1969-03-15 — Page 23

育教僑華真三第張六第 日七廿月正年西巴屦夏WAH KIU YAT PO

報日僑

CC文中學會考試題預習

FORMATION OF A DELTAIC PLAIN.

地理科

(十九)

劉玉領

CITED A PHY ho

34. For each of the following features (a) Rift Valley.

(b) Deltaic Plain, and (c) Intermont: Flateau

(1) Describe its appearance

(11) Explain how it is formed.

(iii) Name and show by a diagram an area where an

Ans.

actual example can be found.

(a) Rift Valley

(1) A rift valley is an elongated trough with steep slopes rising on both sides. Hollows on its surface may be occupied by water forming Lakes. e.g. Lakes Rudolf, Tanganyika, Edward, Nyasa on the Great African Rift Valley. Its surface my also have been obscured by layers of alluvium e.g. the Rhine Rift Valley.

(ii) It 19 formed by the sinking

him between

two roughly parallel faults. It is supposed that the earth surface is subjected to compressional forces acting laterally tom opposite directions. Two raverse faults are developed. There compressional forces then push the blocks outside the faults to thrust up over the centre block whion forms the rift valley. The overhanging sides of the rift valle are worn back by erosion.

111) The Rhire Bift Valley

Position of Wes Bila DELTA

-"THE NEX DIUITA

FORMATION OF RIFT VALLEY

COMPRESSIÑAS Fortza

FAULT'S

六期星一日五十月三年九六九一屦公年八十五國民華中

(接第六張第二頁)

一九六九三

考試題預習

化學科

(十九)

桟習題十八解答

·林錫衡·

I(1)苦澀味滑膩感 藍色

(2)氧氧化師 風氧化釣

(3)潮解二氧化碳

虱氧化鉄

**SEA

Intermont Plateau

As

the name implies, it is a plateau la high. and relatively flat landform) partly or

completely surrounded by high mountain. The plateau may be drained by small rivers but they have no outlet to the sea, forming inlard drainage pattern.

11) lta formation is associated with the formation of fold mountains. Compressional forces acting laterally from opposite directions below the geosyncline cause the neighbouring continental blocks to approach and the sediments in it to fold up forming fold mountains. When the part between two consecutive folds is not affected by these compressional forces, it is raised Since it can retain the more or less level nature of its surface, it forms an interkont plateau.

(4)石灰法電解食盐水

(5)

(6)棕色

(7)氣

(8)鹼類

銨蓝

高铁離子

盐(廢式蛋) 類(正盐)

(7)苛性 焼嶮 純嶮(蘇打)

蘇打

大蘇打

油酸的钠盐 钾盐

(II)二氧化碳碳酸氫鈉

((12)茄酸:碳

(3)紫紅色 無色磯藤鋤

(14)(4)可以滅火因為碳酸氫鈉饔硫酸作用

生成不助燃的二氧化碳及水

6)可以製汽水因為碳酸氫鈉與酒石酸 作用生二氧化碳

(可以中和胃酸周為興胃酸(主要是描 酸 作用生成 化碳因而使署酸裁

可為熔粉田馬磯酸気釼憂熱分解放 氧化碳在麵飽餅乾中形成氣泡故 較鬆化

•I (1) Na2CD, + Ca(OH)- CaCO3 + 2 NCOH

(3) 2 NOCI + 2H2O —> H2 + NaOH (3) NOOH + HOI→ NACI+ H2O

C

POSITION

RAINE RIF

NETHERL

HIND POET VRLARY.

A SIMPER CACES=#Retion Across

RHINE RIFT-VALLEY

·RIVER RANZ

RIVERS

Vase

BLACK FOREST

STEP

FAU ALLDY

(b) Deltaic Plain

(1) It is a fan-shaped alluvial plain formed at

the mouth of a river. The name being originally applied by the greeks to the alluvial tract produced by the Nile, owing to its resemblance in shape to the fourth letter or their alphabet Most of the great deites of the world are extensively cultivated and support dens agricultural population

(11) It is formed by a river which carries its load and ultimtely lays it into the sea into which it flows. As deposition goes on in the river mouth, the river is forced to divide into several channels each of which repeatly subdivides. The deposit grows outwards in the shape of a fan or triangle. Sometimes stretches of the sea may become surrounded by deposited sediments and they form lagoons.

The chief conditions for its formation are that the river must carry a heavy load an that along the coast, there is no strong but weak current otherwise the sediments will be brought out to the sea

PATTERK OF

FOLD MORN

REGION

INTERMONT

ENTAL

PLAT

ETAN PLATEAU

TIDE VAN PLAY

35. trite a concise account on weathering in squator

En equatorial places, the climate is hot and wet throughout the year since temperature a high and uniform all the year round both the diurnal range and annual range of temperature are small. The changes of temperature will have little effect in causing rock minerals to break as a result of: alternate expansion and contraction. Moreover, temperature at night and in the cooler season seldom drops to freezing point, thus the action of action is restricted to a minimum or even negligible

Meanwhile, the breaking up of rocks are largely

caused by the chemically active gases and moisture in the atmosphere. By adding water to the elementa in the minerals (hydration), hydrous oxides and nydrous silicates are produced from the common minerals of the crust For example, felspar is converted to Kaolin in this way (can be found in Cha Ko Lang, Hong Kong) and other clay minerals of tremendous significance because they are the basis of the soil which support all life in the earth.

The effect of oxygen which is aided by the presence of moist air (oxidation) is significant especially on iron compounds Colour changes result and acids are released in a never ending chain of reaction, af

Carbon usux, 100 La saged to rock minerals (carbonation) in the form of carbonic acid which zas derived its content from the atmosphere and regetation. Carbonic acid is sometimes much more effective than pure water in attacking felspar and other minerals. Silica and potassium carbonates are 1lved by this way.

(4) 3 NaOH + FeCl → = NaCl + Fe(OH)

•5) N&OH + NHỊCH → NaCl + NH2T • HaQ

( G7 H35 COO) (H2+ 3 N&OH

(ANH C

•CH, COONa + (3 Haurit

NQ2Cl + H2O + CO2+

(8) Na2 CÔ, + Mg(NO3) → 2 NaNO3 + MgCO3 (?) Na¿CO2+ Cason? Na, son* Cacoşv

HO+COT

*10) NaHCO2+ HCI → NOCI +

D (!) NQ, CO; 10 H30 (2) Na2 CO2

(3) NaOH

(4) NaHCO3

亚(1)皂化作用 脂肪或油類與強酸作用生

成甘油與肥皂的反應称之

(2)鹽析法利用某些物質不溶於食塩溶 液而使之分離之法例如製肥皀時加入 食鹽濃溶液肥皂乃浮出液面得與甘油 分離

工肥皂水解生成脂酸或油酸會令油乳化文 會吸附塵埃隨水冲去乃得潔淨。若遇硬水 則與鈣鎂離子生成脂酸鈣鎂沉澱此等況 澱對去污全無功效投浪费肥皂。

(1) CO2: CaCO3- CaO+ CU2?

(2)1 €101⁄2 2NHall + Ca(OH)+

3) VÀ CO, ANH VA K

NH, HỌ CỤ, NHCHEO

NHCHCOS

Nat

4) NaHCO3 13 Na. CO2

NHC) • NAHCOuk

(1)步副產 Cao 可奥水作用生成CalOHA

CROT H2O →

→ Ca(OH) この(OH)第 (3) 歩副産 NAC 可進行第12 步之反應急又第(4)步所得 CO可供第 (3)步作原料用

In certain occasions, the outer part of a body

is made wet during the rainy season, and some rock minerals may be dissolved. Together with the effect of heat, some of the resistant minerals in the rocks are released, causing the rocks to peel off. This is expoliation or spheroidal weathering -

Though not an important way of wewe plants also play a part in the chemical decay of rock substance: They also help to break up rocka when their roots erow into the tuinis

forcing them

to widen.

It is therefore quite apparent that various ways of chemical weathering is more sperative in equatorial areas, and if may proceed rapidly and extend to several hundred feet deep into the ground. resulting in the formation of new and usually simpler compounds. The soluble constituenta of them are then removed by leaching (percolation of water which absorbs solubles).