Where is the highest amount of organic carbon located and why? | continental margins because they are shallow and high in nutrients, light and upwelling which cause them to have a high primary productivity and more organic matter to be deposited |
Why and how has the OM type and source varied over time? | Evolution, we started with archaea and bacteria, which had a slow deposition of organic matter. There was an evolution in the important contributors to sedimentary OM. There is now a larger range of organisms present, contributing to the OM. |
Autotroph? | organisms using inorganic carbon (CO2 or bicarbonate), can produce its own food using light, water, carbon dioxide, or other chemicals. |
Heterotroph? | organisms using organic carbon, cannot produce its own food/nutrients |
DOM? | dissolved organic matter (not really dissolved but small molecules floating around) |
POM? | particulate organic matter (larger visible structures which sink to the bottom), important for sinking of organic matter |
What controls marine primary productivity | Light (intensity and quality/wavelength) & nutreints |
What can Chlorophyll be used for? | measure for nutrient enrichment of waters and amount of primary productivity |
What factors affect the accumulation of organic matter in sediments | Production & preservation (anoxia, shallow) |
What is marine OM made up of? | carbohydrates (mostly sugars), proteins/DNA/aminoacids, lipids and other miscellaneous stuff |
Which class have the longest degradation rate? | Lipids (than DNA/Proteins and then carbohydrates). So there will be a bias to lipids |
Organic carbon burial efficiency ? | how much of the organic matter actually remains in the sediment and is not degraded. Decreases over time as OET increases.
As organic geochemists we want oxygen exposure time to be short and production high |
What is in the insolubles of organic solvents | kerogen! over time this forms the hydrcarbons for oil and gas |
- Organic matter burial is an important .... in the global carbon cycle | sink |
Organic matter accumulation in marine sediments is determined by .... and .... . Terrestrial organic matter can also be buried in marine or lake sediments | productivity & preservation |
Oxygen exposure time is an important factor in determining ........... | organic carbon burial |
Organic matter getting buried is transformed into .... and .... under the right ......and ...... conditions | oil & gas - temperature & ressure |