James Armstrong

City University of New York

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John Young

Schlumberger (British Virgin Islands)

David Clark

Schlumberger (British Virgin Islands)

Wang Zhen Rong

Michael de Smet

C. Van Baalen

John Young

University of Cambridge

Marilyn L.F. Estep

Geophysical Laboratory

Ge He Ping

Julian A. Pearce

Cardiff University

Cooperative Institutions

Schlumberger (British Virgin Islands)

University of Cambridge

Natural History Museum

United States Geological Survey

Natural Resources Canada

Glasgow Life

University of Greenwich

Harvard University Press

Brown University

The Hunterian

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Sequence Stratigraphy and Hydrocarbon Potential of the Xihu Trough, East China Sea: Abstract

David Clark Wang Zhen Rong Ge He Ping James Armstrong P. Clews

Abstract The Xihu Trough is a back-arc basin situated on the continental shelf of the East China Sea. It comprises a NE-SW trending half-graben bounded on the eastern side by a normal listric fault. It probably originated in the Late Palaeocene or Early Eocene in response to the westward subduction of the Pacific plate beneath the Eurasian continent. Crustal extension and rapid subsidence took place until Early Oligocene. Volcanic activity was widespread at times, and a thick succession of sediments was deposited. Less pronounced extension and more moderate subsidence continued until the Late Miocene. At this point extension ceased and the Okinawa Trough started to form further to the east. The basin axis continued to sag, however, and gentle subsidence continued until the present day. Extension was interspersed by short episodes of compression, particularly in the Early Oligocene, Late Oligocene and Late Miocene, when normal fault movement was partially reversed and gentle anticlines formed as a result of localized inversion. The latter was accompanied each time by widespread uplift and erosion along the eastern margin of the basin, and substantial erosion also took place on the crests of the Late Oligocene and Late Miocene folds. At least 7, or possibly 10, depositional sequences can be recognised in the Xihu Trough. These sequences are the Oujiang/Wenzhou (Palaeocene-Eocene). Pinghu (Eocene?-Early Oligocene), Lower Huagang (Early Oligocene), Upper Huagang (Late Oligocene), Longjing/Yuquan (Early-Middle Miocene), Liulang (Late Miocene), Santan (Pliocene) and Donghai (Quaternary). Each sequence rests unconformably upon the previous one, particularly at the eastern edge of the basin where angular and onlapping relationships can be discerned on seismic. In the basin centre, the sequence boundaries are represented merely by strong reflections. The boundaries between the sequences appear to have resulted from local fluctuations in sea-level superimposed on eustatic fluctuations. The local fluctuations are thought to have been caused by the alternations between extensional and compressional tectonics within the basin. Each sequence can be divided into a lower, sand-dominated section that formed on an alluvial plain or lower coastal plain during a lowstand in sea level, and an upper, mud-dominated section representing lower coastal plain and shoreface conditions during a highstand. The lowstand sections are composed mainly of thick units of stacked fluvial channel sands, interbedded with overbank mudstones and coals deposited on flood plains and in coastal swamps. The highstand sections, in contrast, comprise largely mudstones and coals deposited together with relatively thin distributary channel, mouth bar, and crevasse splay sands. Reservoir potential is best in the lower sand-dominated parts of the sequences, whereas potential seals are more likely to be present in the highstand units. The reservoir quality of the channel sandstones is excellent, particularly in the shallower parts of the basin, although it starts to decline below a depth of 3000 m and is generally very poor below 3600 m. Regional seals are generally lacking in the Xihu Trough because the shales are relatively thin and interbedded with crevasse splay sands. Rich sources for gas, condensate, and oil have been identified within the upper Pinghu Sequence. These sources are principally coals and associated carbonaceous claystones. Oil generation probably started in the Later Miocene (5-10 Ma) in the southern part of the basin, at a time when most of the younger anticlines were being formed. Peak maturity for light oil and condensate was reached slightly later, in Early Pliocene (2.5-5 Ma), and it was followed by the onset gas generation. Peak generation of light oil and condensate had already passed in the northern part of the basin by the end of the Middle Miocene (10 Ma), and gas generation was well underway before any traps had been formed.

Trough (economics)

Paleogene

Anticline

Neogene

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Evidence for the Occurrence of Specific Iron (III)-Binding Compounds in Near-Shore Marine Ecosystems

Applied Microbiology (1975)

Marilyn L.F. Estep James Armstrong C. Van Baalen

Marine ecosystem

10.1128/aem.30.2.186-188.1975

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Citations (39)

XLII. Description of two new shells from the Carboniferous Limestone of Clydesdale

Transactions of the Geological Society of Glasgow (1865)

James Armstrong

Nautilus (Discites) nodiferus, Sp. nov. Pl. 1, Figs. 6, 7. N. testâ discoidali; anfractibus tribus, contiguis, subquadratis, regulariter tuberculatis; umbilico aperto; dorso lato, in medio valde sulcato; superficie lineis undatis; septis multis, cum siphunculo in medio. Shell discoidal, composed of about three gradually enlarging, contiguous, nearly subquadrate whorls, completely exposed in a moderately shallow umbilicus; back broad, rounded at the edges, and traversed in the middle by a wide and deep channel, on the sloping sides of which are two fine thread-like ridges. The remainder of the space on the back and sides of the shell is occupied by six rows of closely set, prominent, obtuse tubercles, elongated in the direction of the aperture, one row of tubercles of large size bounding the back, a double row of equal size between it and the channel, and three on the sides, which decrease in size towards the umbilicus. Surface marked with coarse, squamose, wavy lines of growth which are arched backwards in the dorsal channel. Septa numerous, their edges arched considerably backwards on the periphery, and slightly so at the sides. Siphuncle ⅟12 inch diameter, central. Dimensions,—width of greatest diameter 3¼ inches, width of outer whorl near the aperture 1 inch. Locality .—This elegant Nautilus, which belongs to the section Discites of Professor M'Coy, is an index shell to the upper division of the Carboniferous Limestone series of Clydesdale, to which group it would appear to be restricted, no specimens having been observed in any of the lower beds. Good external casts This 250-word extract was created in the absence of an abstract

Whorl (mollusc)

Aperture (computer memory)

10.1144/transglas.2.1.74

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On the carboniferous fossils of the west of Scotland ; their vertical range and distribution

Geological Society eBooks (1871)

John Young James Armstrong

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Catalogue of the Western Scottish Fossils

Blackie & Son eBooks (1876)

James Armstrong John Young D. S. Robertson

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Citations (48)

XLI. Note on the discovery of the teeth of Dithyrocaris

Transactions of the Geological Society of Glasgow (1865)

James Armstrong

Two species of Dithyrocaris are known to occur in the Carboniferous Limestone of the West of Scotland— D. ( Argas ) testudineus, Scouler, and D. tenuistriatus, M‘Coy. Dr. Scouler’s specimens of D. testudineus, now in the Andersonian Museum, were obtained upwards of thirty years ago, in a limestone excavated for the foundation of Paisley barracks. Mr. Young has found portions of the carapace in the shale at Robroyston, which contains the finely preserved Lingula; and we believe a specimen of the trilobed portion of the tail was found in the shale of Craigenglen, and is in the collection of Mr. James Macrae of Campsie. The only bed from which examples have been obtained in anything like abundance or perfection, is a shale in the “Lingula” limestone at Raes Gill, Carluke. Of D. tenuistriatus we are acquainted with but a single specimen, found by Mr. John Young in the “Lingula” shale, Robroyston. Until lately, our acquaintance with Dithyrocaris was limited merely to the carapace and telson, but our researches, together with those of Mr. James Bennie, have resulted in the discovery of what has proved to be the teeth. This is of considerable interest, as we are now enabled to compare the teeth of Dithyrocaris with the same organs in the living crustacea. Their appearance is that of small, blunt, crushing teeth, with cusps in groups of from five to seven, and they bear a striking resemblance to the molar teeth of certain mammals. On their being submitted to Professor Owen (through the kindness This 250-word extract was created in the absence of an abstract

10.1144/transglas.2.1.73

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IX. Description of Two new species of Cypricardia from the Carboniferous Limestone of Lanarkshire

Transactions of the Geological Society of Glasgow (1865)

James Armstrong

Cypricardia acuticarinata, sp. nov. Pl. 1, Fig. 3. C. testâ subquadratâ, tumidâ; carinâ conspicuâ, acutâ; umbonibus parvis, contiguis; lunulâ cordatâ excavatâ; antice brevi, rotundatâ; postice compressâ, abruptâ, truncatâ; margine dorsali ventralique rectâ; superficie lineis obscuris et latere antico plicis incrementis irregularibus . Shell subquadrate, tumid; keel very prominent, sharp, extending diagonally across the valves from the umbo, and forming an acute point at the posterior ventral margin; umbones small, close; lunule cordate, excavated; anterior side very short, rounded; posterior side, compressed, and abruptly truncated; dorsal margin straight, ventral margin also straight, rounded in front; surface marked with faintly-impressed lines of growth, which generally rise into irregular plications on the anterior side. Length of largest example, 4½ lines; width, 3 lines. Locality. —Gare and Westerhouse north-east of Carluke, in shale at old limestone quarries; very rare. It is also found, not unfrequently, in the shale at Orchard quarry, near Thornliebank. Cypricardia crebricostata, sp. nov. Pl. 1, Fig. 4. C. testâ subquadratâ, subtumidâ; umbonibus parvis; antico latere brevi, rotundo; postice compressâ, ventrali rotundatâ; margine dorsali declivi, ventrali rotundatâ; carinâ obtusâ; superficie costis parvis crebris et concentricis regularibus . Shell subquadrate, slightly tumid; umbones small, close; anterior side short, rounded; posterior side compressed, and rounded at ventral angle; dorsal margin sloping; ventral margin rounded; keel obtuse; surface ornamented with small, close, and regularly concentric ridges. Length, 4 lines; width, 3½ lines. Locality. —Gare and Westerhouse, near Carluke; very rare. The two species here described, so far as I have observed, appear to be confined to the upper This 250-word extract was created in the absence of an abstract

10.1144/transglas.2.1.28

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XXIV. The Fossils of the Carboniferous Strata of the West of Scotland

Transactions of the Geological Society of Glasgow (1874)

John Young James Armstrong

INTRODUCTION. In the introductory remarks to our General Catalogue of the Carboniferous Fossils of the West of Scotland,* we pointed out the desirability of having lists prepared of the fossils found in each particular group of strata in the various localities where they occur, for the sake of comparison with similar lists from the same geological horizons at other places, stating that "it is only when stratigraphical lists of our fossils are prepared on some such exhaustive plan, that we will ever be able to arrive at anything like a correct notion of the alternate changes of condition under which the flora and fauna of the Carboniferous period existed, as indicated by its beds of terrestrial, fresh water, and marine strata." Our distinguished honorary member, Thomas Davidson, Esq., F.R.S., in a paper recently communicated to the Edinburgh Geological Society,† also urges upon its members the necessity of preparing local catalogues, such as those above indicated, and he points out the immense importance of Palæontology to Geology, mentioning one or two instances out of numbers which he could adduce, to show where the correct determination of a few fossils has been the means of unravelling the age and position of strata, not only in Britain, but in distant regions of the globe. In making out these catalogues, therefore, we will endeavour, with the assistance of members of the Society, to give from time to time, in the Transactions, a record of the fossils found in the strata of a particular locality, This 250-word extract was created in the absence of an abstract

Globe

Flora

10.1144/transglas.4.3.267

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Citations (3)

XVIII. Notes on the Fossils of the Orchard Limestone Series

Transactions of the Geological Society of Glasgow (1877)

James Armstrong John Young

Fragments of spines and plates found in

Orchard

10.1144/transglas.5.2.250

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Citations (1)