Archive for the ‘Structural Geology’ Category

Stereonet solution for non-oriented core

Stereonet solution for non-oriented core

Shawn Harvey of Saskatchewan sent me this email earlier this year: Hello again Roger,  You previously helped me out with some alpha-beta stereonet solutions which worked great (thanks again!!). I am now looking into a slightly more complex stereonet issue. I have some semi-oriented core in which […]

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A stereonet solution for alpha beta angles in oriented drill core

A stereonet solution for alpha beta angles in oriented drill core

Using a stereonet to calculate strike and dip from alpha-beta angles in oriented drill core The attitude of a surface in oriented drill core can be determined by the measuring two internal core angles known as alpha (α) and beta (β). These numbers are then normally entered […]

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Sense of movement structures in fault zones Part 3: Identification Criteria

Sense of movement structures in fault zones  Part 3: Identification Criteria

Sense of Movement Structures in Fault Zones.  Part 3: Identification criteria Within or adjacent to a fault zone, various minor structures can be present that enable the sense of movement across the fault to be determined.  These structures are often called kinematic indicators. In Part 1 of […]

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Sense Of Movement Structures in Fault Zones: Part 2: Examples

Sense Of Movement Structures in Fault Zones: Part 2: Examples

Sense of Movement  Structures in Fault Zones :  Part 2 – Examples Within or adjacent to fault zones, various minor associated structures can be present that enable the sense of movement across the fault to be determined. These structures are often called kinematic indicators. This is the […]

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Sense of movement structures – Part 1, Theory

Sense of movement structures – Part 1, Theory

Sense of movement structures in fault zones - Part 1, Theory Within or adjacent to fault zones, various minor associated structures can be present that enable the sense of movement across the fault to be determined. These structures are often called kinematic indicators. Faults are the host to […]

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Drill Hole Targeting

Drill Hole Targeting

  TARGETING DRILL HOLES It is a truism that ore bodies are rare and hard to locate. If this were not so, they would hardly be worth finding.  Explorers search for them by drilling holes into the ground.  A single drill hole produces a very small sample […]

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The Three point problem: Calculating strike and dip from multiple DD Holes

The Three point problem: Calculating strike and dip from multiple DD Holes

The Three Point Problem In the previous post I described how quantitative orientation data can be collected from non-oriented core from a single drill hole.  In this post, techniques for collecting orientation data on planes are described when more than one non-oriented hole is available from a […]

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Measuring Structure in Non-Oriented Drill Core

Measuring Structure in Non-Oriented Drill Core

Measuring Structure in Non-Oriented Drill Core My drill core is not oriented. How do I measure structure? Down-hole orientation surveys record the deviation of a drill hole from its initial azimuth and inclination. However, the solid stick of drill core (sometimes, not so solid) recovered from a […]

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Making sense of 2-D Data – Part 1: Faults

Making sense of 2-D Data – Part 1: Faults

Visualising complex objects in three dimensions isn’t easy, although geologists are better at this than most. Two dimensional objects are an order of magnitude easier to comprehend. Where the object under study is complex we can gain an understanding by visualising or portraying two dimensional slices across […]

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Vergences and Fractals

Vergences and Fractals

Field geologists have long known that the style and relationships of structures seen in a hand specimen, outcrop or drill core can mimic the style and relationships of much larger structures that formed during the same deformation but occur at the scale of a geological map or section. […]

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