Eocene nephelinite and basanite from the Fairway Ridge, North Zealandia

Mortimer, N.; Dadd, K.A.; O'Toole, Lena; Crundwell, MP; Seton, Maria; Williams, S.; Étienne, Samuel; Collot, Julien

doi:10.1016/j.dsr.2019.103101

Cited by 2 publications

(7 citation statements)

References 31 publications

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“…Five basaltic samples from the Fairway Ridge were dated by Ar‐Ar methods, in part to confirm and/or improve on the micropaleontological dating of the IN2016T01 DR1 and DR2 samples reported by Mortimer et al. (2019). The results of the dating of the samples from DR1 and DR2, and the best result of three dated samples from DR4 are shown in Figure 6 (see also Supplemental File 8 in Supporting Information S2).…”

Section: Resultsmentioning

confidence: 94%

“…The R/V Investigator 2016T01 voyage to the Fairway Ridge obtained Late Cretaceous pebbly to cobbly sandstones, bedded sandstones, carbonaceous mudstones, and 41-36 Ma Eocene intraplate lavas including a nephelinite (Mortimer et al, 2019;this study). The plutonic and volcanic cobbles and pebbles in the sandstone were eroded from an Early Cretaceous magmatic arc which is presumed to still lie close to the Fairway Ridge.…”

Section: Discussionmentioning

confidence: 94%

“…DR1 and DR2 were made on and near a 15 km diameter guyot‐like feature (Figure 2a). Post‐cruise work confirmed the guyot as an alkaline to nephelinitic intraplate volcano dated as Eocene by foraminifera in limestones (Mortimer et al., 2019). DR5 was made in the upper part of a submarine canyon incised into the NE side of Lansdowne Bank (Figure 2b); about 30 kg of rock was recovered comprising ∼95% varitextured limestones and ∼5% olive gray mudstone with minor sponge and coral fragments.…”

Section: Rock Samplesmentioning

confidence: 89%

“…Zircon grains in P85722A are all euhedral and there is a well-defined 111. For whole rock compositions of IN2016T1 DR1 and DR2 lavas see Mortimer et al (2019). Table 2 Continued age corrected for common Pb) based on 10 concordant analyses (Figure 5a).…”

Section: Fairway Ridgementioning

confidence: 99%

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Reconnaissance Basement Geology and Tectonics of North Zealandia

Mortimer,

Williams,

Seton

et al. 2023

Tectonics

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New rock dredge samples supply key information to establish the tectonic and geological framework of the northern two‐thirds of the 95% submerged Zealandia continent. The R/V Investigator voyage IN2016T01 to the Fairway Ridge, Coral Sea, obtained poorly sorted poly‐lithologic pebbly to cobbly sandstones, well sorted fine grained sandstones, mudstones, bioclastic limestones, and basaltic lavas. Post‐cruise analytical work comprised petrography, whole rock geochemical and Sr and Nd isotopic analyses, and U‐Pb zircon, Rb‐Sr, and Ar‐Ar geochronology. A Fairway Ridge cobbly sandstone has a ∼95 Ma (early Late Cretaceous) depositional age; two biotite granite cobbles are 111 ± 1 and 128 ± 1 Ma in age, and some volcanic pebbles are also likely Early Cretaceous. Fairway Ridge basalts have intraplate alkaline chemistry and are of Late Eocene age (∼40–36 Ma). By analogy with South Zealandia, we interpret strong positive continental magnetic anomalies of North Zealandia to mainly result from Late Cretaceous to Cenozoic intraplate basalts, many of them rift‐related lavas. A new basement geological map of North Zealandia shows the position of the Mesozoic Gondwana magmatic arc axis (Median Batholith) and other major geological units. This study completes onland and offshore reconnaissance geological mapping of the entire 5 Mkm2 Zealandia continent.

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Section: Resultsmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 94%

Section: Rock Samplesmentioning

confidence: 89%

Section: Fairway Ridgementioning

confidence: 99%

See 2 more Smart Citations

Reconnaissance Basement Geology and Tectonics of North Zealandia

Mortimer,

Williams,

Seton

et al. 2023

Tectonics

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show abstract

“…On the northern slope, canyons are narrower and associated with failure scars on the slope. On the eastern slope, tributary canyons are also present among which the deeply incised (up to 800 m), 3-4 km wide, sinuous Lansdowne Canyon is the most prominent (Williams et al, 2016;Mortimer et al, 2019;Fig. 1).…”

Section: Regional Settingsmentioning

confidence: 99%