visualizing structures
DESCRIPTION
Visualizing structures. An introduction to the geometry of geological structures in the field. Goals. To familiarize you with the 3-dimensionality of geological structures in the field Provide you with simple rules to use in geologic mapping of structures. 3D spaces to deal with. - PowerPoint PPT PresentationTRANSCRIPT
Visualizing structures
An introduction to the geometry of geological structures in the field
Goals
• To familiarize you with the 3-dimensionality of geological structures in the field
• Provide you with simple rules to use in geologic mapping of structures
3D spaces to deal with
• Topographic
• Depositional/intrusive
• Deformational
They all intersect
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Shaded
Non-shaded
QuickTime™ and aAnimation decompressor
are needed to see this picture.
Any structures will intersect an irregular topographyTry picturing how will a horizontal layer cut this relief
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Horizontal plane - follows topo contours
• Let us now put the real topography aside and step into the realm of “primary” geologic structures - layering of sedimentary units, intrusions, viewed in an idealized 3D framework
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Complicating the issue a little bit…
Unconformity, what is it?
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Possible scenario: Deposition, erosion, deformation, new deposition
The way this would look in a canyon near Page, AZ
Igneous intrusions
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Structures on block diagrams
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.QuickTime™ and a
Photo - JPEG decompressorare needed to see this picture.
• Let us know try to drape structures onto topography and come up with some simple rules for the way they will plot on maps.
To keep things simple for now, I will deal mainly with planes and not with lines.
So what can a plane be? A bed, a fault, a dike, a sill an unconformity, anything that is planar.
The simplest scenario: a horizontal bed
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Horizontal beds (a’la water line)
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Some shallow tilt of a plane
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Rule of v’s
An example
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
• So then what is a geological map?
An overlay of geologic structures (e.g. like the planes shown here on the 2D topographic map). Let’s take a look.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Tucson Mts.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Cross-sections
QuickTime™ and aAnimation decompressor
are needed to see this picture.
Remember
• The 3 spaces you deal with: topo, primary structures and deformational (secondary) structures);
• Rule of v’s, overall topography/structure intersections of any planes
• A structure looks very different depending from where you look at it!
A preview of Cottonwood
Be familiar with this lecture and this week’s lab - it will be important for Saturday’s exercise.