• Thumbnail for Dropstone
    Dropstones are isolated fragments of rock found within finer-grained water-deposited sedimentary rocks or pyroclastic beds. They range in size from small...
    7 KB (873 words) - 18:21, 2 January 2024
  • Thumbnail for Cretaceous
    have occurred during this so-called "cold snap", as evidenced by glacial dropstones in the western parts of the Tethys Ocean and the expansion of calcareous...
    95 KB (9,847 words) - 15:10, 10 August 2024
  • Thumbnail for Kilbourne Hole
    present or on older sediments. The ejecta at Kilbourne Hole contains dropstones and a large number of xenoliths derived from the lower crust and mantle...
    11 KB (1,188 words) - 09:24, 22 February 2024
  • train but is eventually discovered by the pair. The train makes a stop in Dropstone, a town celebrating the fiftieth anniversary of its founding. As they...
    35 KB (3,503 words) - 17:48, 4 August 2024
  • Thumbnail for Ice rafting
    Bond event Glacial debris Drift station, a facility built on an ice floe Dropstone Swallow float Glacial erratic Bischof, Jens (January 2002). "Ice In The...
    3 KB (309 words) - 23:11, 6 January 2024
  • Thumbnail for Jurassic
    the accumulation of snow, though there may have been mountain glaciers. Dropstones and glendonites in northeastern Siberia during the Early to Middle Jurassic...
    230 KB (24,881 words) - 15:15, 10 August 2024
  • Thumbnail for Glacial erratic
    glacial movements for periods prior to record retention. Also known as dropstones, these can be correlated with ocean temperatures and levels to better...
    30 KB (3,388 words) - 00:30, 6 June 2024
  • Thumbnail for Ice age
    northeast of Lake Huron, with giant layers of now-lithified till beds, dropstones, varves, outwash, and scoured basement rocks. Correlative Huronian deposits...
    88 KB (10,417 words) - 21:00, 28 July 2024
  • Thumbnail for Lake Bonneville
    dominant carbonate mineral in sediments of post-Bonneville Great Salt Lake. Dropstones, probably mostly derived from shore ice, but possibly also from floating...
    28 KB (3,690 words) - 22:22, 30 June 2024
  • Thumbnail for Zektzerite
    of the mineral were found in a "float boulder" (a glacial erratic, or dropstone) on the north side of Kangaroo Ridge at an approximate elevation of 6...
    4 KB (412 words) - 20:49, 30 March 2024
  • Thumbnail for Banded iron formation
    universally, associated with glacial deposits, often containing glacial dropstones. They also tend to show a higher level of oxidation, with hematite prevailing...
    67 KB (7,104 words) - 18:50, 19 April 2024
  • Thumbnail for Supercontinent
    Pangaea (the southernmost portion of Pangaea was Gondwana). Ice-rafted dropstones sourced from Russia are indicators of this northern boundary. The Jurassic...
    32 KB (3,806 words) - 06:37, 4 May 2024
  • Thumbnail for Karoo
    ice sheets to the north deposited a 1 km-thick layer of mud containing dropstones of varying origins and sizes into this basin. This became the Dwyka Group...
    56 KB (6,461 words) - 01:21, 31 March 2024
  • modern Iberian Peninsula, based on the existence of Hauterivian ice-rafted dropstones in Iberia. Cold conditions are also known to have existed in the Southern...
    8 KB (614 words) - 09:21, 2 January 2024
  • from the 1 Ga Scottish Diabaig Formation in the Torridon Group, where dropstone formations were likely formed by debris from ice rafting; the area, then...
    72 KB (8,149 words) - 15:52, 10 July 2024
  • Thumbnail for Snowball Earth
    This palaeomagnetic location of apparently glacial sediments (such as dropstones) has been taken to suggest that glaciers extended from land to sea level...
    100 KB (12,087 words) - 20:26, 4 August 2024
  • Thumbnail for Roxbury Conglomerate
    have depressed the underlying laminae and giving them the appearance of dropstones. The gravel-size portion of the Squantum Member diamictites consists of...
    20 KB (2,247 words) - 15:32, 17 June 2024
  • was found. The two of them, later joined by Flora, go to the towns of Dropstone and Folsense, eventually finding the true purpose of the Elysian Box and...
    26 KB (3,192 words) - 02:06, 18 July 2024
  • glaciation. In Uruguay, evidence of the Marinoan glaciation is known from dropstones, diamictites, rhythmites, clast layers, and varve-like deposits. According...
    15 KB (1,472 words) - 20:37, 4 August 2024
  • Thumbnail for Azolla event
    between 49 and 47 million years ago, around the Azolla event, is evident; dropstones (which are taken as evidence for the presence of glaciers) are common...
    12 KB (1,469 words) - 10:01, 13 February 2024
  • Thumbnail for Arabian-Nubian Shield
    (3,600 ft) of which include glaciomarine deposits with diamictites and dropstones from the Sturtian and Marinoan glaciations. Gneiss belts and domes forming...
    15 KB (1,836 words) - 22:17, 8 August 2024
  • Thumbnail for Geology of the Death Valley area
    till by being poorly sorted and other parts have large boulder-sized dropstones resting in a fine-grained matrix of sandstone and siltstone. Similar deposits...
    57 KB (5,533 words) - 23:22, 12 August 2024
  • Thumbnail for Deep Sea Drilling Project
    sites were studied for evidence of ice-rafted debris in the form of small dropstones and quartz grains with distinctive microscopic surface textures suggestive...
    22 KB (2,841 words) - 11:09, 21 January 2024
  • Thumbnail for Edaga Arbi Glacials
    fragments in a fine earth mass. Mudstones are predominant. Often, they hold dropstones, what indicates that the sediment was often deposited in fjords or pro-glacial...
    8 KB (791 words) - 20:00, 15 December 2023
  • Thumbnail for Tākaka Terrane
    Nelson. The Cobb Valley is also the location of "Trilobite Rock" a glacial dropstone made from the moulted exoskeletons of trilobites. Asbestos was mined in...
    5 KB (455 words) - 07:22, 23 May 2024
  • Thumbnail for Diamictite
    sediments deposited by melting icebergs or disintegrating ice sheets (dropstones) volcanic origin lahars lahar mass flows entering the ocean marine origin...
    5 KB (399 words) - 03:21, 9 May 2023
  • Thumbnail for Wessex Formation
    equivalent to the extent of Cornwall and Devon, with occasional large dropstones transported in tree roots being found in Wealden sediments over 100 kilometres...
    55 KB (3,575 words) - 23:03, 15 July 2024
  • name-bearing section at Gaskiers (Newfoundland) is packed full of striated dropstones. Its δ13C values are very low (pushing 8‰), consistent with a period of...
    4 KB (440 words) - 14:11, 12 June 2024
  • Thumbnail for Geology of Tasmania
    rich in fossils and dropstones (Malbina Formation, and Deep Bay Formation), and the upper part is dark grey siltstone rich in dropstones. The very top layers...
    80 KB (11,155 words) - 08:47, 14 July 2024
  • Sweetman, Steven C.; Goodyear, Matthew (August 2020). "A remarkable dropstone from the Wessex Formation (Lower Cretaceous, Barremian) of the Isle of...
    6 KB (759 words) - 06:02, 9 May 2024