•- short lived glaciation represented in Midyan formation