North Andes Plate

Classification

plate class

microplate

How this is mapped

2 published representations of where North Andes Plate is. Each is one interpretation, by one identified source, at one scale — not the shape of the thing itself.

• Tectonic model geometry

  Polygon · 62 positionspreferred for publication

  Geometry that exists because a model defines it — a rigid-plate outline, a zone where a model declares itself inapplicable. It is a property of the model, and changes when the model is revised. It is present-day geometry from a present-day model; a palaeogeographic reconstruction is a different thing and Lithoen does not hold one.

  The North Andes Plate as outlined in model PB2002 (Bird, 2003). This is the model’s boundary, not a mapped geological contact: it is where a rigid-plate model puts the edge of a plate, and Bird’s own documentation states that coordinates are given to a precision of about 60 m while "accuracy never equals precision". Where deformation is distributed rather than confined to a line, the model marks the region as an orogen and the outline there is a convenience.

  Boundary certainty

  InterpretedThe boundary was placed by a geologist reading evidence: mapping, geophysics, geochronology, structure. It is reproducible from that evidence and it is an interpretation of it. Most geological boundaries are this.

  Status of this geometry

  modelledThe status of the geometry, which need not match the status of what the entity’s claims assert.

  Dataset

  PB2002 plates, boundaries and orogens as GeoJSON (fraxen/tectonicplates)Plate model PB2002 from Bird (2003), doi:10.1029/2001GC000252; GIS conversion by Hugo Ahlenius, Nordpil, ODC-By 1.0.

  What was done to this geometry

  • By Lithoen — Douglas–Peucker, 145 positions to 62
  • By Lithoen — Coordinates rounded to 4 decimal places, about 11 m of longitude at the equator.
  • Before it reached Lithoen — Bird (2003) digitised the boundary curves from published sources at varying scales; the model is a compilation, not a single survey.
  • Before it reached Lithoen — The GIS conversion (Ahlenius, ODC-By 1.0) split segments spanning the -180/180 meridian and moved them, as its README states. Four plates therefore arrive as multi-part geometries.

• Boundary

  MultiLineString · 34 positions

  A line delimiting or separating things — a plate boundary, a suture, a mapped contact. A boundary is not an extent: it says where the edge runs, not what lies on either side.

  North Andes–Nazca boundary as drawn in model PB2002 (Bird, 2003), from source segments ND/NZ, NZ\ND. The model labels these segments as subduction. Digitised by: Westbrook et al. [1995]; by Peter Bird, 1999.

  Boundary certainty

  InterpretedThe boundary was placed by a geologist reading evidence: mapping, geophysics, geochronology, structure. It is reproducible from that evidence and it is an interpretation of it. Most geological boundaries are this.

  Status of this geometry

  modelledThe status of the geometry, which need not match the status of what the entity’s claims assert.

  Dataset

  PB2002 plates, boundaries and orogens as GeoJSON (fraxen/tectonicplates)Plate model PB2002 from Bird (2003), doi:10.1029/2001GC000252; GIS conversion by Hugo Ahlenius, Nordpil, ODC-By 1.0.

  What was done to this geometry

  • By Lithoen — 2 source features carrying the same identifier were combined into one multi-part geometry; no coordinate was altered by the combination.
  • By Lithoen — Coordinates rounded to 4 decimal places, about 11 m of longitude at the equator.
  • Before it reached Lithoen — Bird (2003) compiled these curves from published sources at varying scales, crediting each segment to its own source; those credits are carried in the caption of every record.
  • Before it reached Lithoen — The GIS conversion (Ahlenius, ODC-By 1.0) split segments spanning the -180/180 meridian and moved them, as its README states.