Circum-Superior Belt age of . Another volcanic series in the Marquette Range Supergroup, known as the Gunflint Formation, has an age of . Further geologic units that are related to the Gunflint Formation include the Badwater volcanics and the Kiernan sills. A number of origins have suggested for the Marquette Range Supergroup magmatism. This includes subsidence being driven ahead related to thrusting of the Penokean orogeny or a possible back-arc basin, and lateral flow through the Pickle Crow dikes transported magma from the Fox River Belt area through the Superior craton for placement in the Marquette Range Supergroup. This suggested long-range origin
Circum-Baikal Railway Trans-Siberian railway on either side of Baikal was linked, and began to be used to transport goods and passengers. The Circum-Baikal was called the "golden buckle on the steel belt of Russia". Initially, only one track was built; from 1911 to 1914 the construction of a second track was undertaken, which increased capacity of the Circum-Baikal to 48 pairs of trains a day. In this stage of the construction of bridges and other engineering structures reinforced concrete was introduced as a new material. As part of these works, considerable attention was paid to the construction of stations and station towns.