Question : Discuss with examples the influence of vulcanism and diastrophism on the evolution of landscape.
(1993)
Answer : There are various geological processes, forces and resultant movements which are involved in the creation, destruction, recreation and maintenance of geomaterials and numerous types of relief features, and thereby in the evolution of landscape. Of these, Endogenetic Forces coming from within the earth introduce various types of vertical irregularities such as mountains, plateaus, plains, lakes, folds, faults, craters etc. Vulcanism and diastrophism are also the expressions of endogenetic forces which contribute significantly in the evolution ....
Question : Define the concept of isostasy and discuss the postulations of Airy and Pratt.
(2007)
Answer : The theory of isostasy postulates a system for the distribution of material in the earth’s crust which conforms to and explains the observed gravity values. This theory was developed from gravity surveys in the mountains of India around 1850s. The results show that the actual force of gravity over the mountain range is considerably less than what it should be theoretically.
The concept of isostasy means that a state of equilibrium or balance exists in the ....
Question : Critically evaluate the continental drift hypothesis of A. Wegener.
(2006)
Answer : The drifing of continents was first suggested by the French scholar Antonio Snider in 1858, but this was so much opposed to the scientific view that nobodytook notice of it.
In 1910, F.B. Taylor of America invoked the hypothesis of horizontal displacement or continental drift with a view to explain the distribution of mountain ranges, but due to various reasons the hypothesis of Taylor received scant attention. German professor Alfred Wegener was the first to present ....
Question : Role of seismic waves in the study of earth’s interior:
(2005)
Answer : Seismology is the only reliable source which gives reliable knowledge about the interior of the earth.
There are three types of seismic wave:
Question : “Structure is a dominant control factor in the evolution of landforms.” Discuss with suitable examples.
(2005)
Answer : The given statement represents the geographical cycle of Davis. The gist of the cyclic concept is that commencing with an initial landscape, generally assumed to be one of low relief, the land surface passes through an orderly sequence of forms and eventually returns to a surface of low relief.
views that in order to understand the evolution of a particular land form/landscape, it is extremely important to know the stages of development were influenced by Davis. ....
Question : Describe the landforms which are products of endogenetic forces.
(2004)
Answer : There are various geological processes, forces and resultant movements which are involved in the creation, destruction, recreation and maintenance of geomaterials and numerous types of relief features. These forces are divided into two broad categories—Endogenetic Forces and Exogenetic Forces. Endogenetic forces refers to the forces coming from within the earth.
The interation of matter and temperature generates endogenetic forces or movements inside the earth. These forces introduce/produce various types of vertical irregularities and land forms such ....
Question : Explain the sequential development of landforms associated with the coastal areas.
(2003)
Answer : The theoretical cycle of marine erosion suggests that shoreline development follows a sequential order in which characteristic land forms are formed in different stages. In the initial stage most coasts are irregular but the normal tendency of marine erosion is to make the coasts regular in course of time. Hence initially erosional land forms are formed. After a period of time, the formation of depositional features start taking place. The depositional process dominates in the ....
Question : Provide a critique of the ‘geographical cycle’ model propounded by Davis.
(2002)
Answer : ‘No vestige of a begining; no prospect of an end’ and present is the key to the past, were few dictums which were debated before Davisian model of geographical cycle, came into existence in 1899. This model is based on the basic concept of sequential change in landform through time like the evolution of an organic life.
Davis has assumed two forces affecting the land surface:
(i)Endogenetic
(ii)Exogenetic
Question : With reference to the theory of Plate Tectonics, explainthe origin and growth of the Young Fold Mountain Systems of the world.
(2000)
Answer : Plate Tectonics is the most comprehensive and systematic theory which provides for the best and the most rational explanation for the distribution of oceans and continents, ridges and trenches and organic zones and the various process leading to these. According to this theory, the upper portion of the lithosphere is believed to consist of a mosaic of rigid plates, with an estimated average depth of about 100 Km. These plates are embedded in a somewhat ....
Question : Bring out the distinctions between the continental drift theory and the plate Tectonics theory.
(1999)
Answer : The most comprehensive and synthetic theory of Plate Tectonics which provides most rational explanation for many geologic and geomorphic phenomena, has evolved in a long process involving many researches, ideas and hypothesize the genesis of which can be rightly traced back to the theory of continental drift. The idea of continental movement relative to each other, originally suggested by Antonio Snider and later enriched by F.B. Taylor, was developed by German meteorologist Alfred Wegener, into ....
Question : Discuss the concept of volcanicity and show how the theory of plate tectonics explains the mechanism of volcanism and volcanic eruption.
(1998)
Answer : Volcanism includes all phenomena connected with the movement of treated material from the interior towards surface of the earth. In other words, volcanicity includes all those processes and mechanisms which are related to the origin of magmas, gases and vapour, their ascent and appearance on the earth surface in various forms.
Now it becomes clear that volcanicity has two components:
Question : Discuss the process of mechanical and chemical weathering and show their relationship with soil formation.
(1996)
Answer : Weathering has been defined as the total of all processes acting at or near the earth's surface to cause physical disruption and chemical decomposition of rocks in situ. Weathering by itself is a static process and does not involve removal of material. In other words, weathering is the process by which rocks are broken down and decomposed by the action of external agencies such as wind, rain, temperature changes, plates, bacteria, etc. Thus weathering is ....
Question : Discuss the limitations of the theory of Continental Drift and show how the theory of Plate Tectonics is an improvement over it.
(1995)
Answer : The modern theory of Plate Tectonics which provides most rational explanation for many geologic and geomorphic phenomena has evolved in a long process involving many researches, ideas and hypothesises the full scale genesis of which can be rightly traced back to the theory of Continental Drift. This view of non- stationary continents, first suggested by Antonio Snider and later enriched by F.B. Taylor,was developed by German meteorologist Alfred Wegener into a full-scale hypothesis.
In his theory ....
