Cave 31 tries to emulate the style of the great Hindu temple on a much smaller scale, but the artists here were working on much harder rock and so abandoned their effort.
( ( ( ( ( ( Cave 31 ) ( tries ( to ( emulate ( ( the style ) ( of ( ( the ( great ( Hindu temple ) ) ) ( on ( a ( ( much smaller ) scale ) ) ) ) ) ) ) ) ) ) , ) but ) ( ( the artists ) ( here ( ( ( were ( working ( on ( ( much harder ) rock ) ) ) ) and ) ( so ( abandoned ( their effort ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (NNP Cave) (CD 31)) (VP (VBZ tries) (S (VP (TO to) (VP (VB emulate) (NP (NP (DT the) (NN style)) (PP (IN of) (NP (NP (DT the) (JJ great) (NNP Hindu) (NN temple)) (PP (IN on) (NP (DT a) (ADJP (RB much) (JJR smaller)) (NN scale))))))))))) (, ,) (CC but) (S (NP (DT the) (NNS artists)) (ADVP (RB here)) (VP (VP (VBD were) (VP (VBG working) (PP (IN on) (NP (ADJP (RB much) (JJR harder)) (NN rock))))) (CC and) (VP (ADVP (RB so)) (VBD abandoned) (NP (PRP$ their) (NN effort))))) (. .)))
Cave 31 ran into problems because it was made of harder rock. 
( ( Cave 31 ) ( ( ( ran ( into problems ) ) ( because ( it ( was ( made ( of ( harder rock ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Cave) (CD 31)) (VP (VBD ran) (PP (IN into) (NP (NNS problems))) (SBAR (IN because) (S (NP (PRP it)) (VP (VBD was) (VP (VBN made) (PP (IN of) (NP (JJR harder) (NN rock)))))))) (. .)))