Petrology and geochemistry of Easter Island

  title={Petrology and geochemistry of Easter Island},
  author={Peter E. Baker and F. Buckley and James Grenville Holland},
  journal={Contributions to Mineralogy and Petrology},
Easter Island has developed around three volcanoes—Poike, an older (3 m.y.) strato-volcano, Rano Kau, a caldera, and the fissure complex of Terevaka and its associated cones. The lavas show a wide compositional spread from tholeiites and olivine tholeiites to hawaiites, mugearites, benmoreites, trachytes and rhyolites (comendites). Hawaiite is by far the most abundant rock type and trachytes and rhyolites are relatively rare. Intermediate and acid rocks are concentrated in the southwestern part… 
A geochemical and petrological study of the Tertiary minor intrusions of Rhum, northwest Scotland
The Rhum minor intrusion suite is petrographically and compositionally variable, the majority of the basic rocks are aphyric dolerites but olivine phyric (picritic) and plagioclase phyric (big
Geochemistry of volcanic rocks from the Tetagouche Group, Bathurst, New Brunswick, Canada
The volcanic rocks of the Tetagouche Group are predominantly dacitic to rhyolitic pyroclastics and lavas; mafic alkaline and tholeiitic volcanic rocks are less abundant. Lavas representing the
Chronology, chemistry, and origin of trachytes from Hualalai Volcano, Hawaii
Hualalai Volcano is unique among Hawaiian volcanoes in that it possesses a relatively high proportion of evolved, trachytic lavas that were erupted at the beginning of the alkalic, postshield phase
Late-orogenic alkaline/subalkaline Silurian volcanism of the Skomer Volcanic Group in the Caledonides of south Wales
Basaltic, andesitic and rhyolitic volcanism was widespread during Ordovician time in the Welsh, Basin. Minor Silurian volcanic rocks occur in the Welsh Borderland and in Pembrokeshire (Dyfed), where
Evolution of the Southwestern Edge of the Poike Volcano, Easter Island
Figure I, Location of the three studied profiles (A, B and C) and rock sample points RN67 and RN83 •• DEAD'· ESCARPMENT _ New K-Ar data Radiometric ages of rocks coming from all over Easter Island
Geochemical evolution of the Juan Fernandez Islands, SE Pacific
The two main islands of the Juan Fernandez group, some 180 km apart are intra-plate volcanoes related to a single hot spot. K-Ar determinations suggest an age difference of c. 3 Ma which is in accord
The Petrogenetic Evolution of Lavas from Easter Island and Neighbouring Seamounts, Near-ridge Hotspot Volcanoes in the SE Pacific
but also the volcanism of non-plume near-ridge seamounts at the Major and trace element, mineralogical and petrographical data are East Pacific Rise. We suggest that the development of each magmatic
Volcanology and eruptive styles of Barren Island: an active mafic stratovolcano in the Andaman Sea, NE Indian Ocean
Barren Island (India) is a relatively little studied, little known active volcano in the Andaman Sea, and the northernmost active volcano of the great Indonesian arc. The volcano is built of
Easter Island, SE Pacific: An end-member type of hotspot volcanism
Easter Island (Rapa Nui, Chile) is an intraoceanic volcanic island on the Easter hotspot, ~350 km E of the Eastern Pacific Rise. We match new field data with previously published age and
Igneous And Metamorphic Petrology Of The Iberian Pyrite Belt Volcanic Rocks
The late Devonian-lower Carboniferous submarine vol— ~ J ■ canic rocks of the Tberian Pyrite Belt have been studied todetermine the origin of magmas, the mC^amorphic processes involved ’in their


Aspects of Magmatic Evolution on Reunion Island
The chemical data indicate a considerable degree of coherence between the various rock types produced during the different stages of development, and it is concluded that they all stem from essentially the same hypersthene-normative, picritic, primitive magma, generated by partial melting of peridotite in the low-velocity layer of the upper mantle.
Petrochemical variations among mildly peralkaline (comendite) obsidians from the oceans and continents
Eleven new analyses and modes of comendite obsidians are presented, and compared with all available data on similar rocks. Most specimens are aphyric or contain only sparse phenocrysts, most commonly
Chemical Characteristics of Oceanic Basalts and the Upper Mantle
Tholeiitic basalts (oceanic tholeiites) that form most of the deeply submerged volcanic features in the oceans are characterized by extremely low amounts of Ba, K, P, Pb, Sr, Th, U, and Zr as well as
Hudson Geotraverse: Geology of the Mid-Atlantic Ridge at 45 degrees N
A strip across the Crest Mountains and High-Fractured Plateau of the Mid-Atlantic Ridge has been surveyed systematically between latitudes 45 and 46° N. Continuous bathymetric, magnetic and
Geology and petrology of Easter Island
INTRODUCTION Of the many volumes on the archeologic problems of Easter Island, only two[1][1] deal with the geology even in a fragmentary manner. Other brief discussions are incomplete. Verlain[2][2]
Genetic Relations of Oceanic Basalts as Indicated by Lead Isotopes
The isotopic composition of lead in oceanic tholeiite suggests that the upper mantle source region of the tholeuite was differentiated from and original mantle material more than 1 billion years ago and that theupper mantle is not homogeneous at the present time.
Islands of the South Atlantic
Since Darwin’s observations during the voyage of the Beagle (1831–1836), the islands of the South Atlantic have figured prominently in the geologic exploration of the ocean basins. The small number
Isotopic Composition of Lead and Strontium from Ascension and Gough Islands
The inter-island differences indicate the existence of regional variations in the uranium-lead and rubidium-strontium ratios of the upper mantle source of these rocks and show that isotope compositions are a means for investigating chemical heterogeneities in the mantle.
Major element variations in ocean-floor basalts
  • J. Cann
  • Geology
    Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
  • 1971
Although ocean-floor basalts form a very convergent group from the point of view of their major element compositions, the variation that they do show can be interpreted in geological terms to a