The phrase "and which continued" is correct and usable in written English.
It can be used to refer to an ongoing action or state that follows a previously mentioned subject or event.
Example: "The project was a success, and which continued to gain recognition in the industry for years."
Alternatives: "and that persisted" or "and which carried on".
That steep rise, which is consistent through all segments of American society and which continued unabated through the 1990's, is the singular feature of the epidemic.
Judy was strongly committed to helping the elderly, which started many years ago when her mother died, and which continued through-out her life time.
This did not stop the flurries of incoming rockets — long gray things — which sent almost everyone fleeing toward Brega, and which continued to come in alongside the retreating cars for several miles.
After 1957, Hill's career ascended to new heights as he began the remarkable output of books on which his reputation will rest, and which continued undiminished until he was well into his 80s.
The wholesale rejection of the new wisdom in the name of simple, robust, and more practical piety (which had been initiated by Ibn Taymiyyah and which continued to find exponents among jurists) made little impression on its devotees.
In rare encounters with my mother, she was polite but sour, struggling to conceal her resentment at the new estate on which we lived and which continued to expand into the fields and woodland around what had once been a nice, respectable residential street.
This is the design idea set out in Holme's Portraiture, and which continues to define Center City, Philadelphia today.
It is co-op businesses that set us up and which continue to affiliate to us, and it is one of the things that marks us out.
This is rich, coming from the head of the regime most culpable for events in Ituri, and which continues to meddle there.
Such perceived shortcomings have been at the root of several difficult compromises the Bush administration has made, and which continue to this day.
Church said that she was pressured into dressing sexually for music videos, a move that she regrets and which continues to plague her career.
