Giant blocks in the South Kona landslide, Hawaii

Research Article| February 01, 1995 Giant blocks in the South Kona landslide, Hawaii James G. Moore; James G. Moore 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Wilfred B. Bryan; Wilfred B. Bryan 2Woods Hole Oceanographic Institute, Woods Hole, Massachusetts 02543 Search for other works by this author on: GSW Google Scholar Melvin H. Beeson; Melvin H. Beeson 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar William R. Normark William R. Normark 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Author and Article Information James G. Moore 1U.S. Geological Survey, Menlo Park, California 94025 Wilfred B. Bryan 2Woods Hole Oceanographic Institute, Woods Hole, Massachusetts 02543 Melvin H. Beeson 1U.S. Geological Survey, Menlo Park, California 94025 William R. Normark 1U.S. Geological Survey, Menlo Park, California 94025 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1995) 23 (2): 125–128. https://doi.org/10.1130/0091-7613(1995)023<0125:GBITSK>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation James G. Moore, Wilfred B. Bryan, Melvin H. Beeson, William R. Normark; Giant blocks in the South Kona landslide, Hawaii. Geology 1995;; 23 (2): 125–128. doi: https://doi.org/10.1130/0091-7613(1995)023<0125:GBITSK>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract A large field of blocky sea-floor hills, up to 10 km long and 500 m high, are gigantic slide blocks derived from the west flank of Mauna Loa volcano on the island of Hawaii. These megablocks are embedded in the toe of the South Kona landslide, which extends ∼80 km seaward from the present coastline to depths of nearly 5 km. A 10–15-km-wide belt of numerous, smaller, 1–3-km-long slide blocks separates the area of giant blocks from two submarine benches at depths of 2600 and 3700 m depth that terminate seaward 20 to 30 km from the shoreline. Similar giant blocks are found on several other major submarine Hawaiian landslides, including those north of Oahu and Molokai, but the South Kona blocks are the first to be examined in detail using high-resolution bathymetry, dredging, and submersible diving. Dredging of two of the giant blocks brought up pillowed tholeiitic lava. Observations from the U.S. Navy submersible Sea Cliff on the asymmetrically steep eastern flank of one block 10 km long and 300 m high revealed a succession of fractured massive basalt, laminar lava flows, hyaloclastite, and pillow lavas. Chemical analyses of dredged lava identified 19 units that overlap compositionally with lavas from the south rift-zone ridge of Mauna Loa. Sulfur content indicates that most of the lavas were erupted in subaerial and shallow submarine (<200 m depth) sites, but some were erupted in deeper submarine sites. These results indicate that the megablocks were carried by a late Pleistocene giant landslide 40–80 km west from the ancestral shoreline of Mauna Loa volcano before growth of the midslope benches by later slump movement. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.