❞ كتاب Principles of Agricultural Economics ❝ ⏤ Dr. Harbans Lal

(Rocks):
Most of the geological research is related to the study of rocks, as rocks are the main record of the geological history of the earth, because rocks are the basic unit in building the earth as they consist of formations containing a group of minerals found in nature, and are an essential part in the composition of the Earth's crust. Thus, the rock has a distinctive feature that separates it from another rock and makes it a self-contained unit. Just as rock is the basic unit of building the earth, the metal is the unit of rock itself. Rocks differ from each other in terms of the types of minerals forming them and the relationship of these minerals to each other in one rock. There are three types of rocks which are igneous rocks, sedimentary rocks and metamorphic rocks. There are environmental processes that affect the rocks that change the type of rock from fiery to mutant or vice versa. , Or from sedimentary to fiery or vice versa, or from metamorphosed to sedimentary or vice versa; these processes are known as rocky cycle.

(Bulk material):
Geologists also study non-hardening materials which are loose materials whose sizes vary between clay and sand gravel. The groundwater can travel between its grains for distances that vary with the size of the grains of the soil, and the study of loose materials is known as the study of the quaternary age and this study includes sedimentology and earth morphology And ancient climatology.

(Tectonic plates):
There is a close relationship between the movement of the plates on the surface and the convection currents of the mantle (which is the transfer of heat resulting from the bulk movement of the molecules inside the fluid). In addition, the plates of the oceans move in the same direction as the convection currents aligned with the mantle , Because the oceanic lithosphere is actually the top thermal solid layer of the thermal layer boundary layer. This relationship between the solid layer on the surface of the Earth and the thermal mantle is called tectonic plates

(Earth structure):
Advances in seismology, computer modeling, metallurgy, and crystallography at high temperatures and pressures provide an insightful and powerful insight into the internal and structural composition of the Earth.

(Geological developments occurring in a region):
The geology of a region changes with the passage of time, such as rock particles, of which what is deposited on its own and the other precipitates over a rock, and the deformation processes change its shape and its location.
The rock units are placed first either by precipitation on a surface or by seizing it on the surface of a rock by its presence in the top of that rock. Sedimentation can occur if sediments settle on the surface of the earth and form layers by hardening them and transforming them from sediments into solid sedimentary rocks or in the case of volcanic material such as volcanic ash or lava that flows in the ground. Fireworks such as: triangles are deep fiery bodies and their shape is Irregular. Likewise, lacoliths are shallow firearms and their shape is uniform. As for cutters (dikes) and horizontal layers, silts are deposited and accumulate in the top of their rock and crystallize as intrusive.
After the first series of rock that has been deposited, the rock particles may be deformed or transformed into another type of rock.

نبذه عن الكتاب:

The Economic problem: Economic theory deals with the law and principles which govern
the functioning of an economy and it various parts. An economy exists because of two basic
facts. Firstly human wants for goods and services are unlimited and secondly productive
resources with which to produce goods and services are scarce.
In other words, we have the problem of allocating scarce resource so as to achieve the greatest
possible satisfaction of wants. This is the economic problem. It is also called economizing
problem. The economic problem arises from the two basic inter related facts:
 Man's unlimited desire for the goods in the aggregate, and
 The limited capital, natural and human resource available to a society for the
production of goods in aggregate.
The content of economic theory: There has been a lot of controversy among economist
about the true content of economic theory or its subject matter. The subject matter of
economics or economic theory has been variously defined.
According to Adam Smith economics enquires into the nature and causes of the wealth of
nations.
According to Ricardo, economist studies," how the produce of the earth is distributed." That
is, economics deals with the distribution of income and wealth.
According to Marshall, economics is a study of mankind in the ordinary business of life and it
examines that part of individual and social action which is connected with material requisites
of well being.

Applied geology
Download Al-Wajeez book on geology
Rock geology
Engineering Geology Book
Economic geology
Earth geology
Yemen Geology Book
Rock properties
The names of the types of rocks