ISSN:0311-5518    

DOI:10.1080/03115517708527762

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

As is widely recognised, fossil florules are difficult to correlate because they appear to have been more controlled by environmental and ecological factors than uniform changes which reflect the passage of geological time. Here I present a worked example of a generally applicable approach to this problem in dating and mapping fossil plant associations.

ISSN:0311-5518    

DOI:10.1080/03115517708527763

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Caledogonia globosagen. et sp. nov. is considered to be a member of the Myophoriidae following the classification of Newell & Boyd (1975). It is a more evolved genus thanAgoniscaFleming from the Ladinian of New Zealand. Both are probably the descendants ofNeoschizodusof the Andean-West Antarctic region, a dispersal route on the southern Gondwanaland coastline.Caledogoniawas probably a rapid burrower in a high energy paleoenvironment. It occurs in a rhythmic sequence of greywackes and conglomeratic shell beds that lie on pre-Triassic basement. Like the associated bivalves,MaoritrigoniaandManticula, Caledogoniais an endemic genus of the Late Triassic Maorian Province.

ISSN:0311-5518    

DOI:10.1080/03115517708527764

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

As a result of plate tectonics, two areas of sedimentation formed in the Neogene of Europe, North Africa, and West Asia: the Mediterranean Tethys and the Paratethys. Their stratigraphic correlation is possible, using planktonic organisms, only in the Early and Middle Miocene. The Late Miocene and Pliocene of the Paratethys are brackish to fresh water, and yield endemic faunas. Their correlation with the marine Mediterranean Tethys is being solved at present within the framework of the Project No. 25 of the International Geologic Correlation Programme.

ISSN:0311-5518    

DOI:10.1080/03115517708527765

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Comparisons of conodont and trilobite communities from the Arenig-Llanvirn of northern Spitsbergen show that both groups were influenced by the same environmental factors, related to a shallow to deep water profile at the western edge of the proto-Atlantic Ocean (Iapetus). The majority of both conodonts and trilobites had benthic or nektobenthic habits; a few genera of both groups were pelagic. Temperature was a major influence on the distribution of conodonts; similar genera could occur on both sides of ancient oceans (e.g. Iapetus) given the same temperature regime.

ISSN:0311-5518    

DOI:10.1080/03115517708527766

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

ISSN:0311-5518    

DOI:10.1080/03115517708527767

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The H.Y.C. Pyritic Shale Member of the Barney Creek Formation (ca1 500 my old; northern Australia) contains several stratiform base metal sulfide deposits of economic significance. Black cherts within these mineral deposits preserve a diverse assemblage of bacterial and algal microfossils. The assemblage differs from most other Precambrian biotas so far described in that it was deposited in deep water, it is not associated with stromatolites or algal mats, and it is dominated by filamentous bacteria, most of which are pyritized. Analysis of the assemblage suggests that the depth of the depositional basin exceeded that of the photic zone, that the bacteria inhabited the basin floor where they maintained anoxic conditions through heterotrophic degradation of detrital organic matter, and that the algae inhabited overlying near surface waters. Most of the algal fossils have been assigned to the Cyanophyta, although two of the described species are potentially referable to the eukaryotic green or red algae. Differences between this assemblage and other biotas described from the McArthur Group suggest that a workable system of biostratigraphic zonation for the Group is feasible.

ISSN:0311-5518    

DOI:10.1080/03115517708527768

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

ISSN:0311-5518    

DOI:10.1080/03115517708527769

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor