FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W3046579520> ?p ?o ?g. }

• W3046579520 endingPage "330" @default.
• W3046579520 startingPage "297" @default.
• W3046579520 abstract "Abstract New field mapping has discovered numerous sections of pillow lavas with hyaloclastites at the lowest levels of Jurassic Karoo volcanic sequences across Lesotho and South Africa. Vesicularity (content and size) and geochemistry of the ca. 1 to 50 m thick pillow lavas sequences presently preserved at 1 670 to 2 150 m asl reveal they originated below 500 m of water. Most of the initial 87Sr/86Sr ratios of the pillow lavas scatter around ca. 0.708, which is also the value of Jurassic seawater. There is an increase in the δ18O values concomitantly with increasing alteration, a well-known feature at low-temperature when marine basalts alter to high-δ18O bearing minerals, such as clays and zeolites, stripping 18O by mass balance from seawater. This feature, combined with element behavior of the most altered samples, as well as the Sr-isotope signatures, suggest that the Karoo pillow lavas and hyaloclastites most likely altered under low-temperature conditions in seawater. Geochemistry of the major oxides and trace elements of the Karoo pillow lavas reveal they define tholeiitic basalt with minor basaltic andesite. The pillow lavas define Th/Yb-ratios well above the mantle array indicating derivation from subduction-related components, and their Ti-V relations are similar to mid-oceanic ridge basalt (MORB). The Nd-Sr isotope data for the pillow lavas indicate that the primary magma assimilated ca. 10 to 15% of continental crust. This is consistent with knowledge from mapping that sills and dykes cover close to 50% of the surface geology surrounding the sub-horizontal pillow lava sequences, and from drill-cores that these dolerites reached a minimum crustal depth of ca. 6 km below Jurassic sea level. The Karoo pillow lavas erupted between 186 and 184 Ma in relatively deep seawater of a possible rift system linked to fragmented continental lithosphere surrounded by ocean spreading domains, such as at the open-end of the East African rift across the Afar. By 183 Ma, Karoo volcanics extruded above sea level and after 182 Ma the pillow lavas were uplifted by at least 1 700 m. Thereafter, during farther up warping across the Karoo Large Igneous Province (KLIP), lavas across Lesotho reached heights over 3 500 masl by 140 Ma, and then eroded to their near present heights around 120 to 100 Ma as determined through a number of thermo-chronology and offshore sedimentation analyses. Thus, unlike the volcanics of the Ethiopian LIP, which erupted across continental crust at 2 000 masl ca. 30 to 40 million years prior to extensional tectonism across the Afar triple junction, KLIP reached its highest topography ca. 30 to 40 Myrs after early initiation across a triple junction system well-below sea level. This difference in timing between crustal extension and epeirogeny has implications for geodynamic and geochemical models that trace dispersal across southern Gondwana between Africa and Antarctica." @default.
• W3046579520 created "2020-08-07" @default.
• W3046579520 creator A5037506417 @default.
• W3046579520 creator A5047150342 @default.
• W3046579520 creator A5062071090 @default.
• W3046579520 creator A5084016293 @default.
• W3046579520 creator A5084944585 @default.
• W3046579520 date "2020-09-01" @default.
• W3046579520 modified "2023-09-27" @default.
• W3046579520 title "Pillow Talk: Volcanic rocks of the Karoo that formed many leagues under the Gondwanan Sea" @default.
• W3046579520 cites W1026197542 @default.
• W3046579520 cites W1170954735 @default.
• W3046579520 cites W1801625845 @default.
• W3046579520 cites W1966934203 @default.
• W3046579520 cites W1970621880 @default.
• W3046579520 cites W1971807450 @default.
• W3046579520 cites W1972365683 @default.
• W3046579520 cites W1973615484 @default.
• W3046579520 cites W1976296871 @default.
• W3046579520 cites W1976620802 @default.
• W3046579520 cites W1978626644 @default.
• W3046579520 cites W1979331501 @default.
• W3046579520 cites W1980406234 @default.
• W3046579520 cites W1982133550 @default.
• W3046579520 cites W1988283630 @default.
• W3046579520 cites W1992736932 @default.
• W3046579520 cites W1993604248 @default.
• W3046579520 cites W1994723472 @default.
• W3046579520 cites W1997682393 @default.
• W3046579520 cites W1997937484 @default.
• W3046579520 cites W2000043936 @default.
• W3046579520 cites W2002019823 @default.
• W3046579520 cites W2003134995 @default.
• W3046579520 cites W2003493304 @default.
• W3046579520 cites W2006211097 @default.
• W3046579520 cites W2006949523 @default.
• W3046579520 cites W2007985002 @default.
• W3046579520 cites W2008350311 @default.
• W3046579520 cites W2010964930 @default.
• W3046579520 cites W2014934612 @default.
• W3046579520 cites W2017377455 @default.
• W3046579520 cites W2017962985 @default.
• W3046579520 cites W2021987309 @default.
• W3046579520 cites W2022552529 @default.
• W3046579520 cites W2022648729 @default.
• W3046579520 cites W2022685764 @default.
• W3046579520 cites W2022948847 @default.
• W3046579520 cites W2024548894 @default.
• W3046579520 cites W2029123591 @default.
• W3046579520 cites W2031186381 @default.
• W3046579520 cites W2033401826 @default.
• W3046579520 cites W2034563996 @default.
• W3046579520 cites W2038814991 @default.
• W3046579520 cites W2039440103 @default.
• W3046579520 cites W2039977514 @default.
• W3046579520 cites W2040305185 @default.
• W3046579520 cites W2040533112 @default.
• W3046579520 cites W2042340633 @default.
• W3046579520 cites W2048935793 @default.
• W3046579520 cites W2050385280 @default.
• W3046579520 cites W2050693654 @default.
• W3046579520 cites W2050817609 @default.
• W3046579520 cites W2051081564 @default.
• W3046579520 cites W2051977240 @default.
• W3046579520 cites W2052917047 @default.
• W3046579520 cites W2054933791 @default.
• W3046579520 cites W2055366343 @default.
• W3046579520 cites W2058312375 @default.
• W3046579520 cites W2059896729 @default.
• W3046579520 cites W2060152348 @default.
• W3046579520 cites W2062346847 @default.
• W3046579520 cites W2063129071 @default.
• W3046579520 cites W2066304428 @default.
• W3046579520 cites W2067527529 @default.
• W3046579520 cites W2069908908 @default.
• W3046579520 cites W2070666153 @default.
• W3046579520 cites W2071548211 @default.
• W3046579520 cites W2071549314 @default.
• W3046579520 cites W2071573714 @default.
• W3046579520 cites W2074129682 @default.
• W3046579520 cites W2074195785 @default.
• W3046579520 cites W2074260736 @default.
• W3046579520 cites W2075083532 @default.
• W3046579520 cites W2077028241 @default.
• W3046579520 cites W2077454732 @default.
• W3046579520 cites W2078010553 @default.
• W3046579520 cites W2078132125 @default.
• W3046579520 cites W2078395190 @default.
• W3046579520 cites W2078768397 @default.
• W3046579520 cites W2080094776 @default.
• W3046579520 cites W2081518814 @default.
• W3046579520 cites W2083583609 @default.
• W3046579520 cites W2085456872 @default.
• W3046579520 cites W2088860686 @default.
• W3046579520 cites W2090012521 @default.
• W3046579520 cites W2091118293 @default.
• W3046579520 cites W2092382739 @default.
• W3046579520 cites W2094718201 @default.

• next