DINOFLAGELLATE CYSTS FROM THE LATEST MIOCENE THROUGH MIDDLE PLEISTOCENE OF THE CARIBBEAN SEA, ODP SITE 1000: BIOSTRATIGRAPHY, PALEOCEANOGRAPHY, AND SHOALING OF THE CENTRAL AMERICAN SEAWAY

This is the first detailed study of organic-walled dinoflagellate cysts (dinocysts) and acritarchs for the latest Miocene–Middle Pleistocene of Ocean Drilling Program Site 1000 in the Caribbean Sea. Well-preserved and moderately diverse dinocysts and other palynomorphs reflect the interplay between neritic (carbonate-platform sourced) and oceanic species. The dinocyst biostratigraphy is tied to an existing marine isotope stratigraphy for the interval 5.5–2.2 Ma. For the interval 5.5–3.8 Ma, palynological samples are coupled to published sea-surface temperature estimates based on planktonic foraminiferal Mg/Ca. Changes in dinocyst assemblage composition are noted at ca. 4.6 Ma when shoaling of the Central American Seaway caused a temperature rise in the Caribbean, ca. 3.8–3.6 Ma, during the cold Marine Isotope Stage M2 when pronounced warming occurred, at ca. 2.7 Ma where possible weak cooling may reflect the onset of Northern Hemisphere glaciation, and in the Middle Pleistocene presumably reflecting global cooling and sea-level fall.

Hiatal surfaces from the Miocene Globigerina Limestone Formation of Malta: Biostratigraphy, sedimentology, trace fossils and early diagenesis

The Miocene Globigerina Limestone of the Maltese islands contains widespread omission surfaces with very different characteristics and origins. The terminal Lower Globigerina Limestone hardground (TLGLHg) formed during a period of falling sea level. Coccolith assemblages suggest shallowness. Sedimentary structures and trace fossil assemblages, indicate increasing frequency of storm events and erosional episodes, towards the surface. Calcite cementation which took place around Thalassinoides burrows and formed irregular nodules was followed by dissolution of aragonite. It is suggested that lithification was linked to microbial reactions involving organic matter. In contrast two later surfaces, the terminal Middle Globigerina Limestone omissionground (TMGLOg), which marks the Lower to Middle Miocene boundary, and the Fomm-ir-Rih local hardground (FiRLHg) both contain early diagenetic dolomite. Lithification took place in two phases. The dolomite is interpreted to have formed beneath the sea floor: it was subsequently exhumed and partially corroded as the precipitation of calcitic and phosphatic cements took place around burrows open to the circulation of sea water. (C) 2008 Elsevier B.V. All rights reserved.

Permophricodothyris pavlova, 1965 (Brachiopoda, Spiriferida) from the Permian of South China: its morphology, biostratigraphy and distribution

A study of both silicified and nonsilicified specimens of Permian reticularioid brachiopods from South China suggests that Permophricodothyris, a genus previously rarely reported from China, is actually very common and abundant in the Middle and especially Upper Permian of South China. This study also clarifies, for the first time, that many of the reticularioid brachiopod species previously described as Squamularia in fact belong to Permophricodothyris. The new data presented in this paper also allows a critical evaluation of Permophricodothyris in relation to its closest allies: Phricodothyris, Squamularia, Bullarina and Neophricodothyris. The revision reveals that a total of 18 Permophricodothyris species are present in the Middle and Upper Permian of South China, with only one species, P. squamularioides, having survived the Permian-Triassic mass extinction. Two species, P. grandis (Chao) and P. guangxiensis Han, Zhou & Wang, are redescribed here, providing critical new information on the morphology and taxonomy of these species.

An overview of Permian marine stratigraphy and biostratigraphy of Mongolia

This paper summarizes the spatial distribution, stratigraphical divisions and biostratigraphical zonation schemes of Permian marine deposits in Mongolia. Where appropriate, correlations of the various Permian marine biostratigraphical units with those of adjacent regions are also reviewed and discussed. In general, Permian marine sequences are developed in two separate basins: one in central and northeastern Mongolia where the Permian stratigraphy and marine faunas bear strong similarities with those of the Transbaikal, Verkhoyansk and Kolyma–Omolon regions of southern and eastern Russia; and the other in southeastern Mongolia where the Permian marine faunas and rock sequences are closest to those of northeast China and southern Primorye of Far East Russia.

Artinskian-Kungurian (Early Permian) brachiopod faunas from the Tarim Basin, Northwest China, part 1: biostratigraphy and systematics of productida

Cancrinella and Costatumulus (Brachiopoda) from the Permian of South Mongolia and South China : their morphology, biostratigraphy and distribution

Two brachiopod genera, Cancrinella Fredericks and Costatumulus Waterhouse, are studied from the Permian of South Mongolia and South China. Many of the specimens previously described as Cancrinella are revised and assigned to Costatumulus. The new data presented in this paper indicate that these two genera are similar to each other, but are distinguishable by different features in relation to their morphology. Several species of both genera are described here, providing critical new information on the morphology and taxonomy of Cancrinella and Costatumulus. The reported biostratigraphical information reveals that species of Cancrinella are present from the Lower Carboniferous (Tournaisian) to Middle Permian (Capitanian), whereas species of Costatumulus are mostly restricted to the Lower Permian (Sakmarian) to Upper Permian (Changhsingian). An analysis of the palaeogeographical distribution of Cancrinella and Costatumulus reveals that Cancrinella was more commonly distributed in the Northern Transitional Zone and the Boreal Realm, in contrast to Costatumulus, which tended to be more common in the Southern Transitional Zone and Gondwanan Realm.

Permian brachiopod faunas of southeastern Mongolia: systematics, biostratigraphy, palaeogeographical and palaeobiogeographical implications

This research systematically studied Permian brachiopod fossils from southeastern Mongolia and correlated them with many places around East Asia. The research found that the fossil faunas are on the mixed affinities between high-latitude cool- to cold-water and low-latitude warm water species. Explanations are provided through southeastern Mongolia’s unique palaeogeographical and palaeoceanographical position in the Permian time.

ESR dating of pleistocene mammal teeth and its implications for the biostratigraphy and geological evolution of the coastal plain, Rio Grande do Sul, southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)