Geology CSS Paper I 2002

FEDERAL PUBLIC SERVICE COMMISSION
COMPETITIVE EXAMINATION FOR RECRUITMENT TO POSTS
IN BPS – 17 UNDER THE FEDERAL GOVERNMENT, 2002.

GEOLOGY, PAPER – I

TIME ALLOWED: THREE HOURS MAXIMUM MARKS:100

NOTE: Attempt FIVE questions in all, including question No. 8 which is COMPULSORY. All questions carry EQUAL marks.

1. Define bedding and stratification. Discuss various types of bedding. Which features are employed to check whether the beds are right side up or over turned?

2. What are unconformities? Discuss various stages involved in their development and describe with the help of diagrams various types of unconformities.

3. What is he base of division of crystals into Systems and Classes? What are the peculiarities of the “Normal class” of a system? Describe the symmetry of the normal class of the Hexagonal System.

4. What are Feldspars? Keeping in view the Al/Si distribution over the non-equivalent tetrahedral sites in the structure of feldspar. What is a disordered feldspar?

5. Write an essay on the Foraminifera with special reference to their distribution in Pakistan.

6. What is incongruent melting? Draw Phase diagram of the binary system-Leucite-Silica. Describe the characteristic features of this system.

7. Discuss the difference in the Petrography; chemistry and occurrence of the Alkali basalt and tholeiitc basalt.

COMPULSORY QUESTION

8. (A) What is the difference between the following pairs (answer only in one or two lines).

(1) Orthoclase and Sanidine
(2) Microcline and Maximum Microline
(3) Biotite and Phlogopite
(4) Octahedral and Six-fold Coordination
(5) Normal and reverse fold
(6) Stalactite and stalagmite
(7) Gabbro and granite

(B) What is wrong with the following sentences:
(8) There is no difference between a fault and a joint.
(9) Forsterite is formed by the thermal metamorphism of sandstone
(10) In the thermal metamorphism of impure Mg-limestone a series of reaction are involved with progressive elimination of O2 from the system.
(11) Essential minerals within Granite and Gabbro are quartz, alkali, feldspar and biotile.
(12) M.K.T. separates the Indo-Pak Plate from the Kohistan Island arc.
(13) Hardness of quartz is 4 in the Hohs Scale of hardness.
(14) Kyanite and sillimanite are polymorphs of AI2O3.

(C) Write only the correct answer in the Answer Book. Do not reproduce the questions.

(15) Mg occupies the octahedral/tetrahedral coordinated positions in the silicate structure.

(16) The average thickness of oceanic crust is:
(a) 5 km (b) 35 km (c) 40 km (d) None of these

(17) Eclogite is the high pressure equivalent of:
(a) Gabbro (b) Diorite (c) Sandstone (d) None of these

(18) The basalt-andesite – dacite-rhyolite series of rocks occur in:
(a) Island arc environment (b) Continental marginal area (c) Orogenic belts (d) None of these

(19) On the A.F.M. diagram, the tholieiitic series exhibit:
(a) A non-iron enrichment trend (b) A high-iron enrichment trend (c) A moderate iron enrichment trend (d) None of these

(20) When there are two generations of crystals in the igneous rocks, the texture is described as:
(a) Porphyritic (b) Porphyroblastic (c) Aphyric (d) None of these

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