Early carboniferous brachiopod faunas from the Baoshan block, west Yunnan, southwest China

38 brachiopod species in 27 genera and subgenera are described from the Yudong Formation in the Shidian-Baoshan area, west Yunnan, southwest China. New taxa include two new subgenera: Unispirifer (Septimispirifer) and Brachythyrina (Longathyrina), and seven new species: Eomarginifera yunnanensis, Marginatia cylindrica, Unispirifer (Unispirifer) xiangshanensis, Unispirifer (Septimispirifer) wafangjieensis, Brachythyrina (Brachythyrina) transversa, Brachythyrina (Longathyrina) baoshanensis, and Girtyella wafangjieensis. Based on the described material and constraints from associated coral and conodont faunas, the age of the brachiopod fauna from the Yudon Formation is considered late Tournaisian (Early Carboniferous), with a possibility extending into earlyViseacutean.<br /

Carboniferous and Permian Rugosochonetidae (Brachiopoda) from West Spitsbergen

The rugosochonetid brachiopod species Lissochonetes geinitzianus from the Kazimovian of the Nordenskioldbreen Formation, and Dyoros (Dyoros) mucronata sp. nov., Dyoros (Dyoros) spitzbergianus and Lissochonetes superba from the Artinskian to latest Permian Kapp Starostin Formation in West Spitsbergen are described and figured. Dyoros is generally restricted to the Boreal Realm, whereas Lissochonetes is mostly distributed in the Boreal Realm, but occasionally present in the Palaeoequatorial and Gondwanan Realms<br /

Lithification of carbonate sediments in the heron island reef, great barrier reef

In this reef area lithification has resulted in the formation of beach rock at the surface and reef rock in the subsurface. The process of lithification which leads to the formation of beach rock is an unusual and interesting one, but does not play a major rôle in the consolidation of reef sediments. Beach rock results largely from the protective action of encrusting algae and to a less degree from carbonate precipitation from sea water. Because of the general lack of “fines” in reef flat and beach sands, matrix recrystallisation plays no part in beach rock formation. By contrast, the reef rock from the subsurface generally contains a higher percentage of fines and, below 100 feet, this material has been largely recrystallised to form a strong binding medium. The process of recrystallisation is apparently selective, those sediments with high matrix, high coral/algal ratio and low MgCO3 content showing the highest degree of recrystallisation. Depth of burial shows no direct relationship to this process. Thus, of the two lithifying processes operative in the reef province, the less spectacular one of compaction and recrystallisation is the more important. Beach rock formation is significant in its influence on the present distribution of carbonate sands, but it makes little or no contribution to the total rock mass underlying the present reef

Contributions to the correlation and fauna of the permian in Australia and New Zealand

Contributions by a number of authors to a Symposium on the correlation and subdivision of the Australian and New Zealand Permian, at the Canberra Meeting of the Australian and New Zealand Association for the Advancement of Science, held in January 1954, are reviewed, together with some recently published works