Glossary

Tourmaline

Fact Sheet:

Chemical Composition: Complex boron silicate (variable formula: XY₃Z₆(T₆O₁₈)(BO₃)₃V₃W) where X = Ca, Na, K; Y = Al, Fe²⁺, Mg, Li, Mn²⁺; Z = Al, Mg, Cr, Fe³⁺; T = Si, Al; V = O, OH; W = OH, F, O
Hardness: 7 to 7.5 on the Mohs scale
Crystal System: Trigonal (hexagonal prisms)
Color Varieties: Black, green, pink, red, blue, yellow, brown, colorless, and multicolored
Major Localities: Brazil, Afghanistan, Pakistan, United States, Madagascar, and Namibia
Common Uses: Gemstone, collector’s mineral, piezoelectric applications, and decorative purposes

Introduction: Tourmaline is a strikingly colorful and complex boron silicate ...

^SStalagmite

A stalagmite is a mineral formation that rises from the floor of a cave due to the deposition of calcium carbonate from dripping water. Stalagmites are significant in speleology and paleoclimatology for understanding past climate conditions, as they can provide valuable records of historical climate changes.

Reference: Baker, A., & Smart, P. (1995). “Cave Studies in Geography and Geology.” Geological Society of London.

^SStratigraphy

Stratigraphy is the study of rock layers (strata) and layering (stratification), primarily in sedimentary and volcanic rocks. This field is crucial for understanding the chronological sequence of geological events, the age of rocks, and the history of the Earth’s surface.

Reference: Catuneanu, O. (2006). “Principles of Sequence Stratigraphy.” Elsevier.

^SStratovolcano

A stratovolcano, also known as a composite volcano, is a large, steep volcano built up of alternating layers of lava, ash, and volcanic debris. These volcanoes are significant in volcanology for understanding explosive eruptions, volcanic hazards, and the formation of volcanic arcs.

Reference: Davidson, J. P., et al. (2007). “The North Atlantic Igneous Province: Stratigraphy, Tectonics, Volcanism.” Cambridge University Press.

^SStrike-Slip Fault

A strike-slip fault is a type of fault where the movement of the fault blocks is predominantly horizontal, parallel to the strike of the fault plane. These faults are significant in tectonics for understanding the lateral movement of Earth’s crust, the formation of transform boundaries, and the generation of earthquakes.

Reference: Aydin, A., & Nur, A. (1982). “Evolution of Pull-Apart Basins and Their Scale Independence.” Tectonics, 1(1), 91-105.

^SStromatolite

Stromatolites are layered sedimentary formations created by the growth of microbial mats, particularly cyanobacteria. These structures are significant in paleontology for understanding the early history of life on Earth, the formation of oxygen in the atmosphere, and the conditions of early marine environments.

Reference: Awramik, S. M. (1971). “Precambrian Stromatolites: A Bibliography.” Geological Society of America Memoir 135.

^SSubaqueous Volcano

A subaqueous volcano is a volcano that erupts beneath the surface of a body of water, such as an ocean or lake. These volcanoes are significant in volcanology for understanding the interactions between magma and water, the formation of pillow lavas, and the development of hydrothermal vents.

Reference: Fisher, R. V., & Schmincke, H.-U. (1984). “Pyroclastic Rocks.” Springer.

^SSubduction Zone

A subduction zone is a region where one tectonic plate is being forced beneath another, leading to the recycling of oceanic crust into the mantle. These zones are significant for understanding the processes of plate tectonics, the formation of mountain ranges, earthquakes, and volcanic activity.

Reference: Stern, R. J. (2002). “Subduction Zones.” Reviews of Geophysics, 40(4), 3-1-3-38.

^SSubduction-Related Volcanism

Subduction-related volcanism occurs when an oceanic plate is forced under a continental or another oceanic plate, leading to the melting of the subducted plate and the formation of volcanic arcs. This type of volcanism is significant for understanding the geochemical evolution of magmas and the hazards associated with explosive eruptions.

Reference: Turner, S., & Hawkesworth, C. (1998). “The Role of the Subduction Zone in Magmatism.” Journal of Geophysical Research: Solid Earth, 103(B1), 819-835.

^SSubmarine Canyon

A submarine canyon is a steep-sided valley cut into the seabed of the continental slope, often extending well below sea level. These canyons are significant in marine geology for understanding sediment transport, underwater erosion, and the dynamics of turbidity currents.

Reference: Shepard, F. P. (1972). “Submarine Geology.” Harper & Row.

^SSubmarine Fan

A submarine fan is a large, fan-shaped deposit of sediment found on the ocean floor, typically at the base of continental slopes. These fans are formed by turbidity currents and are significant in sedimentology for understanding deep-sea sedimentation processes and the distribution of marine sediments.

Reference: Normark, W. R., & Piper, D. J. W. (1991). “Submarine Fan Systems: Process and Products of Turbidity Currents.” Earth-Science Reviews, 29(3-4), 177-236.

^SSubterranean River

A subterranean river is an underground watercourse, often formed through the dissolution of soluble rocks, leading to the development of caves and karst landscapes. These rivers are significant in hydrogeology for understanding groundwater flow, aquifer systems, and the evolution of cave systems.

Reference: Ford, D. C., & Williams, P. W. (2007). “Karst Hydrogeology and Geomorphology.” John Wiley & Sons.

^SSuture

A suture is a major fault zone that represents the boundary between two collided tectonic plates, often marked by distinct geological features such as ophiolites, metamorphic rocks, and volcanic arcs. Sutures are significant for understanding the processes of continental collision, orogenesis, and the assembly of supercontinents.

Reference: Matte, P. (1986). “Tectonics and Plate Tectonics Model for the Variscan Belt of Europe.” Tectonophysics, 126(3-4), 329-374.

^SSyncline

A syncline is a fold in which the youngest rock layers are found in the core, with the layers dipping inward from both sides. Synclines are significant in structural geology for understanding the forces and processes that create folds in the Earth’s crust.

Reference: Ramsay, J. G. (1967). “Folding and Fracturing of Rocks.” McGraw-Hill.

^TTalus

Talus is a slope formed by the accumulation of broken rock fragments at the base of a cliff, produced by physical weathering processes such as freeze-thaw cycles. Talus slopes are significant in geomorphology for understanding the processes of mechanical weathering, mass wasting, and the development of mountainous landscapes.

Reference: Luckman, B. H. (1976). “Rockfalls and Rockfall Inventory Data: Some Observations from Surprise Valley, Jasper National Park, Canada.” Earth Surface Processes, 1(3), 287-298.

^TTaphofacies

Taphofacies is a concept used in taphonomy to describe the assemblage of fossil preservation characteristics within a particular sedimentary environment. This concept is significant in paleontology for understanding the processes that affect fossil preservation, the interpretation of the fossil record, and the reconstruction of past environments.

Reference: Brett, C. E., & Baird, G. C. (1986). “Comparative Taphonomy: A Key to Paleoenvironmental Interpretation Based on Fossil Preservation.” Palaios, 1(2), 207-227.

^TTaphonomy

Taphonomy is the study of the processes that occur after an organism’s death, including decay, preservation, and fossilization. This field is significant in paleontology for understanding how fossils form, the biases in the fossil record, and the interpretation of past environments and ecosystems.

Reference: Behrensmeyer, A. K., Kidwell, S. M., & Gastaldo, R. A. (2000). “Taphonomy and Paleobiology.” Paleobiology, 26(S4), 103-147.

^TTar Sand

Tar sand, also known as oil sand, is a type of sedimentary deposit that contains a mixture of sand, clay, water, and a dense, viscous form of petroleum called bitumen. Tar sands are significant in economic geology for understanding unconventional oil resources, the processes of oil extraction, and the environmental impacts of tar sand mining.

Reference: Mossop, G. D., & Shetsen, I. (1994). “Geological Atlas of the Western Canada Sedimentary Basin.” Canadian Society of Petroleum Geologists.

^TTectonic Plate

A tectonic plate is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere, that moves and interacts with other plates on the Earth’s surface. Tectonic plates are fundamental in understanding the mechanisms of plate tectonics, including continental drift, the formation of mountains, earthquakes, and volcanic activity.

Reference: Cox, A., & Hart, R. B. (1986). “Plate Tectonics: How It Works.” Blackwell Scientific Publications.

^TTectonic Uplift

Tectonic uplift refers to the vertical elevation of the Earth’s surface due to tectonic forces, such as faulting or folding. This process is significant in geology for understanding the formation of mountain ranges, the evolution of landscapes, and the interplay between tectonics and erosion.

Reference: Molnar, P., & England, P. (1990). “Late Cenozoic Uplift of Mountain Ranges and Global Climate Change: Chicken or Egg?” Nature, 346(6279), 29-34.

^TTectonic Window

A tectonic window is an area where older rocks, typically part of a lower structural unit, are exposed through erosion or tectonic processes, surrounded by younger, overlying rocks. Tectonic windows are significant in structural geology for understanding the history of tectonic uplift, erosion, and the exposure of deep crustal rocks.

Reference: Twiss, R. J., & Moores, E. M. (2007). “Structural Geology.” W. H. Freeman.

^TTephra

Tephra is a general term for fragments of volcanic rock and ash ejected during an explosive volcanic eruption. Tephra deposits are significant in volcanology for understanding eruption dynamics, dating geological events, and reconstructing past volcanic activity.

Reference: Thorarinsson, S. (1981). “Tephra Studies and Tephrochronology: A Historical Review with Special Reference to Iceland.” Journal of Quaternary Science, 20(1), 3-21.

^TTephra Layer

A tephra layer is a deposit of volcanic ash, pumice, and other pyroclastic materials that settles out of the air following an explosive volcanic eruption. These layers are significant in stratigraphy and geochronology for dating geological and archaeological events, correlating deposits across regions, and studying past volcanic activity.

Reference: Thorarinsson, S. (1981). “Tephra Studies and Tephrochronology: A Historical Review with Special Reference to Iceland.” Journal of Quaternary Science, 20(1), 3-21.

^TTephrochronology

Tephrochronology is the study and dating of volcanic ash layers (tephra) to create a chronological framework for geological and archaeological events. This method is significant in stratigraphy and archaeology for correlating and dating deposits across wide geographic areas.

Reference: Lowe, D. J. (2011). “Tephrochronology and Its Application: A Review.” Quaternary Geochronology, 6(2), 107-153.

^RArchives: Glossary

Rodinia was a supercontinent that existed during the Neoproterozoic era, approximately 1.3 billion to 750 million years ago. The study of Rodinia is significant for understanding the assembly and breakup of supercontinents, the evolution of Earth’s tectonic plates, and the environmental changes that led to the Snowball Earth events.

Reference: Dalziel, I. W. D. (1997). “Neoproterozoic-Paleozoic Geography and Tectonics: Review, Hypothesis, Environmental Speculation.” Geological Society of America Bulletin, 109(1), 16-42.