undifferentiated rock units

Paleontology and geology

In the Early Jurassic, shallow seas of the continental shelf covered much of the province, but subduction in the west continued to push the volcanic islands in that area up against the continent. These collisions continued through the rest of the period, uplifting, folding, faulting, and pushing the rocks farther east. This process brought magma up near the surface, which formed large blocks of granite under much of the province. Over time, much of British Columbia rose above sea level, and these rocks formed large mountain ranges down the middle of the province. Other parts of the province were still part of the ocean floor and oceanic islands farther out west, but they were fast approaching. Some of the Jurassic limestones, sandstones, and shales in the province contain fossils of radiolarians, foraminifera, bivalves, corals, and ammonites that lived both near shore and in deep ocean waters. A few deposits of mudstone and coal record the footprints of dinosaurs that walked through swamps in low-lying areas to the east.