Geological Processes, Mineral Deposits, and Geohazards
Mineral Deposits and Formation Processes
Mineral deposits are concentrations of materials linked to geological processes, requiring sufficient concentration factors to be economically viable.
Geological Processes
These are categorized into two main types:
- Exogenous Processes: External processes (e.g., weathering, sedimentation).
- Endogenous Processes: Internal processes (e.g., volcanism, tectonics).
Endogenous Mineralization
Associated with volcanic construction at plate boundaries (active margins, destructive
Read MoreAcropolis Masterpieces: Erechtheion Architecture and Parthenon Sculptures
Erechtheion: Classical Architecture and Cults
Historical Context and Construction
The Erechtheion belongs to the Classic Period. It is located in the far north of the Acropolis. The construction was entrusted to Mnesikles. The first phase was initiated during the Peace of Nicias, interrupted by the resumption of the Peloponnesian War. The building, the most grandiose Greek Ionic temple built during the time of Pericles, was finally completed in 406 BCE. It was intended to rebuild the temple destroyed
Read MoreGeographical Processes and Landform Development
Geographical Processes: Weathering and Erosion
Key Definitions
Weathering: The rock is broken down and is weakened but does not move.
Erosion: When rock is worn away and moved by forces of nature.
Types of Weathering
Weathering can be categorized as:
- Mechanical
- Chemical
- Freeze-thaw
- Biological
- Onion-skin (Physical)
Chemical Weathering
This occurs when acids in rain and sea/river water react with rock, causing it to wear away.
Freeze-Thaw Weathering
- Water fills a crack in a rock.
- The water freezes and expands.
- The
Essential Definitions of Earth’s Major Geographical Features
Understanding the terminology used to describe the Earth’s surface is fundamental to geography. Below is a comprehensive list of key landforms, water bodies, and terrestrial features, along with their precise definitions.
Landforms and Terrestrial Features
Mountain
A large natural elevation of the earth’s surface.
Hill
A naturally raised area of land, smaller than a mountain.
Valley
A low area of land between hills or mountains.
Plain
A large area of flat land.
Plateau
An area of relatively level high ground.
Geological Evolution of the Iberian Peninsula Relief
The current relief of the Iberian Peninsula is the result of a geological history spanning millions of years, characterized by alternating orogenic phases and periods of calm dominated by erosion and sedimentation.
A. Archaic or Precambrian Era (4,000–600 Million Years Ago)
- An arched band emerged from the sea, extending from the northwest to the southeast, formed by schists and gneiss. This band included almost all of present-day Galicia.
- Elevations also arose in isolated points of the Central System
Plate Tectonics: Mantle Convection, Subduction, and Orogeny Formation
Mantle Dynamics: Convection and Thermal Plumes
Convective movements consist of updrafts and downdrafts within the fluid mantle. These currents form when the fluid becomes unstable because its top is more dense and tends to sink, while the bottom is less dense and tends to rise to the surface.
Rifting and Thermal Plumes
Rifting is the rupture of a continental plate caused by the action of a thermal plume. Archipelagos of volcanic points, such as the Azores and Hawaii, are often associated with hot oceanic
Read More