Sayles, R.W., 1914, The Squantum Tillite: Memoirs of the Museum of Comparative Zoology at Harvard College.
and Bowring, S.A., 2000, Age of the Squantum "tillite", Boston Basin, Massachusetts: U-Pb zircon constraints on terminal Neoproterozoic glaciation: American Journal of Science, v.
Gevers as the geology of the continents was mapped and the intercontinental distribution of Permo-Carboniferous and Precambrian glacial tillites became evident.
Gevers a redonne vie au concept d'anciennes glaciations planetaires a la faveur de la cartographie gdologique des continents, alors qu'a ete mis en dvidence l'existence de tillites glaciaires permo-carboniferes et prdcambriennes.
He firmly rejected the pre-Wegener hypothesis of 'an Antarctic continent of which Australia, South Africa and a part of South America were possibly but lobes' as an explanation for Permo-Carboniferous tillites in the tropics (Davis, 1908).
Harland accumulated enough data from the scientific literature to show that in the Neoproterozoic tillites, the mineral grains susceptible to magnetism had assumed a nearly horizontal orientation when the glacial deposits were formed, a clear sign that the tillites originated near the equator.
Kirschvink proposed that smaller iron formations interlayered with the Neoproterozoic tillites tell an important part of the snowball Earth story.
Kirschvink had found a way around the twin problems of freeing Earth from the ice and forming the iron deposits in the tillites. But scientists were still hesitant to accept such a controversial idea.
Taking the rock record in Namibia, Africa, as their primary reference, they focused their story on the carbonate rocks that almost always lie atop the Neoproterozoic tillites. These "cap carbonates" indicate precipitation in warm, shallow oceans--a stark contrast to the glacial deposits below.
The Fms are unusual in that many of them are periglacial sandstones often sealed by glacial tillites
. This is one of the few areas in the world where deposits of such type host hydrocarbon reserves in commercial quantities.