cene parts of Sites 643 and 642, to compare the palynological data with other DSDP/ODP sites in the northern Atlantic and with onshore sections, and to identify palynoevents which might help with the interpretation of the Norwegian Sea geological history.

Sedimentary organic matter behaves as sedimentary particles and this study attempts to interpret its occurrence in the Palaeocene sands and mudstones of the Forties Field of the North Sea. New nomenclature and classification of this palynodebris are presented and are used to make quantitative counts of the palynodebris from nearly 600 samples of known sedimentary character. The new categories are further refined by objective testing of the data by Principal Components Analysis and Cluster Analysis. It is argued that two types of sedimentary organic matter are of particular value because they are preferentially deposited in different environments: palynowafers are most commonly deposited in the submarine fan lobes and channel complexes and amorphous matter occurs mostly in the lower energy basin plain sediments.

No abstract

When leaves of the Taxodiaceae are placed in 10% chromium trioxide at 40" C for 6-24 hours, a macerated cuticle is obtained. Examination of the inner surface of these cuticles by the scanning electron microscope reveals a consistent steady state structure, which we show to be usable for comparative study. The variations of the sculpture, both within the same leaf and throughout the family, are presented. Both the structural and the evolutionary significance of the features are discussed. CONTENTS

OLIGOCENE AND MIOCENE OUTLIERS OF CORNWALL 213 held. There is indirect evidence that it formed subaerially over a long period during m id-Tertiary times; essentially, it appears to be an etchplain of tropical and subtropical origins, now largely stripped of its former saprolitic cover. It is demon strated that the grosser physiography of west Cornwall was established by the end of the Palaeogene at the latest and, also, that the area has probably never been inundated by Tertiary seas, except shallowly near to the end of that period (i.e. by the St Erth transgression).The prolonged morphodynamic stability of the region, as established in this paper, has im portant consequences for the interpretation of landscape evolution elsewhere in areas of Oldland (i.e. post-Armorican) western Europe, especially where datable Tertiary deposits have yet to be recognized.