tag:blogger.com,1999:blog-5388608827926699865.post6625275530816618697..comments2023-12-27T11:53:19.572+11:00Comments on Northern Rivers Geology: Disappearing sand from the North CoastRodhttp://www.blogger.com/profile/10962789743908134314noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-5388608827926699865.post-90816702062185695482012-08-30T07:59:34.120+10:002012-08-30T07:59:34.120+10:00Wow, 2 foot of sand in just over a month! I knew t...Wow, 2 foot of sand in just over a month! I knew that beaches could disappear over a such a period, it is amazing that they can come back over such a period too!<br /><br />Sadly, again, I don't know much about the geology of that area though I suspect that the rocks are part of the New England accretionary complex which is composed mainly of regionally metamorphosed marine sediments. Maybe there is some granites in the area too which have intruded through those meta-sediments. Could also be Clarence-Moreton basin sedimenary rocks too but this is the least likely. I'd love to go there and have a look.Rodhttps://www.blogger.com/profile/10962789743908134314noreply@blogger.comtag:blogger.com,1999:blog-5388608827926699865.post-60331304110419867832012-08-29T22:20:42.550+10:002012-08-29T22:20:42.550+10:00The Sand comes and goes. I also don't believe ...The Sand comes and goes. I also don't believe that the sand travels south unless it is a very local and short term event.<br />I was at Yamba on the weekend and at least 2 feet of sand had come back on the beach within 5 weeks.<br />Re my post today on The Gorge, it is such an interesting spot geologically, do you know anything about it?Markhttps://www.blogger.com/profile/03671691808322770184noreply@blogger.comtag:blogger.com,1999:blog-5388608827926699865.post-43471034360790928542012-08-27T15:24:08.553+10:002012-08-27T15:24:08.553+10:00Brilliant!Brilliant!Rodhttps://www.blogger.com/profile/10962789743908134314noreply@blogger.comtag:blogger.com,1999:blog-5388608827926699865.post-33270840716499324102012-08-27T13:46:41.313+10:002012-08-27T13:46:41.313+10:00Sounds like a plan :-)Sounds like a plan :-)Dylanhttps://www.blogger.com/profile/06632657395095391104noreply@blogger.comtag:blogger.com,1999:blog-5388608827926699865.post-70876551455925901032012-08-25T17:44:38.437+10:002012-08-25T17:44:38.437+10:00Hi Dylan,
Somehow I knew you'd comment on thi...Hi Dylan,<br /><br />Somehow I knew you'd comment on this one. And I'm glad you have and a wonderfully detailed comment too.<br /><br />As you may be able to tell from my post, I was hesitant to agree with the author of the newspaper article. I thought it possible that there could be some local influences... maybe as far as Kingscliff????, but then again you'd think the beach south of Fingal Head would be in a worse state if this was the case. I would have been surprised that such a scheme would have such a regional influence. As you rightly point out there are many more explanations which explain the situation better.<br /><br />Bob and Robert know sea levels that is for sure. They've got some very good published work in many journals. I have heard of Patrick Nunn but never read any of his work. It'd be great to get a post on Holocene sea levels in the region, it is an area which I am weak on... but maybe I can ask someone... such as yourself to do one? I know you are very busy at the moment but It'd be great to get your local knowledge and strong educational background on this one.Rodhttps://www.blogger.com/profile/10962789743908134314noreply@blogger.comtag:blogger.com,1999:blog-5388608827926699865.post-87015644342148663322012-08-25T16:06:04.422+10:002012-08-25T16:06:04.422+10:00Hi Rod,
Interesting post, particularly since I ha...Hi Rod,<br /><br />Interesting post, particularly since I have been studying coastal geomorphology and climate change with Robert Baker and Bob Haworth for the last few years. If Bennink thinks sand can move all the way back to Byron from the Tweed, he is off his rocker and is ignoring some very salient points.<br />~ changes in river discharge due to dams and other man made structures<br />~ changes in river discharge due to El Nino and La Nina effects<br />~ industrial sand extraction <br />~ sand locked away by beach capping and development<br />~ sand loss to shelf sediments due to SL rise<br /><br />This last point is the most controversial because it is at the heart of the current climate change debate. Patrick Nunn has written some amazing papers regarding the Lapita Peoples response to oscillating SL, such as the mid Holocene warming and the ascent out of the Little Ice Age. Both of these events have been generally pooh-poohed by the IPCC and ANU, but not for much longer because there is too much supporting evidence.<br />You made a good point with Lake Ainsworth.<br />Sorry to babble on but this is one of my pet subjects.<br />Cheers.Dylanhttps://www.blogger.com/profile/06632657395095391104noreply@blogger.com