IMPLICATIONS FOR LOWER JURASSIC ISLAND ARC MAGMATISM FROM IGNEOUS CLASTS IN THE LOWER CRETACEOUS CONGLOMERATE, NE YUKON-KOYUKUK BASIN, ALASKA

2019 ◽  
Author(s):  
Victoria Pease ◽  
◽  
Charlotte Fredriksson
Keyword(s):  
Lower Cretaceous ◽  
Lower Jurassic ◽  
Island Arc ◽  
Arc Magmatism

MIDDLE JURASSIC-EARLY CRETACEOUS (166-140 MA) ISLAND ARC MAGMATISM OF NW MEXICO: EVIDENCE FROM THE META-IGNEOUS ROCKS OF THE SIERRA EL ARCO AND COEVAL MAGMATIC ROCKS IN BAJA CALIFORNIA

2020 ◽  
Author(s):  
Manuel Contreras-lópez ◽  
◽  
Luis Alberto Delgado-Argote ◽  
Bodo Weber ◽  
Xochitl G. Torres-Carrillo ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Middle Jurassic ◽  
Baja California ◽  
Island Arc ◽  
Igneous Rocks ◽  
Arc Magmatism ◽  
Magmatic Rocks ◽  
Nw Mexico

scholarly journals Mesozoic micropalaeontology of exploration well Elf 55/30–1 from the Fasnet Basin, offshore southwest Ireland

1986 ◽  
Vol 5 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Nigel R. Ainsworth ◽  
Nicola F. Horton
Keyword(s):  
Lower Cretaceous ◽  
Lower Jurassic ◽  
Late Triassic ◽  
Ecological Distribution ◽  
Exploration Well

Abstract. The geology, biostratigraphy and palaeoecology of exploration well Elf 55/30–1 in the Fastnet Basin are summarised. The biostratigraphical and ecological distribution of the foraminifera and Ostracoda from the late Triassic, the Lower Jurassic and the Lower Cretaceous are reviewed with reference to microfaunas elsewhere in Europe. Selected microfossil taxa are illustrated.

Petrogenesis of the meta-igneous rocks of the Sierra El Arco and coeval magmatic rocks in Baja California: Middle Jurassic-Early Cretaceous (166-140 Ma) island arc magmatism of NW México

2020 ◽  
pp. 1-28
Author(s):  
Manuel Contreras-López ◽  
Luis Alberto Delgado-Argote ◽  
Bodo Weber ◽  
Xóchitl Guadalupe Torres-Carrillo ◽  
Dirk Frei ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Middle Jurassic ◽  
Baja California ◽  
Island Arc ◽  
Igneous Rocks ◽  
Arc Magmatism ◽  
Magmatic Rocks ◽  
Nw Mexico

The mantle source of island arc magmatism during early subduction: Evidence from Hf isotopes in rutile from the Jijal Complex (Kohistan arc, Pakistan)

Lithos ◽  
2018 ◽  
Vol 308-309 ◽  
pp. 262-277 ◽  
Author(s):  
Tanya A. Ewing ◽  
Othmar Müntener
Keyword(s):  
Mantle Source ◽  
Island Arc ◽  
Hf Isotopes ◽  
Arc Magmatism

scholarly journals Geochemistry of an Alaskan-type mafic-ultramafic complex in Eastern Desert, Egypt: New insights and constraints on the Neoproterozoic island arc magmatism

2019 ◽  
Vol 10 (3) ◽  
pp. 941-955 ◽  
Author(s):  
Shehta E. Abdallah ◽  
Shehata Ali ◽  
Mohamed A. Obeid
Keyword(s):  
Eastern Desert ◽  
Island Arc ◽  
Arc Magmatism ◽  
Ultramafic Complex

Mesozoic palaeogeography and tectono-stratigraphic features of the northern Amerini Mts. (Central Apennines, Italy): new constraints on their Jurassic and Cretaceous evolution

2020 ◽  
Author(s):  
Costantino Zuccari ◽  
Angelo Cipriani ◽  
Massimo Santantonio
Keyword(s):  
Early Cretaceous ◽  
Lower Cretaceous ◽  
Carbonate Platform ◽  
Indirect Evidence ◽  
Lower Jurassic ◽  
Geological Mapping ◽  
Carbonate Platforms ◽  
Central Apennines ◽  
Sedimentary Evolution ◽  
Structural High

<p>A geological mapping project was performed on the 1:10,000 scale in the northern Amerini Mts. (Narni–Amelia Ridge, Central Apennines), coupled with facies analysis and multidisciplinary outcrop characterisation. This project was focused on the Jurassic-Lower Cretaceous succession, in order to reconstruct the Mesozoic palaeogeography and tectono-sedimentary evolution of the study area. This sector of the Apenninic Chain (i.e. Umbria-Marche-Sabina palaeogeographic domain) experienced the Early Jurassic rifting phase, which dismembered the vast Calcare Massiccio carbonate platform. The development of a rugged submarine topography, coupled with drowning of the benthic factories, were the main effects of this normal faulting. The complex submarine physiography, made of structural highs and lows, is highlighted by facies and thickness variations of the Jurassic and Lower Cretaceous deposits. The hangingwall blocks hosted thick (hundreds of metres) pelagic successions, with variable volumes of admixed gravity-flow deposits. These successions onlapped the horst blocks along escarpments, rooted in the rift faults, where the pre-rift Calcare Massiccio was exposed. The tops of footwall blocks (Pelagic Carbonate Platforms or PCPs) were capped by thin (few tens of metres or less), fossil-rich and chert-free, condensed pelagic successions. This rift architecture was evened out at a domain scale in the Early Cretaceous. Successively, Miocene orogenic and Plio-Pleistocene extensional faulting caused uplift and exhumation of the Mesozoic rocks.</p><p>In the study area, geothematic mapping associated with the analysis of basin-margin unconformities and successions revealed a narrow and elongated Jurassic structural high (Mt. Croce di Serra - Mt. Alsicci structural high), surrounded by Jurassic basinal pelagites. The PCP-top condensed succession is not preserved. The chert-rich basinal units rest on the horst-block Calcare Massiccio through unconformity surfaces (palaeoescarpments), as marked by the silicification of the (otherwise chert-free) shallow-water limestone. The onlap successions embed megablocks of Calcare Massiccio (hundreds of metres across), detached from their parent palaeoescarpments. Very thin, condensed deposits form discontinuous veneers on the olistoliths of Calcare Massiccio (epi-olistolith deposits) and are onlapped by younger basin-fill pelagites. The beds surrounding the olistoliths are characteristically bent due to differential compaction, as their (newly acquired) strikes mimic the outline of the stiff objects they were burying.</p><p>Indirect evidence for a Toarcian, post-rift, tectonic pulse can be locally mapped, and is documented by angular unconformities between the Pliensbachian and Toarcian pelagites, as well as by mass-transport deposits found in the Rosso Ammonitico (Toarcian).</p><p>The same goes for millimetric to centimetric neptunian dykes made of Maiolica pelagites cross-cutting the Corniola Fm. (Sinemurian-Pliensbachian). These dykes, coupled with the occurrence of unconformities between Aptian-Albian pelagites (Marne a Fucoidi Fm.) and Lower Jurassic rocks (Calcare Massiccio and Corniola formations), provide evidence for a further Early Cretaceous tectonic phase, recently reported from the southern sectors of Narni-Amelia ridge.</p>

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