Geology Test 1 Nddc Scholarship

The Resistivity method is the standard geophysical technique for groundwater. It measures how easily electricity passes through the ground; since saltier or contaminated water conducts electricity better than fresh water, this method can effectively determine both the presence of water and its general quality (salinity).

A Geological Map uses colors and symbols to represent the distribution, age, and type of rock units and structural features (like faults and folds) found on or just below the Earth's surface. A topographic map only shows surface elevation and shape.

A Piezometric Contour Map (or Potentiometric Surface Map) represents the hydraulic head of groundwater in a confined aquifer. It shows the imaginary level to which water would rise under its own pressure if tapped by a well. For unconfined aquifers, the similar map is called a water table map.

A Gossan (or 'iron hat') is an iron-oxygen rich cap formed by the oxidation of a primary sulfide ore body. As rain and air hit the sulfides, they weather away, leaving behind a rusty-looking residue of hematite and limonite. Geologists use gossans as 'signposts' to find valuable ore deposits hidden underneath.

In the Sulaiman Range of Pakistan, major oil and gas seepages and source rocks are primarily associated with the Paleocene and Eocene strata. These younger Cenozoic rocks are part of the active petroleum systems in the Indus Basin petroleum province.

By definition, a mineral must be a naturally occurring, inorganic solid with an organized internal structure (crystalline) and a definite chemical composition. Man-made substances are called 'synthetic', and unorganized structures are 'amorphous' or 'mineraloids'.

Based on Mohs Scale of Hardness, the correct sequence from softest to hardest is talc (1), apatite (5), corundum (9), and diamond (10). Sequence B is incorrect because quartz (7) is harder than fluorite (4).

Silicates are classified by how their silica tetrahedra are linked. Micas (like biotite and muscovite) are sheet silicates (phyllosilicates), which gives them their perfect one-directional cleavage. Feldspars are framework silicates (tektosilicates), where the tetrahedra are linked in a 3D network.

The term Sima is derived from Silica and Magnesium. It refers to the denser, basaltic rocks that primarily form the oceanic crust. This is contrasted with 'Sial' (Silica and Aluminum), which refers to the lighter, granitic rocks of the continents.

The viscosity of magma is primarily controlled by temperature, silica content, and volatile content. As temperature increases, the kinetic energy of the atoms increases, which breaks down the silica tetrahedral networks, making the magma more fluid (less viscous). While the other factors listed may have minor indirect effects, temperature is a fundamental physical control on magma flow.