Manganoxyd-Phasen als Pigmente antiker Vasenmalerei
function (dots) and the fitted survivor function (continuous line) for ear thquakes with M ~ 2.0 in Eastern Canada for the period t925-1965 (Ranalli, in preparation). Seismic zoning in terms of frequency isolines of damaging earthquakes is therefore a useful first step in ear thquake risk analysis. In order to refine the ear thquake risk index ~ however, it is necessary to weigh it for magnitude, focal depth, and ground response. Ultimately, an empirically based relation between ground acceleration, distance, and magni tude is required, so tha t ear thquake risk can be translated into terms of more immediate relevance to h u m a n and social problems.
Die Chemie der antiken Keramik
setzung als anderer Eigenschaften verschieden sin& Auch sind die Dauer des Verbleibs unter Wasser und die Art des Wassers nicht zu vernachl~issigen. Gegenw~irtig ist wohl die Konservierung des schwedischen Regalschiffs Wasa nach mehr als 300 Jahren aus dem Wasser geholt ein instruktives 13eispiel. (N~iheres s. [2], S. J84). Zu den fiber tausend Holzfunden gehOrt z.B. ein groBer L6we. Wochenlang wurde dieses S~iiek bei 30~ in einer groBen Wanne mit einer
Correlation of the Upper Cretaceous White Chalk (Turonian to Campanian) in the Anglo-Paris Basin
Using key lithological, biostratigraphic and geophysical borehole-log markers a correlation of the Upper Cretaceous Chalk stratigraphies across the whole Anglo-Paris Basin has been achieved. A common lithological marker bed stratigraphy applies and key fossil markers (inoceramids, Micraster and Echinocorys ) are consistently related to the same lithological markers throughout the basin. The major lithological changes consistently occur at the same levels but are not necessarily equally strongly developed. The magnificent dip section along the French Channel coast between the Somme and the Seine, and the inland sections at Precy-sur-Oise and Verlin (Loiret) illustrate the influence of long-lived tectonic lines on Chalk sedimentation history recognised by: (i) rapid thickness variations; (ii) channel flooring hardgrounds and associated anomalous bedding dips: (iii) stratigraphically anomalous infills of channels which may be metres to kilometres across; (iv) redeposited chalks containing abundant Bathichnus paramoudrae ; (v) tectonically induced slumps and slides with flint and chalk shatter beds (palaeoseismic horizons). These features are found along may axes including the Anticlinal du Bray at Precy and Dieppe, the Anticlinal de Margny-les-Compiegne at Nourard le-Franc and Le Treport (the Bresle Valley Axis) and the Fecamp and Verlin fault systems. The ‘events’ recognised along these axes link with similar events recognised in Sussex (e.g. Kingston Anticline), on Portsdown, at Culver Cliff, Isle of Wight (Sandown Pericline) and on the Weymouth Anticline (White Nothe). Such events are common in the high Turonian, low Coniacian, basal Santonian, and the low and mid Campanian. The recurrence of key marker beds dominated by a particular trace fossil association or sequence, Bathichnus-Thalassinoides suevicus-Zoophycos associated with major changes in lithology, micro and macro-fauna indicates more widespread ‘oceanographic’ cycles of transgression and regression related to Atlantic opening.