12.—Further Observations on some Lower Carboniferous Seeds and Cupules

1975 ◽  
Vol 69 (12) ◽  
pp. 267-293 ◽  
Author(s):  
A. G. Long
Keyword(s):  
Compact Group ◽  
Lower Carboniferous ◽  
Functional Megaspore

SynopsisTwenty-eight specimens of the seed genusDolichospermahave been examined. Fourteen are assigned toD. sexangulatumLong; these possess six or seven integumental lobes which extend apically as free tentacles equal in length to the seed body except when damaged or broken off. Fourteen other specimens are namedD. pentagonumsp. nov. These are smaller and usually have five integumental lobes (less commonly six or seven). Long apical tentacles have not been seen in this species.Evidence is adduced thatAnasperma burnenseLong is the mature prothallial seed developed from the ovuleEurystoma trigonaLong.Eurystoma angulareLong sometimes possesses five integumental lobes and the free apical lobes vary in length.Compressed megaspores macerated from cupules ofStamnostoma huttonenseLong sometimes have three abortive spores in a compact group at the apex.Ovules ofEccroustosperma langtonenseLong were borne in small bunches (probably pendent) on short pedicels; one specimen of this seed shows three well-developed separate abortive spores around the apex of the functional megaspore.The cupule ofCalathospermum fimbriatumBarnard shows a structure suggesting that it may have evolved from a pair of cupules. Twelve to fourteen ovules were sometimes formed in the entire cupule though most of these were probably abortive.Some possible seed embryos are described and discussed, and an outline classification of seeds in the order Lagenostomales is proposed.

IV.—On the Carboniferous Basement Beds at Ingleton

1906 ◽  
Vol 3 (7) ◽  
pp. 320-323 ◽  
Author(s):  
Cosmo Johns
Keyword(s):  
Lower Carboniferous ◽  
Geological Society ◽  
Spring Meeting ◽  
The Subject

During the Spring meeting of the Yorkshire Geological Society at Pateley Bridge it was suggested that, as a first step towards the zonal classification of the Lower Carboniferous rocks of Yorkshire, it would be desirable to determine the horizon of the basement beds at Ingleton as compared with the Avon sequence. As the Yorkshire Naturalists Union had arranged a meeting at Ingleton for May 12–14th, the geological route was arranged so as to include as many exposures of the basement beds as possible. The result of the observations made then and during subsequent visits is the subject of this communication.

A new genus and species of anthracosaur amphibian from the Lower Carboniferous of Scotland and the status of Pholidogaster pisciformis Huxley

1975 ◽  
Vol 269 (900) ◽  
pp. 581-637 ◽  
Keyword(s):  
New Genus ◽  
New Genus And Species ◽  
Lower Carboniferous ◽  
Lower Jaw ◽  
The Family ◽  
Close Relationship ◽  
The Status ◽  
Coal Measures ◽  
Composite Restoration

The isolated skull of a Lower Carboniferous anthracosaur labyrinthodont from the Midlothian coalfield was formerly but erroneously attributed to Pholidogaster pisciformis . It is now redescribed after ‘Airbrasive’ development as the holotype of a new genus and species. The anthracosaur agrees in a number of diagnostic cranial characters with the embolomerous forms of the Coal Measures but other characters, particularly those of the braincase and lower jaw, suggest relationship to the Seymouriamorpha. Its cranial anatomy could well be antecedent to that of both these groups and the sparse evidence available suggests close relationship to the American Mississippian anthracosaur Proterogyrinus . A new classification of the Batrachosauria is presented with a major subdivision into Anthracosauria and Seymouriamorpha. The former group comprises the newly proposed infraorder Herpetospondyli to include the Lower Carboniferous forms, together with the infraorders Embolomeri and Gephyrostegoidea. It is concluded that while no batrachosaur with an otic notch could be a reptile ancestor a primitive ‘notchless’ anthracosaur could be. The cranial anatomy of Pholidogaster pisciformis is then redescribed, after complete ‘Airbrasive’ preparation of the holotype skull. The holotype, like the anthracosaur, comes from the Gilmerton Ironstone of the Edinburgh region, but the earlier holotype skull of Otocratia modesta , long considered to be an ichthyostegid, is also attributed to Pholidogaster . After redescription of ‘ Otocratia ' a composite restoration of the Pholidogaster skull is presented. The nature of the dermal ornament, the post-parietal-supratemporal suture, the absence of tabular horns and the nature of the post-cranial skeleton all demonstrate that Pholidogaster is an early temnospondyl labyrinthodont in no way closely related to anthracosaurs. It is closely similar to the American Mississippian form Greererpeton burkemorani Romer, notably in the presence of large premaxillary fangs and the absence of otic notch and intertemporal. Both may be attributed to the family Colosteidae. It is concluded that there is no strong evidence of close relationship between the colosteids and the Devonian ichthyostegids.

VI.—On the Classification of the Lower Carboniferous Rocks

1910 ◽  
Vol 7 (12) ◽  
pp. 562-564 ◽  
Author(s):  
Cosmo Johns
Keyword(s):  
Great Britain ◽  
Time Interval ◽  
New Classification ◽  
Lower Carboniferous

In this communication it is proposed to briefly note the divisions which have been proposed for the Lower Carboniferous Rocks of Great Britain and Belgium; to discuss their validity in the light of the important additions that have been made to our knowledge during the last few years; and to suggest a new classification which, while expressing the physical and faunal changes which characterized that particular time interval, shall be generally applicable and at the same time do justice to the workers who have contributed most largely to our knowledge.

III.—A Petrological Study of the Arthur's Seat Volcano

1956 ◽  
Vol 63 (1) ◽  
pp. 37-70 ◽  
Author(s):  
R. H. Clark
Keyword(s):  
Present State ◽  
Late Stage ◽  
Volcanic Rocks ◽  
Parental Magma ◽  
Magma Source ◽  
Chemical Analyses ◽  
Lower Carboniferous ◽  
Basaltic Rocks ◽  
History Of

SynopsisAethur's Seat is the remains of a dissected Lower Carboniferous volcano, from which were erupted a series of basaltic rocks representative of the province to which it belongs. The rocks occur as lavas, intrusions and tuffs, and include basalts of Dalmeny, Jedburgh, Dunsapie, Craiglockhart and Markle types, in addition to mugearite. For convenience the basalts of Dunsapie type have been subdivided into Normal and Feldspathic varieties.The volcano has been remapped; some minor departures from the six-inch Geological Survey map are recorded and certain changes in the numbering and classification of the lavas have been made.The petrographic characters of the various volcanic rocks are described in detail, with modal and chemical analyses. The composition of the parental magma of the volcano was probably very similar to that of Normal Dunsapie basalt. Markle and Craiglockhart types were produced as complementary differentiates of the parental liquid by a process of gravity differentiation, in which sinking of ferromagnesian crystals, particularly augites, played an important part. The basalts of Dalmeny and Jedburgh types, which in Arthur's Seat have strong chemical resemblances, probably represent only slightly differentiated parental magma. Concentrations of soda-rich volatiles produced intense albitisation in the Markle basalts and the mugearites. It is considered that the mugearites of Arthur's Seat crystallised initially as Jedburgh or Dalmeny types, and were altered to their present state during a deuteric phase.An attempt has been made to reconstruct the eruptive history of the volcano. The magma source appears to have been replenished with parental magma at least twice during the period of activity. The first and last eruptions were of Dunsapie basalt; the albitised products appeared at a fairly late stage.

VII.—On the Horizon of the Lower Carboniferous Beds containing Archæosigillaria Vanuxemi (Göppert) at Meathop Fell

1910 ◽  
Vol 7 (3) ◽  
pp. 117-119 ◽  
Author(s):  
E. J. Garwood
Keyword(s):  
General Structure ◽  
Careful Study ◽  
Large Area ◽  
Full Account ◽  
Lower Carboniferous ◽  
General Classification ◽  
Northern Area ◽  
Plant Remains ◽  
Geological Magazine

In a note on Archæosigillaria Vanuxemi and Bothrodendron sp., published in the Geological Magazine for February last, Mr. J. W. Jackson speculated on the age of the beds at Meathop, in which these plant remains occur, and refers to the general classification of the Lower Carboniferous rocks of the Westmorland district, which I gave in this magazine in 1907. He remarks: “It is perhaps premature to attempt to fix definitely the exact horizon of these beds, as they appear to have been as yet but superficially studied.” Since the classification above referred to was published, I have devoted such time as could be spared from professional duties to an exhaustive examination of the whole northern area, the result of which has been to confirm the general conclusions already given in this magazine. In my forthcoming account of the district, I have given a detailed description of the Meathop section. The delay in publishing a full account of the northern area has been necessitated by the general structure of the district, which required a careful study of isolated outcrops, extending over a very large area, before an accurate co-ordination of the separate exposures could be established. If any justification for this delay were needed, it is supplied by Mr. Jackson's note, in which he confesses his inability to decide upon the age of the beds displayed in the isolated exposure at Meathop on the evidence afforded by the collections obtained during his visits to that locality.

scholarly journals Classification of certain inductive limit actions of compact groups on af algebras

2020 ◽  
pp. 2050128
Author(s):  
Qingyun Wang
Keyword(s):  
Compact Group ◽  
Inductive Limit ◽  
Complete Classification ◽  
Compact Groups ◽  
C Algebra ◽  
Finite Dimensional ◽  
K Theory ◽  
Af Algebras

Let [Formula: see text] be an AF algebra, [Formula: see text] be a compact group. We consider inductive limit actions of the form [Formula: see text], where [Formula: see text] is an action on the finite-dimensional C*-algebra [Formula: see text] which fixes each matrix summand. We give a complete classification up to conjugacy of such actions using twisted equivariant K-theory.

scholarly journals PETROPHYSICAL MODELS OF TERRIGENOUS RESERVOIRS OF THE CARBONIFEROUS DEPOSITS OF THE CENTRAL PART OF THE DNIEPER-DONETS DEPRESSION

2019 ◽  
Vol 1 (178) ◽  
pp. 63-73
Author(s):  
Yulia LYSAK ◽  
Yuriy SHPOT ◽  
Andriy SHYRA ◽  
Zoriana KUCHER ◽  
Ihor KUROVETS
Keyword(s):  
Petrophysical Properties ◽  
Reservoir Properties ◽  
Lower Carboniferous ◽  
Reservoir Rocks ◽  
Geological Conditions ◽  
Geological Factors ◽  
Characteristic Features ◽  
The Given

The purpose of the work was to construct petrophysical models of reservoir rocks of different rank: typical and unified. Typical models describe connections between the parameters of individual rocks lithotypes occurring in definite geological conditions and serving as the basis for the development of petrophysical classification of reservoir rocks in the oil geology. The principle of unification provides for creation of the models structure for different reservoir lithotypes both in the geological section and in the area. We have studied petrophysical properties of reservoir rocks of Carboniferous deposits in the central part of the Dnieper-Donets depression. Petrophysical properties of rocks in conditions close to the formational ones and relations between them were studied on a number of samples formed by the core samples of different age. Main geological factors that have an influence on reservoir properties of rocks were taken into consideration. While constructing and analysing of petrophysical models we have used a probable-statistic approach with the use of the correlative-regressive analysis. Result of the work is contained in typical petrophysical models for individual areas and in unified models obtained on consolidated samples for Lower Carboniferous deposits of this region. Characteristic features in variations of petrophysical properties of reservoir rocks of Carboniferous deposits and their models have been ascertained. A conclusion has been made that multidimensional models, in which the depth of occurrence of deposits is one of the parameters that are necessary to consider while constructing petrophysical models, are the most informative for determination of petrophysical properties of the studied deposits, and the models obtained by us are known to be a petrophysical basis for quantitative interpretation of data from geophysical studies in the boreholes of the given region.

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