Here's a paper detailing evidence that there were multiple injections of material blown into the early solar system.

Multiple Sources

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Forming opinions as we speak

It's their interpretation of data, data that don't fit in just one supernovae remnant scenario.
Personally, I believe (and I think there is observational evidence for that) our Sun is responsible for at least a part of metallicity seen in Solar system.
So, "multiple injections" can actually be replaced by "multiple ejections" from Sun.
Nuclear fusion H->He requires 15 mio. degrees found in Sun's interior.
On Earth it requires 100 mio. degrees (to compensate for pressure, I guess) to fuse plasma.
In solar flares/coronal mass ejections/prominence the temperature can easily rise above 500 mio. degrees, achieved in the laboratory on Earth.
Like in a scourge, the energy is concentrated in a peak of prominence making the fusion of heavier elements possible.
Since this (and "injection" processes, as well) are chaotic events, there is no way to put such a nice equations forword, as they try.

Multiple sources seems the more likely option. One would expect that the cloud from which the solar system condensed would have been "salted" from multiple sources prior to its start of collapse. How can one distinguish between pre-collapse initiation and post-collapse initiation sources? I assume computation (estimation) of the age of the solar system is based on the ratio of various long half-life radio-isotopes including their stable end products, so would multiple contributors introduce uncertainities in the age estimate?

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?