A blood transfusion is a safe, common procedure in which blood is given to you through an intravenous (IV) line in one of your blood vessels. Blood transfusions are done to replace blood lost during surgery or due to a serious injury. A transfusion also may be done if your body can't make blood properly because of an illness. During a blood transfusion, a small needle is used to insert an IV line into one of your blood vessels. Through this line, you receive healthy blood. The procedure usually takes 1 to 4 hours, depending on how much blood you need. Blood transfusions are very common.
1 The roots of the ancient mountain range that now lies at the bottom of the Grand Canyon were formed about 1.7 billion years ago. 2  There is then an unconformity of about 450 million year in which the rocks are missing. 3  At 1.25 billion years ago the first sedimentary layer, the Bass Formation, was laid down.
Grand Canyon Geology. The Grand Canyon of the Colorado River is a world-renowned showplace of geology. Geologic studies in the park began with the work of John Strong Newberry in 1858 and continue today.The Grand Canyonâs magnificent display of layered rock reveals the regionâs geologic history like no other place.hose rock outcrops suggest that 4,000 to 8,000 feet of sedimentary layers from the Mesozoic, also known as the age of dinosaurs, once covered the Grand Canyon area. Layers from the Cenozoic era (the age of mammals) are limited to western Grand Canyon and terraces near the river.