Creator

Louise D. Hose

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Publication Date

January 1981

Keywords

Geology

Description

Ph.D. dissertation by Louise Hose, California State University Los Angeles (1981) Sistema Purificacion, a large cave system in the northern Sierra Madre Oriental of northeastern Mexico, is developed in the Tamaulipas and Tamabra Formations, a sequence of middle Cretaceous carbonates about 400 meters thick. The formations formed in a basinal to periplatform environment near the Plataforma Valles-San Luis Potosi, a large carbonate platform simultaneously developing to the south and southwest. The Tamaulipas Formation is stratigraphically underlain by shaly limestone, shale, sandstone, and conglomerate of the Early Cretaceous Taraises, the Late Jurassic La Caja, and the Late Jurassic La Joya Formations. The cave system is on the west flank of the Anticlinorio Huizachal-Peregrina, which is one of many large Laramide folds making up the Sierra Madre Oriental. Most of the lateral shortening within the carbonates was accomodated by slippage along decollement surfaces and abundant second-, third-, and fourth-order folds. Except along decollement surfaces, faults are rare and have offsets less - than three meters. Steeply inclined joints trending N5W are common near axial planes, probably resulting from fracturing along incipient axial plane cleavage during stress relaxation following Laramide folding. The cave has several hydrologic systems, all of which ultimately drain northeast into the Rio Purificacion . Impervious beds in the Tamabra, Taraises, La Caja, and La Joya Formations cause groundwater to flow to the surface, resulting in many small springs . Larger springs emerge from karst conduits in the Tamaulipas Formation, particularly during and after intense rains . The Sinclinal de Infiernillo, a north-trending second-order syncline west of the cave, in combination with the impervious beds in the La Joya, acts as a local hydrologic barrier. Water in the carbonates is perched in the trough of the syncline. The principal geologic factors controlling the development of the Sistema Purificacion are the stratigraphy and structure of the area. Passages in the upper and lower cave are commonly formed along the intersection of joints and bedding planes, sub-parallel to the dip. The middle part of the cave is within a third-order, anticline-syncline pair whose axial surfaces are about 150 -meters apart and trend north-south. Passages develop sub-parallel to the axial surfaces where incipient cleavage provides zones of permeability and enhance conduit development. Open Access See Extended description for more information.

Subject: topical

Geology

Type

Article

Genre

Thesis / Dissertation; serial

Identifier

K26-04351

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