New insight on the geology of the Kuwait Group- Jal Al-Zoor Escarpment- Sabah Al Ahmad Natural Reserve, Kuwait Alham Al-langawi PAAET- Science Department College of Basic Education- Kuwait

This Research was based on  Fieldwork investigations and sampling  Petrographic study by polarizing microscope and SEM  Cathodoluminecence  XRF  Icpms  Probe analysis  Carbone and oxygen isotope analysis

Geology Of Kuwait For Jal Azoor Escarpment based on Previous Studies DescriptionFormationGroupAge Include marine beach deposits, sabkha and mud flats sediments, alluvial and fluvial sediments Holocene Conglomerates, gypsum cements Dibdibba Kuwait Group Pleistocene Calcareous fine sandstones, Coarse sandstones, marly limestones, red and green mudstones, sandy Limestones (30-35 m) Lower Fars Lower-Middle Miocene Coarse Quartz Arenites, sandy limestones, marls and green Mudstones (only 20 m exposed) Ghar Lower Miocene- Oligocene Dolomitized limestones with Chirt DammamAlhassaEocene Disconformity Upper Miocene & Pliocene 8.6 Ma ? Fluvial Marine

Field Observations

Disconformity between first (Dibdibba Fm.) and second (lower Fars Fm.) Sharp Contact Undulating Contact

Burrows and Plant Roots Plant roots Burrows

Cross-Bedding Graded-Bedding Change in current Velosity Ripple Marks- Depositional

Nodules Paleosoil leaching Exposure surface marked by conglomerates

Exfoliation- Weathering Geodes- diagenetic Joints  Frost Wedging Weathering Gypsum Cement

Mega Fossils Coiled Gastropods Oysters Gastropod Bivalves

Marker Beds Marker Bed (1) Disconformity Marker Bed (1) Marker Bed (2) Marker Bed (1)

Fossils Burrows Exfoliation Geodes Pebbly Sandstone Cross-Bedding Cross-Bedded Limestone Fractures Gypsum cement R1 R2 R3 R4 R5 R6 R8 R9 R10 R7 R11 R12 R13 R14 R15 R16 R18 R19 R17 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29 R30 R31 R32 R33 R34 R35 R36 R39 R40 R38 R37 R65 R66 R67 R68 R69 R54 R53 R55 R56 R58 R59 R64 South West North East North West R57

Southwest Northeast Reservation Gate Northwest Sabah Al-Ahmad natural reserve northwest of Kuwait bay (330 km 2 )

Petrography

Rock Types  Pebbly Sandstones  Fine Sandstones  Paleo-soils  Fossiliferous sandy Grainstones  Fossiliferous oolitic-sandy Grainstones  fossiliferous oolitic-sandy Packstones  Fossiliferous Mudstones  Peloidal sandy Packstones

Rock Types Fossiliferous Sandstone 2X Packstone 4X Packstone 2XPeloidal limestone 2X

Fine Sandstones with Poikilotopic Cement 4X 2X

Rock Types Carbonate Fossiliferous Mudstone 4X Oolitic-peloidal Grainstone 2X Oolitic Grainstone Sandstone (paleo-soil)

Fossils  Mollusks (Bivalves and Gastropods), some are oysters  Coral fragments  Coralline algae  Foraminifera   Echinoderm Plates   Bone fragments

Fossils Bivalves 2X Corals 2X Coralline algae 4X Foraminifera 4X

Fossils Foraminifera 2X Echinoderm Plate with syntaxial cement 4X Corals 4X 4X

Fossils Foraminifera

Cements Isopachous and Spary calcite 4X Poikilotopic Calcite

Cements 2X Poikilotopic Poikilotopic Gypsum Spary and microcrystalline calcite

Matrix Carbonate Matrix Clay Matrix

Matrix

Geochemistry

Southwestern location Southwestern location ppm

First location toward the East ppm

Second location toward the East ppm

Eastern Location ppm

Elements Concentration Maps -sandy limestone Elements Concentration Maps Fossiliferous -sandy limestone AlMn MgSi Ca

Elements Concentration Maps fine sandstone with Poikilotopic cement AlMn SiMg Ca

Elements Concentration Maps for Peloidal-oolitic sandy- grainstone Al Mn SiMgCa

Elements Concentration Maps-clay Matrix Al Mn Si MgCa

Cathodoluminesence  First diagenetic calcite is with brownish-red luminescence  Second diagenetic calcite is zoned isopachous and spary crystals with yellow, orange, and non - luminescent zones  Third diagenetic calcite is zoned spary crystals with pale blue and non -luminescent zones  Forth diagenetic calcite show yellow-orange luminescence

First and second diagenetic calcite in limestones 4X 10X

Second diagenetic spary calcite crystals 10X In Limestones In Sandstones

Third diagenetic calcite is zoned spary crystals with pale blue and non -luminescent zones 10X 3rd

Forth diagenetic calcite (found in Paleo-soils) 4X

Collecting special parts for Isotope Analysis Oysters

Carbon 13 and Oxygen 18 Distribution for Kuwait Group Normal Marine Isotopic Values ? High Temperature Fresh water

Carbon 13 and Oxygen 18 Distribution for Kuwait Group With depth

Variation in Carbon 13 and Oxygen 18 concentrations within Marker Bed 1 (Grainstones and Packstones) from West to East Southwest and northwest directions (more depletion)

Conclusions

 Fieldwork and petrographic data support the idea of several Depositional environments for the Kuwait Group, which are: 1. Mixed clastic-carbonate shelf 2.High energy beaches 3.Fluvial-marine, which may be delta complex 4.Terrestrial environments- soil horizons

 Fieldwork and petrographic data support the idea of several unconformity surfaces within the Miocene-Oligocene Kuwait Group which were identified by: 1. Karst surfaces 2. Ripple marks 3. Nodules baring levels 4. Paleo-soils 5. Calcified plants roots 6. Reworked (conglomeratic surface)

Ghar Fm. Paleo-soil Roots Dibdibba Fm (Pleistocene) Lower Fars Fm. Ghar Fm.

 Carbone 13 and Oxygen 18 isotopes indicate digenesis under high temperature fresh water for all the formations which was supported by: 1. Depleted Carbone 13 values (-3.70 to -6.59) 2. Depleted Oxygen 18 values (-6.69 to ) 3. Calcified plants roots  (plant decay  organic carbon) 4. Paleo-soils 5. Karsts surfaces

Thank you for sharing this time with me Photo by Alham Al-langawi