Lesson 1X-ray diffraction (XRD): phase identification goals and sample preparation notesDis section cover XRD methods fi BIF, focusin pon phase identification, quantifyin iron oxides, carbonates, an silicates, an recognizin amorphous components. Emphasis place pon samplin, grindin, an avoidin preferred orientation artifacts.
Choosing representative XRD samplesPowder preparation and grain-size controlInstrument settings and scan parametersIdentifying iron oxides, carbonates, silicatesSemi-quantitative phase estimation limitsLesson 2Stable isotopes (O, Si, C): what each proxy reveals about temperature, fluid sources, and diagenesisDis section examine stable O, Si, an C isotopes in BIF-related materials, explainin what each proxy reveal bout temperature, fluid sources, water–rock interaction, an diagenesis, an how fi integrate multi-isotope datasets wid petrographic observations.
Sampling carbonates, cherts, and silicatesO isotope constraints on fluid temperatureSi isotopes and silica source signalsC isotopes in associated carbonatesCombining isotopes with petrographyLesson 3Dating approaches relevant to BIF studies: U-Pb on intercalated volcanics or zircons, Re-Os on sulfides, and stratigraphic correlation methodsDis section review datin tools applicable to BIF successions, includin U-Pb pon zircons from interlayered volcanics, Re-Os pon sulfides, an chemostratigraphic an lithostratigraphic correlation, highlightin strengths, uncertainties, an integration strategies.
Selecting datable interlayered unitsU-Pb zircon sampling and interpretationRe-Os sulfide sampling and limitationsChemostratigraphic correlation in BIFsIntegrating ages with regional stratigraphyLesson 4Designing a sampling plan: sample spacing in outcrop and core, targeting cycles, and strategies for composite sectionsDis section outline how fi design BIF samplin plans in outcrop an core, includin spacin, targetin sedimentary cycles, capturin facies transitions, an buildin composite sections dat preserve stratigraphic context while remainin logistically feasible.
Defining scientific questions and scalesSampling spacing in outcrop and coreTargeting facies and cycle boundariesBuilding composite stratigraphic sectionsDocumenting locations and metadataLesson 5Optical petrography: objectives, thin-section techniques (transmitted and reflected light), and key textures to documentDis section introduce optical petrography fi BIF, emphasizin how transmitted an reflected light thin sections reveal mineralogy, textures, an microstructures dat record depositional processes, diagenesis, deformation, an fluid overprints.
Objectives of BIF petrographic studiesPreparing transmitted light thin sectionsPreparing reflected light polished sectionsRecognizing primary banding and laminationIdentifying diagenetic and metamorphic texturesLesson 6Iron isotope analyses and their interpretive use for redox and source studiesDis section introduce iron isotope analysis in BIF research, coverin samplin strategies, purification methods, mass spectrometry, an how δ56Fe signatures constrain redox processes, iron sources, microbial activity, an diagenetic overprints in ancient basins.
Sampling strategies for Fe isotopesChemical purification of iron fractionsMC-ICP-MS measurement considerationsInterpreting δ56Fe in depositional settingsRecognizing diagenetic isotope overprintsLesson 7Types of samples: bulk rock, oriented slabs, thin sections, polished mounts, and targeted micro-drilled powdersDis section define BIF sample types an dem uses, from bulk rock an oriented slabs to standard thin sections, polished mounts, an micro-drilled powders, emphasizin how each support specific petrographic, geochemical, an isotopic analyses an interpretations.
Bulk rock samples for whole-rock chemistryOriented slabs for structural contextStandard and doubly polished thin sectionsPolished mounts for reflected light and EMPAMicro-drilled powders for isotope analysesLesson 8Whole-rock major and trace element geochemistry (XRF/ICP-MS): elements to measure, expected ranges, and redox-sensitive proxies (Fe, Si, Mn, P, rare earth elements)Dis section explain whole-rock XRF an ICP-MS workflows fi BIF, includin major an trace element targets, expected compositional ranges, an redox-sensitive proxies such as Fe, Si, Mn, P, an REE patterns used fi infer depositional an diagenetic conditions.
Sampling and contamination avoidanceFusion and dissolution preparation methodsKey major elements and Fe/Si ratiosTrace elements and REE pattern metricsRedox-sensitive elemental proxy selectionLesson 9Electron microprobe and SEM-EDS: mineral chemistry, zoning, and micro-texture documentationDis section detail electron microprobe an SEM-EDS methods fi BIF, focusin pon mineral chemistry, zonin, an micro-textures. Learners wi design analytical transects, interpret maps, an link micro-scale observations to whole-rock geochemical patterns.
Sample polishing and coating requirementsBackscattered and secondary electron imagingPoint analyses and line transectsElemental mapping of mineral zoningLinking microtextures to bulk chemistry
