tag:blogger.com,1999:blog-5388608827926699865.post1385929286517590812..comments2023-12-27T11:53:19.572+11:00Comments on Northern Rivers Geology: 'Recent' rhyolite: The Nimbin Rhyolite at Minyon FallsRodhttp://www.blogger.com/profile/10962789743908134314noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-5388608827926699865.post-88072474754037633512011-11-04T19:22:23.696+11:002011-11-04T19:22:23.696+11:00Hi anonymous,
I have not read the earlier work of ...Hi anonymous,<br />I have not read the earlier work of Cotter. I assume you are referring to his honours thesis at SCU? I will have to go to the uni and look it up. The only published work I have seen that relates to the geomorphology and crystal size is Smith and Houston (1995) listed in the blog post above. Smith and Houstons work does not directly imply a mechanism for waterfall formation etc But I think your concept is not contradictory and certainly very plausible. I'll have to spend some more time up that way as well. It certainly sounds like something that would at the very least make a good future blog post or even a good uni level research topic.Rodhttps://www.blogger.com/profile/10962789743908134314noreply@blogger.comtag:blogger.com,1999:blog-5388608827926699865.post-2220682200462120412011-11-04T17:57:52.002+11:002011-11-04T17:57:52.002+11:00Hi Rodney, according to Cotter (in an earlier pape...Hi Rodney, according to Cotter (in an earlier paper)there are variations within the Nimbin Rhyolite. He suggests that grain size is critical in the preservation of these long standing "nick points" or large water falls such as Minyon. The finer grained rhyolite is less susceptible to erosion and therefore the nick point is preserved. Valleys containing coarser grained rhyolite do not generally contain waterfalls of any significant size. This rhyolite is not differing in composition but has undergone a slightly different cooling history. Mechanisms for grain size distribution may have something to with the distribution of overlying (but mostly gone) Blue Knob Basalt. What do you think?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5388608827926699865.post-29147751515410432282011-10-17T16:38:03.045+11:002011-10-17T16:38:03.045+11:00Hi Rod and thanks for alerting me to your new blog...Hi Rod and thanks for alerting me to your new blog. I have put up post - http://newenglandaustralia.blogspot.com/2011/10/rod-northern-rivers-geology-blog.htmlJim Belshawhttps://www.blogger.com/profile/10075614280789984767noreply@blogger.com