Late Cretaceous igneous activity in the Delgo uplift (Northern Province, Sudan)

Vran Kamak paleovolcano is formed during the Upper Cretaceous igneous activity along the Panagyurishte strip of Central Srednogorie Zone, Bulgaria, part of the magmatic-metalogenic arc belt Apuseni-Banat-Timok-Srednogorie. It represents a comparatively well-preserved, eroded stratovolcano built of epiclastics, pyroclastics and lava flow (with typical hyaloclastite and peperite formation) succession surrounded by marine environment, as only a part from the volcanic cone was over the sea level. The central (conduit) parts of the paleovolcano are intruded by a volcanic neck in the area of Vran Kamak summit. The volcanic activity was accompanied by sedimentary gravity flows and volcaniclastic debris is dispersed in the Late Cretaceous basin. The present study provides new petrological and geochronological data for Vran Kamak paleovolcano.The analyzed samples from the lava flows show basaltic andesite to andesite composition with SiO2 contents ranging from 51 to 55.5 wt %, while the volcanic neck of the Vran Kamak summit is trachydacite (SiO2 of 61.54 wt % ). The rocks are medium- to high-K calc-alkaline. On a primitive-mantle normalized diagram, the rocks show peaks in LILE (U, Th, Pb) and troughs in Nb, Ta, Ti and P. Weak negative Eu anomaly (0.83&#8211;0.94) and LaN/YbN (10 to 13) are observed. Fractionation of mafic minerals (amphibole and pyroxene) and plagioclase is visible on the harker diagrams. The 87Sr/86Sr(i) ratio of 0.705141 from the volcanic neck shows small degree of crustal assimilation.The basaltic andesite to andesite lava flows are built of plagioclase (with normal oscillatory zoning, bytownite-labrador, An88-56), amphibole (tschermakite to magnesiohastingsite) and pyroxenes (mostly augite and rare small enstatite crystals embedded in them). Some of the clinopyroxenes form corona texture around the amphibole, showing processes of dewatering. The trachydacite neck is built of porphyries of plagioclase, sanidine, biotite, amphibole (megnesiohornblende to thermakite), magmatically coroded quartz and accessories of zircon, apatite and magnetite set in a fine-grained groundmass. The calculated depths of crystallization and temperatures of the hornblende from the lava flows are 17&#8211;22 km and 930&#8211;970 oC and that from the neck are 5.9&#8211;7 km and 800&#8211;830 oC, that give evidence for a complex volcano-plutonic system.An attempt for LA-ICPMS U-Pb zircon dating of one the lava flows is made, but it contains only xenocrysts which fall in several age intervals: 306&#8211;314 Ma, 440&#8211;450 Ma, 520&#8211;530 Ma, 560&#8211;614 Ma, 810&#8211;830 Ma which represent inherited and recycled component from the local basement. This lava flow has a peperitic contact with sediments faunistically dated at the Turonian/Coniacian boundary (Cremnoceramus deformis erectus, Vangelov et al., 2019). The zircon population of the trachydacite neck is presented mostly by own magmatic grown crystals giving a Concordia age of 91.12 &#177;0.43 Ma.&#160;Acknowledgements. The study is supported by grant DN 04/9 funded by the National Science Fund, Ministry of Education and Science, Bulgaria.&#160;References:Vangelov, D., Gerdjikov, I., Dochev, D., Dotseva, Z., Velev, S., Dinev, Y., Trayanova, D., Dancheva, J. 2019. Upper Cretaceous lithostratigraphy of the Panagyurishte strip (Central Bulgaria) &#8211; part of the Late Cretaceous Apuseni-Banat-Timok-Srednogorie magmatic belt. &#8211; Geol Balc., 48, 3, 11&#8211;33.&#160;

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Rb-Sr whole rock isochron ages of granites from northern Shikoku and Okayama, Southwest Japan: Implications for the migration of the Late Cretaceous to Paleogene igneous activity in space and time.

GEOCHEMICAL JOURNAL ◽

10.2343/geochemj.22.69 ◽

1988 ◽

Vol 22 (2) ◽

pp. 69-79 ◽

Cited By ~ 34

Author(s):

Hiroo Kagami ◽

Hiroji Honma ◽

Teruo Shirahase ◽

Terukazu Nureki

Keyword(s):

Late Cretaceous ◽

Southwest Japan ◽

Space And Time ◽

Igneous Activity

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Paleogeographie, orogenese, metamorphisme et magmatisme des zones internes des Hellenides en Macedoine (Grece); vue d'ensemble

BSGF - Earth Sciences Bulletin ◽

10.2113/gssgfbull.s7-viii.7.1020 ◽

1966 ◽

Vol S7-VIII (7) ◽

pp. 1020-1049 ◽

Cited By ~ 12

Author(s):

Jacques Mercier

Keyword(s):

Early Cretaceous ◽

Late Cretaceous ◽

Middle Eocene ◽

Upper Jurassic ◽

Upper Eocene ◽

Vertical Movements ◽

Lower Oligocene ◽

Upper Paleozoic ◽

Igneous Activity ◽

Two Phases

Abstract Since the end of major Hercynian disturbances in the upper Paleozoic, the inner Hellenide zones, including the Peonia and Almopia troughs and the Paikon and Pelagonian ridges, have been affected by several periods of complex orogenic activity among which were four phases of tangential movements: Portlandian or terminal early Cretaceous, terminal Cretaceous to lower-middle Eocene, latest Priabonian, and post-lower Oligocene. Vertical movements took place before the last tangential phases, during Kimmeridgian-Portlandian and Turonian-Campanian time. Since the Hercynian and pre-Hercynian periods of metamorphism the inner Hellenides have been affected by dynamic metamorphism of post-Jurassic-pre-Albian-Aptian and post-Maestrichtian-pre-lower Oligocene age; post-middle-upper Eocene dynamic metamorphism had localized effects near structural contacts. Igneous activity associated with the metamorphism and orogenic movements was initially (Jurassic) ophiolitic; two phases of synorogenic (upper Jurassic-early Cretaceous and late Cretaceous to lower-middle Eocene) granitic activity followed and were in turn succeeded by three phases of postorogenic (Plio-Quaternary) andesitic, granitic-granodioritic, and basaltic activity.

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Basaltic Lavas of South Kivu, Belgian Congo

Geological Magazine ◽

10.1017/s0016756800070473 ◽

1940 ◽

Vol 77 (2) ◽

pp. 89-101 ◽

Cited By ~ 13

Author(s):

Arthur Holmes

Keyword(s):

Late Cretaceous ◽

Southern Africa ◽

Olivine Basalt ◽

The Other ◽

Early Tertiary ◽

Lake Kivu ◽

The World ◽

Igneous Activity ◽

Belgian Congo ◽

Basaltic Lavas

In a recent memoir (Holmes and Harwood, 1937, p. 276) I had occasion to point out that “one of the most remarkable features of the igneous activity of late Cretaceous and early Tertiary times is the geochemical and petrological contrast between the kimberlite and olivine-melilitite which perforated the crust of Southern Africa and the widespread outpourings of olivine-basalt and basalt (often followed by acid rocks) in many other parts of the world”. An essentially similar contrast is found in the more recent and more localized volcanic fields of the Western Rift of Africa. The Toro-Ankole fields of multiple vents, east and south-east of Ruwenzori, are characterized throughout by undersaturated potassic types, free from felspar; whereas in the great lava fields south of Lake Kivu the dominant lavas are olivine-basalts of various types. Between these two strongly contrasted provinces, and in some respects sharing the characters of each, the Birunga field (including Bufumbira) extends across the Rift north of Lake Kivu. Although many of the lavas of this field contain abundant plagioclase and look like basalts, they have been found, with few exceptions, to be potassic types ranging from leucite-basanites to basanitoid trachybasalts. True basalts appear to be absent (Holmes and Harwood, 1937, pp. 16–18), the nearest approach to basalt—geographically as well as petrographically—being certain trachybasalts and limburgites from the south of the field, which differ from the other rocks of Birunga in having more soda than potash.

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The Timing of Late Cretaceous Alkalic Igneous Activity in the Northern Gulf of Mexico Basin, Southeastern Usa

The Journal of Geology ◽

10.1086/515966 ◽

1997 ◽

Vol 105 (5) ◽

pp. 629-644 ◽

Cited By ~ 15

Author(s):

Ajoy K. Baksi

Keyword(s):

Gulf Of Mexico ◽

Late Cretaceous ◽

Southeastern Usa ◽

Northern Gulf Of Mexico ◽

Igneous Activity ◽

Gulf Of Mexico Basin ◽

Mexico Basin

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Metallogeny of the Zahedan-Nehbandan magmatic belt and implications to porphyry Cu exploration in southeastern Iran

10.5194/egusphere-egu21-249 ◽

2021 ◽

Author(s):

Majid Soleymani ◽

Shojaeddin Niroomand ◽

Abdorrahman Rajabi ◽

Thomas Monecke ◽

Soroush Modabberi

Keyword(s):

Late Cretaceous ◽

Igneous Rocks ◽

Geochemical Composition ◽

Porphyry Deposits ◽

Epithermal Deposits ◽

Porphyry Cu ◽

Continental Block ◽

Igneous Activity ◽

Volcaniclastic Rocks ◽

Alluvial Terraces

The Late Cretaceous to Eocene Sistan suture zone in southeastern Iran separates the Lut continental block in the west from the Afghan continental block in the east. A major belt of Oligocene to Miocene igneous rocks occurs between the cities of Zahedan and Nehbandan, stretching for ~200 km from south to north parallel to the border with Pakistan and Afghanistan. Known porphyry Cu mineralization is associated with the intrusions and intrusive complexes at Kuh-e Janja (16.5+2.0 Ma), Kuh-e Seyasteragi (19.2+ 1.4 Ma), Kuh-e Assagie (27.5+2.0 Ma), and Kuh-e Lar (32.8+3.0 Ma).Small intrusions and intrusive complexes in the Zahedan-Nehbandan magmatic belt are mostly intermediate to felsic in composition and have calc-alkaline or shoshonitic affinities. Associated volcanic and volcaniclastic rocks are common. The igneous rocks are hosted by deformed late Cretaceous to Eocene flysch sequences that formed in the Sefidabeh forearc basin developed during the subduction and closure of the Sistan ocean. The geochemical composition of the intrusive rocks and their ages suggest that igneous activity and related mineralization in the Zahedan-Nehbandan magmatic belt may have formed as a result of post-collisional processes. The locations of the intrusive centers in the Kuh-e Assagie and Kuh-e Lar may be controlled by strike-slip faults, which are major post-collisional structures.The recent discovery of the Janja porphyry Cu-Au-Mo deposit below Quaternary alluvial terraces highlights the exploration potential of the Zahedan-Nehbandan magmatic belt. In addition to post-collisional porphyry deposits, other deposit types such as skarns, polymetallic veins, or epithermal deposits may be hidden below the regionally extensive Quaternary cover.

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Late Cretaceous to Paleogene sand provenance, deposition and tectonomagmatic development in the southern Møre Basin, Norway

10.5194/egusphere-egu2020-8117 ◽

2020 ◽

Author(s):

Hans Jørgen Kjøll ◽

Ivar Midtkandal ◽

Sverre Planke

Keyword(s):

Late Cretaceous ◽

Field Work ◽

Ne Atlantic ◽

Source To Sink ◽

Igneous Activity ◽

History Of ◽

Chemical History ◽

Early Breakup ◽

Sand Provenance ◽

Increased Activity

Upper Cretaceous and Paleocene sandstone strata represent promising reservoirs along the NE Atlantic margins, including new discoveries in recent years that has spurred increased activity in the area. Exploration and seismic imaging is complicated by massive Paleocene magmatism related to late rifting and early breakup, forming voluminous sill and dyke complexes hosted in the sedimentary succession and extrusive complexes, such as volcanic edifices and lava flows along the margin. Such igneous activity may have played an important role in the thermal and chemical history of reservoir zones. Their diagenetic properties as well as their physical appearance is expected to have been altered by the intrusions, breaking predictive trends otherwise common for deep-marine sedimentary strata. A new understanding of the nature and implication of igneous processes and deposition of sediments, combined with new understanding of sand source-to-sink systems in the region, is thus important to better evaluate the prospectivity of the southern M&#248;re Basin. The focus of this project will therefore be to asses sand provenance and depositional systems in basins in this area by incorporating on shore field work with integrated borehole and seismic studies. The main goal is to develop a new understanding of deposition of sand fairways during the Late Cretaceous and Paleogene to better understand this part of the break-up history of the NE Atlantic.

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