Growth History of Sphalerite in a Modern Sea Floor Hydrothermal Chimney Revealed by Electron Backscattered Diffraction

2019 ◽  
Vol 114 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Si-Yu Hu ◽  
Stephen J. Barnes ◽  
A. Matthew Glenn ◽  
Anais Pagès ◽  
Joanna Parr ◽  
...  
Keyword(s):  
Electron Backscattered Diffraction ◽  
Sea Floor ◽  
Growth History ◽  
History Of

The formation of Congo River and the origin of bonobos: A new hypothesis

2018 ◽  
Author(s):  
Hiroyuki Takemoto ◽  
Yoshi Kawamoto ◽  
Takeshi Furuichi
Keyword(s):  
Nous Avons ◽  
Pan Paniscus ◽  
Congo Basin ◽  
Sea Floor ◽  
Terrestrial Mammals ◽  
Congo River ◽  
Il Y A ◽  
History Of ◽  
Area North ◽  
New Hypothesis

The Congo River functions as a strong geographical barrier for many terrestrial mammals in the Congo Basin, separating forest habitat into right and left banks of the river. However, there has been little discussion on the biogeography of the Congo Basin because the history of the river has been obscured. Based on the recent information of the sea-floor sediments near the mouth of the river and the geophysical survey on the continent, this chapter proposes a plausible hypothesis on the Congo River formation and presents a consequent hypothesis on the divergence of bonobos (Pan paniscus) from other Pan populations. The present hypothesis is also helpful for understanding the distribution of other primates and other mammals in the basin. Furthermore, this hypothesis suggests that all hominid clades, including human, chimpanzee and gorilla, except bonobo, evolved in the area north or east of the Congo River. La rivière du Congo a la fonction d’une barrière géographique forte pour plusieurs mammifères dans le bassin du Congo, séparant l’habitat forêt dans les banques gauches et droites de la rivière. Cependant, il y a eu peu de discussions sur la biogégraphie du bassin du Congo, parce que l’histoire de la rivière a été voilée. Récemment, quelque données importantes qui peuvent avoir des liens avec la formation de la rivière du Congo ont été acquise, surtout par la recherche des sédiments du fond marin près de la bouche de la rivière et par l’enquête géographique du continent. À partir de cette nouvelle information, nous avons proposé une hypothèse plausible sur la formation de la rivière du Congo. Nous avons aussi présenté une hypothèse conséquente sur la divergence des bonobos (Pan paniscus) des autres populations Pan (voire Takemoto et al., 2015 pour la publication originale de cette étude). L’hypothèse présente nous aide aussi à comprendre la distribution des autre primates et des autres mammifères dans le bassin. De plus, cette hypothèse suggère que tous les hominidés clades, humains inclus, chimpanzés et gorilla à l’exception du bonobo, ont évolué dans la régions du nord ou de l’est de la rivière du Congo.

scholarly journals Orbital Tumour: Thirty Years' Growth; History of Injury

BMJ ◽  
1896 ◽  
Vol 1 (1833) ◽  
pp. 397-397
Author(s):  
J. B. Ridley
Keyword(s):  
Orbital Tumour ◽  
Growth History ◽  
History Of

scholarly journals Schizocrania (Brachiopoda, Discinoidea): taxonomy, occurrence, ecology and history of the earliest epizoan lingulate brachiopod

2016 ◽  
Vol 72 (3-4) ◽  
pp. 225-238 ◽  
Author(s):  
Michal Mergl ◽  
Lucie Nolčová
Keyword(s):  
Trophic Structure ◽  
Ventral Valve ◽  
Dorsal Valve ◽  
Early Devonian ◽  
Sea Floor ◽  
Open Sea ◽  
History Of ◽  
Barrandian Area ◽  
Floating Objects ◽  
First Time

The lingulate brachiopod Schizocrania (Trematidae, Discinoidea) is reviewed. Ptychopeltis is definitively synonymized with Schizocrania, because new data indicate that convexity of the shell, profile of the anterior margin commissure, density of the dorsal valve costellation, ornamentation of the ventral valve and shape of the pedicle notch are worthless for separation of these genera. Four Ordovician species of Schizocrania are reported from the Barrandian area: S. multistriata (Darriwilian), S. hornyi (Sandbian), S. incola (Sandbian) and the new species S. equestra sp. nov. (Katian). Occurrence of Schizocrania striata is confirmed for the first time around the S/D boundary in the Barrandian area. Schizocrania has a wide geographic range with mid-Ordovician to early Devonian occurrences in Laurentia, Avalonia, West Gondwana and the Silurian occurrence in Baltica. Schizocrania was the earliest lingulate brachiopod adhering to floating objects in an open sea (both living cephalopods and their empty drifting shells), but it was highly opportunistic, and used any vacant hard surface on the sea floor (conulariids, strophomenid brachiopods, trilobites) as a suitable substrate for settlement of the larva. Decline of the genus coincided with disappearance of planktic graptolites, and might have been caused by competition of rapidly evolving planktic dacryoconarids, increased predation pressure, and rebuilding of the trophic structure in the early Devonian seas.

Examples of twinning and parallel growth in zircons from some Precambrian granites and gneisses

1974 ◽  
Vol 39 (305) ◽  
pp. 587-594 ◽  
Author(s):  
J. Jocelyn ◽  
R. T. Pidgeon
Keyword(s):  
Late Stage ◽  
Common Occurrence ◽  
Chemical Corrosion ◽  
Growth History ◽  
History Of ◽  
Growth Zones ◽  
The Common ◽  
Transverse Fractures ◽  
Parallel Growth

SummaryGrowth twins, parallel growths, and necked crystals are described from zircon populations from granitic gneisses from the Precambrian of SW. Greenland. From observations of the distribution of internal growth zones it is concluded that whereas twinning takes place early in the growth history of elbow twins it can occur at any time during crystallization of the zircon. Parallel growth is attributed to a process of synneusis or attachment of zircons that have initially undergone separate growth histories. This implies that viscosity conditions of the rocks were low enough to permit the movement and collision of growing zircon crystals. The common occurrence of zircons with central constrictions, sometimes superimposed on transverse fractures, in zircon suites from the granitic gneisses is explained in terms of late-stage chemical corrosion accompanied by brittle fracturing.

scholarly journals 8200‐year growth history of a Lahontan‐age lacustrine tufa deposit

Sedimentology ◽  
2019 ◽  
Vol 66 (6) ◽  
pp. 2169-2190 ◽  
Author(s):  
Laura M. Demott ◽  
Christopher A. Scholz ◽  
Christopher K. Junium
Keyword(s):  
Growth History ◽  
History Of

Introduction

1967 ◽  
Vol 252 (777) ◽  
pp. 169-171 ◽  
Keyword(s):  
Southern Ocean ◽  
Oceanic Islands ◽  
Sea Surface ◽  
Large Measure ◽  
Sea Floor ◽  
Nature Conservancy ◽  
Antarctic Ecosystem ◽  
History Of ◽  
Antarctic Continent ◽  
The Antarctic

Mr President, ladies and gentlemen: it is my pleasure, in opening this two-day conference on the terrestrial Antarctic ecosystem, to welcome you as contributors of papers and, as I shall hope, participants in the discussions with which we will conclude each of the four sessions of our meeting. This symposium was first suggested and has, in very large measure, been organized by Dr Martin Holdgate whom we regretfully, but nevertheless most warmly congratulate on his recent translation from the post of Senior Biologist of the British Antarctic Survey to that of Deputy Director of the Nature Conservancy. The furtherance of Antarctic biology in recent years owes much to Dr Holdgate’s energetic and imaginative direction, and I am glad to have this opportunity of acknowledging our indebtedness to him for arranging this discussion. The Antarctic continent, half as large again as Australia, and the surrounding Southern Ocean, in area about one-fifth of the world’s sea surface were, by their very remoteness from the maritime nations of the northern hemisphere, late of exploration. But, while it is little more than 75 years since man first set foot on the Antarctic continent, the more accessible waters of the Southern Ocean have an appreciably longer history of exploration, dating from the pioneering voyages of Captain Cook some 200 years ago. Biological investigations in Antarctica were, therefore, for long concerned almost entirely with observations and studies of animals living in the open ocean or on the sea floor rather than with the terrestrial and freshwater floras and faunas of the continental margin and oceanic islands which, either because of difficulties of access or limitations of time imposed by ships’ programmes, were rarely surveyed in detail.

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