Zephyr Posted January 20, 2011 Share Posted January 20, 2011 Hello all. I am new to the forum. I was wondering if anyone might have any speciality in California's Monterey Formation? The MF was apparently high in phosporites. Phosphorite deposition has also been linked to formation of red tide dinoflagellate blooms which cause fish and plankton deaths. We also know that the cause of the Sharktooh Hill bonebed has been debated with red tide being one of the possible causes (though I believe that presently it is thought that it's formation was a slow process over time). I have two questions: 1) I am wondering if it's possible that the massive phosphorite presence in the Monterey Formation in Barstovian waters may have caused a massive, on going red tide which led to a dieoff. 2) Red tides are also luminous affairs. If there were a massive on going red tide along the coast and within the inland Temblor seaway during that time would it not have also been quite a luminous affair like today's red tides, but on a rather larger scale? Thank you. Link to comment Share on other sites More sharing options...
piranha Posted January 20, 2011 Share Posted January 20, 2011 Hi Zephyray and Welcome to TFF from the Oligocene Oregon Trail! Hopefully someone will be able to assist with the specifics of the Monterey Formation. I found this pdf that might have implications for your Barstovian stage questions. LINK Great to have you on board and thanks again for a very fascinating topic! Link to comment Share on other sites More sharing options...
Boesse Posted January 20, 2011 Share Posted January 20, 2011 Phosphorite deposition is not related to red tides. It is related to a combination of high primary productivity and sustained, long-term periods of low to zero net sedimentation. The Monterey Formation in general is characterized by high rates of biosiliceous (diatom) sedimentation. Phosphate deposits in the Monterey Fm. and other units in California are typically also rich in marine mammal remains, which happen to be the same mineral (Calcium phosphate) and which accumulate at higher frequences due to the lower sedimentation rate. The red tide hypothesis for the sharktooth hill bonebed has long been discounted, and as far as I know, is not likely to be related to any bonebed formation in the Neogene of California. There is an assemblage in the Pliocene Pinecrest beds of Florida which has been interpreted as a red tide assemblage, and it is to my knowledge the only marine fossil assemblage that can demonstrably be tied to that phenomenon. The majority of marine vertebrate accumulations and bonebeds in shallow marine sediments through earth's history are largely controlled simply by sedimentary budget - i.e. decreases in sedimentation rate, which prevents vertebrate fossils from being 'diluted' by the sediment they get deposited in. My master's thesis deals with these sorts of questions, and provides the first taphonomic model for shallow marine vertebrate assemblages in the fossil record. I just finished my first draft about a month ago. Bobby 1 Link to comment Share on other sites More sharing options...
Zephyr Posted January 21, 2011 Author Share Posted January 21, 2011 Phosphorite deposition is not related to red tides. Thanks for the reply. I don't get it though, unless I'm misunderstanding since AFAIK phosphate, including phosphorite has been definitely linked to the red tide in Florida, acting as a fertilizer. There's even an invention out there to try to remove it from the environment there for that reason. "Thus phosphorites and fossil bone have about identical negative effects on coastal sands, and both are included herein in the term “phosphatic material”. The presence of small grains of phosphatic material darkens a beach: the presence of larger particles or pebbles of phosphatic material gives the appearance of contamination with charcoal or partially burned items. The phosphatic material contains potentially toxic concentrations of fluorine if ingested. When the phosphorus is solubilized, it can contribute to excessive growth of algae, and to the organisms that cause highly destructive coastal red tides." http://www.freepatentsonline.com/7708144.html What do you mean by "high primary productivity"? Link to comment Share on other sites More sharing options...
Zephyr Posted January 21, 2011 Author Share Posted January 21, 2011 (edited) Thanks much Piranha. Beautiful photos of the dinos luminosity. I remember walking on Pismo Beach at night with my dog when I used to live just a few blocks from there. Often you could rake your hand in the sand and see little glowing stars light up in your path. On a few rare occassions the numbers were so large that the actual tide would glow a light green. Quite lovely. That color though has made me wonder why it's called the red tide. Or are these perhaps a different dino? Edited January 21, 2011 by Zephyray Link to comment Share on other sites More sharing options...
Boesse Posted January 24, 2011 Share Posted January 24, 2011 The occurrence of phosphate on the continental shelf is not generally tied to red tides - I'm sure it may trigger it, as this is suggested by the article you link to, but AFAIK, the literature on phosphogenesis and phosphorites generally lacks any mention of red tides in general, which, IIRC, are generally triggered by more "usual" phenomena. Even if there were a relationship between phosphogenesis and red tides, bonebed formation is a very long, drawn out process, to the point where there would be little difference between any "background" (aka attritional) skeletal supply and that of a red tide-induced skeletal supply. Bobby Thanks for the reply. I don't get it though, unless I'm misunderstanding since AFAIK phosphate, including phosphorite has been definitely linked to the red tide in Florida, acting as a fertilizer. There's even an invention out there to try to remove it from the environment there for that reason. "Thus phosphorites and fossil bone have about identical negative effects on coastal sands, and both are included herein in the term “phosphatic material”. The presence of small grains of phosphatic material darkens a beach: the presence of larger particles or pebbles of phosphatic material gives the appearance of contamination with charcoal or partially burned items. The phosphatic material contains potentially toxic concentrations of fluorine if ingested. When the phosphorus is solubilized, it can contribute to excessive growth of algae, and to the organisms that cause highly destructive coastal red tides." http://www.freepatentsonline.com/7708144.html What do you mean by "high primary productivity"? 1 Link to comment Share on other sites More sharing options...
Zephyr Posted January 24, 2011 Author Share Posted January 24, 2011 Ok, thanks for the info Bobby. I think I've read articles that also link agricultural runoff to phosphorous and thus red tides in the offshore ocean. Rock phosphate is one of the main NPK fertilizers used. Link to comment Share on other sites More sharing options...
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