Notes from exam questions Flashcards
What is the redfield ratio?
C(106) : N(16) : P(1)
What is the extended redfield ratio
C(106) : N(16) : P(1) : 0,1-0,001 Fe
(Fe, Mn, Zn) 0,01
(Cu, Ni, Cd) 0,001
Draw the log C- pH diagram for carbonate
H2CO3 * for pH<6,3
HCO3 - 6,3<pH<10,3
CO3 2- pH>10,3
What four parameters affect the growth rate of phytoplankton?
Availible CO2
Sunlight (wave length 400-700 nm)
Availible nutrients (20 essential elements)
Water
In which order do the element occure in the redox ladder?
O2 –> H2O
NO3 - –> N2
MnO2 –> Mn 2+
FeOOH –> Fe 2+
SO4 2- –> H2S
CO2 –> CH4
What elements doesn’t form “hard dissolved” hydroxides?
Zn (ZnS)
Cd (CdS)
Pb (PbS)
Ni (NiS)
Cu (CuS)
They go into solution (have no acidifying effect)
What is the diffrence between acid base reactions and redox reactions?
Acid base: H+ is exchanged
Redox: e- is exchanged (e- doesn’t exsist as species in water, H+ do)
How is ionic potential defined?
ion charge/ion radius
What material ca be found in the sediment?
Detrital material: silicate minerals and carbonate minerals
Non-deterital material (organic matter): Dead plankton, Diatom shells (SiO2)
How do you define delta 18O?
delta 18O = ( (18O/16O)sample - (18O/16O)standard ) / (18O/16O)standard *1000
How do you define delta 34S?
delta 34S = ( (34S/32S)sample - (34S/32S))standard ) / (34S/32S))standard *1000
What standard is used for oxygen isotope?
VSMOW: Vienna standard mean ocean water
VPDB: Vienna Pee Dee Betemnite (shells)
What standard is used for Carbon isotope?
VPDB: Vienna Pee Dee Betemnite (shells)
What standard is used for sulfur isotope?
CDT: Cañon Diablo troilite (FeS), a meteorite
When is gibbsite formed?
Tropical, wet climate (much water flow)
