Contact zones (discussion)
Economic Geology and The Bulletin of the Society of Economic Geologists
These indica.te Cambrian, do they not?" This species, however, never occurs there nor in the Ordovicic, but is found throughout the entire Siluric and Devonic periods. When I told him this he realized that some one was hopelessly wrong. Another illustration of the Paleontological autocrat! What is wanted is a variety of forms, and it is the combination of species in a faunule that is significant. When fossils are abundant and small, as they so commonly are in marine faunas, the geologist can as
... he geologist can as a rule readily gather enough in an hour's work to enable the paleon=tologist to make a satisfactory time diagnosis. Regarding fossils in continental deposits, the difficulties in getting them are great because they are few and far between, and when present the shells are usually almost valueless as time markers, while the bones require a special training to take them out of the sediments. If leaves or fishes are present, these should be gathered as indicated for marine invertebrates. However, every fossil has some chronogenetic value and the best advice to the geologist is that his salvation lies in collecting what he sees and can get. Finally, do not trim the rock too close to the specimen, because often the essential parts of the fossils are thus lost. As regards packing, all the invertebrate and plant specimens should be so wrapped in old newspapers that they will not rub on one another. When the invertebrates are numerous and small, a number anywhere up to two dozen can be rolled up in a package, and these packages should again be wrapped into a larger bundle, in which case but a single field label is necessary inside the larger package. Each large specimep with its field label, should ,be wrapped independently and with plenty of paper to prevent rubbing in the box during transit. Thin slabs should be set vertically in the box, for otherwise they will be badly broken before they arrive in the laboratory. C•.•.•.s SC•UC•ERT.