What it is
A reconstruction is not a list of positions. Every plate is placed relative to another, up to an anchor, and an ordinary map hides that entirely. This one draws the hierarchy on the globe, Cao et al. 2024, 0–1800 Ma.
Most links carry no motion: 426 of 496 are locked at 0 Ma. A second panel runs those locked groups across the whole 1800 Myr as an alluvial diagram, weighted by continental area.
Contents
- NodesOne per plate with geometry, at its largest polygon's centroid.
- LinksOrange carries relative motion. Faint is locked. Dashed is patched.
- Locked groupsNode colour. 71 groups at 0 Ma, 26 at 100, 11 by 1000.
- RootsYellow: the plates nearest the anchor. Four at 500 Ma.
- Two treesStatic polygons (497 plates) or resolved topologies (46).
- FlowsAlluvial diagram, 173 reorganisation events, area-weighted.
- ProjectionsGlobe, Robinson, Plate Carrée.
Controls
- Drag to rotate, or drag a flat map to scroll longitude.
- Age slider 0–1800 Ma, sampled every 5 Myr.
- Click a plate to trace its circuit to the anchor.
- Toggle supercontinent flows; hover a band for its plate ids.
Lesson sketches
Count the rotations behind one continent
- At 100 Ma, click a plate at the edge of the tree. Read its circuit.
- Count the hops. Mark which move and which are locked.
- Repeat near a root and compare chain lengths.
- Go to 500 Ma. Same route?
If one rotation in a chain is revised, which plates move?
Two trees from one model
- At 0 Ma, record plate and link counts under static polygons.
- Switch to topologies and record them again.
- Explain why static is mostly locked and topological mostly moving.
Asked how many plates the model has, which number would you give?
The supercontinent cycle on one diagram
- Open the flows panel. Find where many bands merge into few.
- Find where one wide band breaks apart.
- Name each event and check the ages against Rodinia, Gondwana, Pangaea.
- Hover the widest band at 300 Ma for its plate ids.
Bands are weighted by continental area. What changes if you weight by plate count?
What a reconstruction really is
- Show the globe at 0 Ma with the tree drawn over it.
- Click a plate; follow the orange line to the anchor.
- Run the slider and let the structure reorganise.
If everything moves relative to something else, what is anything measured against?