physicochemical environment marks is characterized with the help of other methods (radiocarbon, micropaleontology). During a still-existing tropical climate, arid periods are contemporaneous with regressive phases (eolian, fluviatile, or pedogenetic reliefs
of the grains) and humid periods correspond to transgressive phases (infratidal, intertidal, deltaic, lagoonal marks).
After a brief outline of the osteological characters which allow determination of fossil species of fresh-water fish remains, the significance of species assemblages as ecological markers is presented. Moreover significative palethnological data
Volcanic ash layers from three major Holocene eruptions are found throughout southern British Columbia and are useful stratigraphic markers. Here the AA. show that energy dispersive X-ray fluorescence analysis and alpha counting are useful
This paper describes the isotopic fractionations and shows that variations of the oxygen isotopic composition of foraminifera along deep sea cores are generally a continental ice volume index and thus a worldwide oceanic stratigraphic marker
The A. states that territoriality is based on three elements: an individual, an instrument, and an object. Territories are marked by spatial changes over time and through mutual relationships. Every boundary characterizes an area according to its
, occurred about 45-40 000 years BP. An early retreat stage of the glaciers, marked among others by the highest marine terrace/80-100 m a.s.l./took place about 25-20 000 years BP. (D'après les AA.).
degree days per year. The relationship works for Norway, Iceland Spitsbergen, Canada and the People's Republic of Mongolia. There are some marked variations in lapse rate from one environment to another. Calculations of past world climatic change based
far on this very interesting feature which occurred about 12500years b.p. (Oldest Dryas in Europe). This diversion marks the beginning of the retreat of the ice masses following one of the last cold periods during the final stages of the Pleistocene. (The A.).
subject to marked aridity. The onset of drier, windier conditions around 4500yr B.P. brought to an end the more equable climates that had characterized much of West Africa during the earlier Holocene. Aridity, intensified winds, and desert expansion
to a marked rise in lake level. The lake waters were considerably fresher than today allowing expansion of both fauna and flora, and may periodically have overflowed northwards into the Baringo sub-basin. Further fluctuations occured throughout the Holocene