| An interesting array of
rock types of varying ages are found at the Souris Rock Pit. Some of these
rocks will take a polish, but are discussed mainly for their general "rock
hound" interest. For example, a municipality of igneous rocks are found, some
of the very fresh volcanics such as scorias, pumice and prophyritic basalts, in rich
brown, red, yellow and greenish grays. Many of these are collected for their
decorative appearance in flower arrangements and rock gardens. White and pastel
shades of vein quartz and epidote collected here will take a polish and some are collected
for these purposes. Metamorphic rocks show a rich diversity having sampled a wide area of Precambrian Shield of Canada as well as representatives of several types of sedimentary rocks. These latter come from the surrounding area of bedrock of Paleozoic and Mesozoic age. Some of the dendritic shales are of sufficient hardness to take a polish and come in pleasing shades of yellow, tan and gray. Much of the sandstone within the gravel beds and lithified with limonite and calcite cementing the grains together. Some of it shows quite decorative cross bedding, a legacy of the shifting currents that carried the grains of sand to this resting place.
Fossils from these pits come in many forms, representative of several ages including petrified wood and gastrapod agate, some of which appears to have been contributed from more than one source. Some of the wood is well agatized, but much of it is poorly replaced, grading into lignite coal, quite likely coming from the Paleocene Ravenscrag Formation to the west of Souris. Stumps of the petrified wood have been collected from the pits that still retain relatively small fragile roots extending from the base. These more delicate limbs and roots could not have withstood much rough treatment, suggesting a very short distance of transportation. Pieces with bark are rare as well as those showing insect damage. A variety of Paleozoic and Mesozoic marine fossils, preserved in shale or limestone, are found regularly, long ago separated from the formation in which they were preserved. These have chiefly been specimens of brachiopods and corals. One of the more interesting fossils collected from the pits is sample of the teredo or ship worm's (an elongate marine clam) boring in wood. Their burrows are generally filled with calcareous silt or the vacant burrow is completely filled with a honey colored calcite. The material makes attractive bookends. A specimen or two of Tertiary vertebrates have also been found. These were agatized long bones and devoid of diagnostic features. Scientifically, the most interesting specimens were some reworked teeth of Ice Age horses (Equus) and mammoths (Mammuthus). They are of an older age than the gravels they have been secondarily deposited in, but still reflect a Pleistocene age. It is hoped that additional material will be found and that it comes to the attention of someone who can utilize its research value.
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