Article
Geosciences, Multidisciplinary
Sandra M. Barr, Chris E. White, Teodoro Palacios, Soren Jensen, Deanne van Rooyen, James L. Crowley
Summary: This study provides firm constraints on the age of the MacCodrum Formation and enables more precise correlation with sections in southern New Brunswick and eastern Newfoundland through radiometric dating and biostratigraphy.
CANADIAN JOURNAL OF EARTH SCIENCES
(2022)
Article
Engineering, Marine
Jose C. Ferreira, Renato Monteiro, Lia Vasconcelos, Claudio M. Duarte, Filipa Ferreira, Euclides Santos
Summary: The study found that local island fishing communities in Cape Verde are highly aware of the marine litter problem, attributing it to the lack of proper waste management system and inappropriate behaviors of the population. They identified equipment damages and the presence of plastic inside the fish as the main impacts. This highlights the importance of public engagement and environmental education in promoting marine ecosystem conservation.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
Ed Landing, Stephen R. Westrop, Gerd Geyer
Summary: The Avalonia microcontinent in the Ediacaran-Ordovician period underwent significant geological changes, including lithostratigraphy, depositional sequences, and igneous activities. This was caused by the movement of the Avalonian transform fault. During the Cambrian period, Avalonia experienced a color change in both platform and off-platform areas, indicating the onset of a long period (approximately 26 million years) of shallow-marine anoxia and strong dysoxia. The green-black transition in Avalonia highlights its unity and similarities to the Baltica region in terms of paleoenvironments.
CANADIAN JOURNAL OF EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Ed Landing, Stephen R. Westrop, Gerd Geyer
Summary: The Avalonia microcontinent has distinct lithostratigraphy, depositional sequence architecture, and igneous activity that extend for 2000+ km, reflecting tectonic movement related to the Avalonian transform fault. A sudden change in sediment color from green, purple, or light grey to black, dark grey, and brown in platform and off-platform areas marks the beginning of shallow-marine anoxia/strong dysoxia that lasts for approximately 26 million years. The green-black transition highlights the unity of Avalonia and suggests comparable paleoenvironments with Baltica in the later Cambrian period.
CANADIAN JOURNAL OF EARTH SCIENCES
(2023)
Article
Geosciences, Multidisciplinary
Wenpeng Xia, Anqing Chen, Karem Azmy, Shi Sun, Ruixuan Li, Shenglin Xu, Qian Li, Yixin Dong
Summary: The SPICE (Steptoean Positive Carbon Isotope Excursion) is a significant event in the Late Cambrian, recording global carbon cycle perturbations. Its driving mechanism is still controversial, but mainly believed to be related to an increase of organic carbon burial caused by ocean anoxia. Geochemical proxies from the Upper Cambrian Loushanguan Formation indicate an expansion of anoxic seawater to shallow-water areas, resulting in increased nutrient inputs and enhanced primary productivity. The occurrence of the PGMEE (Paibian global marine euxinia event) suggests it was the onset-driving mechanism of the SPICE event, intensifying carbon burial and acting as a superimposed effect.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geography, Physical
M. Gabriela Mangano, Beatriz G. Waisfeld, Luis A. Buatois, N. Emilio Vaccari, Diego F. Munoz
Summary: Estuarine deposits in Argentina contain fossils that help understand the early colonization of marginal-marine environments and the effects of evolutionary and environmental factors.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Deanne van Rooyen, Sandra M. Barr, Chris E. White, James L. Crowley
Summary: The Bras d'Or terrane in Nova Scotia, Canada, provides a well-preserved record of the Ganderian evolution during the Ediacaran to early Cambrian period. The detrital zircon signatures of the metasedimentary rocks support the correlation between the low- and high-grade rocks in the Bras d'Or terrane and the Ganderian Brookville terrane in New Brunswick. The presence of Neoproterozoic zircon rims in the samples indicates the age of peak metamorphism and the related subduction-related magmatism in the region.
CANADIAN JOURNAL OF EARTH SCIENCES
(2023)
Article
Energy & Fuels
Minghui Li, Mingliang Li, Haiping Huang, Lei Gong, Debao Zheng
Summary: Lower Cambrian shale and lower Silurian shale have different thermal maturities, resulting in different pore features. Lower Silurian shale has larger pore volume and surface area, and the formation of organic matter-hosted pores affects the pore characteristics. Rigid particles, clay flakes, and organic matter coexist in shale matrix, enabling the preservation of pores.
Article
Geosciences, Multidisciplinary
Deanne van Rooyen, Sandra M. Barr, Chris E. White, James L. Crowley
Summary: The Bras d'Or terrane in Canada contains a well-preserved record of the evolution of Ganderia during the Ediacaran to early Cambrian. Laser ablation inductively coupled plasma mass spectrometry U-Pb zircon dating was used to determine the ages of the metasedimentary rocks in the terrane. The results support correlation of the low- and high-grade metasedimentary rocks throughout the Bras d'Or terrane and the corresponding Ganderian Brookville terrane. The metamorphism in the Bras d'Or terrane occurred at ca. 550 Ma, coinciding with the emplacement of dioritic to granitic plutons.
CANADIAN JOURNAL OF EARTH SCIENCES
(2023)
Article
Geosciences, Multidisciplinary
Yanan Miao, Fan Zhang, Shuai Wang, Fan Wu, Xin Li
Summary: This study investigated the pore characteristics between Lower Cambrian and Lower Silurian shale. The results showed that the Lower Silurian shale had superior pore characteristics, with higher pore volume, pore surface area, and pore diameter. It was also found that organic matter played a dominant role in pore development in marine shale. The study further revealed that the amount of organic matter-hosted pores peaked at 2.8% Ro and was not monotonously increased with increasing thermal maturity.
FRONTIERS IN EARTH SCIENCE
(2022)
Editorial Material
Geosciences, Multidisciplinary
Ed Landing, Gerd Geyer
Summary: The Appalachian-Caledonian orogen reveals the Avalonian terrane, which stretches from the northeast coast of North America to southern Britain and Belgium. However, the inclusion of the Mira belt in Avalonia is effectively blocked by the confusion caused by locally-defined lithostratigraphic names. Earlier revisions of Mira belt stratigraphy allow precise assignment of its location within the Avalonian strike-slip regime. The Mira belt is a tectonic inlier rather than a terrane in the Appalachian-Caledonian orogen.
CANADIAN JOURNAL OF EARTH SCIENCES
(2023)
Article
Paleontology
Ed Landing, Gerd Geyer
Summary: The Nigali Dhar syncline succession in the north Indian margin reveals the deposition, fauna, and passive margin evolution from the Terminal Ediacaran to late early Cambrian. The study of ichnofauna in the Upper Tal Group provides insight into paleoenvironmental changes and biological evolution, contributing to the understanding of Lesser Himalaya geologic evolution. The KDF-type ichnofaunas do not support a tropical location of Avalonia, highlighting its unique lithofacies and biotas as a high-latitude continent unrelated to Gondwana.
ICHNOS-AN INTERNATIONAL JOURNAL FOR PLANT AND ANIMAL TRACES
(2021)