21. He studied the monazite and rare-earth elements of the Appalachian Mountains. 22. A single monazite grain can contain domains of distinctively different compositions and ages. 23. In natural monazite , the zonation pattern maybe complex and hard to interpret. 24. Monazite geochronology is generally regarded as a powerful tool to reveal metamorphic history.25. This can be observed with monazite -containing sands or bastn�site-containing ore. 26. There are also large monazite deposits in Australia. 27. However, commercial monazite sands typically contain between 6 and 12 % thorium oxide. 28. As a tin-mining area, monazite exists throughout Bangka and Belitung island. 29. Therefore, older monazite is rich in Th while younger monazite contains less Th. 30. Therefore, older monazite is rich in Th while younger monazite contains less Th.
