basaltic rocks nmorb

  • ALEX STREKEISEN-Basalt-

    Mid-ocean ridge basalts (MORB) have long been classified into at least two different geochemical types, so-called "N-MORB" (normal) and "E-MORB" (enriched MORB). in the early literature the enriched MORB were usually called "plume-ridge" or "P-MORB".

  • The mean composition of ocean ridge basalts

    Trace element patterns of the E-MORB, N-MORB, and D-MORB (enriched, normal, and depleted MORB) compositions reported in this study, compared with earlier estimates. The E-MORB pattern is characterized by a strong enrichment in the highly incompatible elements and a depletion in the middle to heavy REE, crossing over the REE patterns of the N- and D-MORB.

  • THE TRIASSIC CONTINENTAL BASALTIC ROCKS FROM NORTH DOBROGEA, ROMANIA – AN EXAMPLE OF WPB TO MORB TRANSITIONAL MAGMATIC ROCKS*

    The Triassic continental basaltic rocks from North Dobrogea 65 finally resulted in the Carpathian ophiolitic suture (Savu18).During the Early Kimmerian movements the North Dobrogea aulacogen underwent a compression process. Therefore, it was crushed between

  • Geochemistry of the Neoarchaean Volcanic Rocks of the …

    The intermediate volcanic rocks have a wide range of SiO 2 contents (52.51–66.80 wt%) spanning from basaltic andesites through basaltic trachyandesites and andesites to dacites. The compositions, however, are skewed to the basaltic andesitic compositions as indicated by the averages (SiO 2 = 52.51–66.80 wt%, average = 55.67 wt%,, Table 1, Figures 5 and 6 ), and only 5 samples have SiO 2 ...

  • Rift-zone magmatism: Petrology of basaltic rocks …

    Compositions of basaltic samples from the southeastern Brazil passive margin (18°–24° S) depict the change from continental to oceanic lithosphere during the opening of the South Atlantic Ocean. Samples studied range from 138 to 105 m.y. old and are from 12 Petrobrás drill cores recovered from the coastline to about 150 km offshore in the Espirito Santo, Campos, and Santos basins ...

  • 10. PETROLOGY, GEOCHEMISTRY, AND MINERALOGY OF THE EARLY CRETACEOUS EVOLVED N-MORB …

    The Early Cretaceous basaltic rocks obtained from Sites 765 and 766 in the eastern Indian Ocean floor were mostly iron-rich normal mid-ocean ridge basalts (N-MORB), which were derived from a depleted mantle source having strongly light rare earth element

  • Rift-zone magmatism: Petrology of basaltic rocks …

    Abstract. Compositions of basaltic samples from the southeastern Brazil passive margin (18°–24° S) depict the change from continental to oceanic lithosphere during the opening of the South Atlantic Ocean. Samples studied range from 138 to 105 m.y. old and are from 12 Petrobrás drill cores recovered from the coastline to about 150 km offshore in the ...

  • Compositional heterogeneity of Archean mantle estimated …

     · These rocks have similar lithostratigraphies to modern oceanic plates, from basaltic lava through pelagic sedimentary rocks to terrigenous sedimentary rocks. The basaltic rocks were, therefore, classified into MORB-type and OIB-type rocks based on their geological occurrence (Komiya et al., 2002a, Komiya et al., 2004).

  • 49. A PB, SR, AND ND ISOTOPIC STUDY OF BASALTIC ROCKS …

    In this paper, we present the results of a high-precision isotopic study of backarc basaltic rocks from the Sea of Japan, drilled during Ocean Drilling Program (ODP) Legs 127 and 128 (Fig. 1), and examine the implications of these rocks for the composition of the mantle beneath the Sea of Japan. The goals of Legs 127/128 in the Sea of Japan were ...

  • geochemistry

     · A wide variety of rocks occur in these islands, not all are basaltic, but all appear to be related to upper mantle melts. One may find tholeiites, alkaline basalts, Hawaiites, trachytes and rhyolites in an OIB environment which span the compositional spectrum of …

  • Geochemistry of Cenozoic basaltic rocks from Jiashan County, …

    and N-MORB. The patterns of basaltic rocks of this study are similar to those of OIB. The negative heavy REE (Yb and Lu) anomalies in the basaltic rocks studied may be attributed to the presence of garnet peridotite in the upper mantle which can hold Fig. 4

  • ALEX STREKEISEN-Basalt-

    OIB Ocean island basalts or OIBs are basaltic rocks found on many volcanic islands away from tectonic plate boundaries typically associated with hot spots. Islands hosting ocean island basalts always lie above the oceanic crust and are not limited to volcanic islands but occur also on volcanoes of …

  • Basalt

    Basalt (pron.: / b ə ˈ s ɔː l t /, / ˈ b æ s ɒ l t /, / ˈ b æ s ɔː l t /, or / ˈ b eɪ s ɔː l t /) is a common extrusive igneous (volcanic) rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. By definition, basalt must be an aphanitic igneous rock with less than 20% quartz and less than 10% feldspathoid by volume, and where ...

  • Basalt Rock | History | Origin

    Information about Basalt Rocks are naturally occurring solids which are composed of minerals & have been used by humans since ages. From Stone Age, rocks are used for various purposes. Also, the metals and minerals found in rock play an important role in our ...

  • Petrology of the basaltic rocks of the Nankai Trough …

    Stratigraphy, petrography, and geochemistry of the basaltic rocks recovered at Site 808 appear very similar to those from the Shikoku Basin basement, analogously identified as normal MORB. -from Authors Original language English Pages (from-to) 197-207 11 ...

  • NITROGEN CONCENTRATIONS AND ISOTOPIC COMPOSITIONS OF ALTERED TERRESTRIAL GLASSY BASALTIC ROCKS…

    basaltic rocks are not common, but ca. 2.7 Ga proto-glassy lavas altered to greenschist-facies exhibit similar enrichments in N content and δ15N air relative to MORB. Whole-rock analyses of both putative ichnofossil-bearing and non-ichnofossil-bearing samplesN

  • Chapter 13: Mid-Ocean Rifts

    9 Layer 2 is basaltic Subdivided into two sub-layers Layer 2A & B = pillow basalts Layer 2C = vertical sheeted dikes Oceanic Crust and Upper Mantle Structure Figure 13-4. Modified after Brown and Mussett (1993) The Inaccessible Earth: An Integrated View of Its

  • High-Ti type N-MORB parentage of basalts from the south Andaman …

    High-Ti type N-MORB parentage of basalts from the south Andaman ophiolite suite, India Rajesh K Srivastava1∗, R Chandra2, Anant Shastry1 1Igneous Petrology Laboratory, Department of Geology, Banaras Hindu University, Varanasi 221 005, India. 2Department of Geology, Bundelkhand University, Jhansi 284 128, India. ...

  • Basaltic & Gabbroic Rocks

    Basalts (MORBs). In some areas, particularly Iceland, where there has been a large outpouring of basalts on the oceanic ridge, basalts called Enriched Mid Ocean Ridge Basalts (EMORBs) have been erupted. Oceanic Islands - these are islands in the ocean basins that generally occur away from

  • Geochemical discriminant diagrams

    Rock classification Barker, 1979 An-Ab-Or diagram for tonalite, trondhmemite, granodiorite, granite. Ewart, 1982 SiO 2 vs. K 2 O for volcanic rocks. LeBas et al., 1986 SiO 2 vs. Na 2 O+K 2 O for volcanic rocks. Streckeisen, 1967 Q - Af - Pf diagram for

  • Geology Science: Study of Earth Science, Rocks and …

    Basalt is the most common rock on Earth''s surface. Specimens are black in color and weather to dark green or brown. Basalt is rich in iron and magnesium and is mainly composed of olivine, pyroxene, and plagioclase. Most specimens are compact, fine-grained, and glassy. They can also be porphyritic, with phenocrysts of olivine, augite, or ...

  • The Rare Earth Elements (REE)

    2 Contrasts and similarities in the D values: All are incompatible Table 9-1.Partition Coefficients for some commonly used trace elements in basaltic and andesitic rocks Olivine Opx Cpx Garnet Plag Amph Rb 0.006 0.02 0.04 0.001 0.1 0.3 Sr 0.01 0.01 0.14 0.001 1

  • Petrology, geochemistry, and mineralogy of the early …

    The Early Cretaceous basaltic rocks obtained from Sites 765 and 766 in the eastern Indian Ocean floor were mostly iron-rich normal mid-ocean ridge basalts (N-MORB) which were derived from a depleted mantle source having strongly light rare earth element ...

  • Iron isotopes constrain the pathways and formation …

    For example, Fe in the Mars system was probably mobilized through dissolution of primary silicates in basaltic rocks by acidic solutions (e.g., Morris et al., 2005). If this Fe mobilization occurred under reducing conditions, where aqueous Fe was largely Fe(II), no Fe isotope fractionation would be expected because no redox change would occur.

  • Basalt

    Basalt - Igneous rocks - Sandatlas

  • Mid-Ocean Ridge Basalts (MORB), Oceanic Crust and …

    1- Oceanic crust and ophiolites. The oceanic crust (made of basalts) is formed on mid-ocean ridges. MORB = Mid-Ocean Ridge Basalt. This is the main site of volcanic activity on Earth, and the most abundant igneous rock! But most of it is underwater….

  • Difference Between Basalt and Granite | Difference …

     · Difference Between Basalt and Granite What is Basalt? Basalt is an igneous, mafic, and volcanic rock which is produced by lava flows in many different volcano types. It contains mainly volcanic glass, pyroxene and plagioclase feldspar and is fine-grained. Basalt is ...

  • Learning Geology: Basalt

     · Basaltic tuff or pyroclastic rocks are rare but not unknown. Usually basalt is too hot and fluid to build up sufficient pressure to form explosive lava eruptions but occasionally this will happen by trapping of the lava within the volcanic throat and buildup of volcanic gases.

  • Basalt

     · In this study, we present a neural network-based model that uses whole rock major and trace elements to discriminate basaltic rocks (SiO 2 45–55 wt%) from a wide range of tectonic settings, including continental arc basalt (CAB), island arc basalt (IAB), intra

  • Geochemical, Sr–Nd–Pb and zircon U–Pb–Hf isotopic …

    However, the studied basaltic rocks are characterized by high field strength element depletions relative to LILEs with negative Nb, Ta, Ti, Zr and Hf anomalies in the N-MORB-normalized multi-element plots (Fig. 9b) in comparison with the N-MORB-derivedet al.

  • In Situ Geochemical Compositions of the Minerals in …

    The igneous rocks in the Huatung Basin are basalts and gabbros, with E-MORB trace element signatures and Indian MORB Sr, Nd, and Hf isotopic signatures []. The igneous rocks of the Kyushu-Palau Ridge are tholeiitic, and they have the geochemical characteristics of oceanic arc tholeiites (Haraguchi et al. 2011).

  • A Tectono-magmatic correlation of basaltic rocks from …

    Ophiolite mélanges of Mts. Kalnik and Ivanščica form the northern sector of the Kalnik Unit and represent the northeasternmost surface tip of Sava-Vardar Suture Zone. Petrological, geochemical and isotopic characteristics of extrusive rock blocks incorporated in the mélanges, particularly of pillow basalts altered to spilite in association with radiolarian cherts, allow the rocks to be ...

  • Geochemistry of Cenozoic basaltic rocks from Jiashan County, Anhui Province, China: Implications for petrogenesis and tectonic …

    E-MORB and primitive mantle data are from Sun and McDonough (1989)[14]. Fig. 4 shows the chondrite-normalized REE patterns of basaltic rocks in the present study as compared with the patterns of the OIB, E-MORB and N-MORB. The patterns of basaltic

  • The following summary of the geology of basalts is …

    As a rule of thumb, the rocks become more basaltic with increasing crustal extension. Because the East African Rift is the best present day example, we shall use it as a case study to illustrate the character of magmatism associated with continental extension.

  • Mid-Ocean Ridge Basalts (MORB), Oceanic Crust and …

    1- Oceanic crust and ophiolites The oceanic crust (made of basalts) is formed on mid-ocean ridges. MORB = Mid-Ocean Ridge Basalt. This is the main site of volcanic activity on Earth, and the most abundant igneous rock!

  • Multi-layer perceptron-based tectonic discrimination of …

     · In this contribution, the tectonic settings that may produce basaltic rocks are classified following Frisch (2010) with some modifications. A two-level classification system is applied: at the first level, three major tectonic regimes (termed as major settings here) are defined according to the plate motions: arc (convergent plate margins), spreading (divergent), and within-plate.

  • Scoria vs Basalt

    Scoria is available in black, brown, dark grey to black, red colors whereas, Basalt is available in black, brown, light to dark grey colors. Appearance of Scoria is Glassy and Vesicular and that of Basalt is Dull and Soft. Properties of rock is another aspect for Scoria vs Basalt. The hardness of Scoria is 5-6 and that of Basalt is 6.

  • Basalt Rock | History | Origin

    1.1 Definition. Basalt is a common extrusive igneous rock formed by the rapid cooling of basaltic lava exposed at or very near the surface of Earth. 1.2 History. 1.2.1 Origin.

  • NITROGEN CONCENTRATIONS AND ISOTOPIC COMPOSITIONS OF ALTERED TERRESTRIAL GLASSY BASALTIC ROCKS…

    Ancient N contents and isotopic compositions: Nitrogen isotope analyses of ancient altered basaltic rocks are not common, but ca. 2.7 Ga proto-glassy lavas altered to greenschist-facies exhibit similar enrichments in N content and δ15N air relative to MORB. relative to MORB.

  • 15. Petrology of Associated Igneous Rocks

    15–3.verage major element composition of basaltic rocks associated with A volcanogenic massive sulfide deposits ... NMORB (normal), TMORB (transi-tional), and EMORB (enriched) depending principally on their K/Ti ratios and incompatible elementsites of ...

  • Geochemical discriminant diagrams

    SiO 2 vs. K 2 O for volcanic rocks. LeBas et al., 1986 SiO 2 vs. Na 2 O+K 2 O for volcanic rocks. Streckeisen, 1967 Q - Af - Pf diagram for classification of felsic and intermediate plutonic rocks. Winchester and Floyd, 1977 Immobile trace 2

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