Physical properties of sea water Water makes up more than 96% of the total mass of seawater, so it is appropriate to begin with a short discussion of the properties of water itself. The weather and climate on Earth are in several ways controlled by the physical properties of water. Some of the important properties are,   a. its expansion when freezing,  b. its infrared absorption causes water vapor to be the most important greenhouse gas,  c. its radiative properties cause water to be important in the radiation of heat away from Earth, d. Variations from place to place in its isotopic composition provide insights into several aspects of Earth science, e. The chemical property of water that is perhaps most important to the marine chemist is its high solvent power for polar substances and substances that form charged ions in solution etc.,    Physical properties of water:      The boiling point of water is unusually high. This very hig...

Hypsography of the continents and ocean floor       Hypsometry is the measurement of land elevation (relative to mean sea level). Bathymetry is the underwater equivalent. A hypsometric curve is a histogram or cumulative distribution function of elevations in a geographical area.         Continental margin Continental margin, the submarine edge of the continental crust distinguished by relatively light and isostatically high-floating material in comparison with the adjacent oceanic crust. It is the name for the collective area that encompasses the continental shelf, continental slope, and continental rise. Continental margins are about 28% of the oceanic area. A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water known as a shelf sea. Much of these shelves has been exposed during glacial periods.           The continental shelf (approx 0.1°), steep continental s...

 From Basics to Advanced Question No. 1. A thin horizontal coal seam outcrops at an altitude of 600 m. Trace the outcrop, describe the topography of the area. Comment on the trend of the outcrop.  Solution Question No. 2.  A thin horizontal coal seam outcrops at point ‘P’. Trace the outcrop, describe the topography of the area. Comment on the trend of the outcrop.  Solution Question No. 3. A thin horizontal coal seam outcrops at an altitude of 325 m contour. Trace the outcrop, describe the topography of the area. Comment on the trend of the outcrop. Solution Question No. 4. A thin Vertical coal seam outcrops at point ‘P’ and its strike is in the N-S direction. Trace the outcrop, describe the topography of the area. Comment on the trend of the outcrop.   Solution Question No. 5. A thin Vertical coal seam outcrops at point ‘P’ and its strike is in the E-W direction. Trace the outcrop, describe the topography of the area. Comment on the trend of the outcrop....

  Rocks of Mechanical Origin – Rudaceous        Sedimentary particles of mechanical (terrigenous) origin are classified according to their size. Particles larger than  2 mm  constitute  gravel  (Latin-rudite), those between  2 and 1/16 mm  constitute  sand  (Latin-arenite), while those  finer than 1/16 mm  constitute  silt and clay  (Latin-lutite). Accordingly, sedimentary rocks of mechanical origin are classified broadly into three groups:  Rudaceous, Arenaceous  and  Lutaceous  (aka  Argillaceous ). Rudaceous Sedimentary Rocks  (Conglomerates and Breccias) Unconsolidated sediments coarser than 2 mm are grouped under the term gravel. Indurated gravels are called conglomerates. While the particles constituting a conglomerate are essentially rounded, a breccia consists of gravel-size clasts which are angular. The term rubble is applied to an assemblage of loose angular fragm...

  Classification of sedimentary rocks      After transportation and deposition loose sediments are consolidated into sedimentary rocks by a process called diagenesis. The sedimentary rocks thus formed may be broadly divided into two groups: Exogenetic and Endogenetic      Exogenetic  rocks are the products of fragmentation of the source rock outside the basin of sedimentation.  Endogenetic  rocks are produced out of precipitation from solution within the basin. The exogenetic and endogenetic rocks can be distinguished by their textures. While the endogenetic rocks show an interlocking or crystalline fabric (‘non-clastic’ texture), the exogenetic rocks show discrete framework grains separated by voids. The latter texture is called ‘clastic’ from the Greek clastos, meaning broken      Classification of sedimentary rocks into  clastic  and  non-clastic , though popular among sedimentologists, may at times lead ...

  Residual deposits What is it? The residual deposits are the insoluble products of rock weathering which have escaped transportation. They are found over the rocks from which they have been formed. The rocks belonging to this class are made up of two components. Unaltered minerals from the original rock The insoluble products of chemical weathering. Its texture? The residual sediments are composed of unsorted and angular materials as they have not suffered transportation. The grain size of the deposits are determined by the nature and grain size of the weathered rock.  Some of its types: (a) Terra Rossa: This deposit is found in limestone countries in arid regions. Terra rossa is a reddish clayey soil covering the limestone country rock. constituting the insoluble residue of clay and other mineral matter after removal of the limestone by solution. In areas of comparatively high rainfall, the terra rossa is washed into depression, swallow holes and caves soon after its formati...

  What is a sedimentary texture?      The term texture refers to the pattern formed within a sedimentary rock by the constituting grains. This can best be studied under a microscope. Classification of sedimentary texture      In sedimentary rocks of  Mechanical origin , formed by weathering, erosion, transportation, deposition followed by diagenesis & Lithification, the framework grains are joined together, either by finer fragmental particles or by chemically precipitated cement. The former is called  matrix  and the latter, c ement . The pattern formed by framework grains, matrix and cement is called (a) Clastic texture . Sandstones show this kind of texture.      The texture of a rock of  Chemical origin  is produced wholly by chemically precipitated materials. No inter-granular space is to be found in such a rock. Limestones of orthochemical origin show this kind of (b) Non clastic texture .    ...