Geography

Continental Drift Theory and its evidence

Q: The term sial is mainly related to which elements?

Silica and aluminium Correct answer: A, silica and aluminium. The traditional term “sial” is formed from the first parts of silica (Si) and aluminium (Al). In older descriptions of Earth’s crust, especially continental crust, sial referred to material rich in these components. B is incorrect because “sima,” another traditional term, is associated with silica and magnesium. C is associated more closely with the metallic composition commonly discussed for the core, not the meaning of sial. D does not define sial. These terms are traditional broad compositional labels, so they should not be treated as exact descriptions of every mineral or as a complete modern chemical analysis. Memory cue: SIAL = SIlica + ALuminium; SIMA = SIlica + MAgnesium.

Q: The term sima is mainly related to which elements?

Silica and magnesium The word sima is formed from the first parts of the words silica and magnesium. It was used in older descriptions of the Earth’s outer layers for material considered rich in these components and comparatively dense. In school geography, sima is commonly associated with the lower or oceanic part of the crust, while sial is associated with silica and aluminium and with lighter continental material. These terms belong to the traditional explanation of crustal composition. Option B, silica and magnesium, is correct. Option A describes the usual meaning of sial, so it is a useful contrast but not the answer to this question. Gold and silver, or oxygen and hydrogen, do not define sima. The simplest memory aid is “sima = silica + magnesium,” while “sial = silica + aluminium.” Thus the elements named in option B identify the term accurately.

Q: In Wegener's theory westward drift of continents was linked with which force?

Tidal force Wegener explained westward drift by tidal force. Exam tip: link tidal force with attraction of the Moon and Sun.

Q: According to Wegener pole-fleeing force was related to movement in which direction?

From poles toward the equator Pole-fleeing force was considered to move continents toward the equator. Exam tip: identify the direction from the name.

Q: The Continental Drift Theory helps explain which topic?

Distribution of continents and oceans The theory explains how present continents and oceans developed. Exam tip: connect it with Earth's landform pattern.

Q: Mesosaurus fossils are considered evidence of what?

Former connection of South America and Africa Mesosaurus fossils are found in South America and Africa. Exam tip: remember it as fossil evidence.

Q: Lystrosaurus fossil comes under which evidence category?

Fossil evidence Lystrosaurus fossils are found in several southern landmasses. Exam tip: connect it with fossil distribution.

Q: Similar mountain chains found on different continents indicate what?

Their former geographical connection Similar mountain structures suggest landmasses were once connected. Exam tip: treat structural similarity as evidence.

Q: How did Wegener view continents in his idea?

Moving landmasses Wegener viewed continents as landmasses moving over time. Exam tip: compare it with the old fixed-continent idea.

Q: Which map observation is useful for the Continental Drift Theory?

Matching of coastlines Some coastlines appear to match on a map. Exam tip: remember Africa and South America while seeing maps.

In Class 11 Geography, this topic explains the Continental Drift Theory within the chapter “Distribution of Oceans and Continents.” Students learn Alfred Wegener’s idea that the continents were once joined as Pangaea and gradually moved apart. They examine evidence such as the matching shapes of coastlines, similar fossils, continuous rock formations, mountain belts, and past glacial deposits found on continents now far apart. The topic also introduces the theory’s limitations and its importance in the later development of plate tectonics.

Easy · Level 2 · 25 questions

Practice questions

01The term sial is mainly related to which elements?

0 reads0 helpful★ – (0)

Answer and explanation

Correct answer: A. Silica and aluminium

Correct answer: A, silica and aluminium. The traditional term “sial” is formed from the first parts of silica (Si) and aluminium (Al). In older descriptions of Earth’s crust, especially continental crust, sial referred to material rich in these components. B is incorrect because “sima,” another traditional term, is associated with silica and magnesium. C is associated more closely with the metallic composition commonly discussed for the core, not the meaning of sial. D does not define sial. These terms are traditional broad compositional labels, so they should not be treated as exact descriptions of every mineral or as a complete modern chemical analysis. Memory cue: SIAL = SIlica + ALuminium; SIMA = SIlica + MAgnesium.

Continental Drift Theory and its evidence

Practice questions

01The term sial is mainly related to which elements?सियाल मुख्य रूप से किन तत्वों से जुड़ा शब्द है?

02The term sima is mainly related to which elements?सिमा मुख्य रूप से किन तत्वों से जुड़ा शब्द है?

03In Wegener's theory westward drift of continents was linked with which force?वेगनर के सिद्धांत में महाद्वीपों का पश्चिम की ओर खिसकना किस बल से जोड़ा गया?

04According to Wegener pole-fleeing force was related to movement in which direction?वेगनर के अनुसार ध्रुव पलायन बल किस दिशा में गति से जुड़ा था?

05The Continental Drift Theory helps explain which topic?महाद्वीपीय विस्थापन सिद्धांत किस विषय को समझाने में मदद करता है?

06Mesosaurus fossils are considered evidence of what?मेसोसॉरस जीवाश्म किस बात का प्रमाण माना जाता है?

07Lystrosaurus fossil comes under which evidence category?लाइस्ट्रोसॉरस जीवाश्म किस प्रमाण श्रेणी में आता है?

08Similar mountain chains found on different continents indicate what?समान पर्वत श्रृंखलाओं का अलग महाद्वीपों पर मिलना किसका संकेत है?

09How did Wegener view continents in his idea?वेगनर ने अपने विचार में महाद्वीपों को किस रूप में देखा?

10Which map observation is useful for the Continental Drift Theory?महाद्वीपीय विस्थापन सिद्धांत के लिए मानचित्र का कौन सा अवलोकन उपयोगी है?

11Gondwanaland was considered a large landmass of which side?गोंडवानालैंड किस दिशा का बड़ा भूभाग माना गया?

12Laurasia was considered a large landmass of which side?लॉरेशिया किस दिशा का बड़ा भूभाग माना गया?

13Tillite is related to what?टिलाइट का संबंध किससे है?

14The Continental Drift Theory challenged which old belief?महाद्वीपीय विस्थापन सिद्धांत ने किस पुरानी धारणा को चुनौती दी?

15According to Wegener the breaking of Pangaea was the beginning of which process?वेगनर के अनुसार पैंजिया का टूटना किस प्रक्रिया की शुरुआत थी?

16In evidence of continental drift coal deposits may relate to what?महाद्वीपीय विस्थापन के प्रमाण में कोयला भंडार किस बात से जुड़ सकते हैं?

17In Wegener's theory what type of movement of continents was considered?वेगनर के सिद्धांत में महाद्वीपों की गति किस प्रकार की मानी गई?

18What is important in fossil evidence?जीवाश्म प्रमाण में किस बात का महत्व होता है?

19The explanation of continental drift was later strengthened by which modern idea?महाद्वीपीय विस्थापन सिद्धांत की व्याख्या बाद में किस आधुनिक विचार से मजबूत हुई?

20What does similarity of rocks show in continental drift?महाद्वीपीय विस्थापन में चट्टानों की समानता क्या दिखाती है?

21Wegener's Continental Drift Theory is important in which topic?वेगनर द्वारा दिया गया महाद्वीपीय विस्थापन सिद्धांत किस पाठ में महत्वपूर्ण है?

22What is the main basis of glacial evidence in continental drift?महाद्वीपीय विस्थापन में हिमानी प्रमाण का मुख्य आधार क्या है?

23In Wegener's theory how was the continental part considered compared to the oceanic part?वेगनर के सिद्धांत में महासागरीय भाग की तुलना में महाद्वीपीय भाग कैसा माना गया?

24Why is Antarctica important in the Continental Drift Theory?महाद्वीपीय विस्थापन सिद्धांत में अंटार्कटिका की भूमिका क्यों महत्वपूर्ण है?

25How can the Continental Drift Theory be explained in simple words?महाद्वीपीय विस्थापन सिद्धांत को आसान शब्दों में कैसे समझाया जा सकता है?

Was this question useful?

Student Reviews

Analytics choices

01The term sial is mainly related to which elements?

02The term sima is mainly related to which elements?

03In Wegener's theory westward drift of continents was linked with which force?

04According to Wegener pole-fleeing force was related to movement in which direction?

05The Continental Drift Theory helps explain which topic?

06Mesosaurus fossils are considered evidence of what?

07Lystrosaurus fossil comes under which evidence category?

08Similar mountain chains found on different continents indicate what?

09How did Wegener view continents in his idea?

10Which map observation is useful for the Continental Drift Theory?

11Gondwanaland was considered a large landmass of which side?

12Laurasia was considered a large landmass of which side?

13Tillite is related to what?

14The Continental Drift Theory challenged which old belief?

15According to Wegener the breaking of Pangaea was the beginning of which process?

16In evidence of continental drift coal deposits may relate to what?

17In Wegener's theory what type of movement of continents was considered?

18What is important in fossil evidence?

19The explanation of continental drift was later strengthened by which modern idea?

20What does similarity of rocks show in continental drift?

21Wegener's Continental Drift Theory is important in which topic?

22What is the main basis of glacial evidence in continental drift?

23In Wegener's theory how was the continental part considered compared to the oceanic part?

24Why is Antarctica important in the Continental Drift Theory?

25How can the Continental Drift Theory be explained in simple words?