The NSS Bulletin - ISSN 1090-6924
Volume 40 Number 1: 7-18 - January 1978
A publication of the National Speleological Society

Geology and Speleogenesis of Ogle Cave
David H. Jagnow

Abstract

The Ogle Cave system developed by preferential solution at the interseciton of major vertical joint swarms, trending N20°W, and the sloping geologic contact between the breccia and massive members of the (Permian) Capitan Limestone. Impermeable siltstones in the overlying Yates Formation channeled groundwater from as far away as the Guadalupe Ridge anticline into vertical joints and 15 sandstone dikes directly over Ogle Cave.

The author proposes that sulfuric acid played a major role in the solution of the Guadalupe Mountain caves. Finely disseminated grains, large crystals, and massive cencentrations of pyrite in the overlying Yates Formation provided a sulfide source. Late Pliocene faulting and uplift of the Guadalupes initiated pyrite oxidation, releasing sulfuric acid down dip into the more soluble Capitan Limestone. Episodic uplift, and resultant drops in base level concentrated shallow phreatic solution near 1390m and 1417-20m asl. During the last stage of cavern development, ponded waters high in sulfate and calcium precipitated varved gypsum on the floors and ledges of Ogle and other Guadalupe caves. Beds of massive gypsum were commonly redissolved under vadose conditions, or covered by breakdown from exfoliation [spalling]. Displays of massive carbonate speleothems developed under vadose conditions in Ogle Cave

This page last updated: 17 June, 2002 10:53
Web Author: Jim Pisarowicz