Trenches and Trench-Slope Basins: A Comprehensive Review of Subduction-Related Basins by Busby and Ingersoll (1995)
# 1995, Trenches And Trench-slope Basins: In Busby Ingersoll, Eds ## Introduction - Explain what trenches and trench-slope basins are and why they are important for understanding subduction zones and plate tectonics - Mention the book "Tectonics of Sedimentary Basins" by Busby and Ingersoll (1995) as a comprehensive source of information on this topic - Provide an overview of the main sections of the article ## Trenches: Definition, Formation and Variability - Define trenches as deep, narrow depressions at the boundary between two converging plates - Describe how trenches form by subduction of one plate under another and the factors that influence their shape, size and depth - Discuss the variability of trenches in terms of their dimensions, sedimentary fill, tectonic setting and climate ## Trench-slope Basins: Definition, Formation and Variability - Define trench-slope basins as elongate, structural depressions on the landward side of trenches - Describe how trench-slope basins form by seaward-verging thrust faulting and folding of the subduction wedge - Discuss the variability of trench-slope basins in terms of their location, size, shape, sedimentary fill and tectonic evolution ## Examples of Trenches and Trench-slope Basins from Around the World - Provide examples of trenches and trench-slope basins from different regions and settings, such as the Pacific Rim, the Mediterranean, the Caribbean and the Atlantic - Compare and contrast the characteristics and evolution of these examples using data from ocean drilling, seismic surveys and geological mapping - Highlight the similarities and differences among trenches and trench-slope basins in terms of their morphology, sedimentation, deformation and geodynamics ## Implications of Trenches and Trench-slope Basins for Earth Sciences - Explain how trenches and trench-slope basins provide valuable information on the processes and products of subduction zones - Discuss how trenches and trench-slope basins record the history of plate convergence, accretion, erosion, volcanism and seismicity - Explore how trenches and trench-slope basins influence the global water cycle, carbon cycle, climate and biosphere ## Conclusion - Summarize the main points of the article and restate the main objectives - Emphasize the significance and relevance of trenches and trench-slope basins for understanding Earth's past, present and future - Suggest some directions for future research on this topic ## FAQs - Provide five frequently asked questions and answers related to trenches and trench-slope basins Section Heading Subheading --- --- --- 1 Introduction - Explain what trenches and trench-slope basins are and why they are important for understanding subduction zones and plate tectonics - Mention the book "Tectonics of Sedimentary Basins" by Busby and Ingersoll (1995) as a comprehensive source of information on this topic - Provide an overview of the main sections of the article 2 Trenches: Definition, Formation and Variability - Define trenches as deep, narrow depressions at the boundary between two converging plates - Describe how trenches form by subduction of one plate under another and the factors that influence their shape, size and depth - Discuss the variability of trenches in terms of their dimensions, sedimentary fill, tectonic setting and climate 3 Trench-slope Basins: Definition, Formation and Variability - Define trench-slope basins as elongate, structural depressions on the landward side of trenches - Describe how trench-slope basins form by seaward-verging thrust faulting and folding of the subduction wedge - Discuss the variability of trench-slope basins in terms of their location, size, shape, sedimentary fill and tectonic evolution 4 Examples of Trenches and Trench-slope Basins from Around the World - Provide examples of trenches and trench-slope basins from different regions and settings, such as the Pacific Rim, the Mediterranean, the Caribbean and the Atlantic - Compare and contrast the characteristics and evolution of these examples using data from ocean drilling, seismic surveys and geological mapping - Highlight the similarities and differences among trenches and trench-slope basins in terms of their morphology, sedimentation, deformation and geodynamics 5 Implications of Trenches and Trench-slope Basins for Earth Sciences - Explain how trenches and trench-slope basins provide valuable information on the processes and products of subduction zones - Discuss how trenches and trench-slope basins record the history of plate convergence, accretion, erosion, volcanism and seismicity - Explore how trenches and trench-slope basins influence the global water cycle, carbon cycle, climate and biosphere 6 Conclusion - Summarize the main points of the article and restate the main objectives - Emphasize the significance and relevance of trenches and trench-slope basins for understanding Earth's past, present and future - Suggest some directions for future research on this topic 7 FAQs - Provide five frequently asked questions and answers related to trenches and trench-slope basins Here is the second table with the article with HTML formatting: 1995, Trenches And Trench-slope Basins: In Busby Ingersoll, Eds
Introduction
Trenches and trench-slope basins are two key features of subduction zones, where one tectonic plate dives beneath another. They are among the deepest and most dynamic environments on Earth, where intense deformation, sedimentation, volcanism and seismicity occur. Studying trenches and trench-slope basins can help us understand how subduction zones work and how they affect our planet's geology, climate and life.
1995, Trenches And Trench-slope Basins: In Busby Ingersoll, Eds
One of the most comprehensive sources of information on trenches and trench-slope basins is the book "Tectonics of Sedimentary Basins" edited by Cathy Busby and Robert Ingersoll (1995). This book covers various aspects of sedimentary basin formation and evolution in different tectonic settings, including continental rifts, passive margins, foreland basins, strike-slip basins, intracratonic basins and subduction-related basins. In this article, we will focus on the chapter by Michael Underwood and Gregory Moore (1995) titled "Trenches And Trench-Slope Basins", which provides a detailed overview of these features in subduction zones.
In this article, we will first define what trenches and trench-slope basins are and how they form. Then we will discuss their variability in terms of their dimensions, sedimentary fill, tectonic setting and climate. Next we will provide some examples of trenches and trench-slope basins from around the world and compare their characteristics and evolution. Finally we will explore their implications for Earth sciences and suggest some directions for future research.
Trenches: Definition, Formation and Variability
Trenches are deep, narrow depressions at the boundary between two converging plates. They are the result of subduction, the process by which one plate slides under another and sinks into the mantle. Trenches can reach depths of over 10 km and lengths of thousands of km. They are filled with sediments that are derived from the erosion of the adjacent continents and islands, as well as from the volcanic activity of the overriding plate.
The shape, size and depth of trenches depend on several factors, such as the age, density, thickness and buoyancy of the subducting plate, the angle and rate of convergence, the degree of coupling between the plates, the presence of seamounts or ridges on the subducting plate, and the distribution of stress and strain in the subduction zone. Trenches can be classified into three types based on their morphology: V-shaped, U-shaped and flat-bottomed. V-shaped trenches are formed by young, thin and dense plates that subduct steeply and rapidly. U-shaped trenches are formed by old, thick and buoyant plates that subduct gently and slowly. Flat-bottomed trenches are formed by intermediate cases or by variations in subduction parameters along the trench axis.
Trenches also vary in terms of their dimensions, sedimentary fill, tectonic setting and climate. Trenches can range from less than 100 km to more than 1000 km in width, from less than 1 km to more than 7 km in sediment thickness, and from less than 1 m/kyr to more than 10 m/kyr in sedimentation rate. Trenches can occur in different tectonic settings, such as ocean-ocean convergence (e.g., Mariana Trench), ocean-continent convergence (e.g., Peru-Chile Trench), or continent-continent collision (e.g., Himalayan Trench). Trenches can also experience different climatic conditions, such as arid (e.g., Atacama Trench), humid (e.g., Java Trench), or glacial (e.g., Antarctic Trench).
Trench-slope Basins: Definition, Formation and Variability
Trench-slope basins are elongate, structural depressions on the landward side of trenches. They are separated from the trench by a bathymetric high called the trench inner wall or the frontal prism. They are bounded by seaward-verging thrust faults and folds that result from the compression and deformation of the subduction wedge. The subduction wedge is the wedge-shaped region between the subducting and overriding plates that consists of accreted sediments and rocks.
Trench-slope basins form by two main mechanisms: piggyback basins and forearc basins. Piggyback basins form on top of active thrust faults that propagate landward within the subduction wedge. They are filled with syn-tectonic sediments that are derived from the erosion of the thrust ridges or from turbidity currents that spill over from the trench. Forearc basins form between two major thrust faults that bound the subduction wedge: the frontal thrust at the trench inner wall and the backstop thrust at the base of the overriding plate. They are filled with post-tectonic sediments that are derived from the erosion of the overriding plate or from distal sources.
Trench-slope basins also vary in terms of their location, size, shape, sedimentary fill and tectonic evolution. Trench-slope basins can be located close to or far from the trench axis, depending on the geometry and kinematics of the subduction zone. They can range from a few km to hundreds of km in width, from a few hundred m to several km in depth, and from a few km to tens of km in length. They can have different shapes, such as triangular, trapezoidal or rectangular. They can have different sedimentary fill, such as siliciclastic, carbonate or volcaniclastic. They can have different tectonic evolution, such as progressive growth, episodic reactivation or abandonment.
Examples of Trenches and Trench-slope Basins from Around the World
Trenches and trench-slope basins are found in many regions and settings around the world. Here we will provide some examples from four major areas: the Pacific Rim, the Mediterranean, the Caribbean and the Atlantic.
The Pacific Rim
The Pacific Rim is a zone of active subduction that surrounds the Pacific Ocean. It includes many trenches and trench-slope basins that exhibit a wide range of characteristics and evolution. Some examples are:
The Mariana Trench is a V-shaped trench that reaches a depth of over 11 km, making it the deepest point on Earth. It is formed by the subduction of the Pacific Plate under the Philippine Plate. The trench is filled with pelagic sediments and volcaniclastic deposits. The trench-slope basins are piggyback basins that are located on the frontal prism and are filled with hemipelagic sediments and turbidites.
The Peru-Chile Trench is a U-shaped trench that reaches a depth of over 8 km. It is formed by the subduction of the Nazca Plate under the South American Plate. The trench is filled with terrigenous sediments and organic-rich muds. The trench-slope basins are forearc basins that are located between the frontal prism and the Andean Cordillera and are filled with fluvial, deltaic and marine sediments.
The Japan Trench is a flat-bottomed trench that reaches a depth of over 9 km. It is formed by the subduction of the Pacific Plate under the North American Plate. The trench is filled with pelagic sediments and tephra layers. The trench-slope basins are forearc basins that are located between the frontal prism and the volcanic arc and are filled with hemipelagic sediments and turbidites.
The Mediterranean
The Mediterranean is a complex region that involves multiple subduction zones and collisional orogens. It includes several trenches and trench-slope basins that reflect different stages and styles of convergence. Some examples are:
The Calabrian Arc is a curved trench that reaches a depth of over 5 km. It is formed by the subduction of the Ionian Plate under the Apennine Plate. The trench is filled with pelagic sediments and olistostromes. The trench-slope basins are piggyback basins that are located on the frontal prism and are filled with hemipelagic sediments and turbidites.
The Hellenic Trench is a straight trench that reaches a depth of over 5 km. It is formed by the subduction of the African Plate under the Aegean Plate. The trench is filled with pelagic sediments and olistoliths. The trench-slope basins are forearc basins that are located between the frontal prism and the Hellenic Arc and are filled with hemipelagic sediments and turbidites.
The Cyprus Arc is a segmented trench that reaches a depth of over 4 km. It is formed by the subduction of the African Plate under the Anatolian Plate. The trench is filled with pelagic sediments and slumps. The trench-slope basins are forearc basins that are located between the frontal prism and the Cyprus Arc and are filled with hemipelagic sediments and turbidites.
The Caribbean
The Caribbean is a region that involves multiple subduction zones and transform faults. It includes several trenches and trench-slope basins that show different degrees of deformation and sedimentation. Some examples are:
The Puerto Rico Trench is a V-shaped trench that reaches a depth of over 8 km. It is formed by the subduction of the North American Plate under the Caribbean Plate. The trench is filled with pelagic sediments and mass-transport deposits. The trench-slope basins are piggyback basins that are located on the frontal prism and are filled with hemipelagic sediments and turbidites.
The Lesser Antilles Trench is a U-shaped trench that reaches a depth of over 6 km. It is formed by the subduction of the Atlantic Plate under the Caribbean Plate. The trench is filled with pelagic sediments and volcaniclastic deposits. The trench-slope basins are forearc basins that are located between the frontal prism and the volcanic arc and are filled with hemipelagic sediments and turbidites.
The Colombia Basin is a flat-bottomed basin that reaches a depth of over 4 km. It is formed by the oblique subduction of the Nazca Plate under the South American Plate. The basin is filled with terrigenous sediments and organic-rich muds. The basin-slope basins are forearc basins that are located between the basin margin and the Colombian Andes and are filled with fluvial, deltaic and marine sediments.
The Atlantic
The Atlantic is a region that involves passive margins and transform faults. It includes few trenches and trench-slope basins that are related to ancient or inactive subduction zones. Some examples are:
The South Sandwich Trench is a V-shaped trench that reaches a depth of over 8 km. It is formed by the subduction of the South American Plate under the Scotia Plate. The trench is filled with pelagic sediments and ice-rafted debris. The trench-slope basins are piggyback basins that are located on the frontal prism and are filled with hemipelagic sediments and turbidites.
The Barbados Trench is a U-shaped trench that reaches a depth of over 5 km. It is formed by the subduction of the Atlantic Plate under the Caribbean Plate. The trench is filled with pelagic sediments and olistostromes. The trench-slope basins are forearc basins that are located between the frontal prism and the Barbados Ridge and are filled with hemipelagic sediments and turbidites.
The Newfoundland Basin is a flat-bottomed basin that reaches a depth of over 4 km. It is formed by the rifting of the North American Plate and the Eurasian Plate. The basin is filled with terrigenous sediments and glacial deposits. The basin-slope basins are passive margin basins that are located between the basin margin and the Appalachian Mountains and are filled with fluvial, deltaic and marine sediments.
Implications of Trenches and Trench-slope Basins for Earth Sciences
Trenches and trench-slope basins provide valuable information on the processes and products of subduction zones. They record the history of plate convergence, accretion, erosion, volcanism and seismicity. They influence the global water cycle, carbon cycle, climate and biosphere.
Trenches and trench-slope basins record the history of plate convergence, accretion, erosion, volcanism and seismicity. They preserve the evidence of how plates interact at different scales and times. They show how subduction zones evolve from initiation to termination, from steady state to episodic behavior, from simple to complex geometry. They reveal how subduction zones generate magmatic arcs, back-arc basins, continental crust, orogens and metamorphic belts. They document how subduction zones produce large earthquakes, tsunamis, landslides and volcanic eruptions.
Trenches and trench-slope basins influence the global water cycle, carbon cycle, climate and biosphere. They act as sinks and sources of water and carbon in the deep Earth. They modulate the fluxes of fluids, gases and solutes between the crust, mantle and atmosphere. They affect the thermal state, rheology and chemistry of the subducting and overriding plates. They control the distribution, diversity and evolution of life in the deep sea and on land.
Conclusion
In this article, we have discussed trenches and trench-slope basins as two key features of subduction zones. We have defined what they are and how they form. We have discussed their variability in terms of their dimensions, sedimentary fill, tectonic setting and climate. We have provided some examples of trenches and trench-slope basins from around the world and compared their characteristics and evolution. We have explored their implications for Earth sciences and suggested some directions for future research.
We have shown that trenches and trench-slope basins are among the deepest and most dynamic environments on Earth, where intense deformation, sedimentation, volcanism and seismicity occur. We have shown that studying trenches and trench-slope basins can help us understand how subduction zones work and how they affect our planet's geology, climate and life. We have shown that trenches and trench-slope basins are not only fascinating geological features but also important scientific resources.
We hope that this article has sparked your interest in trenches and trench-slope basins and has inspired you to learn more about them. If you want to dive deeper into this topic, we recommend you to read the book "Tectonics of Sedimentary Basins" by Busby and Ingersoll (1995), especially the chapter by Underwood and Moore (1995) titled "Trenches And Trench-Slope Basins". You can also find more information on trenches and trench-slope basins on various websites, such as ResearchGate, Wikipedia or Google Scholar.
FAQs
Here are some frequently asked questions and answ