(S (S (BASENP (JJ Additional) (NNS discoveries)) (VP (VBD yielded) (NP (BASENP (DT an) (JJ extensive) (NN array)) (PP (IN of) (NP (BASENP (NNP Copper) (NNP Age) (NNS artifacts)) (VP (VBG dating) (PP (TO to) (ADVP (BASENP (QP (RB between) (NN 6,200) (CC and) (NN 5,900)) (NNS years)) (RB ago))))))))) (PERIOD .))