Several cretaceous sedimentary rocks are present and they include buda, boquillas, santa Elena, and del rio. The site also consists of two faults which include the basin and range high angel fault and Laramide thrust fault which create a graben.
The Dagger Mountain has an elevation of 4173 feet and 1300 feet of relief. The anticline of the mountain is trending at north- northwest within the Sierra del Carmen. There are a number of reverse faults and folds. They are located on the eastern side of cordilleran orogen. On the eastern Trans-pecos province, there are mafic sills found near the Dagger Mountain. The mafic sills are made up of magmas that crystallized after cordilleran contraction and at the beginning of range and basin extension (Cloud et al 121).
The anticline of Dagger Mountain is one of the laramide orogen (Cullen et al 105). This is a period of mountain building which started seventy to eighty million years ago in the late cretaceous. It then ended thirty to fifty five million years ago. Laramide orogen was triggered by subduction of tectonic plate and took place in sequence of pulses.
The intrusions of Sierra del Carmen towards the Trans-Pecos province, occurred during the mafic and alkali rich felsic lava flows, and the pyroclastic flows (Cullen et al 106). The lava flow formed a northwest trending belt which intruded the north part of Mexico. This belt holds the Dagger Mountain. At the end of laramade orogeny, most of the magmas were produced by the mantle upwelling. The production of magmas was triggered by the foundering subduction of farallon plates.
The field trip made to the big bend national park was based on the study and observation of dagger mountain’s cretaceous sedimentary rocks as well as igneous intrusions. The following were some of the discovery made in the field:
There are a number of cretaceous sedimentary rocks discovered within and around