T292 Geophysical Solutions to Geological Problems: Current Research Results and the Annual George P. Woollard Award Presentation (Posters)

Wednesday, 4 November 2015
9:00 AM - 6:30 PM
Exhibit Hall


SUBORBITAL IMPRINT MATCHING

Paper number: T292-14
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM


Authors


Abstract

A suborbital sand transport model explains many observed features of the Carolina Bay sand unit including: highly fractured, sub angular grain texture, and remarkably void of any terrigenous or biogenous detritus. The unit is deposited by a single process, yet the entire ~1,600 km3 sand unit shows no signs of any conventional depositional means, as if the sand “fell from the sky." 45,000 Carolina Bay samples over 5% of the continental U.S. all fit just 6 (six) shapes, reproduced in Suborbital Analysis. Carolina Bays unit age is bounded between 140 ka and 1.6 Ma, and the Australasian tektite event at 786 ka has no parent impact structure.

Carolina Bay alignment varies systematically with latitude, with an area of central convergence about 8 degrees west of Saginaw Bay, Michigan. Did a mid Pleistocene oblique ice sheet impact disrupt and regionally distribute sandstone substrate, and globally distribute the Australasian tektites?

Shock vaporization of ice sheet overburden explains 1) endogenic comminution of hydrated porous sandstone substrate via phase change steam-wedge fracturing from within, and 2) local steam plasma for transport motive potential via adiabatic expansion. This implies thousands of km^3of ice involvement and orbit injection for some of that mass.

If a sand-rich density flow of expanding steam/plasma encountered obstruction(s) while in transport to emplacement as the Carolina Bay formation, each obstruction would shadow the density flow and leave a lower sand flux in that shadow. Upon emplacement, the obstructed regions of the density flow would express as depressions or voids in the sand blanket; the Carolina Bays.

This density impedance model also explains observed adjacent overprinting, or displacement of one Carolina Bay by an adjacent bay, via upstream-down stream wake interaction. A leeward obstruction would displace the wake of a windward obstruction, leaving a pocket or “bite” out of the rim of the first. Adjacent overprinting of Carolina Bays is otherwise unexplained after 80 years of attempts.

A suborbital sand transport model explains the many observed features of the Carolina Bay sand unit of age 140 ka to 1.6 Ma. Did an oblique ice sheet impact pulverize and distribute sandstone in the mid Pleistocene to form the Australasian tektites and Carolina Bays? Where should we look for more ground truth?