Exam question

·       Sedimentology

à Study of modern sediments such as sand, silt, clay and the processes which lead to their formation (erosion, weathering), transport, deposition and diagenesis. Interpretation of geological history through observations of sedimentary rocks and sedimentary structures

·       Tectonics

à Process that controls the structure and properties of the Earth’s crust and its evolution through time. In particular, it describes the processes of mountain building, growth and behavior of strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that constitute the Earth’s outer shell interact with each other. Plate tectonics describes the large-scale features on Earth’s surface.

·       Volcanology

à Study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomena

·       Micro-Paleontology

à Paleontology = study of life that existed prior to, and sometimes including, the start of the Holocene (11,700 BP). It includes the study of fossils to determine organisms’ evolution and interactions with each other and their environments (their paleoecology). Fossils are used to age date sediment layers -> stratigraphy

·       Bio-Geochemistry

à Geochemistry uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth’s crust and its oceans. In marine biogeochemistry processes and rates of material turnover in the upper sediment column causing changes to the sediment are studied

·       Seismology

à Study of earthquakes and the propagation of elastic waves through Earth or planet-like bodies. Also includes earthquake effects such as tsunamis as well as seismic sources like volcanic, tectonic, artificial processes. Seismic mapping uses artificial pressure waves to visualize the sub-surface structures on land and in the ocean bottom

o   the "stripes" are smaller (slow spreading)

from highest gibbs energy to lowest (from negative to positive) high negative is getting reduced at first

1. oxygen

2. nitrate

3. manganese

4. iron

5. sulphate

6. methane

-        Highest penetration on open ocean, because less pp leads to less OM and high OM leads to anoxic conditions on bottom

-        Amount of oxygen: Open ocean > coastal ocean > eutrophic waters > upwelling areas

-        Sink: in low oxygen conditions: denitrification and anammox (also DNRA)

o   Therefore in shallow areas (less oxygen)

-        Source: n2 fixation: deep waters

• thermal water expansion

• coastal melting of ice

• plate boundaries

• along transform faults

-        Ice melting

-        Warming waters (expansion)

-        Slowing gulf stream

-        Sinking land

only 2

1. H+

2. CO2

3. TA

4. HCO3-

5. DIC

6. CO3 2-

-        Anoxia: when oxygen, nitrate, manganese and iron already reduced

-        Also slphides linked to hydrothermalism: massive sulphides: MOT and subduction zoned

·       Terrigenous: from continents so on continental shelf -> there lays more

·       Pelagic: mostly biogenous (calcerous and siliceous) -> deep sea but far less

·       General: decrease with increase depth: most on margin/shelf, least in deep sea

yes: most reliable in carbonate for reconstructing pH, DIC and atm pCO2

• stable

• conservative

·       800 tmol/y Rain

·       24 tmol/y Burial

·       160 tmol/y Export

·       4500 tmol/y PP

-        Primary production > Rain rate >export > burial in sediment

1. eccentricity: 400 ka and 100 ka

2. obliquity: 41 ka

3. axial precession: 23 ka

1. microfossilassemblage transfer function

2. oxygen isotope in biogenic calcite

3. mg/Ca in planktonic foraminifers

4. calcium isotope in planktonic foraminifers

5. sr/ca in corals

6. biomarker: alkenones Uk´37

7. biomarker: TEX 86 (lipids)

7-3 Ma ago, lead to loss of high temp waters through pacific

caused:

• sal contrast between carribbean and east pacific

• caribbean warm pool

• gulf stream intensification (NW europe heating and increased formation of n antlantic intermediade and deep water mass)

• Glaciation of nh:

  • high evaporation due to gulf stream

  • freshening of arctic ocean

  • sea ice formation -> increased albedo

  • decreased heat exchange between surface and atm -> cooling

• continental margin

• high org content with high sedimentation rate results in high burial efficiency

• -> high pp -> high OM

• terrigeneous material and nearby also leads to high sedimentation rate

-        Reconstructing seawater carbon budget -> ocean circulation

-        13C isotope composition average in pcean

• high DIC = low 13C

• changed by suess effect (carbon burning) = 12C more included in corals

·       Because of age differences and different CO2 concentrations:

·       Atlantic waters are younger and contain less CO2 than deep waters of the Pacific. Therefore, CaCO3 is better preserved in Atlantic sediments than in Pacific deposits.

·       Increasing CO2 leads to shallower CCD (increasing solubility)

-        Deep sea: less than 30 m/ 10^6 years

-        Coast much higher

-        Porosity and density of solid

o   Carbonate

o   biogenic opal

o   organic matter

o   RIGHT terrigenous material 13.6 x 10^15 g /yr

·       800 tmol/y Rain

·       24 tmol/y Burial

·       160 tmol/y Export

·       4500 tmol/y PP

-        Primary production > Rain rate >export > burial in sediment

-       60% 1 Africa. 1.1 Angola. 1.2 Botswana. 1.3 South Africa. 1.4 Others.

-       2 Asia. 2.1 Russia. 2.2 India. 2.3 Indonesia.

-       3 Australia.

-       4 North America. 4.1 Canada. 4.2 United States

1. carbonate formation

2. barite formation

3. anaerobic oxidation of methane (AOM)

·       Differing Mg/Ca rates in shells of foraminifers

·       Oxygen isotopes (d18O) in biogenic calcite

·       Alkenones in Coccolithophores (temperature sensitive partially unsaturated carbon chains)

·       Radioactive SO4 can be used to determine the rate of Sulphate reduction and therefore turnover in the diagenetic sequence

·       Want to have mass/unit volume or area

-        Magma forms from partial melting of mantle rocks.

-        1. Hydration, heating, decompression

o   (RIGHT)Different acoustic data sets (e.g.  multibeam bathymetrics and sidescan sonar) can be collected simultaneous

o   FALSE High resolution seismic images with deep penetration can easily be collected by large sources

o   (FALSE)Sound waves are the only means of surveying large regions of the seafloor

300-400 ° C

- the bicarbonate or carbonate concentration increases through

1.     anaerobic oxidation of methane (AOM)

2.     dissociation of organic matter

-        Composed of calcite, low‐Mg calcite, aragonite and even dolomite, MDACform a variety of rocks ranging from pure aragonite, to breccias of clasts of mg‐calcite cemented sediment, micritic cemented slabs or roundish concretions, to dolomitic rocks. Typical are very low 13C isotopic values

-        that result from the oxidation of methane as the carbon source.

-        D = ct/2

-        T = time

-        C (or lamda) = velocity

-        C = f x v

-        F= frequenzy (herz)

-        v = wavelength

Radiometric Dating methods

Radioactive decay

o   RIGHT Hydroacoustic multibeam systems

o   RIGHT Multichannel seismic (used for subsurface, but of course also gives the bottom reflecting layer)

o   RIGHT Single beam echosounder

-        After lava comes out, it cools quickly under water

-        Lack of bubbles in lava suggests that rock crystallized on ocean floor under pressure of deep water shaping the pillow formed bodies

-        These can break open to extrude more hot lava

-        Granite is an igneous rock

-        When granite is subjected to intense heat and pressure -> deep burial

à Study of modern sediments such as sand, silt, clay and the processes which lead to their formation (erosion, weathering), transport, deposition and diagenesis. Interpretation of geological history through observations of sedimentary rocks and sedimentary structures

à Process that controls the structure and properties of the Earth’s crust and its evolution through time. In particular, it describes the processes of mountain building, growth and behavior of strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that constitute the Earth’s outer shell interact with each other. Plate tectonics describes the large-scale features on Earth’s surface.

à Study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomena

à Paleontology = study of life that existed prior to, and sometimes including, the start of the Holocene (11,700 BP). It includes the study of fossils to determine organisms’ evolution and interactions with each other and their environments (their paleoecology). Fossils are used to age date sediment layers -> stratigraphy

à Geochemistry uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth’s crust and its oceans. In marine biogeochemistry processes and rates of material turnover in the upper sediment column causing changes to the sediment are studied

à Study of earthquakes and the propagation of elastic waves through Earth or planet-like bodies. Also includes earthquake effects such as tsunamis as well as seismic sources like volcanic, tectonic, artificial processes. Seismic mapping uses artificial pressure waves to visualize the sub-surface structures on land and in the ocean bottom

o   RIGHT: Good fit between South America and African coastline

o   RIGHT: Similarity of faunal and floral fossils in South America and Africa

o   According to Wegener the continents raised out of the oceanic crust

o   RIGHT: In modern plate tectonics the continents are part of the moving plates or form own plates

o   RIGHT: According to Wegener the continents were drifting within the oceanic crust

o   In modern plate tectonics the continents are in a fixed position and the oceanic crust is formed at mid-ocean ridges or destroyed in subduction zones

·       Dykes

·       Gabbro

·       Pillow basalt

·       Massive sulphides

·       Granite

·       a: normal fault

·       b: reverse fault/thrust fault

·       c: strike slip fault / transform faults

·       left lateral faults

• 1912: Alfred wegener: theory of continental drift

• Marie Tharp 1960: seafloor spreading

• 1960: theory of plate tectonics

·       A: active margin, convergent, accretionary, the upper plate is growing due to “scraped” material from the lower plate

·       B: active margin, convergent, erosive, the upper plate is shrinking due to erosion, eroded material of the upper plate is “pulled” in, between the plates and finally subducted.

·       1:         Deep-Sea Sediment

·       2A/B:   Basaltic Pillow lavas

·       2C:      sheeted dike complex

·       3A:      Gabbro

·       3B:      Layered Gabbro

·       4:         Layered and unlayered peridotite

à There is no CHEMICAL difference between Basalt and Gabbro. It is only the lattice   structure, that is differing. This is dependent on how much time they had to form.

Intrusive (gabbro) and extrusive (basalt) igneous rocks

o   RIGHT: Chains of seamounts and volcanic islands

o   Upwelling zones

o   RIGHT: the mirrored pattern of magnetic polarity preserved in the oceanic crust parallel to mid-ocean ridges

o   RIGHT: increasing age of marine sediments with increasing distance from mid-ocean ridge

o   Temperature records of the oceanic crust

o   Temperature

o   Density

o   RIGHT: Gravity

o   RIGHT: Velocity

1. Add water -> reducing solid curve

2. Increase temperature

3. Reduce pressure

·       Chlorine 55%

·       Na 30.6 %

·     Sulfate  7.7 %

·       Mg 3.7%

·       Ca, K, Sr, Br, HCO3

·       Magma -> intrusive rock formed and stuck in the earth -> uplifted into the atmosphere -> creates an outcrop -> weathering -> grinds down outcrop -> forms a sediment, loose mixture of ground down rock -> transportation into rivers/streams and beaches à forms compacted sediment -> cemented sediment -> sedimentary rock is formed (e.g.: sandstone) -> buried in earth again à heat and pressure recrystalizes -> formation of metamorphic rock -> can form new magma -> constantly happening

·       No chemical difference!

·       1500 m/s

·       1852 m (1 Knot = 1 Nautical Mile/hour)

Normal mile: 1609 m

·       D= ct/2

·       Multibeam echosounder: emits acoustic pressure waves in a fan shaped way. By forming directional beams, the echosounder can also extract the angle of the returning acoustic pressure wave. The time the acoustic pressure wave needs to travel to the seafloor and ping back is referred to as the two-way travel time and by knowing the sound velocity and TWT, we can calculate the water depth. The resolution is determined by the wavelength, which we can only alter with the acoustic pressure waves frequency, as the velocity in water is fixed.

·       Water: 1500m/s         Air: 340m/s     Marine sediment: 1800m/s

·       Sound velocities are pressure waves. The speed of propagation of a pressure wave is proportional to the density of the medium, in which it propagates. Air has a lower density than water, has a lower density than marine sediments, and therefore, the pressure waves propagate slower in air, than in water, than in marine sediments.

·       Two-way travel time is given with 3 seconds. Thus: Depth [m] = sound velocity [m/s]*(TWT [s] / 2) = 1500 m/s * (3s/2) = 2250m is the approximate depth.

·       Substance that exists in a solid state under standard conditions temperature and pressure conditions

·       must be a natural occurring, inorganic substance

·       has a fixed chemical formula

describes the temperature at which minerals crystallize when cooled, or melt when heated

• mafic

  a: discontinuous -> during each step a new minerals forms : the first silicates to crystallize are olivine, the cooler it gets, the more pyroxene, amphibole and biotite minerals form. (From high temp to low)

  rock type defined by amounts of different minerals ?

  B: continuous -> -> plagioclase changes elemental composition and no change of minerals (Ca-rich and Na-rich plagioclases)

• Intermediate: branches merching together

• Felsic: less iron and magnesium, more luminum and potassium -> potassium feldspar, Muscovite

  

·       The lower boundary of gas hydrate containing sediment layer is the BSR (Bottom Simulating Reflector). It is a horizon of strong reflection in seismic profiles due to distinct change density. Clatherates/gas-hydrates are low in density

·       Heating:

à Intrusion of hot melt, frictional heating

à Just increased temperatures, does not happen a lot

·       Decompression (isothermal):

à Convective upwelling

à Bring up material, one of the most effective ways!

·       Hydration:

à Addition of volatiles reduces the solidus

·       On Land: ca. 30 °C per km

·       In the Ocean: 60°C per km, or 40°C per km

à These temperature increases only hold true for the curst, if you go deeper, they change

·       Differing Mg/Ca rates in shells of foraminifers

·       Oxygen isotopes (d18O) in biogenic calcite

·       Alkenones in Coccolithophores (temperature sensitive partially unsaturated carbon chains)

·       Exponential relationship between Mg/Ca and SST.

·       Correlation between Mg/Ca and ∂18O-Derived Calcification Temperature ->- Mg/Ca SST closer to Alkenon-biomarker estimates than to ∂18O estimates.

Composition: CaCO3

·       Radioactive SO4 can be used to determine the rate of Sulphate reduction and therefore turnover in the diagenetic sequence

o   source energy

o   RIGHT: source frequency

o   RIGHT: lithology of the sediments

o   RIGHT: sound velocity of the sediment

o   water depth

o   multibeam bathymetry

o   multichannel seismics

o   RIGHT: sediment echosounder

o   RIGHT: sidescan sonar

o   RIGHT: different acoustic data sets (e.g. multibeam bathymetry and seismic) can be collected simultaneously

o   RIGHT: a seismic source, receivers (hydrphone) and an acquisition unit are the main components of a seismic system

o   high resolution seismic images with deep penetration can easily be collected by using large sources

o   detailed bathymetry images with a vertical resolution of ~ 10 m can be achieved by using satellite altimetry

o   RIGHT: sound waves are the only means of surveying large regions of the seafloor with reasonable accuracy.

·       Main ingredient: SiO44-

·       Shield volcano:

à At oceanic islands, continental rift zones (where crust gets thinner through spreading)

à low angle flanks, small top caldera, has rift zones

à mainly basaltic lava flows

à Hawaii island chain

Bsp: Mauna Loa (Hawaii), Fernandina (Galapagos)

·       Stratovolcano:

à At Subduction zones, oceanic islands, continental intraplate volcanos (everywhere)

à Surrounded by ring planes of pyroclastic and epiclastic deposits

à Large edifices à steep flanks, often glaciated top, abundant lahars, satellite vents on flanks

à Landslides/edifices collapses occur

à Mostly andesitic, but basaltic to rhyolitic

à Pyroclastic dominates over lavas

Bsp: Krakatoa (Indonesia), Vesuvius (Italy)

·       A: Hawaiian eruption à shield volcano à so called fissure eruption à coarse, hot splatter but also cooled ash fallout

·       B: Plinian eruption à stratovolcano à extremely eruptive, high volatile content (from magma), high eruption column, large gas and ash extrusion

·       Order of explosivity:  Super volcanic > Plinian > Vulcanian > Strombolian > Hawaiian

·       Tephras (from Plinian eruptions) allow for analysis of sedimentation rates, that have occurred between eruption events. These ash layers are very distinct in their chemical fingerprint, so we can tell them apart from other sediments. By looking at the thickness of layers, between two distinct tephra eruption layers, we can tell the age, or number of years, in which the “sandwiched” layer has accumulated. Further, by the distinguishing the “thinning” of the tephra layers, as one moves away from the supposed eruption site, one can calculate the volume of eruption.

·       In coastal margins

·       continental margins

·       Atlantic waters are younger and contain less CO2 than deep waters of the Pacific. Therefore, CaCO3 is better preserved in Atlantic sediments than in Pacific deposits.

• Increasing CO2 leads to shallower CCD (decreasing solubility)

·       a: Sand, silt and clay particles derived from continents by physical erosion. They are deposited in the coastal zone and at the continental shelf -> some transported further offshore. Dust particles derived from continents deposited at the deep-sea floor (red clay).

·       b: Biogenic particles formed by marine plankton (calcium carbonate, biogenic opal, organic material). Carbonate formed at tropical shelves by calcifying benthic organisms (e.g., corals) Shell sand, oyster banks

·       c: Precipitated from seawater or sediment pore water. E.g.: Evaporites (salt), manganese nodules, phosphorite concretions

·       Most of the sediments deposited at the seafloor are of terrigenous origin. Terrigenous Most sediments are deposited at the shelf. Sedimentation rates at the deep-sea floor, therefore are lower, because most of the material has sedimented already and there is less material suspended, which might possibly be deposited. Difference between Pacific and Atlantic? -> Atlantic is smaller, generally closer to continents.

·       Also: Sedimentation rates of biogenic material decreases with water depth, because remineralization processes diminish the sedimentation on the way down. It shows a regressive decline from shallow to deep, so that the possibly deposited amount declines.

·       Pelagic N2-fixation via diazotrophic bacteria is the main source for bioavailable nitrogen

·       Benthic denitrification of NO3 to N2 is the main sink for bioavailable nitrogen.

·       Over half of the overall nitrogen loss occurs in the sediment via denitrification. This process is very strong because of the prevailing absence of oxygen as an electron acceptor. Thus, nitrate is used as an acceptor during OM degradation. Further, anammox (anaerobic ammonium oxidation) is another loss process.

·       Lithostratigraphy

à classifies, describes and traces the different rock units laterally

à compare lithologies from different core samples and correlate the same rock units

à isochronism (= assuming, that similar rock units evolved at the same time) is not guaranteed

à lithological boundary and the change in facies may be diachronous or time transgressive

à subunit: “event” stratigraphy -> tephra ash layers!

·       Biostratigraphy

à Classifies rocks using fossil appearance and abundance, they are time markers

à Establishes relative age relationship between rocks, based on the principle of irreversible morphological evolution

à Best approach to isochronism Foraminifera!

à High abundance, rapid evolution, easy to identify, wide and rapid dispersal

·       Magnetostratigraphy

·       Correlation technique to date sedimentary and volcanic sequences. Look at magnetic orientation within samples at measured intervals throughout a section. The orientation is similar to the polarity of Earth's magnetic field at the time the sample has formed from volcanic flows. Meanwhile this is also possible for sediments and the technique is very useful for samples lacking fossil records.

o   10 - 20 ° C

o   200 - 250 ° C

o   RIGHT: 80 - 130 ° C

o   400 - 450 ° C

1. H+, hence pH

2. CO2, aqueous dissolved carbon dioxide -

3. HCO3-, dissolved bicarbonate -

4. CO32-

5. DIC: dissolved inorganic carbon = CO2 + HCO3- + CO32-

6. TA: total alkalinity = CO2 + HCO3- + CO32- + OH- + B(OH)4 – H+

à Any of these two parameters are enough to calculate the rest

·       Global ocean ice volume has an effect on the ratio of 18O/16O.

·       H2O with the lighter 16O evaporate more easily from the water, than heavy 18O. Global moisture transport to the poles leads to precipitation and freezing of 16O H2O rich waters, leaving behind an ocean with 18O enriched water. This fractionation process is happening to differing amounts, when looking at geological changes between warm and cold periods, and therefore differing ratios, relate to differing geological periods.

·       Given that calcifying organisms use Bicarbonate, which has previously been built from CO2 and the presently fractionated H2O, these changes are incorporated into shells of e.g.: foraminifera. This can be used to estimate temperatures at which these organisms have built up their shell. However, this does not allow for absolute dating. But: changes in the oxygen isotope ratios of planktonic and benthic generated calcite are globally synchronous; allows to corelate and date marine deposits globally.

·       Microfossil assemblage transfer functions

·       In (planktonic/benthic) foraminifers:

à Oxygen isotopes (benthic/planktonic)

à Mg/Ca (planktonic)

à Calcium isotopes (planktonic)

·       In corals:

à Strontium

à ∂18O

·       Biomarker:

à Alkenones (Coccolithophores)

à TEX 86 (Crenarchaeota)

• According to model results, the closing of the Panama Gateway should have caused:

·       modern salinity contrast between Atlantic (Caribbean) and Pacific (in surface waters)

·       development of modern Caribbean Warm Pool

·       Intensification of Gulf Stream System

·       Increased heat, salt and moisture transfer into N Atlantic

·       heating of NW Europe

·       Increased formation for N Atlantic intermediate and deep-water masses

• Other possible effects might be the glaciation of the northern hemisphere (NHG):

·       (Closing of Panama Gateway, Intensification of Gulf Stream System)

·       enhanced Evaporation in N Atlantic (since ~4.3 Ma) -> Moisture source

·       Freshening of Arctic Ocean -> Facilitation of sea ice formation

·       Increased Albedo; Decreased heat exchange between ocean surface and atmosphere

-> COOLING

Problem: these events are separated by 2 million years

1. Eccentricity: deviation of earths normal ellipsoid-form rotation around the sun; every 400kyrs and 100kyrs

2. Obliquity: Deviation in the “tilt”-angle of earths N-S axis resulting in different radiation budgets for northern and southern hemisphere; every 41kyrs

3. Axial precession: “tumbling” of earths axis like a spinning top; every 23kyrs

·       Boron isotopes in carbonates of calcifying organisms!

·       11B and 10B are stable isotope fractions without decay or so

·       In aqueous solutions boron exists as two species

·       Uncharged boric acid [B(OH)3] prefers light isotope of B

·       Borate ion [B(OH)4-] prefers heavy isotope of B

à Usually, only borate ion is incorporated into biogenic carbonate because of the isotopic preferences à fractionation of Boron isotopes in calcifying organisms à tell the pH at which they were growing!

·       Common archives: forams (planktic and benthic), tropical and cold-water corals, coralline algae

·       pCO2 is high during interglacial timescales. Carbon partitioning between deep and surface ocean is the cause.

·       Control 1: Changing Ocean circulation due to extended Antarctic ice sheet -> hinders the formation of North Atlantic deep water -> NADW circulates much shallower and deep circulation from AABW stays confined -> does not bring up CO2!

·       Control 2: Changes in the biological pump -> increased Fe input during the last glacial maximum (LGM), mostly due to dust. Enhanced primary production -> enhanced CO2 sequestration and sedimentation out of the surface layer.

·       Control 3: Even at formation site in Antarctica -> AADW sinks and Circumpolar Deep Water rises (usually stream closely past each other) -> less mixing and exchange of DIC, due to the extended ice sheet of Antarctica and the increased spatial separation of the two current systems.

·       Antarctic

·       Fennoskandian

·       Laurentide

·       Greenland

·       Only very little/no methane will reach the atmosphere, as it is highly soluble and goes into the dissolved state. This of course is dependent on Henrys Law c = a * p(CH4). Alpha is the diffusion coefficient, which is highly temperature dependent and p(CH4) is the partial pressure of methane, within the bubble. Therefore, the amount of dissolution is of course highly site specific. However, the amount of released methane is not relevant for climate change.

Albitisation: replacement of alkali and plagioclase feldspars by albite

o   Lead (Pb)

o   Sulphur (S)

o   Natrium (Na)

o   RIGHT: Cobalt (Co)

o   RIGHT: Nickel (Ni)

o   RIGHT: Barium (Ba)

·       When sediments depositing: compact sediment and reduce pore space and squeeze out water (Short: sediment layers-> compaction)

·       Tectonic lateral stress

·       Mineral conversion (smectite->illite) (silicate tetraeders)

·       Respiration of organic matter (e.g..: AOM anaerobic oxidation of methane) = decomposition of OM

·       smectite illte conversion -> illite creates when smectite pore water gets out and in deeper depths other material gets in

·       Oxygen has the highest Gibbs free energy yield (in negative kJ/mol) and SO42- the lowest. Sulphates still play a substantial role because of their high concentration in seawater.

·       O2 > NO3- > Mn4+ > Fe3+ > SO42-; CH2O

·       Oxygen availability in sediments is a function of POM deposition. Sedimentation rates and thus deposition is a function of proximity to the coast (high nutrient input -> high productivity) and the respective water depth (overall amount of POM remineralization increases with water depth = time to remineralize before deposition). Therefore, generally, POM deposition is higher at continental margins and remineralization processes within the sediment respire the available oxygen quickly. Oxygen penetration into the sediment is therefore less.

·      

o   lower magma temp

o   RIGHT: hydrothermal cooling

o   natural variations

o   measurement uncertainties

·       A large submarine volcano with a record of intense pyroclastic activity

·       A region of anomalously thick oceanic crust created by plume-related melts in the upper earths mantle

·       Area containing extensive granite intrusions into oceanic crust

o   Is a measure of the ratio of stable isotopes -> used as a measure of the temperature of precipitation and groundwater interaction

o   Measured though differences of 18O and 16O

o   Right: Surface Structural 

-       60% 1 Africa. 1.1 Angola. 1.2 Botswana. 1.3 South Africa. 1.4 Others.

-       2 Asia. 2.1 Russia. 2.2 India. 2.3 Indonesia.

-       3 Australia.

-       4 North America. 4.1 Canada. 4.2 United States

PO43– release upon reductive Fe-oxide dissolutions. In deeper sediment layers, the anoxic conditions redissolve previously bound (O/OH) irons to Fe2+. Phosphate shows high adsorption to particulate Fe(III) species, thus, if these get dissolved, PO33- will also resuspend.

a.     K-feldspar

b.     Na-feldspar

c.     Biotite

d.     quartz

1. lithostratigraphy

2. biostratigraphy

3. magnetostratigraphy

4. absolute dating

   1. radiometric dating

   2. ice cores

   3. wave chronology

   4. growth rings

   5. snow accumulation

5. oxygen isotope stratigraphy

a.     More carbon storage in deep sea: CO2 low in atm

b.     Changing ocean circulation; glacial max: much shallower mixing -> efficiently carbon storage in deep sea

c.     Boil pump: glacial max: increase dust imput-> iron leads  to high pp ->take up of co2 and downward flux