Lesson 1X-ray diffraction (XRD): phase identification goals and sample preparation notesThis section covers XRD methods for BIF, focusing on phase identification, quantifying iron oxides, carbonates, and silicates, and recognising amorphous components. Emphasis is placed on sampling, grinding, and avoiding preferred orientation artefacts.
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 diagenesisThis section examines stable O, Si, and C isotopes in BIF-related materials, explaining what each proxy reveals about temperature, fluid sources, water–rock interaction, and diagenesis, and how to integrate multi-isotope datasets with 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 methodsThis section reviews dating tools applicable to BIF successions, including U-Pb on zircons from interlayered volcanics, Re-Os on sulfides, and chemostratigraphic and lithostratigraphic correlation, highlighting strengths, uncertainties, and 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 sectionsThis section outlines how to design BIF sampling plans in outcrop and core, including spacing, targeting sedimentary cycles, capturing facies transitions, and building composite sections that preserve stratigraphic context while remaining 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 documentThis section introduces optical petrography for BIF, emphasising how transmitted and reflected light thin sections reveal mineralogy, textures, and microstructures that record depositional processes, diagenesis, deformation, and 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 studiesThis section introduces iron isotope analysis in BIF research, covering sampling strategies, purification methods, mass spectrometry, and how δ56Fe signatures constrain redox processes, iron sources, microbial activity, and 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 powdersThis section defines BIF sample types and their uses, from bulk rock and oriented slabs to standard thin sections, polished mounts, and micro-drilled powders, emphasising how each supports specific petrographic, geochemical, and isotopic analyses and 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)This section explains whole-rock XRF and ICP-MS workflows for BIF, including major and trace element targets, expected compositional ranges, and redox-sensitive proxies such as Fe, Si, Mn, P, and REE patterns used to infer depositional and 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 documentationThis section details electron microprobe and SEM-EDS methods for BIF, focusing on mineral chemistry, zoning, and micro-textures. Learners will design analytical transects, interpret maps, and 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
