Thanks for the interesting reading of the above links,
But first i did i deed ask a couple of the young door-knocking Mormons about the Ancient texts and methods of translation.It was their belief that in fact the Mormon church doesn,t have any of the item and that they returned to heaven after the translation.They then had to rely on their faith.That sure helped poor J Smith when the angry crowd came for him.*

So pretty much got only their word that indeed the items ever existed.I used this example as the best known claim to ancient world cultures traveling to the America's. Wish i hadn't as it has not very creditable in my opinion.
The first link that you gave to read is a single find and the if you follow the the link to the main page this too is a modern day church"s religious info page.

?? once again based on faith .
The second link which a text written by a Mr White which gives every reason why the rock art is infact fake.

And Mr white has distanced him self from this text and claims some else wrote it.
The Links you can follow get even more interest, most wild claims and no evidence at all.Names of locations in wrong places Out by thousands of miles.
The people how wrote this have little unstanding of aboriginal culture let alone of that of Romes , Greeks or any of the others.25 % are well know legends and many have tried to prove of there existance but have NOT.
50 % make no sence at all.25% i can answer on the spot. No and Why. Please go back and read the links and other links provided by this site. you see will see what i mean.
There's a big issue with the map link.There is not one item being cultural or structures or animals or vegatation that has any to do with Australia and as the title Say's* BIG JAVA that's dead right the largest island in Indoneasia and the line Australia was called Big Java.Just another theory.
Also i would like to express this line of thought to you, yes Australia is vast and untouched place but would be indeed an advantage* in fact you were looking for evidence of other cultures.untouched sites which could be picked up* by satellite and easier to find.This process is infact used on many historic site in Australia today
The oldest known chinese structure of its type infact found in Australia is less than 1 mile from me and it dates 1850's.This has been comfirmed by experts from 3 countries.Against the finds and relics found was indeed a vase that dated from the 14 century but it was brought by chiness gold miners in 1850's.
Thanks for interesting post and i will add some links for you to read in relation to enviromental and climate factors that will truely show that no ancient race could* or would have wanted to stay here.welcome to the land of peoples of rainbow serpant.Sole owners for 50,000 years.Each single tribe had little time for the next and to cross breed is called BAD BLOOD and against their law. so infact they would have killed any persons of what ever race and era on the spot.
* * * * * tinpan