GEOCHEMISTRY Flashcards
- Who first coined Geochemistry, where and when?
Christian Friedrich schonbein, 1838, Univ of Basel, SZ
- Who is the Father of Geochemistry considered as the first Geochemist?
Frank Clarke
- What was his book and when was it published?
Data of Geochemistry, 1908
- This refers to the average concentration of Elements in the crust
Clarke of Concentration
- Who is the father of modern geochemistry and crystal chemistry who correlated the mineral formation and structure to its chemical composition?
Victor Goldschmidt
Classification of Minerals according to preferred Hosts
Lithophiles = Rock and Oxygen Loving
Chalcophiles = Ore Loving Sulfur Loving
Siderophiles = Iron Loving
Atmophile = Gas Loving
- Study of the Chemistry of the universe
Cosmochemistry
- Theoretical Age of the UNiverse
13.7 Ga
- Who proposed big bang theory?
Belgian Priest, George Lemaitre
Model of the evolution of the universe that postulates its origin from a hot dense mass that expanded rapidly and cooled
Big Bang
- When was big bang proposed?
1920s (1927)
- Evidences or Supporting observation of Big Bang?
1) REd Shift or the Expansion of the Universe
2) Abundance of light elements such H, He, Li, and
3) Pervasive Background Radiation or Cosmic Microwave Background (CMB) radiation
- Who proposed Red Shift and when?
Edwin Hubble in 1929
- Who obseved the Cosmic Microwave Radiation?
Arno Penzias and Robert Wilson in 1965
- Where was CMD first observed?
Bell Telephone Laboratories
- What 2 methods were used by scientists to date the universe?
1) Oldest Stars, and
2) Extrapolation though the rate of expansion of galaxies
A segment of universe formation wherein the universe became neutral and Opaque
Dark Age
End of Dark Age
Cosmic Ionization
Nuclear Process which forms stars
Nuclear Fusion
- This is the process of creation of elements
Nucleosynthesis
- This refers to the creation of H, He, and Li during the first few moments of big bang and became the starting ingridients for all other elements?
Cosmological Nucleosynthesis
- This refer to the creation of elements with atomic masses up to 26Fe through variety of nuclear reactions
Stellar Nucleosynthesis
- How are elements with atomic masses greater than 26 created?
Through explosive burning during supernova
- Sequence of burning during nucleosynthesis
H - He - C - O - Si- Fe
- What is the constant H:He ratio which is largely dictated by Big Bang?
12.5
- Why is Li, B, Be anomalously low in concentration?
Because they are unstable and are tend to be used and destroyed in the production of C12
- What is Oddo Harkins Rule?
sawtooth pattern of elemental abundance in the universe in whic elements with even atomic numbers are more abundant than those with odd atomic numbers
- This element has the highest binding energy per nucleon and is the most stable
Fe
- This is the diagram used to classify stars
Hertzsprung-Russel Diagram
- Which are the hottest stars?
White Dwarfs
- Who proposed Nebular Hypothesis (2)?
Immanuel Kant and Pierre Simon de Laplace
- How did scientist discover the age of the solar system?
Determining the age of the oldest rock
- What is the oldest rock in the earth?
Rock 14321 found in Moon
- Who and when was the rock discovered?
Alan Shepard, Apollo 11 Astronaut in Feb 6, 1971
- How old is the rock and what dating technique was used?
4.011 Ga, Zircon Dating
- What is the oldest Material on earth
Pre-Solar Grains of Murchison Meteorite which fell in Australia in 1969
- Age of the oldest materials and what dating technique used?
7.5 Ga Neon21 Isotope
Oldest material formed on Earth and its age?
Jack Hills Zircon in a Quartzite/Metaconglomerate 4.4Ga
Where was this oldest material found?
Western Australia
- What similar compositions do terrestrial plaents have?
high temp minerals, Fe-Mg Silicates Metallic Alloy
- What similar compositions do Jovian Plaents have?
Low temp minerals, Methan, Ammonia and Water
- This is the arrangement of condensation of minerals depending on the temperature and distance from the sun
Condensation Sequence
- The line which marks that the temperature is cold enough for volatile compounds to condense into solid grains
Frost line
- Relative abundance of Materials in the Solar Nebular
98% Light gases
1.4% H cmpds
0.4% Rocks and
0.2% Metals
39 Solar system composition by mass
Sun 99.85%,
0.10% Jupiter
0.04% other planets,
0.01% Comets
0% satellites, rings and asteroids, Meteroids and
dut 0.0000001%
- Meteorite whch comes from differentiated planetisimals with Taenite as primary composition?
Magmatic Fe Meteories
- Composed of Pallasites and Mesosiderites?
Stony Fe
- Composed mostly of basaltic rocks from crusts and mantle of planetisimals
Achrondrite
- Most abundant meteorite
Ordinary Chondrites
- Meteorites composed of Magnesium Pyroxene
Enstatite Chondrites
- These are the most primitive Chondrites
Carbonaceous Chrondrites
- What does Carbonaceous Chronites represent?
Bulk Composition of the Sun
- Difference between chemical and physical classifications of earth’s layers?
The former depends mainly on composition while the latter depends on the rheology
- Differentiate Oceanic and Continetal Crust based on Composition?
Oceanic is Basaltic (SiMg) in COmposition while Continental is Granitic to Granodioritc (SiAl)
- Differentiate Oceanic and Continental Crust based on Ave. Thickness?
Oceaning is 6.5-7 km while Continental is 35km
- Thickness range for Oceanic Crust
3-15 km
- Thickness range for Continental crust
20-60km
- DEnsities of Oceanic and Continental Crust respectively?
3.3g/cc and 2.7g/cc
- Differentiate Lithosphere and Asthenosphere based on Rheology and COmposition?
Lithosphere is brittle and is composed of the whole Crust and the Upper Mantle while Asthenosphere is ductile and is composed of the Upper Mantle
- The discontinuity between Curst and Mantle?
Mohorivicic
- The discontinuity between Mantle and COre?
Gutenberg
- The discontinuity between outer and inner core?
Lehmann
- Bulk density of earth?
5.52 g/cc
- Why do earthquakes have a maximum depth of 100km?
BEcause the lithosphere’s rigid environment generates earthquakes and it exists only up to 100 lkm
- What generates the magnetic field of the earth?
Convection of the liduid outer core and the rotation of the earth
- Beta polymorph of Olivine?
Wadsleyite
- Gamma polymorph of Olivine?
Ringwoodite
- Why is there a discontinuity at 400km in the mantle?
Because Olivine has undergone phase transformation
- Composition of the Lower Mantle?
Brdigmanite or Mg Pervoskite
- Who and when was periodic table discovered?
Dmitri Mendeleev 1864
- Nuclides of the same chemical ellement having diff atomic masses?
Isotopes
- What is the name of the Group IA of the periodic table?
Alkali metals
- What is the name of Group IIA?
Alkali Earth Metals
- What is the name of Group IIIB to IIB?
Transition Metals
- What is Group IIIA to VIIA
Non-Metals
- What is Group VIIA?
Halogens
- What is Group VIIIA?
Noble Gases
- Bonds wherein electrons are shared?
Covalent
- Bonds wherein Electrons are transferred?
Ionic
- Elements which accepts Electrons and is negatively charge?
Anions which are mostly non Metal
- Elements which donates electrons and is positively charged?
Cations which are mostly metal
- Bonds in which positively charged nucleus are surrounded by a sea of electrons that are freely moving?
Metallic bond
- Minerals with same chemical composition but have diff crystal structure?
Polymorph
- Minerals with the same crystal structure but have diff chemical formula?
Isomorph
- What is the difference between Calcite and Aragonite?
Calcite is Hexagonal, Araonite is Orthorhombic
- What is the difference between Pyrite and Marcasite?
Pyrite is Isometric while Marcasite is Orthorhombic
- This silica polymorph is used as an indicator of an ultra-high pressure environment or rocks
Coesite
- This silca polymorph are usually found in impact craters and display birefringence uner the microscope?
Shock Quartz
- Difference between Kyanite, Sillimanite and Andalusite?
Sillimanite and Andalusite are Orthorhomnbic and goes extinct under the microscope while Kyanite is Triclinic
- Difference between Diamond and Graphite?
Diamond is Isometric while Graphite is HExagonal
- Differentiate Sanidine, Orthoclase, and Microcline?
They are all k-felds but Sanidine and Orthoclase are Monoclinic while Microcline is triclinic. Sanidin forms in the highest T among the three while Microcline is the lowest. They are polymorphs based on order-disorder
- Which of the Goldschmidt Classification of Elements are mostly found in the Core?
Siderophiles because these element have high density and sink into the core and readily dissolves in Iron
- Which of the Goldschmidt Classification of Elements are mostly found in the Crust?
Lithophiles because these elements readily combine with oxygen
