Age and origin of the Tanghu Granite, southeast China: Results from U-Pb single zircon and Nd isotopes

Journal Article · Mon May 01 00:00:00 EDT 1989 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1989)017<0395:AAOOTT>2.3.CO;2· OSTI ID:7144931

Xianhua, Li; Tatsumoto, M; Premo, W R ^[1]; Xuntang, Gui ^[2]

---

1. Geological Survey, Denver, CO (USA)
2. Institute of Geochemistry, Guiyang (China)

U-Pb single-zircon and Sm-Nd whole-rock isotopic data for the Tanghu Granite of the Zhuguangshan batholith suggest that a basement either composed of or derived from Middle Proterozoic of Late Archean rocks underlies southeast China. The granite contains two kinds of inherited zircon components, whole anhedral zircons and small cores within younger magmatic zircons. The U-Pb data for a single analysis of four magmatic zircons yielded a concordat age of 433 {plus minus} 2 Ma, whereas single zircons yielded two linear arrays with lower intercepts of 435 {plus minus} 1 and 434 {plus minus} 14 Ma and upper intercepts of 1415 {plus minus} 3 and 2516 {plus minus} 6 Ma, respectively. Xenocrystic zircons of Archean age had not previously been recognized in any rocks from southeast China. Two whole-rock samples from the granite yielded {epsilon}{sub Nd} values of -7.1 and -8.3 at 434 Ma and Nd model ages of {approximately} 1750 Ma relative to a depleted mantle. The authors conclude from this isotope data that the Tanghu Granite crystallized at 434 {plus minus} 1.6 Ma (weighted average) and was derived from a source of unknown age, but a had an average crustal-residence age of {approximately} 1750 Ma, and was partially composed of a mixture of continental crustal material of at least two age ({approximately} 1400 and {approximately} 2500 Ma).

• OSTI ID: 7144931
• Journal Information: Geology; (USA), Vol. 17:5; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CHINA
GEOLOGIC DEPOSITS
AGE ESTIMATION
CRYSTALLIZATION
GEOLOGIC HISTORY
GEOLOGY
GRANITES
ISOTOPE DATING
ISOTOPE RATIO
LEAD
NEODYMIUM
ORIGIN
SAMARIUM
SAMPLING
URANIUM
ZIRCON
ACTINIDES
ASIA
ELEMENTS
IGNEOUS ROCKS
METALS
MINERALS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PLUTONIC ROCKS
RARE EARTHS
ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM SILICATES
580000* - Geosciences