Presentation on theme: "Sedimentary Environments. Fossil Sedimentary rocks record environmental information."— Presentation transcript:
Fossil Sedimentary rocks record environmental information
Continental Shelf 10-15K feet of compacted sand and mud
Cementation Lithification: Compaction and cementation At depth, SiO 2 and CaCO 3 go into solution, water is driven out (dewatering). This solution permeates throughout open pore spaces, forming a cement.
Cemented Sandstone SiO 2 cement
Cemented Limestone CaCO 3 cement
Classification of Sedimentary Rocks
Clastics Increasing water energy
Clastic Sedimentary Rock
Fast Stream Fast moving water does not allow clay-sized particles to accumulate. They stay in suspension. Larger particles, like pebbles, drop through the water column and accumulate.
Clastic Breccia Breccia
Limestone Biogenic rocks - Accumulation of dead critters. Shallow, warm, marine environment.
Limestone Thin Section Fossils cemented together by CaCO 3 cement.
Coal Accumulation of organic material in a swampy environment. Anaerobic, dark, murky water. Biogenic rocks -
Lagoon Care for a swim?
Evaporite - Salt Chemical rocks - What happens when salty water evaporates?
Salt Flat Wet in the spring and early summer Water evaporates in late summer and fall
Chert Microcrystalline silica Chemical rocks - Deep water ocean environment, too cold for CaCO 3 precipitation.
Oil Traps Oil & gas are less dense, so they migrate toward the surface.
Salt Dome Salt is very impermeable Salt is also less dense than the country rock, so it too is migrating toward the surface.
Given many thousands of years, a stack of mud and organic remains many kilometers thick may pile up on the sea floor, especially in nutrient-rich waters. Given enough time, the overlying sediments that are constantly being deposited will bury these organic remains and mud so deeply that they will eventually be turned into solid rock. It is believed that high heat and intense pressure help along various chemical reactions, transforming the soft parts of ancient organisms found in the deep-sea sludge into oil and natural gas. At this point, this ooze at the bottom of the ocean turns into source rock. Maturation
Reservoir Rock High porosityLow porosity Oil must be allowed to move between pore spaces: permeability
Stratigraphic Trap Oil migrates into ‘traps’
Oil rig: Gulf of Mexico
Gulf of Mexico 130 active drilling rigs 4,489 producing oil wells 3,813 producing gas wells
Worldwide Offshore Oil Rigs Gulf of Mexico 215 Latin America 109 November 2001 North Sea: 88 West Africa: 42Middle East: 33 S. Asia: 25 Far East: 23 Pacific Rim: 42
Known Oil Reserves
United States: 19.6 million barrels per day. 25% of world total. World: 75 million barrels daily and rapidly increasing. Oil Consumption How much is left? Forecasted at 40 years (2K billion barrels).
World Oil Consumption
Oil barrel What A Barrel Of Crude Oil Makes (42 gallons) Product Gallons per barrel gasoline 19.5 distillate fuel oil 9.2 (Includes both home heating oil and diesel fuel) kerosene-type jet fuel 4.1 residual fuel oil (Heavy oils used as fuels in industry, marine transportation and for electric power generation) 2.3 liquefied refinery gasses 1.9 still gas 1.9 coke 1.8 asphalt and road oil 1.3 petrochemical feedstocks 1.2 lubricants 0.5 kerosene 0.2 other 0.3
Oil makes gas, right? Well… saccharine (artificial sweetener) roofing paper aspirin hair coloring heart valves crayons parachutes telephones bras transparent tape antiseptics purses deodorant panty hose air conditioners shower curtains shoes volleyballs electrician's tape floor wax lipstick sweaters running shoes bubble gum car bodies tires house paint hair dryers guitar strings pens ammonia eyeglasses contacts life jackets insect repellent fertilizers hair coloring movie film ice chests loudspeakers basketballs footballs combs/brushes linoleum fishing rods rubber boots water pipes vitamin capsules motorcycle helmets fishing lures petroleum jelly lip balm antihistamines golf balls dice insulation glycerin typewriter/ computer ribbons trash bags rubber cement cold cream umbrellas ink of all types wax paper paint brushes hearing aids compact discs mops bandages artificial turf cameras glue shoe polish caulking tape recorders stereos plywood adhesives TV cabinets toilet seats car batteries candles refrigerator seals carpet cortisone vaporizers solvents nail polish denture adhesives balloons boats dresses shirts (non-cotton) perfumes toothpaste roller-skate wheels plastic forks tennis rackets hair curlers plastic cups electric blankets oil filters floor wax ping pong paddles cassette tapes dishwashing liquid water skis upholstery chewing gum thermos bottles plastic chairs transparencies plastic wrap rubber bands computers gasoline diesel fuel kerosene heating oil asphalt motor oil jet fuel marine diesel butane Sorry, this is only a partial list…