Found a 43-101 with Boron:.... At an average grade of 114.0 mg/L and assuming 5.7 billion cubic metres of water the inferred resource estimate for boron is 650,000 tonnes (2,093,000 tonnes of B2O3)... May 2016
https://www.accesswire.com/439479/Canadian-International-Minerals-and-Noram-Ventures-Sign-Letter-of-Intent-to-Advance-Alberta-Lithium-Brine-Project
E3:
2017 Apex Report mineral section:
Boron 100 mg/L.
From press releases:
"...that contains an estimated total of 59 billion cubic meters of brine formation water..."
Neodynium - Iron - Boron are "super magnets", & E3 has an enourmous amount of Boron, for REE alloying.
The only US producer is of course hard rock & produces 1m tons a yr.
A Rio Tinto company:
https://www.borax.com/about/borax-operations/boron-california
.