Quote:Because if you want to understand sedimentology, it is helpful to know that fossil bearing strata ARE 'fossil bearing' because most often they were laid down quickly
Ignorance is bliss, why shall I alter your state?
"The differences between professionals and laymen is that the pros take interest in those processes that dont always follow an easily accepted (and explainable)rule". We ofetn take trips into arcane areas that lay people consider "obviously stupid" because they already "know" the way things really work.
In sedimentology labs for undergraduates we often do lab experiments in the areas that concern such things as depositions of colloids which are often the means by which very fine (supermolecular sized)particle sediments and precipitate sediments are laid down. Colloids follow rules that often challenge normal density separation of particulate sediments and account for more than 35% of all sediments and , are among the most economically important deposits. Consequently if you wish to fully understand how the planets processes work, you have to recognize that precipitates, colloids, reduzates , evaporates etc, seemingly defy standard lay understandings of how sedimentary rocks are formed. Whether you wish to take up the information or not, is immaterial to me. Just please dont try to sound authoratative and try to make vast sweeping statements that are just not true in the main.I understand that youve got a lot of your credibility invested in the concept of a "Flood" so I wont even go there since its just plain foolishness on my part to impart false credibility to you by making any argument to the contrary of your worldview. Its like beating my head against a wall (and Im not so dumb that Im gonna keep giving myself impact welts
The processes of sedimentology are often delved into in great detail because the processes that control colloids and precipitates and evapoites , often signal conditions that give us initial information that economic minerals are often nearby.
For example, colloidal gold is often found in suspension deposits from anoxic lakes such as the Chatanooga, and oil deposits are often trapped by very fine shales adjacent to sandstone deposits, and natural gas deposits are now all the rage in exploration of colloidal limestones (oolites and pisolitic forms that develop secondary porosity fetures that act as traps for ntural gas formed as a secondary deposit when acids react with specific layers in the limestones.
The fossils associated with "slow deposition" sedimenats are often numerous and are often environmentally sensitive(in other words , these fossils show us that were "getting close " to a mineralized zone.
You may wish to dismiss all this but this very phenom has given me a very comfortable life, so Im kind of smiling at your naive outlook in how you wish the earth processes to be "simply stated--simply understood"
ENjoy yourself, but , if you ever want any additional resources please dont hesitate to ask, Ill try to point you in the direction of elementary texts and papers that may help if you really wish to understand better.
Pauligirl saidQuote: And, by chance, did you notice the order they were in?
The very process of slow deposition gave rise to Eldredge and Goulds "punctuated Equilibrium" hypothesis, because they werent certain about the amount of time that separated their brachiopod species gave rise to their hypothesis that rapid evolution can occur in "saltation" jumps. When, later sampling of these same units are now showing that the deposition was on a micro scale and the interval of time represented by what they thought was demonstrating their hypothesis wasmerely a phenomenon of micro slow deposition.