Topic F3: TIME AND CHANGE Key Idea 2:Geological events can be placed in relative and absolute time scales Knowledge and Geological techniques Comments understanding and skills a. Geological events can be Interpretation of age relations placed in relative time of rocks and rock sequences scales using criteria of using maps, cross-sections relative age: evolutionary and in the field. change in fossils, superposition of strata, unconformities, cross- cutting relationships, included fragments,‘way- up’ criteria. b. Some rocks and minerals Simple use of the principles of Candidates will need to can be dated radiometric dating (decay know that differences radiometrically to give an rates and the half-life concept) between the K Ar and Sm – absolute age. This to calculate the absolute age Nd methods and – involves radioactive of a sample. understand the principle of decay and the principles using the gradient of an of radiometric dating; Evaluation of the assumptions, isochron to establish radioactive series and accuracy and limitations relative age in the latter. radioactive half-life; inherent in the radiometric Candidates will not be radiometric dating as dating method. expected to plot isochrons exemplified by Potassium or calculate age from Argon (40K– isochrons but simply – 40Ar), Samarium Neodymium interpret relative age. – (147Sm –143Nd). c. Fossils are used in Observation and identification Candidates are expected to relative dating. of appropriate morphological be able to provide a features and their changes relative date to a formation through time: based on graptolite or cephalopod assemblages graptolites number and – within the appropriate time position of stipes, thecal frame (Early Palaeozoic shape in the Early and Mesozoic). Palaeozoic. cephalopods suture – lines in the Late Palaeozoic and Mesozoic (goniatite, ceratite and ammonite).
Topic F3: TIME AND CHANGE Key Idea 2:Geological events can be placed in relative and absolute time scales Knowledge and understanding Geological techniques and skills Comments a. Geological events can be placed in relative time scales using criteria of relative age: evolutionary change in fossils, superposition of strata, unconformities, cross- cutting relationships, included fragments,‘way- up’ criteria. Interpretation of age relations of rocks and rock sequences using maps, cross-sections and in the field. b. Some rocks and minerals can be dated radiometrically to give an absolute age. This involves radioactive decay and the principles of radiometric dating; radioactive series and radioactive half-life; radiometric dating as exemplified by Potassium – Argon (40K– 40Ar), Samarium – Neodymium (147Sm –143Nd). Simple use of the principles of radiometric dating (decay rates and the half-life concept) to calculate the absolute age of a sample. Evaluation of the assumptions, accuracy and limitations inherent in the radiometric dating method. Candidates will need to know that differences between the K – Ar and Sm – Nd methods and understand the principle of using the gradient of an isochron to establish relative age in the latter. Candidates will not be expected to plot isochrons or calculate age from isochrons but simply interpret relative age. c. Fossils are used in relative dating. Observation and identification of appropriate morphological features and their changes through time: graptolites – number and position of stipes, thecal shape in the Early Palaeozoic. cephalopods – suture lines in the Late Palaeozoic and Mesozoic (goniatite, ceratite and ammonite). Candidates are expected to be able to provide a relative date to a formation based on graptolite or cephalopod assemblages within the appropriate time frame (Early Palaeozoic and Mesozoic).
Geology%20Eduqas%20A%20level%20Guidance%20for%20Teaching%20word%20version.docx