PHYSICAL GEOGRAPHY.

 
   

 

 

 

  

 

 

Fig. 55. Orographic Chart of Australia.
(White portions, mountains; shaded portions, plains.)

1, Australian Alps; 2, Kosciusko; 3, 4, 5, Secondary Systems; 6,
Murray River.

VI. AUSTRALIA.

141. Surface Structure.—The Predominant
Mountain-System is in the east.

The Secondary Systems are in the west and
north-west. _ -

The Great Low Plain lies between the pre-
dominant and secondary systems, and slopes
gently to the southern coast.

The Predominant System extends along the
entire eastern shore, from Torres Straits to the
southern extremity of Tasmania. It is for the
most part composed of broad plateaus. The
system is highest in the south-east, where the
name Australian Alps is given to the range.
Mount Kosciusko, 7000 feet, probably forms the
culminating point of the Australian continent.

The system descends abruptly on the east, but
on the west it descends by gentle slopes to the
low plains of the interior.

142. The Secondary Systems, on the west and
north-west, are of but moderate elevation.

143. The Great Low Plain lies in the interior. Ac-
curate information as to its peculiarities is yet wanting.
A moderate elevation on the north connects the eastern
and western systems, The south-eastern portion, which
is the best known, is well watered and remarkably fertile.

Basin-shaped valleys are found in the west. The lower
parts are occupied by Lake Eyre, Torrens, and Gairdner.

144, Approximate Dimensions of Australia.
Area of continent, 3,000,000 square miles.

Coast line, 10,000 miles.

Greatest length from east to west, 2400 miles.
Greatest breadth from north to south, 2000 miles.
Culminating point, Mount Kosciusko, 7000 feet.

145. Contrasts of Africa and Australia—In
the north, the African continent resembles Europe
and Asia in the arrangement of its forms of
relief. In the south, it resembles the Americas.
As a whole, the African continent resembles
Australia more closely than any other. In both

 

 

Fig. 56, Australian Scenery.

Africa and Australia the predominant system is
in the east, and extends along the entire coast.
In each the secondary systems are in the west
and north. But Africa terminates in a plateau
which descends abruptly to the sea, while Australia
is terminated by a great low plain which descends
by long, gentle slopes from the interior.

 

RRR IAS

SYLLABUS.

 

—.079300—.

Rock-masses are divided, according to their origin, into
{gneous, aqueous, and metamorphic. According to their con-
dition, into stratified and unstratified. According to the
presence or absence of organic remains, into fossiliferous
and non-fossiliferous. Stratified rocks are sometimes called.

    

 

fragmental. Unstratified rocks are sometimes called crys-
talline. Aqueous rocks are sometimes called sedimentary.

Aqueous rocks are stratified. Igneous rocks are un-
stratified. Metamorphic rocks were originally stratified,
but lost their stratification through metamorphism.