Transitional Vertebrate Fossils FAQ: Part 1A

The assumption that the geologic column is a base from which to calibrate the C dates is not wise. With a half-life of only years, carbon dating has nothing to do with dating the geological ages! Whether by sloppiness or gross ignorance, Dr. Hovind is confusing the carbon “clock” with other radiometric “clocks. Being ancient, the C content has long since decayed away and that makes it useful in “zeroing” laboratory instruments. It’s just one of the tricks that have been used to make the work a little more precise. The entire geologic column is based on the assumption that evolution is true. Radiometric Dating and the Geological Time Scale: Circular Reasoning or Reliable Tools? Andrew MacRae deals with claims that the geologic column is just circular reasoning.

Carbon, Radiometric Dating

Early history[ edit ] In Ancient Greece , Aristotle BCE observed that fossils of seashells in rocks resembled those found on beaches — he inferred that the fossils in rocks were formed by living animals, and he reasoned that the positions of land and sea had changed over long periods of time. Leonardo da Vinci — concurred with Aristotle’s interpretation that fossils represented the remains of ancient life.

Steno argued that rock layers or strata were laid down in succession, and that each represents a “slice” of time. He also formulated the law of superposition, which states that any given stratum is probably older than those above it and younger than those below it.

The standard approach to looking at fossils in the geological column is to assume that lower is older. Since the geologic column represents millions of years of Earth’s history, then obviously the fossils in each of the layers must be the same age as the layer in which they are found. What is especially interesting is that the fossils do appear to show a progression from the most “simple” of.

Mammutidae, Gomphotheriidae and Elephantidae. Because Mammoths such as the Imperial or Woolly Mammoth are different than Mastodons, they are included in the Elephantidae. The last surviving mastodon was the American mastodon. When standing aside a mammoth, the mastodon looks just like a Neanderthal version of the proboscideans.

The body form is shorter, more stout and robust and lends itself to a much more muscular physique in contrast to the more graceful and taller mammoth. Mastodons had a pair up upward curving main tusks and some had a much smaller set of straight rod-like lower tusks. In some species, the lower tusks fell out as the animal grew in years. The cheek teeth of mastodons are also more primitive with sharp crests and a dramatic lobed surface in unworn examples compared to the flat and fine ridged surface of mammoth teeth that resemble the sole of a boating sneaker.

These differences tell us about the types of food that both types of creatures ate. The mastodon was more suited for forest environments with teeth that were well adapted for chewing tougher vegetation like twigs, leaves, shrubs, fruits, pinecones, pine needles and mosses. The mammoth with its smoother teeth, was best suited for the open plains feeding on a variety of grasses.

A mastodon, like all proboscideans, has a system of horizontal tooth replacement whereby new molars erupt from the rear of the jaw and move forward.

The Fossil Record

The various branches of geology specialise in particular topics. Thus Palaeontology is the study of life in ancient times and is largely based on fossil records. Stratigraphy is the study of the order and relative position of strata, or layers, in sedimentary rocks as a means of historical interpretation. An exposed section of a sedimentary rock face will show the layers of sediment that built up the rock.

If the layers are reasonably free from significant folding it may be supposed that the upper layers were deposited on top of lower layers, and that the lower layers are therefore older.

Precambrian time, period of time extending from about billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, million years brian time encompasses the Archean and Proterozoic eons, which are formal geologic intervals that lasted from 4 billion to about million years ago, and the Hadean Eon, which is an informal interval spanning.

Its energy is found in fossil fuels as well as all living things. There is a great deal of information and enthusiasm today about the development and increased production of our global energy needs from alternative energy sources. Solar energy, wind power and moving water are all traditional sources of alternative energy that are making progress.

The enthusiasm everyone shares for these developments has in many ways created a sense of complacency that our future energy demands will easily be met. Alternative energy is an interesting concept when you think about it. In our global society, it simply means energy that is produced from sources other than our primary energy supply: Coal, oil and natural gas are the three kinds of fossil fuels that we have mostly depended on for our energy needs, from home heating and electricity to fuel for our automobiles and mass transportation.

The problem is fossil fuels are non-renewable. They are limited in supply and will one day be depleted. There is no escaping this conclusion. In fact, the earliest known fossil fuel deposits are from the Cambrian Period about million years ago, way before the dinosaurs emerged onto the scene.

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After that comes a more difficult process: Finding a fossil merely places one organism within a time span. Finding many organisms places the group within a time span.

Carbon dating is used to determine the age of biological artifacts up to 50, years old. This technique is widely used on recent artifacts, but educators and students alike should note that this technique will not work on older fossils (like those of the dinosaurs alleged to be millions of years old).

Has any kind of fossil DNA ever been found? Will extinct dinosaurs ever be brought back to life? With today’s technology it is impossible to recreate extinct dinosaurs. It is extremely unlikely that scientists will ever be able to bring them back to life. Only with a quantum leap in scientific understanding could such a project be successful. How were dinosaurs in “Jurassic Park” created? In the movie, researchers find fossilized blood-sucking insects that had bitten living dinosaurs.

Soon afterward, these insects were caught in oozing tree sap that fossilized into amber. The scientists in the film extracted dinosaur blood from the fossilized insects and used the DNA in the blood to recreate dinosaurs.

Geologic time scale

These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus slowing decomposition. Stromatolites Lower Proterozoic Stromatolites from Bolivia , South America Stromatolites are layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms , especially cyanobacteria. While older, Archean fossil remains are presumed to be colonies of cyanobacteria , younger that is, Proterozoic fossils may be primordial forms of the eukaryote chlorophytes that is, green algae.

One genus of stromatolite very common in the geologic record is Collenia. The earliest stromatolite of confirmed microbial origin dates to 2. The most widely supported explanation is that stromatolite builders fell victims to grazing creatures the Cambrian substrate revolution , implying that sufficiently complex organisms were common over 1 billion years ago.

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Early history[ edit ] In Ancient Greece , Aristotle BCE observed that fossils of seashells in rocks resembled those found on beaches — he inferred that the fossils in rocks were formed by living animals, and he reasoned that the positions of land and sea had changed over long periods of time. Leonardo da Vinci — concurred with Aristotle’s interpretation that fossils represented the remains of ancient life.

Steno argued that rock layers or strata were laid down in succession, and that each represents a “slice” of time. He also formulated the law of superposition, which states that any given stratum is probably older than those above it and younger than those below it. While Steno’s principles were simple, applying them proved challenging. Over the course of the 18th century geologists realized that: Sequences of strata often become eroded, distorted, tilted, or even inverted after deposition Strata laid down at the same time in different areas could have entirely different appearances The strata of any given area represented only part of Earth’s long history The Neptunist theories popular at this time expounded by Abraham Werner — in the late 18th century proposed that all rocks had precipitated out of a single enormous flood.

It has been said[ by whom? This theory, known as ” Plutonism", stood in contrast to the"Neptunist” flood-oriented theory. Formulation of geologic time scale[ edit ] The first serious attempts to formulate a geologic time scale that could be applied anywhere on Earth were made in the late 18th century. The most influential of those early attempts championed by Werner , among others divided the rocks of Earth’s crust into four types: Primary, Secondary, Tertiary, and Quaternary.

Fossil

Carbon , Radiometric Dating and Index Fossils Carbon dating is used to determine the age of biological artifacts up to 50, years old. This technique is widely used on recent artifacts, but educators and students alike should note that this technique will not work on older fossils like those of the dinosaurs alleged to be millions of years old. This technique is not restricted to bones; it can also be used on cloth, wood and plant fibers.

Carbon dating has been used successfully on the Dead Sea Scrolls, Minoan ruins and tombs of the pharaohs among other things. Carbon is a radioactive isotope of carbon.

Figure 2. How relative dating of events and radiometric (numeric) dates are combined to produce a calibrated geological time scale. In this example, the data demonstrates that “fossil B time” was somewhere between and million years ago, and that “fossil A .

A single watch or clock for the entire class will do. Return to top PART 1: After students have decided how to establish the relative age of each rock unit, they should list them under the block, from most recent at the top of the list to oldest at the bottom. The teacher should tell the students that there are two basic principles used by geologists to determine the sequence of ages of rocks. Younger sedimentary rocks are deposited on top of older sedimentary rocks.

Principle of cross-cutting relations: Any geologic feature is younger than anything else that it cuts across. For example, U is an unstable isotope of uranium that has 92 protons and neutrons in the nucl eus of each atom.

Fossils and Geologic Time

The four types of fossils are: There are six ways that organisms can turn into fossils, including: More rarely, fossils have been found of softer body tissues. Bones – these fossils are the main means of learning about dinosaurs. The fossilized bones of a tremendous number of species of dinosaurs have been found since , when the first dinosaur bone was discovered. Teeth and Claws – Sometimes a bit of a broken tooth of a carnivore is found with another dinosaur’s bones, especially those of herbivores.

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Sedimentary Rocks slowest to form, and weather the fastest! The material is deposited in layers that will eventually form the sedimentary rock. These may be transported, usually by water or wind in the case of sand and deposited to form sediments. These become buried under later forming sediments and water or by major tectonic activity, and then become subjected to compression as enormous pressures are created deep in the crust from the weight of rocks or sediments above them.

Over millions of years from the fragments of eroded pre-existing rocks, water is squeezed out and the particles cement together with the help of dissolved salts and silica crystallising out. Other changes come about depending on the type of material from which the sedimentary rock is formed. It then becomes compressed under the weight of water and other sediments and the water is squeezed out and the particles cement together.

These rocks are clearly layered and crumble easily. Shale can contain significant amounts of oil-like organic material.

Relative Dating of Rock Layers