URUANA — SÃO DOMINGOS: GRAVITY CROSS-CHECK

Purpose
Test whether the localized magnetic intensification along the São Domingos fault is independently reproduced by a bulk-density signal.

Data
2008 processed gravimetry from the same survey.
Gb = raw Bouguer anomaly (mGal).
The metadata states that terrain correction was applied using 2.67 g/cm^3.

Results
At the two fault crossings nearest Uruana:
- line 10: magnetic step = +11.743 nT; Bouguer step = +2.160 mGal
- line 20: magnetic step = +13.074 nT; Bouguer step = -0.865 mGal

The Bouguer response does not preserve a common sign or a localized maximum on lines 10–20.
A larger Bouguer step occurs farther north (e.g. line 40 ~ -5.35 mGal) where the magnetic response is already weak.
Across the available crossings, |magnetic step| and |Bouguer step| are not strongly concordant (exploratory Spearman rho ~0.40).

Verdict
FAIL for independent gravity replication of the localized magnetic response.
Do not count free-air or Bouguer as a second independent axis supporting the Uruana inversion.
The current core evidence remains magnetic + geological structure, not gravity.

Physical implication allowed:
The data are compatible with a magnetic-susceptibility contrast that need not produce a comparably localized bulk-density contrast.
This is a possible interpretation, not a demonstrated mechanism.