Among the scattered rubble were massive stones of manifestly artificial shaping, and a little examination disclosed
the presence of some of that prehistoric Cyclopean masonry found on certain Pacific islands
and forming a perpetual archaeological puzzle.
我现在的理解仅能看出第一个句子是倒装句，Among the scattered rubble是表语，massive stones of manifestly artificial shaping是主语，and连接几个并列的句子，但不懂forming为何用ing。
我猜测可能是后面3个句子是并列主语，forming a perpetual archaeological puzzle是一个名词性从句，但如此中间那个句子就应该是定语从句，如此中间那个句子就有点翻译不同。
还望老师指点迷津。
found on certain Pacific islands and forming a perpetual archaeological puzzle 这是过去分词短语和目前分词短语，分别做some of that prehistoric Cyclopean masonry的后置定语。过去分词表示被动意义，目前分词表示主动意义。