Indian Institute of Technology Guwahati (IIT-G) 2006 M.Sc Computer Science JAM (ENTRANCE FOR IN IITs) GEOLOGY - Question Paper

principal indices of refraction 1.486 and 1.658. ans the subsequent.
(i) What is the maximum birefringence of the mineral? (3)
(ii) Giving reason, state the value of n ? (3)
(b) (i) Draw and tag the interference figure of the above mineral for orientation
perpendicular to the c – axis. Show vibration directions of the ordinary and
extraordinary rays in all the quadrants. (3+3)
(ii) Which 3 optical properties do you study in part parallel to (010) of a
monoclinic crystal? (3)
33. (a) (i) What is an aquifer ? (3)
(ii) describe the term ‘water table’. (3)
(iii) Draw a neat, tagged sketch to show perched water table (3)
(b) (i) describe a confined aquifer. (3)
(ii) describe an aquifuge. (3)

34. (a) (i) Draw a tagged diagram to show the earth’s ‘S-wave shadow zone’. (6)
(ii) Mention its significance. (3)
(b) Name the submarine mechanisms that can trigger a ‘Tsunami’. (6)

35. The map beneath indicates the outcrop trend of a folded sequence of beds A, B, C and
D. Also shown is the projected cross bed in the north-western part of the map.
(a) (i) Interpret the structure. (6)
(ii) Locate the possible hinge zone on the map, and provide justification. (3)
(b) Draw a part along X-Y and establish the stratigraphic sequence, based on the
assumption that there is no stratigraphic inversion of strata. (3+3)

36. The geological map indicates the outcrop trend

of the 1st appearance of mineral/mineral
assemblage in metamorphic rocks of fixed
bulk composition. ans the subsequent
questions.
(a) (i) What is the protolith of these rocks? (3)
(ii) elaborate these lines called? (3)
(iii) Name a model metamorphic reaction,
which produces K-feldspar-sillimanite
assemblage.
(3)
(b) (i) Name the metamorphic facies series and the tectonic setting, which discuss the
occurrence of these minerals. (3)
(ii) Can garnet reappear in any other part of the metamorphic sequence? Justify. (3)

37. The cross-section beneath indicates the relationship ranging from various igneous features.
Also shown are the igneous textures related to a few of these igneous features.
(a) (i) Name the igneous features in locales B, C and D. (3)
(ii) Identify the igneous textures in A and B. (3)
(iii) Name the rocks at A, B and D. (3)
(b) What causes textural variation in rocks A, B and D? (6)

38. Study the isobaric binary phase diagram of NaAlSiO4 - SiO2 provided beneath and ans
the subsequent ques..
(i) obtain out the mineral assemblages in A, B, C, D, and the line Y and
composition X. (9)
(ii) Using this diagram, discuss why nepheline and quartz do not co-exist in nepheline
syenite. (6)

39. (a) Name the 3 main suture kinds obtained in ammonoid cephalopods, and provide tagged
diagrams for every. (3+3+3)
(b) (i) How does a brachiopod shell differ from a pelecypod shell with respect to the
valve size and the plane of symmetry? (3)
(ii) Name 1 formation known for yielding late Cretaceous dinosaurs in India.
(3)
40. (a) Name the subsequent
(i) Precambrian basement underlying the Proterozoic succession in the
Aravalli belt. (3)
(ii) Early Cretaceous continental flood basalts in Peninsular India. (3)
(iii) Youngest formation of the Siwalik Group. (3)
(b) Name the subsequent
(i) Any 3 chronostratigraphic units and their corresponding geochronologic
equivalents. (3)
(ii) The 3 successive tectonic divisions of the Himalaya starting from the
southernmost division. (3)
41. (a) (i) Why does a SiO4 tetrahedra never share edges or faces with its neighbouring
tetrahedra ? (3)
(ii) Why does a 5 -, 7 - or ten - fold symmetry not exist in crystals? (3)
(iii) Deduce the H-M symbol from the stereogram provided beneath. (3)
b) (i) State 3 reasons that can reason twinning in minerals. (3)
(ii) What is a twin law? (3)

42 a) (i) What is sublimation process?
(ii) elaborate stockwork and saddle reef ore deposits?
(iii) Name at lowest 3 common surface mining methods. (3+3+3)
b) (i) elaborate eluvial placer deposits? (3)
(ii) Name any 2 lignite deposits of India. (3)

43. (a) describe
(i) throw and heave of a fault.
(ii) disconformity and nonconformity . (3+3)
(b) A sequence of beds A, B and C dipping due west, is affected by a vertical strike
ault with downthrown block to the east. If the fault is passing through the
western- most bed, show the effect of faulting and erosion on the outcrop trend
through block diagrams. (9)

44. (a) Draw a tagged diagram to show 3 major plate boundaries. (3+3+3)
(b) Mention the 4 evidences for continental drift. (6)

Earning:   Approval pending.