GEOLOGY FREE NOTES

  PRECIPITATION Precipitation : Any atmospheric water coming on Earth’s surface Infiltration : Vertical movement of water from earth’s surface to below earth’s surface Run off : Horizontal or sub-horizontal movement of water on Erath’s surface Precipitation = Infiltration + Run-off TYPES OF GROUNDWATER Connate water : Sedimentary origin (Fossil water) - during compaction of sediments Meteoric water : Atmospheric water formed due to precipitation Juvenile water : Magmatic water formed from magma Metamorphic water : Metamorphic origin Hydrogen-3 (Tritium) and Carbon-14 used to date groundwater VERTICAL DISTRIBUTION OF GROUNDWATER 1) ZONE OF AERATION Voids are partially filled with water and air Movement of groundwater is vertical Water lies in this zone is called vadose water Atmospheric water > Water pressure divided into 3 zone : Soil water zone, Intermediate zone and Capillary zone 2) ZONE OF SATURATION Also known as phreatic zone Voids are fully saturated with water ...

                             TWINNING  TWINNING : Two or more crystals of same or relative mineral in which individual parts are reversed to each other TWIN PLANE: Imaginary plane which divide the twin crystal into two equal halves TWIN AXIS : Axis along which rotation takes place to bring twin into untwinned state TYPES OF TWINNING Contact : Consist of two halves united by compositional plane eg: Orthoclase Penetration : Twin appears as individuals were crossing each other eg: Staurolite, Pyrite, Fluorite, etc Repeated : Consist of three or more individual crystals twinned according to same law Polysynthetic : Twin planes are parallel to each other eg: Plagioclase, calcite Symmetric or Cyclic : Twin planes are not parallel to each other (mimectic twin) eg: Aragonite, Rutile, Gypsum, etc IMPORTANT MINERALS AND THEIR TWIN ORTHOCLASE Braveno : (021) Manebach : (001) Carlsbad : (001) QUARTZ Brazil : (1...

         ORE MINERAL AND INDIAN DISTRIBUTION IRON Abundant element in whole earth (Fe>O>Si>Mg) Second abundant metal in crust (Al>Fe) OXIDES Hematite - Fe2O3 Magnetite - Fe3O4 Turgite - 2Fe2O3-H2O Goethite (Limonite) - Fe2O3-H2O SULPHIDE Pyrite - FeS2 CARBONATE Siderite INDIAN DISTRIBUTION 1. Gorumohisani iron ore deposit - Mayurbhanj (Odisha) - Singhum craton 2. Barajamda iron ore deposits - Keonjhar (Odisha). 3. Tomka and daitari Iron ore deposits - Jajpur (Odisha) 4. Noamundi Iron ore deposit - Singhbhum (Jharkhand) 5. Chiria Inore deposit - Singhbhum (Jharkhand) 6. Biiladila iron ore deposits - Bastar (Chattishgarh) - Bastar craton 7. Dhalli-Rajhara Iron ore deposits - Durg (Chhattishgarh) 8. Kudremukh Iron ore deposit - Chikmaglur (Karnataka) 9. Bababudan hill lron ore deposit - Chikmaglur (Karnataka) 10. Goa Iron ore deposit - Goa (Blue dust found) MODE OF OCCURENCE BIF - Chemical or biochemical process Magnetite or Titaniferous magn...

 CLASSIFICATION OF SEDIMENTARY ROCKS SANDSTONE CLASSIFICATION Arenite < 15% matrix Wacke > 15% matrix Mudstone > 75% matrix Arkose > 25% feldspar Quartz arenite > 95% quartz BASED ON MATURITY Quartz wacke : Mineralogically mature but texturally immature Quartz arenite : Both mineralogically and texturally mature Feldspathic wacke : Both mineralogically and texturally immature CONGLOMERATE CLASSIFICATION Conglomerates are rounded grains belongs to Rudaceous rocks Oligomict : Clasts are of single rock type Polymict : Clasts are of different rock type Diamict : Matrix % is high (Clasts are completely surrounded by matrix) Petromict : Unstable or metastable clasts OTHER TERMS Agglomerate : volcanic origin Fanglomerate : found in case of alluvial fan DUNHAM’S CLASSIFICATION MUD SUPPORTED Mudstone < 10 % grain Wackestone > 10% grain GRAIN SUPPORTED Grainstone < 10% grain Packstone > 10 % grain FOLK CLASSIFICATION Oolite : Spherical grains with internal structur...

  TRACE FOSSILS 1) Fugichnia : Escape structure 2) Repichnia : Crawling 3) Cubichnia : resting 4) Domichnia : Dwelling 5) Paschnia : Surface feeder 6) Fodinichinia : Feeding DIFFERENT TERMS 1) Taphonomy: Study of organism from discovery to final death 2) Necrolysis : Breakup and decay of organism immediately after death 3) Biostratinomy : Study of processes operating after death to final burial 4) Diagenesis : Study of processes after final burial CHARACTERISTIC FEATURES Lopophore : Brachiopods Water vascular system : Echinodermata Jet propulsion system : Cephalopods Torsion : Grastropoda Ecdysis and moulting : Trilobita Dentition pattern : Pelecypods Distinct suture lines : Cephalopods Siphuncle : Cephalopods Rhabdosome : Graptolites Neca, Secula : Graptolites Strepto spiral coiling : Foraminifera Theca, Epitheca : Corals Five ray pentameral symmetry : Echinoderamata Peristome, Periproct, Madreporite plate, Corals : Echinodermata Ectoderm, Endoderm : Cnidar...