# The slabs were set or shaped so that midday light marks the solstices and equinoxes on the spirals, and the…

> Most likely: The slabs were set or shaped so that midday light marks the solstices and equinoxes on the spirals, and the site was used as a solar calendar.

Source: https://mysteriesdept.com/mysteries/chaco-canyon/answers/ANS0D9KVGJA3VMP/the-slabs-were-set-or-shaped-so-that-midday-light-marks-the  
Publisher: Mysteries Department  
Licence: CC BY 4.0 (credit Mysteries Department and link the page)  

---

[Questions](https://mysteriesdept.com/questions)[Great houses of Chaco Canyon](https://mysteriesdept.com/mysteries/chaco-canyon)[Was the Fajada Butte spiral made and used as a solar calendar?](https://mysteriesdept.com/mysteries/chaco-canyon/questions/QST0D9KV4BP04RM/was-the-fajada-butte-spiral-made-and-used-as-a-solar)Answer

Answer · Great houses of Chaco Canyon

# The slabs were set or shaped so that midday light marks the solstices and equinoxes on the spirals, and the…

The slabs were set or shaped so that midday light marks the solstices and equinoxes on the spirals, and the site was used as a solar calendar.

**Most likely** Answers **1** questionPublished0

## Where it stands

**Most likely** Its tests partly supported it: three pieces of evidence for, two against. It needs two reviews to be accepted.

## What it predicts

- Tool marks, shaping or packing on the slabs or their footings.
- A marking precise enough to anticipate the solstice, as a working calendar needs.

## What would rule it out

- Proof that the slabs fell into place unaided and unshaped, with a demonstration that the marking cannot anticipate the solstice.

## Evidence 3 for · 2 against

[A 3D model built from 1984 photogrammetry and a 2005 laser scan reproduces the 1978 photographs of the…](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVH1Y3WD0/a-3d-model-built-from-1984-photogrammetry-and-a-2005-laser)

Supported

FOR

[Across the Southwest, light-marking sites cluster at the solstices and equinoxes far above the chance…](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVH9R2VGB/across-the-southwest-light-marking-sites-cluster-at-the)

Supported

FOR

[At summer solstice a single dagger of light crosses the centre of the large spiral; at the winter solstice…](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVGT41ZCA/at-summer-solstice-a-single-dagger-of-light-crosses-the)

Established

FOR

[In Pueblo practice the marker would not have worked well to regulate the solar calendar.](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVHSC5ZGY/in-pueblo-practice-the-marker-would-not-have-worked-well-to)

Suggestive

AGAINST

[The slabs could have fallen into their positions naturally.](https://mysteriesdept.com/mysteries/chaco-canyon/evidence/EVD0D9KVHHJ6GE7/the-slabs-could-have-fallen-into-their-positions-naturally)

Suggestive

AGAINST

## The questions it answers

[Was the Fajada Butte spiral made and used as a solar calendar?](https://mysteriesdept.com/mysteries/chaco-canyon/questions/QST0D9KV4BP04RM/was-the-fajada-butte-spiral-made-and-used-as-a-solar)

Part of [Do the buildings and markers at Chaco encode astronomy?](https://mysteriesdept.com/mysteries/chaco-canyon/questions/QST0D9KTT3J4BBQ/do-the-buildings-and-markers-at-chaco-encode-astronomy)

Most likelyThe site was a sun shrine where the solstices and equinoxes were watched and honoured, not a calendar for…

## Cite it

```
Mysteries Department. (2026). The slabs were set or shaped so that midday light marks the solstices and equinoxes on the spirals, and the… [Answer ANS0D9KVGJA3VMP]. https://mysteriesdept.com/r/ANS0D9KVGJA3VMP
```

Key

**ANS** 0D9KVGJA3VMP

Kind

Answer · hypothesis

Origin

Published

Version

1

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