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We reexamine the relationship between energy spectral indices and elementabundance enhancements in solar energetic particle (SEP) events at energies ofa few MeV/amu. We find a correlated behavior only in the largest gradual SEP4events when all ions are accelerated from the ambient coronal plasma by shockwaves driven by fast, wide coronal mass ejections (CMEs). This correlatedabundance behavior can track complex time variations in the spectral indicesduring an event. In other (SEP3) events, CME-driven shock waves, days apart,sample seed particles from a single pool of suprathermal impulsive ionscontributed earlier. Of the smaller, Fe-rich, impulsive SEP events, previouslyrelated to magnetic reconnection in solar jets, over half are subsequentlyreaccelerated by CME-driven shock waves (SEP2) causing typical ion intensitiesto have a 64% correlation with shock speed. In these SEP2 events, onset ofshock acceleration is signaled by a new component in the abundances, largeproton excesses. The remaining SEP1 events lack evidence of shock acceleration.However, for all these events (SEP1 - SEP3) with abundances determined bymagnetic reconnection, spectra and abundances are decoupled.

Energy Spectra vs. Element Abundances in Solar Energetic Particles and the Roles of Magnetic Reconnection and Shock Acceleration