Popular in Earth Science
Popular in Department
This 2 page Class Notes was uploaded by Cara-Liesel Ransom on Wednesday October 5, 2016. The Class Notes belongs to EAR 105 - M001 at Syracuse University taught by C. Junium in Fall 2016. Since its upload, it has received 8 views.
Reviews for EAR101-10/5
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 10/05/16
Wednesday 10/5/16 The Sedimentary Cycle Sediment transport processes cantransport sediments over very long distances. The grainsizechanges the farther gets from the source of sediment. Farther from the source, the grains become better sorted. The sorting and the grain sizedefines the concept of “maturity.” You can getsome idea of the distanceand the sort of transport it’s been through. A sandstone with fine, uniform grains is considered‘mature’ and is likelyv.far from its source material. The remaining grains leftbehind, mostly clay,goes into the ocean. Deposition of clastic material in the ocean happens on continental shelves and in ‘basins’where sediment accumulates Rivers distribute the sediment to the lowest lying area. (the Mississippi delta) As the sediment continues to fall in,it keeps piling up and slowlymoves out further into a ocean, river etc. This is how sedimentary basins form, it is a dumping ground for sediment. Continental shelves –most of where our sediment is There is enough mass inthe sediment basins that itactuallypushes the mantle down to make room. Classifications Classifiedbythetexture and composition, justlike igneous rocks The rock type defines the environment from which is was deposited. We us the rock type to saysomething about past environments. Rocks! Breccia /brechia/ - its as ifyou chipped awaythe sideof a mountain, this is what you would get. Largeangularclass ofrocks deposited in alpineenvironments. Conglomerate is composed of largepebbles and cobbles. They’re ina specific formof arrangement, they’ll look likechannels.Theseare very popular around rivers. They all lineup likeshingles whichshows which way the river was flowing atthe time. Arkose – immature type of sediment, not super common. Composed of sand-sized angular clasts ofrock and minerals. It’s deposited in “alluvial fans” closetothe sediments sources.At the baseof a mountain and piles up. A mixture of largeand small grains and very little weathering touches it. Sandstone –defines a sizeof grain,mostly quartz and a little feldspar.Very, very common gindeserts, dunes, and BEACHES Shale and Siltstones – finer grain,deposited in much less energetic environments. Can be found in the ocean, but deep sea and lakes. Limestone – it’s not clastic,it’s a chemical sedimentary rock. Abiological process mediating its formation. (coral and fossils) Evaporites – likehaliteare deposited when oceans and lakes dry up. It’s a chemical sedimentary rock. Popular here in Syracuse. Coal – found inswamps. It’s not something that’/s transported but it’s grown and placed into somewhere where it festers into coal.We associateitwith sandstone The sequence of rocks suggests thenature of changethat occurred in environments through time. The arrangement shows what’s happened in the past.We call them formations and it’s a rock type that is widely distributed. The sedimentary structure within the rocks help better define the environment of deposition. Dunes Grains are very round. We canseethe dunes and ripples on rock surfaces.The symmetry canalsotell you which way the water flowed. We canseedunes and ripples in the outcrop. From the sidethey show that there were moving grains that were either in water or in deserts. Deep-Sea Graded –the grains getsmallerand smaller,from the bottom to the top. It suggests deposition from a turbidity current. Deep marine environments: chalk Calciumdeposits Mud cracks and Fossils Something was wet and it dried. Helps decipher the environment at that stage.Fossils of course help too. Certain organisms in certain environments. The rocky type are sedimentary structures are usedto define depositional environments. EXAM: 1. Multiple choice 2. Not exactlymemorization, testing understanding of concepts 3. Goes UP TO minerals 4. How fastplates move, cm/yr : order of magnitude 5. Plate boundaries 6. 45-50 questions, 1 question per minute. 7. Matching related, broader understanding of how plate tectonics work 8. Chapters 1-5 9.