By Victor A. Ramos, J. Duncan Keppie
Read or Download Laurentia-Gondwana connections before Pangea PDF
Similar geology books
Introducing Geology: A Guide to the World of Rocks
This introductory publication explains only what geology can let us know concerning the global. Many gadgets of significant good looks which excite our interest, similar to crystals or fossils, are to be chanced on by way of interpreting rocks. these looking for and studying such gadgets achieve even more by way of understanding how and after they originated.
Coastal Evolution: Late Quaternary Shoreline Morphodynamics
This booklet assesses how coastlines switch and the way they've got advanced over the last few thousand years. It introduces a few of the most modern recommendations in coastal morphodynamics, spotting that coasts advance via co-adjustment of procedure and shape. The authors research specific sorts of coasts--deltas, estuaries, reefs, lagoons and polar coasts--in aspect with conceptual versions built at the foundation of well-studied examples.
This quantity supplies an outline of the geotectonic evolution of the critical Andes. The contributions hide the complete spectrum of geoscientific learn: geology, petrology, geochemistry, geophysics and geomorphology. They take care of the interval from past due Precambrium as much as the youngest phenomena within the Quaternary.
- Petrology of the Sedimentary Rocks
- Orbital Forcing Timescales & Cyclostratigraphy. (Geological Society Special Publication Ser. No 85.)
- Perisphinctacean ammonites of the Late Jurassic in northern Switzerland. A versatile tool to investigate the sedimentary geology of an epicontinental sea
- Hydrogeology of an Arid Region: The Arabian Gulf and Adjoining Areas
Additional info for Laurentia-Gondwana connections before Pangea
Example text
The eastern belt consists mainly of carbonates and shallow marine clastics of shelfal and restricted environments, whereas the western tectofacies includes a thick wedge of slope to basin olistostromes, turbidites, and basinal black shales, the latter interbedded with mafic lava flows (some pillowed) and intruded by basic dikes. The overall western belt succession is affected by a very low-grade regional metamorphism. Figure 1. Location map showing basins and geologic regions mentioned in the text.
Among the latter, one of the most important is the type of larval development. At the end of the larval stage, the success of settling in a new area depends on the availability of a niche to colonize, the absence of competitors, and an adequate substrate-level environment. Influence of such factors depends, in turn, on the opportunistic or highly selective character of the species. Abiotic factors include direction and velocity of marine currents, water salinity, oxygenation, and temperature. Some planktotrophic larvae can survive several weeks before settlement.
Several additional factors could have been important to sponge dispersal, such as flotation of colonies and rafting. Biogeographic distribution of present-day sponges shows remarkable differences between interoceanic populations (Wilkinson, 1987). During the Ordovician, some genera were widespread while others are endemic or have more restricted distribution. Sponges have been considered as a very conservative group (long stratigraphic ranges of genera and families), which implies slow but persistent migration rates and, conversely, low rates of speciation.