Michel Helen V Asaro Frank Alvarez Walter 1991 Abunance of Iridium and other elements from ODP Hole 121-752B (Table 1) dataset https://doi.org/10.1594/PANGAEA.759097 Michel Helen V Asaro Frank Alvarez Walter 1991 Geochemical study of the Cretaceous-Tertiary boundary region at Hole 752B book chapter In: Weissel, J; Peirce, J; Taylor, E; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program) 121 https://doi.org/10.2973/odp.proc.sr.121.177.1991 415-422 Following neutron activation, a study was made with the Iridium Coincidence Spectrometer (ICS) of the abundance profile of iridium in the Cretaceous-Tertiary boundary region of cores from Hole 752B taken from the Indian Ocean west of Australia. The ICS was modified to measure 13 other elements simultaneously with the Ir determination, and data are included for Co, Cr, Cs, Fe, Hf, and Se. The K-T region was sampled continuously in 1 cm increments from 8 cm below to 22 cm above the boundary, and an additional 30 spot samples were taken in the region from 10 m below to 6.7 m above. A large Ir anomaly of 3800 parts per trillion (ppt) over a background of 22 ppt was found in interval 121-752B-11R-3, 91-93 cm. This interval overlaps the extinction level of globotruncanids determined by the Shipboard Scientific Party. After correcting for the estimated clay content, no Ir over the background was found in the region from 22 cm to 10 m below the main Ir peak. Iridium above background levels, however, was observed in all of the remaining samples up to 1 m above the main Ir peak. Between 2 and 5.7 m above the main Ir peak, the Ir level averaged 59 ppt and is attributed to basaltic volcanism. Another large Ir anomaly of 1500 ppt was found in a spot sample from interval 121-752B-11R-3, 13-14 cm, and its tails extend from at least 10 cm below to at least 20 cm above the anomaly. The stratigraphic extent of this second anomaly parallels that of reworked Cretaceous nannofossils determined by the Shipboard Scientific Party, and the anomaly is attributed to reworking of K-T boundary Ir from another location. 93.5775 93.5775 -30.891 -30.891 93.5775 -30.891 1988-05-18T09:00:00 1988-05-22T12:30:00 352.03 367.12 ODP Ocean Drilling Program https://www-odp.tamu.edu:443/ Ocean Drilling Program, Texas A&M University ODP http://www-odp.tamu.edu/ https://ror.org/01f5ytq51 121-752B -30.891 93.5775 South Indian Ridge, South Indian Ocean -1097.0 1988-05-18T09:00:00 1988-05-22T12:30:00 Leg121 Leg121 1988-04-30T00:00:00 1988-04-30 1988-06-28T00:00:00 1988-06-28 Joides Resolution https://www-odp.tamu.edu:443/resolutn.html Weissel, Jeffrey K Weissel, Jeffrey K Peirce, John W Peirce, John W doi:10.2973/odp.proc.ir.121.1989 Joides Resolution https://www-odp.tamu.edu:443/resolutn.html Drilling/drill rig DRILL 435.6 m 112.34 m 17 cores; 158 m cored; 0 m drilled; 71.1 % recovery 660 CC-BY-3.0 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Sample code/label Sample label DSDP/ODP/IODP sample designation hdl:10013/epic.27914.d001 Michel Helen V Sample label DEPTH, sediment/rock Depth sed m depth http://purl.obolibrary.org/obo/PATO_0001595 sediment http://purl.obolibrary.org/obo/ENVO_00002007 rock Length L http://dbpedia.org/resource/Length Depth sed [m] Iridium Ir ng/kg iridium Michel Helen V Ir [ng/kg] Iridium, standard deviation Ir std dev ± iridium standard deviation std dev https://en.wikipedia.org/wiki/Standard_deviation Michel Helen V + err Ir std dev [±] (+ err) Iridium, standard deviation Ir std dev ± iridium standard deviation std dev https://en.wikipedia.org/wiki/Standard_deviation Michel Helen V - err Ir std dev [±] (- err) Cobalt Co mg/kg cobalt Michel Helen V Co [mg/kg] Iron Fe % Dimensionless Ratio ψ Michel Helen V Fe [%] Caesium Cs mg/kg caesium Michel Helen V Cs [mg/kg] Hafnium Hf mg/kg Michel Helen V Hf [mg/kg] Chromium Cr mg/kg chromium Michel Helen V Cr [mg/kg] Selenium Se mg/kg selenium Michel Helen V Se [mg/kg] Tantalum Ta mg/kg Michel Helen V Ta [mg/kg] supplement citable author33661 author33664 author37326 basis5 campaign3397810 campaign93 event13543 geocode1 geocode1599 geocode1600 geocode1601 geocode8128 inst34 license101 method10974 method5059 param1552 param2204 param2841 param683 param698 param77 param790 param85 param87 param94635 pi37326 project3 ref33906 term1073131 term20827 term37764 term38263 term40686 term40848 term41024 term41056 term43794 term43863 term44258 term44327