u/Bradinator-

Himalayan Salt today (the Salt Range Formation) originates from a section of the Proto-Thethyan Ocean which was closed off around 600 Ma from terranes. The area was near the equator which lead to rapid evaporation and the formation of the halite (rock salt). Today this salt is just exposed in Pakistan's "Salt Range" due to faulting, but the Salt Range Formation itself can be found in parts of Oman, Southern China, and Iran.

Image from: https://www.researchgate.net/publication/388784828_Decoding_the_Ediacaran_Enigma_Gondwana_paleogeography_revisited_through_a_provenance_study_of_the_Salt_Range_Formation_Salt_Range_western_Himalayas_Pakistan