British stages[ edit ] The Tremadoc corresponds to the modern Tremadocian. The Floian corresponds to the lower Arenig; the Arenig continues until the early Darriwilian, subsuming the Dapingian. The Llanvirn occupies the rest of the Darriwilian, and terminates with it at the base of the Late Ordovician. The Sandbian represents the first half of the Caradoc; the Caradoc ends in the mid-Katian, and the Ashgill represents the last half of the Katian, plus the Hirnantian. Gondwana started the period in equatorial latitudes and, as the period progressed, drifted toward the South Pole. Early in the Ordovician, the continents of Laurentia in present-day North America , Siberia , and Baltica present-day northern Europe were still independent continents since the break-up of the supercontinent Pannotia earlier , but Baltica began to move towards Laurentia later in the period, causing the Iapetus Ocean between them to shrink. The small continent Avalonia separated from Gondwana and began to move north towards Baltica and Laurentia, opening the Rheic Ocean between Gondwana and Avalonia. The Taconic orogeny , a major mountain-building episode, was well under way in Cambrian times. In the early and middle Ordovician, temperatures were mild, but at the beginning of the Late Ordovician, from to Ma, volcanoes along the margin of the Iapetus Ocean spewed massive amounts of carbon dioxide, a greenhouse gas, into the atmosphere, turning the planet into a hothouse.
Primary source references As a preface to this document, I want to point out that it is a shame that we have to continue to refute the same arguments that evolutionists keep bringing up over and over again in their attempts to argue against the fact of creation, which fact has been well established since the day the earth was created ex nihilo several thousand years ago.
It is also a shame that the masses have bought all this based on some circular reasoning about fossils, where fossils tend to be found buried, similarities between various life forms, the presence of certain decay products in rocks, and other inherently speculative arguments about the past, based on phenomena that exist in the present. If I hope to accomplish anything, it will be to simply encourage critical thinking. One must get past the arguments ad populum that its popularity counts for something , ad hominem that if you attack the person making the argument, this counts for something , and especially ad baculum that there are people who have the clout to decree it as true , to ask the key questions and challenge the unsubstantiated assumptions and thinking of those who would hold to the evolution position.
I looked and looked for the methods explained and the data summarized in one place that leads scientists to confidence in the age of the earth.
Click here to download a PDF version of this webpage Summary The widely accepted mantle plume model e. Geological and geophysical data from the Deccan provide no support for the plume model and arguably undermine it altogether Sheth, a ,b. The interplay of several intersecting continental rift zones in India is apparently responsible for the roughly circular outcrop of the Deccan. Published Ar-Ar age data for the Lakshadweep-Chagos Ridge basalts have been seriously questioned Baksi, , , and geochemical data suggest that they likely represent post-shield volcanism Sheth et al.
I relate CFB volcanism to continental rifting, which often but not always evolves into full-fledged sea-floor spreading Sheth, a , a. Non-plume, plate tectonic models are capable of explaining the Deccan in all its greatness. The 1, m-thick exposed section through the Deccan basalt pile at Mahabaleshwar, Sahyadri Western Ghats region. Photo by Hetu Sheth. These papers are in unanimous agreement on two issues: Nevertheless, the following observations and deductions suggest that the plume model is not valid for the Deccan Sheth, a , b , a.
Map showing the approximate boundaries of the Precambrian cratons making up the Indian shield e.
The sun, moon, and stars 2. The fish and the birds 3. The fertile earth 6.
The Ordovician (/ ɔːr d ə ˈ v ɪ ʃ ən /) is a geologic period and system, the second of six periods of the Paleozoic Ordovician spans million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya.. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in to resolve a.
These are K-Ar data obtained on glauconite, a potassium-bearing clay mineral that forms in some marine sediment. Woodmorappe fails to mention, however, that these data were obtained as part of a controlled experiment to test, on samples of known age, the applicability of the K-Ar method to glauconite and to illite, another clay mineral. He also neglects to mention that most of the 89 K-Ar ages reported in their study agree very well with the expected ages.
Evernden and others 43 found that these clay minerals are extremely susceptible to argon loss when heated even slightly, such as occurs when sedimentary rocks are deeply buried. As a result, glauconite is used for dating only with extreme caution. The ages from the Coast Range batholith in Alaska Table 2 are referenced by Woodmorappe to a report by Lanphere and others Whereas Lanphere and his colleagues referred to these two K-Ar ages of and million years, the ages are actually from another report and were obtained from samples collected at two localities in Canada, not Alaska.
These formations and therefore the river and community are called chat-a-wa-pis-shkag in Swampy Cree. The overall purpose of the project was to help the regional Council and its associations develop a strategy for natural resource co-management, self-government, and sustainable regional development. Their results published in , showed “that geographically extensive land use for hunting and fishing persists in the Mushkegowuk region, some km2. Although the First Nations control only km2 0.
The town or hamlet of Attawapiskat now covers 1.
RADIOMETRIC DATING. he question of the ages of the Earth and its rock formations and features has fascinated philosophers, theologians, and scientists for centuries, primarily because the answers put our lives in temporal perspective.
Inteendeel, meeste sillabusse in skole en universiteite aanvaar die konsep van evolusie as die wetenskaplike basis vir die verstaan van die fisiese kosmos soos ons dit vandag ken. A gradual process in which something changes into a different and usually more complex or better form. See Synonyms at development. The process of developing. Change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species.
The historical development of a related group of organisms; phylogeny. A movement that is part of a set of ordered movements. Mathematics The extraction of a root of a quantity. The gradual process by which the present diversity of plant and animal life arose from the earliest and most primitive organisms, which is believed to have been continuing for the past million years.
Important We believe any unbiased reader will realize that we were fair with our treatment of the two models in the table above. Yet, although the theory of evolution matches the facts in some cases, evolution is still an unproven theory. By now, you may believe it should be your first choice also. Unlike many others that preceded us, we attempted to find a clear defense of evolution for two reasons:
Scandal of the Evangelical Mind: A Biblical and Scientific Critique of Young-Earth Creationism by Bruce L. Gordon. History and Philosophy of Science, Houston Baptist University, USA & Center for Science and Culture, Discovery Institute, USA.
Idealized and simplified diagram of the Grand Canyon There are a number of lava flows on the plateau that the canyon is cut into yellow in Figure 1, above. These lava flows are Cenozoic in age, and some of them spill into the canyon. The walls of the canyon are mostly cut into horizontal rock layers of Paleozoic age green in Figure 1, above. There is an angular unconformity at the bottom of the Paleozoic layers.
An angular unconformity is the result of tilting and eroding of the lower layers before the upper ones are deposited. These tilted and eroded layers are Precambrian in age blue in Figure 1, above.
The Radiometric Dating Game Radiometric dating methods estimate the age of rocks using calculations based on the decay rates of radioactive elements such as uranium, strontium, and potassium. On the surface, radiometric dating methods appear to give powerful support to the statement that life has existed on the earth for hundreds of millions, even billions, of years. We are told that these methods are accurate to a few percent, and that there are many different methods. We are told that of all the radiometric dates that are measured, only a few percent are anomalous.
Our understanding of the shape and pattern of the history of life depends on the accuracy of fossils and dating methods. Some critics, particularly religious fundamentalists, argue that neither fossils nor dating can be trusted, and that their interpretations are better.
Stansfield Macmillan, , pp. All quotations are consecutive, except where noted. The quotations are presented here in the order in which they appear in the book; since Patton quotes them out of order, I have inserted notes to help keep track of them. Geologists now assume that most of the water in the oceans was produced by volcanic outgassings.
There are now approximately active volcanoes and about 10, dormant ones. Six hundred volcanoes comparable to Paricutin could account for the present oceans in approximately 0. Since volcanic activity presumably was much greater during early earth history than at present, creationists argue that the age of the oceans would appear to be considerably less than 0. How much water vapor was lost to space during the early warmer stages of geological history is also a big unknown.
Of course, half a billion years is still too long to help young-earth creationists. In this next quotation, Patton ignores inconvenient weaknesses:
These formations and therefore the river and community are called chat-a-wa-pis-shkag in Swampy Cree. This has been contended by the present day chief and council [oral history], is supported by documentation in the archives of the HBC [Hudson’s Bay Company], and was documented by Honigmann [ ] Cummins, The overall purpose of the project was to help the regional Council and its associations develop a strategy for natural resource co-management, self-government, and sustainable regional development.
However, the activity pattern of Omushkego West Main Cree harvesters has changed much over the decades; contemporary harvesting involves numerous short trips of a few days’ duration instead of the traditional long trips. The town or hamlet of Attawapiskat now covers 1. It is in the James Bay drainage basin.
Creation Versus Evolution: We compare the theory of evolution with the Bible’s creation account in easy-to-understand terms, using evidence from the fields of paleontology, geology, biology, and provide links and a bibliography for those who want to study both sides of the issue.
January Fossils provide a record of the history of life. Smith is known as the Father of English Geology. Our understanding of the shape and pattern of the history of life depends on the accuracy of fossils and dating methods. Some critics, particularly religious fundamentalists, argue that neither fossils nor dating can be trusted, and that their interpretations are better. Other critics, perhaps more familiar with the data, question certain aspects of the quality of the fossil record and of its dating.
These skeptics do not provide scientific evidence for their views. Current understanding of the history of life is probably close to the truth because it is based on repeated and careful testing and consideration of data. The rejection of the validity of fossils and of dating by religious fundamentalists creates a problem for them: Millions of fossils have been discovered.
Outlook Other Abstract U-Pb radioisotope dating is now the absolute dating method of first choice among geochronologists, especially using the mineral zircon. A variety of analytical instruments have also now been developed using different micro-sampling techniques coupled with mass spectrometers, thus enabling wide usage of U-Pb radioisotope dating. However, problems remain in the interpretation of the measured Pb isotopic ratios to transform them into ages.
Among them is the presence of non-radiogenic Pb of unknown composition, often referred to as common or initial Pb.
Magmatism in the South Atlantic traditionally attributed to hotspots and plumes eg at Tristan da Cunha can be explained by leakage from cracks that open as a result of changing stress in the plates.
The enhanced detail of plate tectonic processes provided by these new data did not, however, result in such a dramatic advance as would have been expected. Hot spots and mantle plumes were by then firmly established concepts in explaining the observed linear chains of volcanic islands and in providing a super-deep mantle frame of reference the hotspot reference frame that was independent of plate motions at the surface.
Accumulating scientific evidence over half a decade and recent GPS-derived absolute plate motions suggest that both the mantle plume frame of reference and the age dependence along volcanic lineaments are not as strong as once believed. This article investigates the complex tectono-magmatic processes involved in the opening of the Central, Equatorial and South Atlantic Ocean and asks the simple question of whether there is an alternative tectonic model to explain the phenomena seen in the satellite gravity field.
The case is made that hot spots or mantle plumes are not necessarily required to explain the volcanic lineaments and that most, if not all, features result from deformational processes during the evolution of the plates. Such a model has a range of implications which, hopefully, can be tested to further refine the model. To evaluate and develop the proposed model the resolution of the satellite gravity needs to be increased to about 10 km.