The HaloLots of debate still on going at CEO.ca
In situ nuggets often display a 1 -2 mm halo of fine remobilized gold surrounding them.
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/6AB34DCA740C96F1E7DF1027638E7E56/S1431927616010916a.pdf/morphologic-evidence-of-in-situ-gold-deposition-in-lateritic-placer-deposits-from-guyana-shield-of-venezuela.pdf
......"clearly shows a growth halo of discrete nanometer to micrometer scale gold particles adjacent to a gold nugget, along the surface, as well as in the pore spaces of the laterite material. The non-uniform size distribution of the gold in conjunction with well-formed crystal faces further suggests the gold particles were precipitated in-situ and not deposited mechanically. The exact mechanism of in-situ gold growth is unclear"