Glossary

Kernite

Fact Sheet:

Chemical Composition: Na₂B₄O₆(OH)₂·3H₂O (Hydrated Sodium Borate)
Hardness: 2.5 to 3 on the Mohs scale
Crystal System: Monoclinic
Color Varieties: Colorless, white, pale yellow, or gray
Major Localities: United States (California), Argentina, Turkey, and Russia
Common Uses: Source of boron, used in glassmaking, detergents, ceramics, and as an insecticide

Introduction: Kernite is an important borate mineral, mainly valued for its high boron content, which makes it a key raw material in various industrial applications. Discovered in Kern County, California, after which it is named, kernite is primarily mined for its use in producing boron compounds, essential ...

^HHydraulic Conductivity

Hydraulic conductivity is a measure of a material’s ability to transmit water through its pore spaces or fractures. It is a critical parameter in hydrogeology, influencing groundwater flow, the design of wells, and the assessment of aquifers. Hydraulic conductivity depends on factors such as porosity, permeability, and the fluid’s viscosity.

Reference: Bear, J. (1972). Dynamics of Fluids in Porous Media. Dover Publications.

^HHydraulic Fracturing

Hydraulic fracturing, commonly known as fracking, is a technique used to extract oil and natural gas from deep underground reservoirs by injecting high-pressure fluid to fracture the rock. This process enhances the permeability of the rock, allowing hydrocarbons to flow more freely. Hydraulic fracturing is significant in the energy industry but also raises environmental concerns related to groundwater contamination and induced seismicity.

Reference: Zoback, M. D., & Gorelick, S. M. (2012). Earthquake Triggering and Large-Scale Geologic Storage of Carbon Dioxide. Proceedings of the National Academy of Sciences, 109(26), 10164-10168.

^HHydraulic Gradient

The hydraulic gradient is the slope of the water table or potentiometric surface, reflecting the change in hydraulic head per unit of distance. It is a crucial concept in hydrogeology, influencing groundwater flow direction and velocity, and is fundamental in the design of wells, drainage systems, and in the study of aquifers.

Reference: Fetter, C. W. (2001). Applied Hydrogeology. Prentice Hall.

^HHydraulic Head

Hydraulic head is a measure of the potential energy of groundwater, expressed as the height to which water would rise in a well. It is a key concept in hydrogeology for determining the direction and rate of groundwater flow, and is fundamental in the study of aquifers and groundwater management.

Reference: Fetter, C. W. (2001). Applied Hydrogeology. Prentice Hall.

^HHydrocarbon

Hydrocarbons are organic compounds composed of hydrogen and carbon atoms, forming the basis of fossil fuels such as oil, natural gas, and coal. They are produced from the decomposition of organic matter under heat and pressure over millions of years. Hydrocarbons are a major source of energy globally, and their extraction and use have significant economic and environmental implications.

Reference: Tissot, B. P., & Welte, D. H. (1984). Petroleum Formation and Occurrence. Springer.

^HHydrogeology

Hydrogeology is the branch of geology concerned with the distribution, movement, and quality of groundwater in the Earth’s crust. It encompasses the study of aquifers, groundwater flow, and the interaction between groundwater and surface water. Hydrogeology is essential for water resource management, environmental protection, and understanding the hydrological cycle.

Reference: Fetter, C. W. (2001). Applied Hydrogeology. Prentice Hall.

^HHydrographic Basin

A hydrographic basin, also known as a drainage basin or watershed, is an area of land where all surface water converges to a single point, usually a river, lake, or ocean. The study of hydrographic basins is crucial in hydrology, water resource management, and environmental science for understanding the movement and distribution of water across the landscape.

Reference: Chorley, R. J., & Kennedy, B. A. (1971). Physical Geography: A Systems Approach. Prentice Hall.

^HHydrosphere

The hydrosphere encompasses all the water on Earth, including oceans, rivers, lakes, glaciers, and groundwater. It plays a crucial role in the Earth’s climate system, the hydrological cycle, and the distribution of life. The study of the hydrosphere is essential for understanding water resources, environmental processes, and the impact of human activities on water systems.

Reference: Kump, L. R., Kasting, J. F., & Crane, R. G. (2009). The Earth System. Pearson.

^HHydrostatic Pressure

Hydrostatic pressure is the pressure exerted by a fluid at equilibrium due to the force of gravity. In geological contexts, it plays a crucial role in fluid dynamics, groundwater flow, and the behavior of subsurface fluids. Hydrostatic pressure is a key concept in hydrology, petroleum geology, and understanding fluid behavior in porous media.

Reference: Bear, J. (1972). Dynamics of Fluids in Porous Media. Dover Publications.

^HHydrothermal Alteration

Hydrothermal alteration refers to the chemical alteration of minerals in rocks by hot, mineral-rich fluids, typically associated with volcanic activity or deep-seated geothermal systems. This process can lead to the formation of economically important ore deposits, such as gold, copper, and silver. Hydrothermal alteration is key in understanding mineralization processes and the evolution of hydrothermal systems.

Reference: Guilbert, J. M., & Park, C. F. (1986). The Geology of Ore Deposits. Waveland Press.

^HHydrothermal Eruption

A hydrothermal eruption occurs when superheated water trapped beneath the Earth’s surface rapidly expands due to pressure release, causing an explosive release of steam, hot water, and rock fragments. These eruptions are common in geothermal regions and can significantly alter the landscape. Understanding hydrothermal eruptions is important in volcanic hazard assessment.

Reference: Browne, P. R. L., & Lawless, J. V. (2001). Characteristics of Hydrothermal Eruptions, with Examples from New Zealand and Elsewhere. Earth-Science Reviews, 52(4), 299-331.

^HHypabyssal Intrusion

A hypabyssal intrusion refers to a shallow-level igneous intrusion, typically occurring at depths of less than a few kilometers below the Earth’s surface. These intrusions are often associated with dikes, sills, and laccoliths and are important in understanding the processes of magma emplacement and the formation of fine-grained igneous rocks.

Reference: Johannsen, A. (1931). A Descriptive Petrography of the Igneous Rocks. University of Chicago Press.

^HHypabyssal Rock

Hypabyssal rocks are igneous rocks that form at medium depths, typically within the Earth’s crust, between volcanic (extrusive) and plutonic (intrusive) environments. These rocks are often fine-grained due to their intermediate cooling rates and are important in studying the processes of magma intrusion and solidification within the crust.

Reference: Johannsen, A. (1931). A Descriptive Petrography of the Igneous Rocks. University of Chicago Press.

^HHypersaline Environment

A hypersaline environment is characterized by water with extremely high salinity levels, often found in evaporative basins, salt flats, and certain coastal lagoons. These environments are significant in studying extreme ecological conditions, evaporite mineral formation, and the geochemistry of saline waters.

Reference: Warren, J. K. (2006). Evaporites: Sediments, Resources, and Hydrocarbons. Springer.

^HHypocenter

The hypocenter is the point within the Earth where an earthquake rupture begins, located directly beneath the epicenter on the Earth’s surface. Understanding the hypocenter is crucial in seismology for determining the depth, location, and magnitude of earthquakes and for assessing seismic hazards.

Reference: Stein, S., & Wysession, M. (2003). An Introduction to Seismology, Earthquakes, and Earth Structure. Wiley-Blackwell.

^HHypogene

Hypogene processes refer to geological processes that occur deep within the Earth’s crust, typically involving the formation of minerals and rocks through high temperatures and pressures, often in association with magmatic activity. Hypogene mineralization is crucial in the formation of primary ore deposits, distinguishing it from supergene processes that occur closer to the Earth’s surface.

Reference: Guilbert, J. M., & Park, C. F. (1986). The Geology of Ore Deposits. Waveland Press.

^IIgneous Intrusion

An igneous intrusion is a body of magma that has forced its way into pre-existing rocks and solidified beneath the Earth’s surface. Types of intrusions include dikes, sills, laccoliths, and plutons. These features are important in understanding the structure of the Earth’s crust, the formation of mineral deposits, and the processes of magmatic emplacement.

Reference: Pitcher, W. S. (1997). The Nature and Origin of Granite. Springer.

^IIgneous Province

An igneous province is a region of extensive igneous rock formations, often associated with large-scale volcanic activity and the emplacement of large volumes of magma. These provinces, such as the Deccan Traps or the Siberian Traps, are crucial in understanding the processes of mantle plume activity, continental break-up, and mass extinction events.

Reference: Courtillot, V. E., & Renne, P. R. (2003). “On the Ages of Flood Basalt Events.” Comptes Rendus Geoscience, 335(1), 113-140.

^IIgneous Rock

Igneous rock is formed through the cooling and solidification of magma or lava. It is classified into two main types: intrusive (plutonic), which cools slowly beneath the Earth’s surface, and extrusive (volcanic), which cools rapidly at the surface. Igneous rocks are significant in understanding the processes of magmatism, the formation of the Earth’s crust, and tectonic activity.

Reference: Best, M. G. (2003). Igneous and Metamorphic Petrology. Wiley-Blackwell.

^IImbricate Structure

An imbricate structure is a geological feature where layers or slices of rock are stacked on top of each other, typically due to compressional forces. These structures are common in thrust fault systems and accretionary prisms. Understanding imbricate structures is important in studying mountain building processes, tectonics, and the deformation of the Earth’s crust.

Reference: Davis, G. H., & Reynolds, S. J. (1996). Structural Geology of Rocks and Regions. Wiley.

^IIncised Valley

An incised valley is a river valley that has been deeply cut into the landscape, often due to a drop in sea level or tectonic uplift. These valleys are important in studying the response of river systems to environmental changes, the development of sedimentary basins, and the preservation of ancient river systems in the geological record.

Reference: Dalrymple, R. W., Boyd, R., & Zaitlin, B. A. (1994). Incised Valley Systems: Origin and Sedimentary Sequences. SEPM Special Publication No. 51.

^IInclusion (Geology)

An inclusion is a fragment of one rock type enclosed within another, typically occurring when magma incorporates pieces of surrounding rock as it intrudes. Inclusions provide valuable information about the conditions of magma formation, the history of the host rock, and the processes of magmatic differentiation.

Reference: Gill, R. (2010). Igneous Rocks and Processes: A Practical Guide. Wiley-Blackwell.

^IIndex Fossil

An index fossil is a fossil that is used to define and identify geological periods or faunal stages. These fossils are typically widespread, abundant, and limited to a short range of geological time. Index fossils are crucial in biostratigraphy, helping to correlate rock layers across large distances and establish the relative ages of strata.

Reference: Benton, M. J., & Harper, D. A. T. (2009). Introduction to Paleobiology and the Fossil Record. Wiley-Blackwell.

^UArchives: Glossary

Ultramafic rocks are igneous rocks with very low silica content and high levels of magnesium and iron. These rocks, which include peridotite and dunite, are significant in petrology for understanding the composition of the Earth’s mantle and the processes of mantle melting and magma formation.

Reference: Le Maitre, R. W. (2002). “Igneous Rocks: A Classification and Glossary of Terms.” Cambridge University Press.