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 Group Formation Pleistocene Dibdibba Kuwait Group Lower MioceneOligocene Eocene Alhassa Fluvial Include marine beach deposits, sabkha and mud flats sediments, alluvial and fluvial sediments Disconformity Holocene Lower-Middle Miocene Description Conglomerates, gypsum cements Upper Miocene & Pliocene 8.6 Ma ? Disconformity Lower Fars Calcareous fine sandstones, Coarse sandstones, marly limestones, red and green mudstones, sandy Limestones (30-35 m) Ghar Coarse Quartz Arenites, sandy limestones, marls and green Mudstones (only 20 m exposed)Disconformity Dammam Marine Age Dolomitized limestones with Chirt Field Observations Disconformity between first (Dibdibba Fm.) and second (lower Fars Fm.) Sharp Contact Undulating Contact Burrows and Plant Roots Plant roots Burrows Plant roots Burrows Burrows Cross-Bedding Graded-Bedding Change in current Velosity Ripple Marks- Depositional Paleosoil leaching Nodules Exposure surface marked by conglomerates Nodules Exfoliation- Weathering Gypsum Cement Joints Frost Wedging Weathering Geodes- diagenetic Mega Fossils Coiled Gastropods Oysters Coiled Gastropods Bivalves Gastropod Marker Beds Marker Bed (1) Disconformity Marker Bed (1) Marker Bed (1) Marker Bed (1) Marker Bed (2) R11 R1 R20 R2 R12 R13 R3 R21 R14 North West R4 R32 R5 R33 R22 R15 R34 R6 R16 R65 R17 R7 R8 R23 R9 R36 R10 R38 R66 R69 R24 R58 R39 R67 R68 North East R35 R18 R19 South West Fossils R37 Burrows R40 Exfoliation Geodes Pebbly Sandstone Cross-Bedding Cross-Bedded Limestone Fractures Gypsum cement R59 R54 R25 R53 R26 R27 R55 R28 R56 R29 R30 R31 R64 R57 29.43 29.42 29.41 29.4 29.39 29.38 29.37 29.36 29.35 29.34 Northeast Northwest 29.33 29.32 29.31 29.3 Reservation Gate Southwest 29.29 Sabah Al-Ahmad natural reserve northwest of Kuwait bay (330 km2) 29.28 29.27 29.26 47.4 47.41 47.42 47.43 47.44 47.45 47.46 47.47 47.48 47.49 47.5 47.51 47.52 47.53 47.54 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 2X Peloidal limestone 2X Fine Sandstones with Poikilotopic Cement 4X 2X 4X 2X Rock Types Carbonate Fossiliferous Mudstone 4X Oolitic Grainstone Oolitic-peloidal Grainstone 2X Sandstone (paleo-soil) Fossils Mollusks (Bivalves and Gastropods), some are oysters Coral fragments Coralline algae Foraminifera Echinoderm Plates Bone fragments Fossils Bivalves 2X Foraminifera 4X Corals 2X Coralline algae 4X Fossils Echinoderm Plate with syntaxial cement 4X Foraminifera 2X 4X Corals 4X Fossils Foraminifera Cements Isopachous and Spary calcite 4X Poikilotopic Calcite Cements Spary and microcrystalline calcite Poikilotopic Gypsum Spary and microcrystalline calcite 2X Matrix Clay Matrix Clay Matrix Carbonate Matrix Matrix Matrix Geochemistry Southwestern location 50000 40000 30000 2 Al 3 4 20000 1 2 10000 0 70 60 50 40 30 20 Fe 4 K 5 Mn 6 6 MgCO3 Na 7 P 8 9 9 9 8 8 7 7 10 0 6 3 4 5 CaCO3 5 1 1 2 3 ppm Mole % First location toward the East 1 30000 25000 20000 4 Fe 5 K 6 Mn 7 Na 8 P 9 10 15000 3 Al 8 10000 2 3 5000 1 1 0 40 35 30 25 20 15 5 MgCO3 9 10 0 CaCO3 9 10 10 7 7 8 6 6 4 4 5 5 2 3 ppm Mole % 2 Second location toward the East 40000 3 4 30000 Al Fe 4 2 3 20000 1 3 10000 0 90 80 70 60 50 40 30 20 0 K 5 MgCO3 Mn 6 Na 7 P 8 9 9 9 8 8 7 7 6 6 5 5 10 2 CaCO3 2 4 1 1 ppm Mole % Eastern Location 1 2 2 3 3 Al 4 Fe 5 K 6 7 Mn 8 Na 9 P 10 9 70000 60000 50000 40000 30000 20000 10000 0 90 80 70 60 50 40 11 12 11 30 10 20 0 MgCO3 7 10 CaCO3 12 12 6 5 8 6 7 8 9 10 11 5 3 4 4 1 2 ppm Mole % 1 Elements Concentration Maps Fossiliferous -sandy limestone Al Si Mg Mn Ca Elements Concentration Maps fine sandstone with Poikilotopic cement Al Si Mg Mn Ca Elements Concentration Maps for Peloidal-oolitic sandy- grainstone Al Si Mg Mn Ca Elements Concentration Maps-clay Matrix Al Si Mg Mn Ca 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 10X 4X Second diagenetic spary calcite crystals In Limestones 10X In Sandstones Third diagenetic calcite is zoned spary crystals with pale blue and non -luminescent zones 3rd 3rd 3rd 10X Forth diagenetic calcite (found in Paleo-soils) 4X Collecting special parts for Isotope Analysis Oysters Carbon13 and Oxygen18 Distribution for Kuwait Group Normal Marine Isotopic Values ? 18 O -11.00 -10.00 -9.00 -8.00 -7.00 -6.00 -5.00 -4.00 -3.00 -2.00 0.00 -1.00 0.00 -1.00 -2.00 High Temperature Fresh water -3.00 -4.00 -5.00 -6.00 -7.00 13 whole limestones shells whole sandstones Spary cements C 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 Carbon13 and Oxygen18 Distribution for Kuwait Group With depth R12 D18O R15 R16 R18a R19 D13C Sample Number With Depth R13 Variation in Carbon13 and Oxygen18 concentrations within Marker Bed 1 (Grainstones and Packstones) from West to East Marker Bed 1 (Limestone) 0.00 -1.00 -2.00 -3.00 -4.00 -5.00 -6.00 -7.00 -8.00 -9.00 -10.00 Southwest D13C D18O Notheast 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. 2. 3. 4. 5. 6. Karst surfaces Ripple marks Nodules baring levels Paleo-soils Calcified plants roots Reworked (conglomeratic surface) Dibdibba Fm (Pleistocene) Paleo-soil Roots Lower Fars Fm. Paleo-soil Paleo-soil Paleo-soil Roots Roots GharFm. Fm. Ghar Carbone13 and Oxygen18 isotopes indicate digenesis under high temperature fresh water for all the formations which was supported by: 1. Depleted Carbone13 values (-3.70 to -6.59) 2. Depleted Oxygen18 values (-6.69 to -10.06) 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