Results 51 to 60 of about 34,869 (280)
Abstract We investigated the structural framework of the north–northwestern Paraná Basin in Brazil to test whether the pre‐impact structures in this region may have had any influence on the first‐order formation and morphostructure of the Araguainha impact structure (AIS).
Renato B. Bernardes +5 more
wiley +1 more source
THE NEOPROTEROZOIC ISLAND-ARC ASSOCIATION OF THE MUKODEK GOLD-ORE FIELD, NORTHERN BAIKAL AREA
Metamorphosed volcanic rocks of the Ushmukan suite were studied in the Mukodek gold-ore field located in the Baikal-Muya belt in the Northern Baikal area, Russia. The Ushmukan suite shows interleaving of ortoschists which compositions are widely variable.
V. A. Vanin +2 more
doaj +1 more source
Revisiting the Hummeln structure, Sweden—A shallow marine Cambrian impact structure
Abstract Hummeln is a simple impact structure located in south‐eastern Sweden. It is approximately 1.2 km in diameter and almost completely covered by a lake. Here, we present the first detailed investigation of impactites and mapping of the 164.25 m deep drill core Hummeln‐1 with a focus on impact metamorphism and the impact process.
S. Alwmark +8 more
wiley +1 more source
Weathered residual Kaolin deposits on the northern margin of the Qinzhou-Hangzhou Suture Zone are characterized by more feldspar-containing minerals and fewer dark minerals.
Chunhai Li +8 more
doaj +1 more source
Photosynthetic primary production in the Mesoproterozoic
Summary The Mesoproterozoic atmosphere had more CO2 and less O2 than at present. While the upper ocean was oxygenated, the deeper ocean was euxinic or ferruginous. Primary production was performed by Chlorobia, Cyanobacteria, Proteobacteria, and Archaeplastida.
Patricia Sánchez‐Baracaldo +1 more
wiley +1 more source
The Enigma of Neoproterozoic Giant Ooids—Fingerprints of Extreme Climate?
Geologists have documented at least 14 occurrences of “giant ooids,” a geologically rare type of carbonate allochem, in Neoproterozoic successions at low paleolatitudes.
Elizabeth J. Trower
doaj +1 more source
Geochronology and Lu-Hf isotope of mafic-intermediate rocks from SW Salmas: implication for Neoproterozoic juvenile melts [PDF]
The southwest Salmas metamorphosed mafic-intermediate intrusive rocks are located in Sanandaj-Sirjan zone in NW of Iran. The metamorphosed intrusives rocks comprise metagabbro and metadiorite that intruded the Precambrian metamorphosed volcanic ...
Fahime kozekoulani +2 more
doaj +1 more source
Tellurium, selenium and cobalt enrichment in Neoproterozoic black shales, Gwna Group, UK : Deep marine trace element enrichment during the Second Great Oxygenation Event [PDF]
We are grateful to John Still for his skilled technical support and the ACEMAC facility at the University of Aberdeen. Research funded by NERC grant NE/M010953/1 and NERC facility grant IP-1631-0516. AJB is funded by NERC support of the Isotope Community
Armstrong, Joseph +5 more
core +2 more sources
ABSTRACT The c. 1 Ga Diabaig Formation of north‐west Scotland preserves diverse lacustrine and fluvial facies and abundant microbial and non‐microbial surficial sedimentary features. 172.6 m of section was logged across seven localities to assess the distribution of microbially induced sedimentary structures (MISS) relative to lithofacies, substrate ...
Seán T. Herron +2 more
wiley +1 more source
Objective The Changjiaoba Group, located in the Foping area of the South Qinling Belt, is one of the few poorly-studied strata in the belt. The lack of an accurate composition and formation age of these strata has restricted research on the tectonic ...
LIU Zhihui +4 more
doaj +1 more source

