Land as a resource : Geophysical

SUSTAINABLE SITE PLANNING& LANDSCAPE

Land as a resource : Geophysical K. Vineetha 19171NB003

Discussion Outline CONTENTS

Geology and Geo morphology Definitions Types of Rocks Types of Land forms : Origin Process

19171NB003 | Contents

Mt. Shasta, California. eg. for Dynamic geology.

GEOLOGY EARTH SCIENCE

Geology is the study of the solid matter that makes up the earth. It includes the study of rocks that make up the earth.

It is a comprehensive science founded upon Astronomical, Physical and Biological principles and consequently it is divided into many fields of which the most important are as follows: Dynamic Geology: The analysis of various forces and agents working within the body of the earth & upon & above the surface.

Petrographic Geology: Study of the materials composing the earth. It considers the character & evolution of the various aggregates or colonies of minerals called Rocks.

Canyon De Chelly, Arizona. eg. for Petrographic geology.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Grand Canyon, Colorado. eg. for Structural & Historical geology.

GEOLOGY EARTH SCIENCE

Structural or Tectonic Geology: The nature and evolution of the internal make-up or structure of the earth, particularly of its outer most layers.

Historical Geology: The history of the various stages through which the earth has passed since the time of its creation.

Physiography or Geo morphology: An analysis of the nature & evolution of the present relief of the earth's surface & of landscapes which are buried in the eearth's outer most layer.

Coast of Oregon eg. for Physiography or Geomorphology.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

GEOMORPHOLOGY SCIENCE OF LAND FORMS

Geomorphology is made up of the Greek terms, "ge"- Earth, "morphe"- Form, "logos"- a Discourse.

Geomorphology is defined as comprehensive of all aspects of science dealing with the surface configuration of the solid earth.

In geomorphology chief attention is given to land forms because these are directly observable and are the site of human experience.

It is a division of geological science & had its beginnings coincidently with modern geology.

19171NB003 | Geomorphology, systematic and regional by O. D. von Engeln

The Pancake Rocks of New Zealand.

ROCKS RAW MATERIALS INVOLVED IN LANDSCAPE EVOLUTION

They are masses of lithosphere which are composed chiefly of grains of various minerals & in many cases grains of rocks broken from larger masses.

Some types like, peta & other varieties of coal & certain limestones, consist of organic material more or less changed from its original state.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

ROCKS The term rock denotes a hard solid mass derived from the earth, but the geologist gives the term much wider scope, for he includes masses of clay, loose sand, gravel & boulders as well as granite, sandstone, marble & ice.

Perito Moreno Glacier of Santa Cruz Province, Argentina.

The Moeraki Boulders of New Zealand

Sand stone hill of Northumberland 19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Classification of Rocks:

other bodies of water at the Earth's surface.

IGNEOUS OR PRIMARY ROCK: When the magma is

THE ROCKS OF THE LITHOSPHERE ARE DIVIDED INTO THREE TYPES:

forced upward into

the crust from the core, some of it often

They are classified on the bases of mode of origin.

comes out on the earth's surface, the

Clastic or Fragmental

magma eventually cools and solidifies into

Organic

rocks which are known as Igneous.

Chemical prespitates.

They are classified based on the place of the solidi-faction as Intrusive or Extrusive.

It is the rock that has changed from one

SEDIMENTARY ROCKS: The

rocks

that

are

formed

METAMORPHIC ROCKS:

by

the

accumulation or deposition of small particles and subsequent cementation of mineral or organic particles on the floor of oceans or

type of rock to another by pressure or heat.

They

can

be

formed

from

Igneous,

Sedimentary or even other metamorphic rocks.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Papa Stour of Shetland Islands in Scotland

THE ORIGIN & PROCESS OF

COASTAL LAND FORMS THEY ARE DEVELOPED PRINCIPALLY BY OCEANS, SEAS, & ON A MUCH LESS EXTENSIVE SCALE BY LAKES, SWAMPS & MARSHES. 19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Emerald Lake of Western Wyoming

The formation of Coastal land forms SERIES OF EVENTS WHICH OCCURRED LED TO THEIR FORMATION, AND THEY ARE AS FOLLOWS.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Excelsior Geyser Crater, of Yellowstone national park Wyoming

Coast at Gokarna, Karnataka

EROSION Wave erosion is partly Hydraulic and partly Abrasive.

The impact of storm waves especially is violent enough to shatter jointed rock along the face of the cliffs.

Waves are supplied with abundant sediment.

DEPOSITION

Most of the sediments in the ocean accumulates on the continental shelf, some reaches the continental slope & a very little finds its way to the floor the deep oceans.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

The Channel Islands of California

Navagio Beach of Greece

DEPOSITIONAL FORMS SHORELINE TOPOGRAPHY Where waves attack a hilly shore, they cut into the rock vigorously close to the sea level.

It continues till the rock doesn't have sufficient support to maintain itself.

This action generates a steep face called a Wave-cut cliff.

During marine epochs, continental shelf deposits cover enormous areas.

The shelves are extremely broad & gently sloping.

During the times of emergence, most of the shelf is elevated above sea level 1st as coastal & later as both interior & coastal plain.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Land forms evolved by deposition along or close to the shore line are: BEACHES:

Anse Source D'Argent of Seychelles in East Africa

Sediment deposited along the shore of oceans & lakes is called a beach.

The beach is the inner margin of the wave-built terrace, therefore the inner margin of the continental self sediment.

They form when waves shift sand & pebbles along the BARS & LAGOONS: beaches, this is know as long-shore drift & some beaches get longer.

Lagoons are the areas of shallow sea that have been separated the main sea.

Some long beaches extend completely across the mouth of the river or a bay and they are known as Bars.

The bars form sandy banks with the sea on one side & lagoons on the other.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Lençóis Maranhenses National Park in Brazil

Types of Shorelines: DIAGRAM OF A LAGOON BEHIND A BAR BUILT BY LONG SHORE CURRENTS WHOSE DIRECTIONS ARE INDICATED BY ARROWS

Continental

&

island

coasts

are

best

classified on th bases of movements of land with respect to the sea level: 1. Shorelines of submergence where the land

has

been

deformation

&

depressed

by

elevation

by

deformation.

2. Compound

shore

lines

where

the

effects are expressed.

3. Natural shorelines where there is no evidence

of

recent

respect to the sea level 19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

change

with

Limestone Reef Coasts: The principle landforms built from organic accumulations are limestone reefs of various types which are aggregates of skeletons & their structures of plants & animals growing upward from submerged continental or island basements to the level of the ocean.

These structures are commonly known as Coral reefs.

As these colonies grow, older organisms die & upon the structures left by them the younger ones build new structures.

Thus the reefs grows upward & outward until its surface reaches sea level.

They usually grow in shallow warm waters with temp. above 68'F, or in tropical oceans & around islands.

Great Barrier Reef, of Australia

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Types of Reefs: FRINGING REEF:

ATOLL: It is a circular or horseshoe-shaped ring of reef rock rising from a submerged platform & encircling a shallow lagoon.

It is a platform of limestone extending outward from the shore line.

Built by coral & other organisms which are attached to the shallow ocean bottom & away from shoreline.

BARRIER REEF: The exposed parts of such reefs are separated from shore line by shallow lagoons.

19171NB003 | Geomorphology, the evolution of landscape by Norman E. A. Hinds

Makua Beach of KAUAI, Hawaii eg. for Atoll

THE ORIGINS OF ISLANDS

Virgin Islands of British Overseas Territory

ISLANDS ARE THE ISOLATED FEATURES OF EARTH

Which rise either from continental shelves, from the floor of the lakes, or from the floor of the deep sea/ocean.

The midoceanic islands, rising from the deep ocean floor, are mainly volcanic & are composed of basaltic lava, liimestone reef, but these structures seems to have grown up on an eroded basement of volcanic rock 19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

The Islands are evolved in the following ways: EPEIROGENIC ELEVATION: The higher part of the rising continental shelves above the sea levels appears as islands, & eveuntuly join them to the continental lands.

FOLDING:

FAULTING: If the elevation or depression of fault blocks takes place along the continental margin islands maybe formed. Eg. Madagascar.

VOLCANIC ACTION:

When a geosycline which is below sea level is folded, its crests of the anticlinal ridges will first appear above sea level as islands.

Probably all of the islands rising from the floor of the deep oceans are or once were volcanic mountains.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

The Islands are evolved in the following ways: CHANGE IN OCEAN LEVEL: Rising of the ocean level which has occurred during the waning of the last ice sheets submerged low areas along continental margins & isolated higher areas as islands.

GLACIAL DEPOSITION: Islands composed of morainic deposits are present off glaciated sections of the present shore line.

WAVE ACTION: Waves beating against bold shores, isolate small masses of land as sea stacks.

Waves also construct islands by piling put loose sediments.

ORGANISMS: Corals & organisms built islands uon submerged platforms in the tropical waters. Isolated islands are present in fringing & barrier reefs.

19171NB003 | Geomorphology, the evolution of landscape by , Norman E. A. Hinds

Inference COASTAL LANDFORMS LIKE ANY OTHER LANDFORM EXPERIENCES A CYCLIC DEVELOPMENT. COAST LINES MAY RUN PARALLEL WITH CONTINENTAL STRUCTURE. UPLIFT

AND

SINKING

OF

THE

LAND

THROUGH

MILLIONS OF YEARS FORMED THE PRESENT ISLANDS AND THE CONTINENTAL LANDS. THE

PRESENT

MOUNTAINS.

ISLANDS

WERE

ONCE

VOLCANIC

Bibliography GEOMORPHOLOGY, THE EVOLUTION OF LANDSCAPE BY HINDS, NORMAN E. A. GEOMORPHOLOGY,

SYSTEMATIC

AND

ENGELN, O. D. VON. GEOLOGY BY CLIFFORD TIM. GEOLOGY BY DANA, JAMES DWIGHT. ENCYCLOPÆDIA BRITANNICA

REGIONAL

BY