SEDIMENTS & SEDIMENTARY ROCKS

ROCK CYCLE

Relative Percentages of Sedimentary Rocks

SEDIMENT Unconsolidated- NOT cemented From Weathering & Erosion Precipitation from saturated solution calcite, quartz Product of evaporation halite, gypsum Unconsolidated- NOT cemented

SEDIMENT Particle size Pebbles, cobbles, boulders Gravel- > 2mm Sand- 2mm - 0.063mm Silt - 0.063mm - 0.004mm Clay- < 0.004 Deposition Clay-sized particle vs. clay mineral

SEDIMENT Preservation Transportation Abrasion Rounding Sorting Deposition Environment of deposition- specific Preservation

SEDIMENT Preservation Transportation Abrasion Rounding Sorting Deposition Environment of deposition- specific Preservation

SEDIMENT Lithification Compaction Cementation Crystallization Decrease in pore space for very fine grain size (clay) Cementation Clastic texture Cements- silica, calcite, iron oxide Crystallization Crystalline texture

SEDIMENT Lithification Compaction Cementation Crystallization Decrease in pore space for very fine grain size (clay) Cementation Clastic texture Cements- silica, calcite, iron oxide Crystallization Crystalline texture

SEDIMENT Lithification Compaction Cementation Crystallization Decrease in pore space for very fine grain size (clay) Cementation Clastic texture Cements- silica, calcite, iron oxide Crystallization Crystalline texture

TYPES OF SEDIMENTARY ROCKS Clastic or Detrital Chemical- inorganic precipitation or evaporation Biochemical- Organic remains shells, charcoal, plant fragments

CLASTIC (Detrital) ROCKS Breccia and Conglomerate (> 2mm) Sedimentary Breccia- angular fragments Conglomerate- rounded fragments Sandstone (2mm - 0.063mm) Quartz sandstone Arkose (feldspar) Graywacke (appreciable amounts of silt/clay) Fine-grained Matrix Usually from turbidity currents

CLASTIC (Detrital) ROCKS Breccia and Conglomerate (> 2mm) Sedimentary Breccia- angular fragments Conglomerate- rounded fragments Sandstone (2mm - 0.063mm) Quartz sandstone Arkose (feldspar) Graywacke (appreciable amounts of silt/clay) Fine-grained Matrix Usually from turbidity currents

Quartz Sandstone

CLASTIC ROCKS Fine-grained Rocks Shale- fissile (in ‘sheets’) Siltstone Claystone Mudstone (silt and clay)

CHEMICAL SEDIMENTARY ROCKS Carbonate Rocks Limestone- made of calcite Inorganic varieties micrite, oolites, travertine Dolomite Recrystallization Chert- silica Evaporites Rock gypsum Rock salt

BIOCHEMICAL SEDIMENTARY ROCKS Coal Develops from peat plant fragments Lignite Bituminous Coal Carbonate Rocks Limestone- made of calcite organic varieties Coquina Fossiliferous Limestone Chalk

BIOCHEMICAL SEDIMENTARY ROCKS Coal Develops from peat plant fragments Lignite Bituminous Coal Carbonate Rocks Limestone- made of calcite organic varieties Coquina Fossiliferous Limestone Chalk

SEDIMENTARY STRUCTURES BEDDING- Principle of Original Horizontality Bedding plane Cross-bedding Graded bed Mud cracks Ripple marks Fossils

SEDIMENTARY STRUCTURES BEDDING- Principle of Original Horizontality Bedding plane Cross-bedding Graded bed Mud cracks Ripple marks Fossils

DUNES

SEDIMENTARY STRUCTURES BEDDING- Principle of Original Horizontality Bedding plane Cross-bedding Graded bed Mud cracks Ripple marks Fossils

SEDIMENTARY STRUCTURES BEDDING- Principle of Original Horizontality Bedding plane Cross-bedding Graded bed Mud cracks Ripple marks Fossils

Mudcracks

SEDIMENTARY STRUCTURES BEDDING- Principle of Original Horizontality Bedding plane Cross-bedding Graded bed Mud cracks Ripple marks Fossils Body Fossils Trace Fossils

FORMATIONS Large enough to show on a map Distinctive from neighboring rock units Named after geographic locations CONTACT separation between 2 distinct rock units Sedimentary contact Other contacts

INTERPRETATION OF SEDIMENTARY ROCKS Source Area Environment of Deposition Glacial environments Tillites Alluvial fan Arkose River channel and flood plain Interbedded shales and sandstones; cross-bedded Lake Shales; interbedded siltstones and mudstones Delta

INTERPRETATION OF SEDIMENTARY ROCKS Source Area Environment of Deposition Glacial environments Tillites Alluvial fan Arkose River channel and flood plain Interbedded shales and sandstones; cross-bedded Lake Shales; interbedded siltstones and mudstones Delta

Glacial Environment & Till

INTERPRETATION OF SEDIMENTARY ROCK Environment of Deposition Beach, Barrier Island, Dune Very well sorted quartz sandstones Lagoon Shales Shallow marine shelf Interbedded sandstones and shales; burrowed Reef Skeletal Limestones Deep marine environment Turbidites- sequence of GRADED sandstones to shales

INTERPRETATION OF SEDIMENTARY ROCK Environment of Deposition Beach, Barrier Island, Dune Very well sorted quartz sandstones Lagoon fine grained sediment Shallow marine shelf Interbedded sandstones and shales; burrowed Reef Skeletal Limestones Deep marine environment Turbidites- sequence of GRADED sandstones to shales

CALCAREOUS

INTERPRETATION OF SEDIMENTARY ROCK Environment of Deposition Beach, Barrier Island, Dune Very well sorted quartz sandstones Lagoon Shales Shallow marine shelf Interbedded sandstones and shales; burrowed Reef Skeletal Limestones Deep marine environment Turbidites- sequence of GRADED sandstones to shales

INTERPRETATION OF SEDIMENTARY ROCK Plate Tectonics and Sedimentary Rocks At convergent boundaries Uplift results in Very rapid rates of erosion Thick accumulations of clastic sediment At transform boundaries Rapid rates of erosion, deposition and burial Good basins for petroleum exploration At divergent boundaries Initial stages of rifting- thick wedges of gravel and coarse sediment

Resources Non-Metallic Energy Resources Sand and gravel Limestone Clay Gypsum Energy Resources Oil and gas Coal

Formation of Oil and Gas

U.S. Coal Production