Exploring the Dimensions of Magmatic Sulfide Mineral Systems
Understanding timescales and lengthscales in magmatic sulfide mineral systems. Importance of spatial and temporal dimensions in system analysis and exploration programs.
00:00:03 Dr. Steve Barnes discusses timescales and lengthscales in magmatic sulfide mineral systems, emphasizing the importance of considering both spatial and temporal dimensions in understanding these systems. He provides an analogy with storm cells and explains how different processes at different scales interact. The talk includes a case study on the Nova deposit in Western Australia.
🌍 Understanding mineral systems requires considering length and time scales.
⛈️ Mineral systems can be compared to storm cells, with various processes operating at different scales.
📊 A length scale-time scale diagram can help visualize and analyze the interactions of different processes in mineral systems.
00:07:23 This video discusses the timescales and lengthscales involved in magmatic sulfide mineral systems. It explains the various processes and their positions on the scaling diagram. The video also explores geological processes and examples of volcanic events. The talk concludes with the importance of understanding these timescales and lengthscales for designing exploration programs.
🔑 Different processes control magmatic sulfide mineral systems, including magmatic flow, thermal diffusion, and chemical diffusion.
🧪 Chemical diffusion processes are much slower than thermal diffusion processes and only matter at very small length scales.
🌋 Geological processes in magmatic sulfide systems can be observed and analyzed based on their timescale and length scale.
00:14:42 Timescales and lengthscales in magmatic sulfide mineral systems. The process of thermal erosion is faster than thermal oriole formation. The presence of disaggregated xenoliths in the magma is an important clue. Dissolution of xenoliths and equilibration of cellphones happen on longer timescales. Chemical equilibration is slower compared to transport and settling rates. Deposits form on longer lengthscales and timescales. Sulfide liquids have high density.
🔥 Thermal erosion can happen over meters and on the scale of days, while the formation of thermal orioles takes much longer.
💡 The main way of getting sulfur into the magma is by physically incorporating cellphone-bearing warm rock into the magma through the process of thermal erosion.
🌋 Disaggregated xenoliths in the magma can transport sulfur a long way before they melt, and this has implications for the formation of different types of deposits.
⏰ The process of mixing sulfide droplets with magma and scavenging metals is relatively slow due to the diffusion of sulfur in the magma.
00:22:01 The video discusses the timescales and lengthscales involved in magmatic sulfide mineral systems. It explores the balance of sulfide liquid, the importance of keeping systems open and operating on large scales and for long periods of time, and the formation of sulfide accumulations within the plumbing system.
🔑 In magmatic sulfide mineral systems, there is a strong tendency for sulfide liquid to reactivate and move downwards.
🔒 To form a deposit, these systems need to operate on large enough scales and time scales of hundreds of thousands of years.
🌋 In shield volcanoes, magma can flow both vertically and laterally, and a major eruption at a distance can lead to collapse in the summit caldera.
🌡️ Magma withdrawal and vertical and horizontal motions happen at length scales of thousands of feet and on a timescale of days.
⚙️ Forming nickel sulfide deposits involves major channel switching events, backflow, and accumulation in choke points within the plumbing system.
🧪 An analogy to an elutriation column is used to explain the efficient segregation of particles from the fluid in the formation of deposits.
📜 Magma flows quickly, melting of xenoliths is important, and multiple stages of recycling occur in conduit systems for oil formation.
00:29:20 This video discusses the geological composition and formation processes of a mineral deposit called the Albany Fraser origin. It explores the textures and phases of the rocks and their implications for understanding the magmatic sulfide mineral systems.
⚫️ The video discusses the study of layered intrusions and the challenges of deriving rates for processes within them.
🔴 The speaker applies their findings to a specific location, the Albany Fraser origin, and discusses the composition and structure of the intrusions found there.
🟢 The video highlights the unique textures and characteristics of the rocks found in the intrusions, such as zoned crystals and complex patterns.
00:36:38 This video discusses the timescales and lengthscales in magmatic sulfide mineral systems. It explores the different textures and processes involved in the infiltration of sulfide into country rocks.
🌋 Magmatic sulfide mineral systems involve the infiltration of sulfides into country rocks.
⚒️ Sulfide infiltration causes melting and fracturing of the country rocks.
🔍 Magmatic textures and reactions can be observed within the sulfide minerals.
00:43:58 The video discusses the timescales and lengthscales involved in magmatic sulfide mineral systems. It explains how sulfide infiltration is self-reinforcing and propagates under its own weight. The cooling of the sulfides takes millions of years, while the growth and percolation of the sulfides happen on shorter timescales.
🔍 Sulfide infiltration process is self-reinforcing, leading to the propagation of sulfide veins under their own weight.
🌡️ The timescales of magmatic sulfide mineral systems depend on the thermal regime, with cooling taking around a thousand years and sulfide solidification potentially taking millions of years.
⏰ The formation of certain minerals, such as zone purakh scenes, can happen on the timescale of hours to days, while other processes, like percolation of sulfide liquids, may take thousands to hundreds of thousands of years.
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