while monazite deposits in Australia, South Africa, China, Brazil,
Bastnaesite occurs as a primary mineral, while monazite is found
to proceed in the exploitation of high-thorium monazite deposits where
This is obviously due to monazite inclusions in garnet.
It has been shown that monazite can form at different stages during metamorphic evolution, and can preserve ages corresponding to peak temperatures up to granulite facies conditions or may even record prograde growth ages (DeWolf et al.
Following the above remarks it is suggested that the age of 1778 [+ or -] 2 Ma for monazite is close to the peak metamorphic stage, ca.
The mineral, believed to be part of some 20 tons of monazite that have been found unaccounted for earlier this month, was discovered Wednesday inside the storage room of the 72-year-old Sawara assemblyman, officials said.
The Tokyo Metropolitan Police Department's Public Safety Bureau has launched a nationwide hunt for the missing monazite since the Prime Minister's Office Residence and nine other government offices received packages containing small amounts of monazite in the mail earlier this month.
Hiroshi Ikeda, 84, head of the organization, reportedly imported 40 tons of monazite from Thailand about 20 years ago for research and sale to hot springs that use radium and thorium.
At this point quantitative examination was undertaken by one of us (LCP) and the yellow mineral was determined to be monazite-(Ce), believed to be a first occurrence of the monazite group reported from Franklin.
Significant effort would be required to find dolomite by digging, and additional work would be needed to search for the rare rug that might contain monazite.
Five small specimens (typically 5 x 5 x 10 ram) each containing monazite were examined in the course of this study.
We used laser-ablation split-stream (LASS) ICP mass spectrometry to measure U/Th-Pb ages and compositions of monazite from garnet + aluminumsilicate +- staurolite pelites in the Kangmar and Mabja domes.
Our LASS measurements show that staurolite- and sillimanite-bearing samples, typically with homogeneous garnet, have monazite with equivalent 208Pb/232Th and 206Pb/238U ages ranging from 29 Ma down to 20 Ma.
