Category Archives: Geology

9. Mining

Posted on 27/02/2009 by Vitor Pacheco

9.1 PRIMITIVE EXTRACTION I include under mining all human activities concerned with the extraction of inert natural materials. As such, the extraction of stone for construction, is mining, and at the beginning, perhaps the easiest was the excavation in relatively soft … Continue reading →

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8. Prospecting

Posted on 20/02/2009 by Vitor Pacheco

8.1 GRASS ROOTS Grass roots exploration is the general term for the very initial stage of prospecting that starts from a zero base, that is, neither geological maps, nor aerial photos are available, and often not even topographic maps. Of … Continue reading →

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7. Structure and Metamorphism

Posted on 11/02/2009 by Vitor Pacheco

7.1 General As mentioned in the introduction, faulting, folding and metamorphism are a consequence of the movement of the plates that form the earth’s crust, and these plate movements encompass huge areas, developing topographical features with spectacular characteristics, particularly noticeable … Continue reading →

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6. Sedimentation

Posted on 08/02/2009 by Vitor Pacheco

For the majority of cases, rocks are fragmented by erosion and\or weathering  and transported elsewhere. Sedimentation is the processes to which these materials termed clasts, are subjected to until they are deposited, and the main mechanisms involved are presented in … Continue reading →

Posted in Geology, Sedimentary Rocks | 2 Comments

5. Unconformity

Posted on 27/01/2009 by Vitor Pacheco

A sediment is a mass of material that originates from the weathering and or erosion of the earth’s surface substances which, in the majority of cases, have been transported and deposited elsewhere. Naturally, the transporting agents are the same as … Continue reading →

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4. Erosion

Posted on 22/01/2009 by Vitor Pacheco

According to the American Geological Institute Glossary, erosion is the natural process whereby the materials of the earth’s crust are loosened or worn away and simultaneously removed to another place. These natural processes, in an increasing order of power, are … Continue reading →

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3. Weathering

Posted on 18/01/2009 by Vitor Pacheco

3.1 Initial Stage Weathering is the chemical alteration caused by the atmospheric water in vapor and/or liquid form, due to the reacting agents carried in solution. Thus, this was the first step in the alteration of the original consolidated rocks … Continue reading →

Posted in Geology, Sedimentary Rocks, Weathering | 5 Comments

2. Igneous Rocks

Posted on 31/12/2008 by Vitor Pacheco

2.1 Origin and Composition Convection cells must have developed in the Earth’s Mantle at a very early stage, consequently initiating the differentiation of the elements composing the original magma. Just like foam in a boiling pot, the less dense elements … Continue reading →

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1. Introduction

Posted on 31/12/2008 by Vitor Pacheco

Geology is the study of the Earth’s crust and its continuous process of modification. At the beginning of solidification, approximately 3,9 Ga (giga annum = 109 years) ago, there were only Igneous Rocks, originating from the consolidation of the initial magma. … Continue reading →

Posted in Geology, Introduction | 1 Comment