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Post by RickB on Nov 14, 2019 12:35:59 GMT -5
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Post by fernwood on Nov 14, 2019 14:04:06 GMT -5
Beautiful sand dollar. What are your plans for it?
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Post by RickB on Nov 14, 2019 14:43:26 GMT -5
I've dried it out and will find something to stabilize it "as is" with the matrix.
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Post by Lapidaryrough / Jack Cole on Nov 14, 2019 16:54:52 GMT -5
clear lacquer mix with thinner. for bone use 1:1 ratio. allow to soak in. several coats first off to saturate the material then let dry for a day. need to stand it up? off the base use 3 tooth picks. for run off.
Woodburn Oregon mammoth park, Peat bog fossils are soak in Floor wax, Then air dried, NO HEAT. same for the wood material. the Bogs last wash out was 12,500 BP.
Though their were two others 30,000 & 20,000 yrs. Bp. for the last ice age. I fell were still in the middle of the fourth quarter.
Jack
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pizzano
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Post by pizzano on Nov 14, 2019 17:19:01 GMT -5
Careful with the "fossil" designation......."
"The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock"........is the common reference related to "fossil"
Just a thought....!
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NRG
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Post by NRG on Dec 1, 2019 20:17:55 GMT -5
This is the remains of the organism. I would not consider it a fossil. Heck, it may still be extant.
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Fossilman
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Post by Fossilman on Dec 3, 2019 10:31:06 GMT -5
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Post by RickB on Dec 3, 2019 17:10:14 GMT -5
Fossil From Wikipedia, the free encyclopedia
A fossil (from Classical Latin fossilis; literally, "obtained by digging")[1] is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood, oil, coal, and DNA remnants. The totality of fossils is known as the fossil record.
Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old.[2] The oldest fossils are around 3.48 billion years old[3][4][5] to 4.1 billion years old.[6][7] The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host.
There are many processes that lead to fossilization, including permineralization, casts and molds, authigenic mineralization, replacement and recrystallization, adpression, carbonization, and bioimmuration.
Fossils vary in size from one-micrometre (1 µm) bacteria[8] to dinosaurs and trees, many meters long and weighing many tons. A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates. Fossils may also consist of the marks left behind by the organism while it was alive, such as animal tracks or feces (coprolites). These types of fossil are called trace fossils or ichnofossils, as opposed to body fossils. Some fossils are biochemical and are called chemofossils or biosignatures.
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Post by RickB on Dec 3, 2019 17:15:46 GMT -5
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Post by fernwood on Dec 4, 2019 4:20:35 GMT -5
Whatever the proper designation of it is, doesn't matter to me. That it was found intact in a limestone formation away from the ocean makes it special. Does it have the characteristics of a sand dollar washed up on an ocean beach?
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Post by RickB on Dec 4, 2019 13:48:43 GMT -5
Whatever the proper designation of it is, doesn't matter to me. That it was found intact in a limestone formation away from the ocean makes it special. Does it have the characteristics of a sand dollar washed up on an ocean beach? Through the years we've hunted sand dollars on the SC coast and have found literally buckets of the recent fragile ones. This one is hard as a rock and doesn't resemble any sand dollar that we have along our coast now. The ones we have around here now have five holes that go through it. Rick B
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Post by fernwood on Dec 4, 2019 13:50:34 GMT -5
If it is hard as a rock, then it is a fossil.
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Post by rockpickerforever on Dec 4, 2019 20:22:57 GMT -5
If it is hard as a rock, then it is a fossil. What if it is not hard as a rock? Is being petrified, silicified, agatized, etc., a prerequisite for being a fossil? I have seen and collected many shells, sand dollars,and fossils that pass the age test (what is the actual number?), but they have not been permineralized. Are they still fossils by definition?
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EricD
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Post by EricD on Dec 4, 2019 20:35:57 GMT -5
If it is hard as a rock, then it is a fossil. What if it is not hard as a rock? Is being petrified, silicified, agatized, etc., a prerequisite for being a fossil? I have seen and collected many shells, sand dollars,and fossils that pass the age test (what is the actual number?), but they have not been permineralized. Are they still fossils by definition? Copied from above wikipedia article:
A fossil (from Classical Latin fossilis; literally, "obtained by digging")[1] is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood, oil, coal, and DNA remnants.
Basically anything that died and is preserved naturally.
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Post by rockpickerforever on Dec 4, 2019 20:52:13 GMT -5
So nothing said about them being "hard as a rock?" I understand remains or traces of "any once-living thing from a past geological age." But is there a minimum age?
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EricD
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Post by EricD on Dec 4, 2019 21:01:40 GMT -5
I believe that just as long as it is preserved in a place where it cannot deteriorate unless it is exposed to sun/wind/weather (like within rock, where it would likely last indefinitely), or if it has been exposed but preserved un-naturally afterwards (say, by a human, as in when one grabs it and takes it indoors to their fossil display case), it can be classified as a fossil.
Edit: Of course things that are being bleached out by the sun and crumbled by weather can still be a fossil. But the point that they were preserved to a distinguishable point, aka being identifiable or complete, seems to give it "fossilness". Preserved sand dollars in my opinion, are fossils. Identifiable remains of a past being.
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pizzano
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Post by pizzano on Dec 4, 2019 22:52:08 GMT -5
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EricD
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Post by EricD on Dec 4, 2019 22:55:59 GMT -5
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jamesp
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Post by jamesp on Dec 5, 2019 6:00:13 GMT -5
RickB Silica, calcite and apatite are common minerals found in fossils along the Atlantic coast. Ice age mammal bones that Florida is known for are most often permineralized apatite(calcium phosphate). A fast acting fossilizing mineral ala recent ice age preservations thank you Florida phosphates. Most coastal chert and silicified coral gets it's silica from dissolving fossil diatom skeletons. The fossil aged diatom skeletons loaded in older limestone are an easy source of silica because their silicon based skeletons are so fine and dissolvable. Coastal chert and coral is super tough and hard material as you well know from knapping it. Fossil diatoms rock when it comes to making dense hard silicifications. It is hell to tumble shape too. "A fossilization, or taphonomic, process characterized by the deposition of a mineral or mineraloid (an amorphous “gel mineral”) in the pore spaces of an organism's body structures. Pores in bone, shell, or plant material may be impregnated by minerals or mineraloids precipitated from groundwater, lake or stream water, or ocean water. Minerals commonly involved in permineralization are *****quartz, ******calcite, pyrite, siderite (iron carbonate), and ****apatite (calcium phosphate). Opal, a mineraloid, is also a common agent of permineralization. Normally, the structural parts of organisms undergo little, if any, shape change as the pores are filled, leading in many examples to exquisite preservation of the fine structural details of bodily remains." A fossilized diatom paleontologist lol: joidesresolution.org/so-what-exactly-is-a-diatom-paleontologist/Fossil age diatom skeletons, a key source for silicification of other fossils due to tropical (tannic)acidic leaching from organic matter causing it to dissolve: "Hi, everyone! I will be sporadically blogging about my time sailing on the Joides Resolution as a diatom paleontologist during Expedition 362: Sumatra Seismogenic Zone." Indonesia, another fine location for silicified coral where lots of diatomaceous limestone and tannic acid from rotting tropical forests exist on a much larger scale than Florida..
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jamesp
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Post by jamesp on Dec 5, 2019 6:34:30 GMT -5
If it is hard as a rock, then it is a fossil. Careful, mammal and reptile bones, horns and teeth can be tricky to delineate at times fernwood. Alligator bones and teeth and shark teeth are real tricky to tell. Add manatee and shells. Only idiots that snorkel in gator infested waters where lots of gator kills occur on deer and hogs would know that lol.
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