Geochemistry Geochemistry of Rocks Igneous
Rocks Metamorphic Rocks Sedimentary Rocks
Geochemical Geochemical Cycles Chemical Weathering
Geochemistry of Isotopes Geochemistry of Water Environmental Geochemistry Exploration Geochemistry
Faure (1996): Principles and Applications of Inorganic Geochemistry Krauskopf & Bird (1995): Introduction to Geochemistry Albarede: Essentials of Geochemistry Rollinson: Using Geochemical Data
The field of geochemistry involves: Study of the chemical composition of the Earth and other planets.
Chemical processes and reactions that govern the composition of rocks, water, and soils, The cycles of matter and energy that transport the Earth's chemical components in time and space.
In this class, we will use Geochemistry to understand: : natural distributions of chemicals in global and local environments. : The birth of matter in our solar nebula, formation of the solar system and early Earth history. : chemical distributions in anthropogenically "perturbed“ systems (using chemical fundamentals to explain the condition of the environment there).
Isotope geochemistry: Determination of the relative and absolute concentrations of the elements and their isotopes in the earth and on earth's surface. Examination of the distribution and movements of elements in different parts of the earth (crust, mantle, hydrosphere etc.) and in minerals with the goal to determine the underlying system of distribution and movement.
Cosmochemistry: Analysis of the distribution of elements and their isotopes in the cosmos. Organic geochemistry: A study of the role of processes and compounds that are derived from living or once-living organisms. Environmental and exploration geochemistry: Applications to environmental, hydrological and mineral exploration studies.
Until 16th century, it was believed that earth is made up of four elements. Fire Clay Water Air The name “geochemistry” was first introduced by since more than 150 years.
Two factors played key role in development of Geochemistry Discovery Methods
of elements
of rock analysis
Clark, who was a chief chemist of the US. Geological Survey from 1884 to 1925, has contributed a lot to the science of geochemistry. He published a very large number of chemical analyses of the various rocks in the earth's crust. He computed averages for each common rock type and studied the mutual abundance and distribution of many major and minor elements. Goldschmidt (1888 - 1947) contributed significantly to the roles of ionic size, coordination and atomic substitution in crystal lattices. He gave a practical definition for the science geochemistry, as it deals with: 1) the abundance of elements in rock, mineral or crystal, 2) the distribution of the elements, and 3) laws governing the abundance and distribution of elements in rock, mineral or crystal.
The combined forces of cause materials to move about Earth from place to place. This movement of matter often includes chemical transformations conducted by .
The more we understand natural cycles, the better equipped we are to caused by our continuing industrialization, which usually involves altering the natural order of things. Earth Scientists often find it convenient to think of various parts of our planet as containers between which matter moves. These containers are referred to as
Movement of material between these reservoirs is known as a flux. Concentration changes in space and time in reservoirs are determined by Transport equations.
Reservoir A
Flux
Reservoir B
Reservoir is any of the natural world that acts semi-independently We can define reservoirs differently depending upon the problem we are studying i.e., the hydrosphere might be defined as the location of all water on Earth. Sub-reservoirs can also be defined, such the oceans, rivers, glaciers, lakes, etc...)
We divide earth in four major reservoirs
Atmosphere Biosphere Hydrosphere Lithosphere All earth material and energy moves within these reservoir.
Hydrosphere broadly consist of all water bodies on earth. E.g. oceans, rivers, lakes etc Hydrological cycle is an important process in which water moves within various reservoirs.
Obvious compositional contrast, and physical location clearly differentiates the atmosphere from the rest of the Earth.
This is up to the person defining the cycle to some extent but it is unlikely that one would choose to include the gases in soil pore spaces as part of the atmosphere.
It is also the called lithosphere and includes the solid Earth including soils.
Our emphasis will be on surface processes that part of the geosphere which is connected to the exogenic cycle.
The sum total of all living entities on the Earth. Life resides in the hydrosphere, geosphere and atmosphere. A key aspect of the biosphere is its ability to create “stored chemical” energy through processes such as photosynthesis.
The effects of human activity on various natural processes can cause imbalances. The chemical signatures of human activity touch nearly every natural process. Can you think of any such activity which has alter the natural equilibrium????
Atmosphere
Hydrosphere
Biosphere
Geosphere Anthrosphere
