What's the adjective for amalgamations? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs amalgam, amalgamate and amalgamize which may be used as adjectives within certain contexts.
amalgamated
Combined from two or more entities into one specific entity whilst retaining the defining characteristics of the original source entities.
“Each of these units shows an amalgamated upper-shoreface sandstone section over 20 meters thick, sharply overlain by transgressive shales about 50 meters thick.”