We prove a characterisation, in terms of regularity and cancellation conditions, of the convolution kernels of Marcinkiewicz multiplier operators m (𝔏 1 ,…,𝔏 n , iT ) on the Heisenberg group ℍ n , where 𝔏 1 ,…,𝔏 n are the n partial sub-Laplacians. The necessity of these regularity and cancellation conditions was established by Fraser (2001); here, we prove their sufficiency.

Exploration drilling for hydrocarbons in southern England commenced over 50 years ago prompted by numerous seepages along the Dorset coast and gas shows in water boreholes. The two main depocentres, the Weald and Wessex basins, exhibit many similarities in both tectonic and stratigraphic evolution through Early Triassic-Tertiary limes, reflecting the regional influences of Atlantic Margin rift-subsidence processes and subsequent Tertiary (Alpine) inversion tectonics. Given these similarities, the development of the hydrocarbon play system in bath these areas can be compared using a common tectono-stratigraphic framework which has been identified and calibrated using well and seismic data. In detail, facies variability recognized within individual depositional units highlights differences in both source and reservoir distribution between the Weald and Wessex areas, which have in turn exerted fundamental controls on the hydrocarbon prospectivity of the two basins. These differences are influenced by the position of major basin-bounding fault systems and by the changing importance of the Cornubian-Armorican and the London-Brabant Massifs as elastic provenance areas through time. Sequence isopachs illustrate the same discrete episodes of rift-related subsidence in both areas. These rifting episodes led to the development of extensional trapping geometries particularly during Late Jurassic-Early Cretaceous times. Subsequent Late Cretaceous the;mal subsidence led to the formation of mature source kitchen areas focused within the hanging walls of the earlier extensional faults. Hydrocarbon expulsion from the source kitchen areas ceased during Tertiary uplift and subsequent cooling. Inversion movements on the old extensional faults led to the development of hanging wall anticlines which rely upon remigration mechanisms, including exsolution of gas from uplifted Liassic source rocks, to receive hydrocarbon charge. To date over 300 million barrels of oil and 100 bcf of gas have been discovered.

This volume reflects the current broad interest in exploration and production in the energyhungry SE Asia region. Analysts currently predict that energy production in SE Asia will increase by 85% over the next 15 years and, by the end of this period, consumption may be double that of Europe. Although fairly modest in a global context, production is still sufficient to underpin economic growth rates of up to 8-12% in regions such as Indonesia, the Philippines, Vietnam, Malaysia and Brunei. In contrast, those economies that do not currently benefit from substantial oil and gas production are more stagnant, e.g. Laos, Cambodia and Burma. SE Asia, including Indonesia, Thailand, Malaysia, Brunei and the Philippines, contains ten oil and gas provinces that individually contain more than three billion barrels of oil equivalent. All of these provinces are Tertiary basins with Tertiary-aged petroleum systems. This represents a considerable resource that has been actively exploited in the past and continues to expand with further exploration. Two main reservoir systems contribute to the majority of petroleum reserves in the region. These are deltaic clastics, e.g. Baram, Rajang and Mahakam deltas, and carbonates, e.g. Luconia, Terumbu and Nam Con Son platforms. They were charged by two key sources types. Lacustrine source rocks which are associated with 'oily' basins and paralic source beds which are typical of gas-prone basins. Key trap types are inversion anticlines and three-way-dip and fault-controlled traps in low net/gross clastic reservoirs, often with variable fluid types in stacked reservoirs with over 1000ft plus pay zones. Carbonate traps are characterized by broad regional drape features that are seldom full to spill. The volume covers all aspects of the petroleum geology of SE Asia from economic background, through plate tectonic models, petroleum charging and reservoir systems to detailed field and reservoir studies. In the first paper Sladen provides the economic context for all the other papers. He summarises current energy trends in SE Asia and emphasizes the global importance of the regions coal output. Current SE Asia GDP growth is quite phenomenal and fuel oil, gas and coal will be required to underpin this growth. Sladen notes a steady growth in oil and gas production particularly in China, Malaysia, Vietnam and Papua New Guinea. In terms of total oil production, SE Asia is a minor world player, but gas may become increasingly important for both domestic and export markets particularly in the emerging gas production areas of Vietnam, PNG and the Philippines. The next three papers complement this economic overview with regional reviews of plate tectonics, petroleum charging and lacustrine systems. Hall reconstructs plate movements in SE Asia over the last 50Ma based on new palaeomagnetic data. He discusses rotational models for Borneo and the resulting implications for the evolution of the South China Sea regions and the progressive motion of the Australian continent. Todd et al. develop the idea that there are two dominant petroleum source-rock types in SE Asia: paralic and lacustrine. Their presence in any particular basin is reflected by the distribution of oil and gas in the basin. Lacustrine source rocks are associated with oil-prone basins such as Malay, Bohai and Central Sumatra whereas paralic source rocks are typical of gas-rich basins such as Sabah, Luconia, Nam Con Son and West Natuna. Sladen, in his second paper, considers the lacustrine source rocks in the context of SE Asian Mesozoic and Cenozoic lacustrine basins and reviews the development of reservoirs in the basins and the charge issues which link exploration for specific sources and reservoirs in these basins. The 20 papers that lie at the heart of the volume focus on specific areas of SE Asia and the issues and problems of their petroleum geology. The Bongkot gas field in the Gulf of Thailand is the subject of the first of these case studies. Leo describes the reservoir characteristics of the deltaic/fluvial sandstones of Oligocene to mid-Miocene age encountered in the field. He concludes that seismic facies analysis was an essential exploration tool in this area, highlighting the Bongkot accumulation as a complex of largely independent structural and statigraphic closures. Vietnam is addressed in the next three papers. First Matthews et al. review the Nam Con Son Basin, offshore South Vietnam, highlighting reservoir issues. Worden addresses the controls on porosity reduction with depth in the area of the southern Vietnam continental shelf. He concludes that porosity was mainly controlled by lithic content and in particular compaction of ductile grains and is able to demonstrate a strong relationship between permeability and percentage of ductile grains. The paper by Mayall et al. complements this contribution focusing on the large carbonate plays of the Nam Con Son Basin. Indonesia is the focus of the next four papers. Wight addresses the petroleum geology and production history of the Sumatra-Java area

Late Westphalian inversion structures on the Variscan foreland display wide variations in orientation that are the product of the underlying basement grain. The orientation of the major basement lineaments in relation to the direction of maximum shortening also determined the severity of deformation of the inverted basins. NE–SW-trending faults were oriented roughly perpendicular to the NW–SE to NNW–SSE direction of maximum shortening determined from thrust transport directions in the Variscan orogen to the south. As a consequence, NE–SW-trending basins in the Variscan foreland have been strongly inverted, the Silesian post-rift fill has commonly been expelled from the basins and the syn-rift sediments have been deformed by chevron folds (Dublin and Bowland Basins). In contrast, the N–S- and NW–SE-trending faults were oriented more obliquely to the direction of maximum shortening and, as a consequence, display a significant component of oblique slip. This oblique slip component is manifested as en-echelon periclines and flower structures. In general, the N–S- and NW–SE-trending basins were less strongly inverted and the Silesian post-rift fill has been retained.

Systematic variations in sequences, their component units and their stacking patterns exist within rift basins. These variations can be related to displacement gradients associated with the large-scale (12–50 km) segmentation of normal fault zones, which control accommodation, sediment supply and basin physiography. Sediment supply is also strongly influenced by the nature of pre-rift drainage networks and variations in bedrock lithology. High rates of hangingwall subsidence close to the centre of normal fault segments may cancel out the effects of glacio-eustatic sea-level fall, so that accommodation development is normally characterized by the continual addition of new space. The resulting sequences lack type 1 sequence boundaries and lowstand systems tracts, and stack into aggradational sequence sets. The adjacent footwall is subject to uplift, which may lead to subaerial exposure and incision, generating a composite type 1 sequence boundary. Away from the fault zone and near segment boundaries, slip rates are much lower and hence relative sea-level change is dominated by eustasy. Here, falls in relative sea level are important, resulting in type 1 sequences. Sequence stacking patterns reflect not only eustasy and local fault-controlled subsidence, but also the interaction of these with adjacent uplifting footwalls and/or regional uplift. Tectonic influence on sequence development will be more pronounced during greenhouse times than icehouse times.

Over 70 years of exploration in the Carboniferous of northern England has resulted in the discovery of rather modest recoverable reserves totalling 75 million barrels of oil and 27 billion cubic feet of gas. Nevertheless during this time the petroleum industry has amassed a substantial quantity of borehole and seismic information. Integrating this essentially subsurface database with information derived from outcrop studies has permitted a hitherto unachievable understanding of the Carboniferous in terms of its tectonostratigraphic development and hydrocarbon habitat. The strong NW-SE and NE-SE structural trends developed in the northern England Carboniferous were inherited from the late Palaeozoic Caledonian orogeny. These fault trends were consistently reactivated throughout the Carboniferous in both an extensional and compressional sense. The main influence on Carboniferous basin evolution in northern England was the Variscan collision-type orogeny. The Variscan plate cycle controlled the development of syn-rift, post-rift and inversion megasequences from late Devonian to early Permian times. Sequences developed within these Carboniferous megasequences are primarily controlled by episodic rifting and periodic fault reactivation with eustatic sea-level changes providing only minor control at the subsequence level. The late Carboniferous-early Permian culmination of the Variscan orogeny is seen to be the main trap forming event. All hydrocarbon discoveries to date display some element of Variscan inversion in their geometry. Variscan tectonics have also exerted a subtle but important control on play fairway evolution. The main source rocks (pro-delta shales) are confined to isolated, syn-rift depocentres. Syn-rift siliciclastic reservoirs are also restricted to the rifted half graben. Carbonate grainstone reservoirs rim the margins of the deeper half graben where terrigenous input has been limited. Delta top channel and mouth bar reservoirs are best developed where they axially infill remnant syn-rift bathymetry. Mesozoic burial, ensuring hydrocarbon generation post Variscan trap formation, is, however, the main control on the present day distribution of hydrocarbons in the Carboniferous of northern England. Several key areas where Carboniferous source rocks have generated significant hydrocarbons during the Mesozoic have been identified; the East Midlands being the most significant in terms of produced hydrocarbons and perceived future potential.

Adult and late copepodite stages of Calanus finmarchicus (Gunnerus), Pseudocalanus sp. and Temora longicornis Muller sampled from a nutrient-enriched seawater enclosure containing a natural phytoplankton population were all rich in neutral lipid. Pseudocalanus sp. and C. finmarchicus contained mainly wax esters (WE) whereas T. longicornis contained mainly triacylglycerols (TAG). The WE of C. finmarchicus were characteristically rich in 16:0,20:1(n-9) and 22:1(n-11) fatty alcohols and 28% of the WE fatty acids were (n-3) polyunsaturated fatty acids (PUFA). Low levels of TAG in C. finmarchicus contained 28% of their fatty acids as (n-3) PUFA. The fatty alcohols of WE in Pseudocalanus sp. were primarily 16:0 and 14:0, with traces of 20:1(n-9) and 22:1(n-11). Of the WE fatty acids, 37% were (n-3) PUFA which was similar to the percentage of (n-3) PUFA in the TAG of this species. Triacylglycerols of T. longicornis contained 48 % of their fatty acids as (n-3) PUFA while the small amounts of WE in this species contained 45% (n-3) PUFA. The WE of T. longicornis contained primarily 16:0, 18:0, 20:1(n-9),22:1(n-11) and 24:0 fatty alcohols. The data are discussed with particular reference to the abundance and retention of (n-3) PUFA in marine food chains.

Changes in the lipid class and fatty acid composition of developing eggs and unfed larvae of cod (Gadus morhua L.) were studied with the objective of determining probable requirements of cod larvae for dietary lipid. The eggs were collected on 24 March 1985 from holding tanks containing cod which had been caught off the northwest coast of Scotland. Phosphatidylcholine (PC) was the only lipid class to decline in absolute terms during embryogenesis. Catabolism of neutral lipid was initiated during the first week after hatching, and the rate of neutral lipid utilisation increased after the larvae had completely absorbed their yolk sacs. The quantity of triacylglycerol (TAG) remained constant during embryogenesis, but the percentage of 22:6(n-3) int TAG increased substantially during this period. It was calculated that ca. 33% of the 22:6(m-3) released during the process of PC catabolism was incorporated into TAG and sterol ester. The results suggest that PC, replete in appropriate essential fatty acids, should represent a major proportion of the lipid in artificial diets for fish and crustacean larvae.

The lipid class compositions of Atlantic herring eggs and larvae were determined immediately before fertilization, after fertilization and at various times during subsequent embryonic and early larval development. Total lipid constituted 15% of the dry wt of ripe eggs, 70% of the total lipid being polar lipid with phosphatidylcholine (PC) accounting for almost 90% of the polar lipid. In general, the total lipid content decreased gradually during embryogenesis and in particular during larval development. Within 3 hr after fertilization the relative percentage of neutral lipid decreased slightly. This was followed by a general decrease in polar lipid which, by the stage of yolk sac absorption, was reduced to 52% of the total lipid. The decreased percentage of polar lipid was due entirely to a decrease in PC, which was reduced to 66% of the polar lipids at the stage of yolk sac absorption. The accompanying increase in the percentage of neutral lipids was mainly due to increased percentages of triacylglycerols (TAG) up to yolk sac absorption and cholesterol esters in the larval stages. During the first 4 days after hatching, phospholipids and to a lesser extent cholesterol were preferentially depleted in the yolk sacs, which also had higher levels of free fatty acids. The results are discussed in relation to possible roles of different lipids during embryonic and early larval development.

Lipid class and fatty acid analyses were carried out on developing salmon eggs at four clearly defined pre-feeding stages, namely, fertilization, eyed egg stage (50 days), hatching (yolk sac fry, 98 days) and swim up fry (138 days).

A method is described whereby a complete analysis of individual neutral lipid and phospholipid classes in marine animal total lipid can be achieved using an latroscan TLC-FID analyser. The method involves separate analyses of two samples of total lipid in solvents designed to separate neutral and polar lipid classes, together with calibration by a composite standard similar in composition to the sample under analysis. The method does not depend on the degree of unsaturation of the fatty acids present, is rapid and compares well in accuracy with conventional combined gravimetric, colouritnetric, and densitometric procedures.