Results 51 to 60 of about 29,296 (274)
THE NEOPROTEROZOIC ISLAND-ARC ASSOCIATION OF THE MUKODEK GOLD-ORE FIELD, NORTHERN BAIKAL AREA
Геодинамика и тектонофизика, 2015 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
The Unexpected Discovery of Paleocene? Coals in Outcrops Thought to Be Cambrian, Al Huqf, Oman
Journal of Petroleum Geology, EarlyView.ABSTRACT Two brown organic deposits were encountered whilst investigating kaolinitic claystones thought to occur at the base of a Cambrian formation at outcrop. The age of these organic deposits is probably Paleocene from palynology. Organic petrography shows that they are subbituminous coals with some oil source potential.
Mohammed H. Al Kindi +4 more
wiley +1 more source
Fossil Preservation in the Neoproterozoic Doushantuo Phosphorite Lagerstatte, South China
, 1999 Phosphorites of the late Neoproterozoic Doushantuo Formation exposed in the vicinity of Weng'an, Guizhou Province, and Chadian, Shaanxi Province, South China, contain exceptionally well-preserved algal thalli, acritarchs, and globular microfossils ...
Knoll, Andrew, Xiao, Shuhai
core +1 more source
Confirming the impact origin of the São Miguel do Tapuio structure, northeastern Brazil
Meteoritics &Planetary Science, EarlyView.Abstract The São Miguel do Tapuio structure (SMT) is a remarkable, nearcircular feature of about 21 km diameter, centered at 5°37.6′ S, 41°23.3′ W in Piauí state, northeastern Brazil. The structure is located within the sedimentary strata of the Paleozoic–Mesozoic Parnaíba Basin and predominantly comprises sandstones of the Devonian Pimenteiras and ...
Alvaro Penteado Crósta +9 more
wiley +1 more source
Magnetic properties of geraisites, the first tektite strewn field identified in Brazil
Meteoritics &Planetary Science, EarlyView.Abstract Geraisites are a newly recognized class of tektite from Brazil. They occur as centimeter‐sized, elongated to subspherical bodies scattered across surface gravel and shallow subsurface layers within a ~90‐km‐long strewn field extending between the municipalities of São João do Paraíso and Curral de Dentro, near the border between the states of ...
Melissa De Andrade Nunes +7 more
wiley +1 more source
Dizhi lixue xuebaoObjective 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
The Enigma of Neoproterozoic Giant Ooids—Fingerprints of Extreme Climate?
Geophysical Research Letters, 2020 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]
پترولوژی, 2018 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
Frontiers in Earth Science, 2022 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
Current Biology, 2019 Life was microbial for the majority of Earth's history, but as very few microbial lineages leave a fossil record, the Precambrian evolution of life remains shrouded in mystery.
D. Lahr +10 more
semanticscholar +1 more source