tag:blogger.com,1999:blog-5859094080858570248.post8317141512095398457..comments2024-03-29T13:05:30.522+05:30Comments on Rapid Uplift: Secondary Mineralization In Deccan Basalts: Timing And Precipitation EnvironmentsSuvrat Kherhttp://www.blogger.com/profile/18281172632784780810noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-5859094080858570248.post-62074107561824676142019-08-03T11:24:03.174+05:302019-08-03T11:24:03.174+05:30A comment on the point of zonation raised by Dr. V...A comment on the point of zonation raised by Dr. Vaddadi- <br /><br />Regarding zonation , they do refer to previous work (table 1) which suggested that the common minerals occurred in all formations and levels giving no evidence of zonation. Also, laumontite which forms at higher temperature (>200 deg C) occurs both in the once more deeply buried lava in Nasik area, as well as in the thinner sequence in Malad (Mumbai)which was not deeply buried. Such a scatter may imply a role for local hydrothermal processes. Suvrat Kherhttps://www.blogger.com/profile/18281172632784780810noreply@blogger.comtag:blogger.com,1999:blog-5859094080858570248.post-27665671189385425082019-08-03T10:34:14.783+05:302019-08-03T10:34:14.783+05:30Posting a comment via email from Dr. Sudha Vaddadi...Posting a comment via email from Dr. Sudha Vaddadi, ex Geological Survey of India, who has extensive field experience in the Deccan basalts - <br /><br />"Thank you. Interesting paper. Lot of unanswered questions though. <br />As it has been mentioned, the work is limited to a small and limited area, considering the vast expanse of DVP.<br />Apophyllite occuring as a Stage 3 event is interesting. <br />The famous Rahuri green and the dull light moss green ones from Jalna, occur in areas where there are many lineaments delineated. Could there be any link??<br />Again dowmstream of Yedgaon dam, Madhohal dam there are cavities with colourless apophyllite. From Yedgaon area Phadke and Mukherjee have found small quantities of cavansite. Here again there are numerous fractures and dykes. <br />The cavansite and pentagonites from wagholi are associated with calcites, occassionally with tiny cavansite crystals within calcite. These then should relate to Stage 3. <br />In the same quarry, pentagonite and cavansite directly on heulandite is also seen. <br />Another thing I noticed is that there is no mention of zonation in the overall distribution, as mentioned by earlier workers. <br />Scope for future work. Some young geologists should take it up".<br /><br />My reply - <br /><br />Thanks for those additional observations and I agree, as also stressed by the authors, that this study is limited. What I did like is the combined use of fluid inclusions, stable isotopes and geochronology, which has given valuable information on nature of fluids and timing. I wish they had presented isotope work on stage 3 calcite. It is puzzling why they missed out on that.<br /><br />Hopefully this is just the beginning. Your field observations indicate that there is a lot of work to be done, not just on specific mineral assemblages, but drawing connections between mineralization and regional geology/stratigraphy and structure. <br /><br />thanks. Suvrat Kherhttps://www.blogger.com/profile/18281172632784780810noreply@blogger.comtag:blogger.com,1999:blog-5859094080858570248.post-75033054861360721562019-08-02T19:14:19.290+05:302019-08-02T19:14:19.290+05:30Wow! It's gorgeous. Well, this is clearly my f...Wow! It's gorgeous. Well, this is clearly my fav! :)Anonymoushttps://www.blogger.com/profile/05693306905038438344noreply@blogger.com