Results 101 to 110 of about 92,675 (274)

Hydroclimatic development from the Early Holocene to anthropogenic times: a comparative study of diatom oxygen isotope records and multiproxy data from Lake Khamra, eastern Siberia

open access: yesBoreas, EarlyView.
Northern Eurasia underwent major hydroclimatic changes since the beginning of the Holocene interglacial. A rapid warming period reaching the Holocene Thermal Maximum (HTM), followed by a general cooling trend until recent times, was observed in Eurasian lacustrine diatom oxygen isotope (δ18Odiatom) records.
Amelie Stieg   +6 more
wiley   +1 more source

Reservoir space characterization of vuggy carbonate reservoirs with multiple scales: a case study of Ma 5-7 interval, Middle Ordovician Majiagou Formation, Daniudi area, Ordos Basin

open access: yesShiyou shiyan dizhi, 2021
The reservoir space of carbonate rocks is of multiple scales and genesis mechanisms, and it is difficult to accurately demonstrate the reservoir space as well as physical properties.Millimeter-, micro- and nano-scale reservoir spaces were all developed ...
Xiaoqi DING   +4 more
doaj   +1 more source

Tropical weathering of the Taconic orogeny as a driver for Ordovician cooling

open access: yes, 2017
Author(s): Swanson-Hysell, NL; Macdonald, FA | Abstract: © 2017 Geological Society of America. The Earth's climate cooled through the Ordovician Period leading up to the Hirnantian glaciation.
N. Swanson‐Hysell, F. Macdonald
semanticscholar   +1 more source

The evolution of reproduction in Ediacaran–Cambrian metazoans

open access: yesBiological Reviews, EarlyView.
ABSTRACT The evolution of reproductive style is a fundamental aspect of metazoan life history but has not been explored holistically through the Ediacaran–Cambrian rise of metazoans. Recent molecular clock analyses based on only unequivocal metazoan fossil calibrations suggest that Porifera were present by at least 590 million years ago (Ma), all major
Rachel A. Wood, Mary L. Droser
wiley   +1 more source

Middle Ordovician conodonts and graptolites at Los Cauquenes range, central Precordillera of San Juan, Argentina [PDF]

open access: yes, 2013
The Ordovician System is superbly represented in the Precordillera of western Argentina, at the Andean foothills. During the Middle Ordovician, an important paleogeographical rearrangement of depocenters and source areas took place associated with the ...
Albanesi, Guillermo Luis   +2 more
core  

Re‐make, re‐model: evolution and development of vertebrate cranial lateral lines

open access: yesBiological Reviews, EarlyView.
ABSTRACT Lateral lines are placodally derived mechanosensory systems on the heads and trunks of many aquatic vertebrates. There is evidence of lateral lines in the earliest known vertebrate fossils, and they exist in organisms with widely different craniofacial morphologies – including the presence or absence of jaws, external or internal nostrils, and
Vishruth Venkataraman   +3 more
wiley   +1 more source

Lungfish‐like antero‐labial tooth addition and amphibian‐like enameloid‐enamel transition in the coronoid of a Devonian stem actinopterygian

open access: yesJournal of Anatomy, EarlyView.
The tooth patterning logic, which cannot be inferred from surface morphology, is revealed by visualizing buried tooth remnants in 3D. The primary teeth are added labially, initially organized in radial rows, which transition into linear rows where the coronoid becomes slender.
Donglei Chen
wiley   +1 more source

Microtextures and structures in metal–sulfide grains in NWA 869 meteorite and their relation to thermal history of L‐chondrite parent body

open access: yesMeteoritics &Planetary Science, Volume 60, Issue 3, Page 616-631, March 2025.
Abstract Results of microanalysis study of NWA 869 meteorite, an ordinary chondrite, where silicates, Fe‐Ni alloys, and troilite are major constituents, are reported. The presented study of microtextures in metallic and sulfide grains provides information on processes occurring from the asteroid's accretion, through the impacts until cooling.
Paulina Skirak   +4 more
wiley   +1 more source

Selective sampling of asteroids, the Moon, and Mars: Factors affecting the numerical abundances of members of meteorite groups

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Meteorite collection inventories show that many related meteorite groups have very different numerical abundances (e.g., lunar versus Martian meteorites; Eagle Station pallasites versus main‐group pallasites; eucrites versus diogenites; ungrouped Antarctic irons versus ungrouped non‐Antarctic irons; carbonaceous chondrite‐related (CC) iron ...
Alan E. Rubin
wiley   +1 more source

Tectonic overview of the West Gondwana margin [PDF]

open access: yes, 2008
The oceanic southern margin of Gondwana, from southern South America through South Africa, West Antarctica, New Zealand (in its pre break-up position), and Victoria Land to Eastern Australia is one of the longest and longest-lived active continental ...
Pankhurst, Robert J., Vaughan, Alan P.M.
core   +1 more source

Home - About - Disclaimer - Privacy