hello Scholars welcome Mr Hinkle here to tell you about a very special type of sedimentary rock that we call biochemical sedimentary rock so let's get into it we're going to discuss well first I want to discuss how they form where they come from and then I've got some examples to show you so there are organisms in the ocean that float and use the power of the sun to reproduce they're called Marine phytoplankton and Marine phytoplankton take up minerals from the ocean calcium carbonate and silica to create extravagant unique shapes and appendages so that they can float utilizing the sun's solar energy well in certain periods the accumulation the primary productivity will explode in the accumulation will deposit at the bottom of the ocean forming a celicious ooze or a calcarius ooze that then later turns into sedimentary rock so I know I GL I glazed over a few properties there but just bear with me marine marine phytoplankton deposit the bottom of the ocean and this is the basis for forming biochemical sediment AR Rock now the types of rock that they form are going to be made of primarily the mineral calite giving us Limestone or Dolomite when the calite is chemically altered in this environment of lithification to form Doo Stone and we could see it up here I'll go back one the dolomites in Italy are rock that formed in a sedimentary Basin and through the processes of plate tectonics traveled across the surface of the Earth were unburied or ex zoomed uplifted and then now create the Majestic Dolomite mountains geology is utterly amazing how our Earth came to be the way that it is never stops just knocking my socks off I absolutely love it dolomites made of marine f Plankton millions of years ago let's keep going so we've got Limestone Doo Stone fossiliferous Limestone so this is limestone that also incorporates fossils so you can see the imprints of shells a fossil is the remains of a once living organism and there's kind of a cool property that goes on here because the rock is made primarily of calite from the calcium carbonate shells of the marine organisms this is diluted hydrochloric acid which reacts to calite so when we see here we put this on the rock it starts to Fizz and it starts to Bubble very cool what's happening is the reaction of the C carbonate that makes up the rock that makes up the Limestone with the hydrochloric acid so this is a test is this a limestone made of calite reacts with HCL yes it is so fossiliferous Limestone would be one of our biochemical sedimentary rocks the bio comes from the fact that it's made from the remains of once living organisms the chemical is because it chemically precipitates into the rock type of limestone as opposed to clastic sedimentary rocks are that are from the physical weathering and the transportation of broken pieces of rock known as class or detrius okay cool let's keep going coina is shells that have not been fossilized but they have been lithified together to form a predominantly uh Loosely cemented shell and shell fragmented Rock different than our fossiliferous Limestone which are shell fossils that have lithified into limestone this is kind of like gluing a bunch of cement or gluing a bunch of shells together to form coina the White Cliffs of do this is a very famous popular outcrop of the United Kingdom here's a big Lighthouse it's this uh Cliff face is hundreds of feet tall and this comes from a very specific marine phytop plantonic species known as cith fores when you have the deposition of Coco lithop fores at the bottom of the ocean they then form a very unique type of biochemical sedimentary rock known as chalk chalk like if I had a chalkboard I could be riding on the chalkboard because everything on this Earth everything that we have comes from this Earth everything that we have produced manufactured created that we utilize on our planet comes from our planet and they are all earth materials that's a pretty cool thing okay Mite is when you have a calite mud super fine grain very very fine grain lime Stone it's a very challenging Rock to identify but it has microfossils in it that can only be seen using a microscope so op Optical minerology and Optical petrology is a very useful counterpart when identifying rocks and minerals to see the unique properties of how rocks and minerals display under the thin uh thin scope microscope what else do we got identifying and classifying so biochemical is part of the biochemical chemical and organic kind of cluster which are a little bit different than the classic sedimentary rocks and we're looking at these by identifying the composition that make up the sedimentary rock and then the description so textural descriptions reactional descriptions really we're looking at composition and description to identify biochemical chemical and organic also but in the case of this lecture biochemical sedimentary rocks so these are awesome rocks that are created from geological process processes that highlight the dynamic planet that we live on thank you so much and I'll see you again