From west to east, the North Delhi Fold Belt (NDFB) is composed of the Khetri sub-basin, the Alwar subbasin and the Lalsot-Bayana sub-basin. The metamorphic history of the easternmost Lalsot-Bayana sub-basin is considerably different from the other two as it has been reported to be nearly unmetamorphosed, while the other two subbasins display medium grade metamorphic assemblages. Textural, mineralogical and geothermometric data obtained for metabasic lithology, indicate metamorphism in the sub-greenschist facies conditions (~300°C temperature). This is corroborated by the development of chemically distinct authigenic phengitic muscovite in metasiltstone. The Alwar and the Khetri sub-basins preserve evidence of ~1000 Ma orogeny signifying closure of the Delhi basin in the form of amphibolites facies metamorphism which is lacking in the Lalsot-Bayana sub-basin. The lithopackage and metamorphism of this sub-basin suggests it to be a pre-Delhi intracratonic rift related volcanosedimentary sequence.