[vc_row][vc_column][vc_empty_space][/vc_column][/vc_row][vc_row][vc_column width=”1/2″][vc_column_text]CamaSed promotes and encourages the study of geology of Cameroon with a focus on Sedimentology and associated disciplines in order to solve scientific problems and add a value to local development of the Country. Special consideration is given to education, research and improvement of local standards.
CamaSed promote dialogue and communication among the various geoscientists specialists in Cameroon and encourage international projects and meetings.[/vc_column_text][/vc_column][vc_column width=”1/2″][vc_single_image image=”109″ img_size=”full”][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]
Occurrence, Environment, and Age
Fossil cetaceans occur in sedimentary rocks. Originally, remains accumulated in mud, silt, sand, or gravel which, as flesh decayed, was buried and turned to rock through compaction and/or deposition of cementing minerals. Sedimentary rocks are recognized as discrete formations (genetically unified bodies of strata), and are named formally, e.g., . Marine mammals come from strata including sandstone, mudstone, limestone, greensand, and phosphorite, most of which are marine rocks now exposed on land. Rare fossils have been recovered from the sea floor. Because broadly similar rock types may form at different times and places, sedimentary rocks must be dated to establish their time relationships.
Two correlated timescales, relative and absolute, are used for the fossil record. The relative timescale has named intervals (epochs; Fig. 1) in an agreed international sequence: Eocene, Oligocene, Miocene, Pliocene, and Pleistocene. These epochs are usually subdivided into early, middle, and late. Stages (e.g., Aquitanian of Fig. 1) may provide finer subdivision. Typically, distinct age-diagnostic fossils are used to recognize time intervals. The most reliable dates are based on oceanic microfossils with short-time ranges, such as foraminifera, which allow correlation between ocean basins. Because of compounded errors of long-distance correlation, ages are rarely accurate to within 1 million years, and many fossils can be placed only roughly within a stage. Beyond the relative timescale, absolute dates in millions of years are needed to understand rates of processes in phylogeny (involving, e.g., molecular clocks) and in geology (involving, e.g., rates of sediment accumulation or of climate change). Absolute dates are usually obtained from radiometric analysis of grains of volcanic rock interbedded with fossiliferous strata.