Results 61 to 70 of about 12,768 (231)
Meteoritics &Planetary Science, EarlyView.Abstract The majority of planetary impacts occur at oblique angles. Impact structures on Earth are commonly eroded or buried, rendering the identification of the direction and angle of impact—using methods such as asymmetries in ejecta distribution, surface topographic expression, central uplift structure, and geophysical anomalies—challenging. In this
Eloise E. Matthews +5 more
wiley +1 more source
Frontiers in Earth ScienceThe type-Silurian Cellon section in the Carnic Alps in Austria underpins much of the current Silurian conodont zonations, forming the basis for the Silurian timescale.
Michiel Arts +5 more
doaj +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
Geophysical investigation of the Santa Marta impact structure—Piauí State, Brazil
Meteoritics &Planetary Science, EarlyView.Abstract The Santa Marta impact structure in northeastern Brazil, recognized as a partially preserved complex crater, was investigated through an integrated geophysical study employing magnetotelluric (MT) and gravity methods. Our research provides constraints on the crater's subsurface architecture.
Elienara Vasconcelos +5 more
wiley +1 more source
Novel evidence for the youngest Naraoia and a reassessment of naraoiid paleobiogeography [PDF]
Fossil RecordNaraoiids are nektaspidid arthropods that display two exoskeletal shields, typically lack thoracic tergites, and have an exceptional Cambrian diversity. Despite their predominantly Cambrian fossil record, Naraoia species have been documented in deposits ...
Russell D. C. Bicknell +3 more
doaj +3 more sources
Terrane evolution of the paratectonic Caledonides of northern Britain [PDF]
, 2001 A stratigraphically constrained re-evaluation of terrane amalgamation in the Caledonides of northern Britain allows the development of a new orogenic scenario which accounts for many of the outstanding problems in the paratectonic Caledonides and ...
H. A. ARMSTRONG +5 more
core +1 more source
From subduction to collision in the northern Tibetan plateau : evidence from the early Silurian clastic rocks, northwestern China [PDF]
, 2012 The Qilian Orogen records early Paleozoic collisional suturing of the Qaidam Block and the Central Qilian Block to the North China Craton. The composition and U-Pb age of detrital zircons and the composition of Cr-spinels from the Early Silurian ...
Jianghai Yang +7 more
core +1 more source
, 1997 Since its designation as the Global Stratotype Section and Point (GSSP) for the base of the Silurian System, the choice of Dob's Linn, Southern Scotland, has received criticism due to the difficulties of relating its well constrained graptolite ...
Marshall, J.D. +10 more
core +1 more source
Highly tectonized Silurian and Lower Devonian sediments at Funtanamare (SW Sardinia) [PDF]
, 2009 A very few trilobites have been found during the preparation of this stop.
CORRIGA M. G. +7 more
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