Abstract
RbSr whole-rock analyses were made of 90 samples from basement rocks and various intrusives (mainly granites) in the Precambrian tin province of Rondônia. On the basis of these data, an age of 1539 ± 36 Ma (Sr 0 = 0.7035 ± 0.0010) is assigned to the gneissic basement (Xingu Complex). The basement was intruded by (calc-alkaline) granites during one or more magmatic events between about 1545 and 1300 Ma, and by granites with alkaline affinities during three subsequent phases of anorogenic magmatism: 1268 ± 15 Ma (Sr 0 = 0.7071 ± 0.0024); 1025 ± 24 Ma (Sr 0 = 0.7117 ± 0.0026); and 956 ± 9 Ma(Sr 0 = 0.7104 ± 0.0056). The important SN mineralization of Rondônia appears to be associated with these three groups of anorogenic granites.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
