Understanding ancient climate changes is hampered by the inability to disentangle trends in ocean temperature from trends in continental ice volume. We used carbonate "clumped" isotope paleothermometry to constrain ocean temperatures, and thereby estimate ice volumes, through the Late Ordovician-Early Silurian glaciation. We find tropical ocean temperatures of 32° to 37°C except for short-lived...

Ordovician trilobites are reviewed based on a new species-level relational database. The stratigraphical ranges of all 56 families with occurrences in the Ordovician are documented and the content, phylogenetic status, diversity and Ordovician distribution by major palaeocontinent/terrane are discussed. Aspects of higher classification are also dealt with. Global sampling is heavily biased towa...

Abstract Although much is known about the Ordovician tectonics of South European Variscides, aspects their geodynamic evolution and palaeogeographic reconstruction remain uncertain. In Sardinia, Variscan tectonic units include significant vestiges evolution, such as a fold system that affected only Cambrian–Lower successions, are cut by regional angular unconformity. A comparison stratigraphy s...

The oldest reported occurrence of cryptospores supposed to derive from land plants (embryophytes) is currently considered be in the Middle Ordovician. two genera Virgatasporites and Attritasporites, described 1960ʹs Early Ordovician (Tremadocian) Algeria, are morphologically close miospores, therefore pose a dilemma, because these spore-like microfossils recorded before first appearance plant d...

It has been hypothesized that predecessors of today's bryophytes significantly increased global chemical weathering in the Late Ordovician, thus reducing atmospheric CO2 concentration and contributing to climate cooling and an interval of glaciations. Studies that try to quantify the enhancement of weathering by non-vascular vegetation, however, are usually limited to small areas and low number...

In order to clarify the sedimentary development law under Cambrian Ordovician regional stratigraphic framework in Tadong area, and lay a theoretical foundation for further oil gas exploration study area. The distribution, characteristics evolution of main facies belts are studied by means drilling core observation, cast thin section identification, logging curve feature analysis, seismic profil...

Detrital zircon populations of the South Qiangtang terrane (SQT) provide vital information for reconstructing Tethyan evolution Tibetan Plateau but are obscured by undefined affiliation detrital samples and superimposition multiple tectonothermal events. We outlined SQT based on geological mapping collated Cambrian-Triassic to investigate representative populations. Although diachronous strata ...

A rise in atmospheric O(2) has been linked to the Cambrian explosion of life. For the plankton and animal radiation that began some 40 million yr later and continued through much of the Ordovician (Great Ordovician Biodiversification Event), the search for an environmental trigger(s) has remained elusive. Here we present a carbon and sulfur isotope mass balance model for the latest Cambrian tim...