Abstract
We detail a method for hand picking potassium-rich feldspars from silicic tephra. The method, based on the well known sodium cobaltinitrite staining technique, is applicable to any sample where K content of feldspar exceeds ∼2 wt%. The method is well suited to mineral grains >0.25 mm and useful for grains as small as ∼0.125 mm. Alkali feldspar, plagioclase, and quartz are easily distinguishable after staining. Rinsing the stained feldspars along with ultrasonic treatment in distilled water and nitric acid removes the stain. 40Ar/ 39Ar analysis of sanidine separated by staining yields precise age estimates which are in excellent agreement with published ages for the youngest (2.06 Ma) Cerro Galán ignimbrite, NW Argentina.
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.
