The results so far obtained may be summarized as follows.The Hongshan intrusion is a dome-shaped and isolated body and deep-seated n origin.The iatrusion took place in the post-Carboniferous time The iron deposit was probably formed through metasomatie replacement of the Ordovieian limestone and therefore only extends downward for an insignifieunt depth.As a rogoureo for modern industry,it is absohtely valuess.The variation in the composition of the diorite is probably don not so much to magmatic differentiation but rather to the assimilation fo the overlying rocks.