Know hows

1. magmatic rocks: igneous rocks

• Intrusive: gabbro granite

• Extrusive: basalt andesite

1. metamorphic rocks

   • foliated: schist

   • Non foliated: marbie

2. sediments

   • clastic: mudstone

   • Chemical: limestone, evaporites

   • Biologic: chert, ceal

basalt

1. below ccd

2. low sedimentation rates

3. moderate sea surface productivity

• Development of modern salinity contrast between

Atlantic (Caribbean) and Pacific in surface waters

• Development of modern Caribbean warm pool

• Intensification of Gulf Stream System

• Increase of heat, salt and moisture transfer into

the N-Atlantic (heating of NW-Europe)

• Increased formation of N-Atlantic intermediate

and deep water masses

-> leading to intensification of northern hemisphere glaciation

1. due to warming: enhanced evaporation of n atlantic

2. freshening of arctic ocean -> sea ice formation

3. raises albedo and reduces heat exchange -> cooling

4. fresher arctic outflow slows down AMOC -> cooling

• Strengthening of the East Australian Current (EAC)

• Weakening of the Leeuwin Current (LC)

• Cooling of the Indian Ocean and warming of the W-Pacific

• Intensification of the E-W temperature gradient across the eq. Pacific

• El Niño >>> La Niña dominated climate state

• Onset of Pliocene Northern Hemisphere glaciation

(Cane und Molnar Hypothesis, 2001)

which led to: effects on indian pcean and east africa

• Weakening, cooling, freshening of Australasian Mediterrane Water (AAMW) throughflow

• Intensification of E-W temperature gradient in the eq. Indian Ocean

• Shoaling of the thermocline

• Cooler surface ocean, less evaporation over Indian Ocean

• Less precipitation over E-Africa expected

Boron isotopes

Ø boron is conservative in seawater (t > 10 Myr)

Ø open ocean concentration: 432.6 μmol/kg * S/35

Ø two isotopes: 11B (~80%) and 10B (~20 %)

Ø expressed in delta notation relative to a standard:

• aqueous solutions: born in 2 species

  • uncharged boric acid B(OH)3

  • borate ion B(OH)4-

• usually only borate ion is incorporated into biogenic carbonate

• -> isotopic composition can be measured and then conversed into pH estimates

A measured benthic marine 14C age will always be older than the

corresponding planktic 14C age. The difference tells us about deep ocean

ventilation rates.

• sw also lower delta14c than ambient atm

• -> reservoir effect

• therefore not simply a calendar age

• no, is in constant state of change

1. temporarily variable carbon partitioning between deep ocean and atm

• deep water ventilation rates over past 30 ka

• boron isotopes, B/Ca and delta13C help assess the marine carbon budged in older sedimentary phases

• but: reliable long term marine carbonate system data production is expensive and challenging to achieve

1. changing ocean circulation

2. more efficient glacial export production

• benthic and pelagic denitrification: primary sink of fixed nitrogen

  • N decrease if reduced conditions (low oxygen)

• P released into pore water upon remineralization of OM

  • anoxic: p and fe can be recycled back to water

  • sediments: source for p and iron

  • P and fe increase if reduced conditions

• externally triggered changes in marine productivity and oxygen levels can trigger these mechanisms -> marine ecosystems

• higher methane flux = lower sulfate bc methane pushes out sulfate reductions

• reduces sulfate -> methane then oxidied and smaller portions are coming to shallower depth, rest is oxidated

• -> very little is released to atmosphere

• f.e. in subduction zones

• methanogenesis from archea with other microbes or via abiotic processes

• methane important green house gas

• 
  

1. nitrate limitation

2. phosphorous limitation

3. iron limitation (iron is limiting pp)

o   Blue: oxygen concentration increased, red decreased, mostly due to global warming

o   Less oxygen transported by currents when warmer temp, and oxygen cant be hold in water column in warmer temperatures

affect on sedimentary nutrient fluxes:

1. nitrate (1000y): low oxygen leads to less nitrate

   1. due to more denitrification (more N2) -> nitrate inventory becomes smaller

   2. less pp and less oxygen consumption

   3. -> negative feedback

2. Phosphorous (10.000y)

   1. positive feedback bc of more release (coupled with iron)

   2. release due to sediments during anoxic conditions

3. Iron: more release -> positive feedback

   1. iron concentrations are low -> low residence time bc taken up rapidly (around 10y?)

   2. release due to sediments during anoxic conditions

feedback will unfold in different timescales!

and also interact with each other -> question hard to answer hoe oxygen changes is shaping future

1. OM consists of range of constituents with more labile components disappearing during early stages of diagenesis

2. inorganic minerals which are more abundant at c margins, protect OM from oxidation

3. aerobic OC degradation is more efficient than anaerobic degradation

gibbs free energy (calculated using concentrations measured in field)

= available energy which determines the vertical redox zonation observed in marine sedimentary environments

1. rate of POC degradation

2. thickness of various biogeochem zones

• continental shelf: OC remineralization coupled to sulfate reduction

  • receive a lot POC -> O2 consumed early -> sulfate reduction starts at 10cm sediment depth

  • starts after nitrate mn and iron ocides consumed

• deep sea: aerobic remineralization of OC

  • receive less POC, O2 more in sediment -> little POC left to drive szlfate reduction (already consumed by aerobic respiration)

Diagenesis is the process by which sediments evolve after they are deposited and begin to be buried,

o   Atlantic bottom is younger= more oxygen

o   Oxygen minimum zones more pronounced in pacific

1. infiltration of cold seawater

2. heating of seawater > 400°C

3. dissolution of metals from volcanic rocks

4. precipitation of element-enriched hot water at contact with cold seawater

5. black smokers -> massive sulfides

• potential: ca. 600 mio tons of sulfides

strato volcano

pyroclastic flow

plinian eruptions

phreatomagmatic eruption

phreatomagmatic eruptions

etna - violent strombolian eruption

strombolian

hawaiian - lava fountains

hawaiian

submarine eruptions

maars and tuff rings

scoria cones

atlantic: 5000m

indian: 4300 m

pacific: 4200–4500 m

calderas

Uniformitarianism is the notion that the geological processes occurring on Earth today are the same ones that occurred in the past. This is an important idea because it means that observations we make today about geological processes can be used to interpret and understand the rock

record

• Terrestrial and marine geological principles and processes are the same • Some geological processes almost exclusively happen in the ocean and are thus specific to marine geology (e.g. hydrothermal vents, ocean seafloor spreading, subduction zones, …)

• Some rocks are only formed in the ocean, e.g. massive sulphide deposits • Different and additional methodologies are needed compared to terrestrial

geology to acquire data and samples

Fold belts Appalachians - Caledonides

Age provinces Geological age provinces are found on different continents, e.g. Pre-Cambrian rocks of the South American and African shields can be correlated across the Atlantic.

Igneous provinces Similarity of belts of extrusive and intrusive rocks (e.g. South Africa, Antarctica and Tasmania).

Stratigraphic sections

Metallogenic provinces Similarity of natural mineral deposits

(e.g. Mn, Fe, Au, Zn)

Convergent plate boundary: plates are colliding with each other (compressional) -> subduction

Divergent plate boundary: plates are pulling apart from each other (extensional) -> rifting

Transform plate boundary: plates are sliding past each other (“strike-slip”)

convergent and divergent also habe significant component of transform motion

formed by divergent plate boundaries

amount of magma supplied to ridge is controlled by

1. sea level change

2. mantle processes

• dextral movement (right lateraL

• this geological process, at divergent marins, is called-> strike-slip faulting

σ1 is the greatest principal stress (highest stress) σ2 is the intermediate principal stress σ3 is the least principal stress (lowest stress)

Generally speaking, we can say the following: Divergent plate boundaries: σ1 is vertical, normal faults form Convergent plate boundaries: σ3 is vertical, reverse faults form

Transform plate boundaries: σ2 is vertical, strike slip faults form

Stress / Pressure = density x G x depth (where G is gravitational acceleration = 9.81 m/s2

1. Calcite (CaCO3) and dolomite (CaMg(CO3)2)

2. Gypsum (CaSO4 • 2H2O) and anhydrite (CaSO4).

3. Halite (i.e. common salt, NaCl)

4. Potassium and magnesium salt

• forming sediments due to erosion from mountains -> transported trough river

• grinded down (smaller) and may come to ocean and into deep waters

• also tracked due to winds

• < 2 µm: Clay

• < 2 mm: sand

• silt: in between

• both structured in organisms

• CaCo3 but different cristal structures

  • Aragonite: hexagonal

  • Calcite: Trigonal

• Aragonite dissolves in anaerobic environment dissolves quicker than calcite

• longitudal: sound

• Transversal: light, wifi (electromagnetic)

• primary waves dont go through liquid

• earth quakes due to seismic waves (sound)

1500 m/s

= topography underwater

north Atlantic and southern ocean (sou ocean is upwelling from deep water)