Facies architecture and mechanical stratigraphy of Mississippian grainy and muddy carbonate sediment gravity-flow deposits: Rancheria Formation, Sacramento Mountains, New Mexico

Carbonate slope deposits are of considerable scientific importance, economic significance, and academic interest, but remain understudied in terms of depositional processes, facies architecture, fracture distribution, and the resultant mechanical stratigraphy. Outcrops of the Rancheria Formation in the Sacramento Mountains, New Mexico represent a Mississippian carbonate slope system that is spectacularly exposed for sedimentologic and fracture characterization. Using these outcrops, this study establishes a correlation between facies architecture, depositional processes, and fracture parameters. Eight primary facies were identified, ranging from grain-dominated to carbonate-mud dominated deposits, reflecting influence from various depositional processes. In addition, a total of 1,201 fractures were documented along 36 scanlines, revealing two principal fracture types: IntraBed (confined within single beds) and PackageBound (crossing at least one bed boundary). The results of this study demonstrate the profound influence that bed thickness, stacking patterns, and textural heterogeneity pose on fracture dimensions and propagation trends. Thicker, more homogeneous intervals typically host taller fractures as vertical propagation continues until a substantial mechanical boundary is encountered. In contrast, thinner beds exhibit shorter fractures. Additionally, in intervals with abrupt internal mechanical contrasts (i.e., textural differences), vertical fracture propagation is arrested, in some cases causing fractures to increase in aperture (and likely in length) rather than height. Conversely, the absence of significant mechanical contrasts allows fractures to propagate vertically until encountering a more substantial facies/textural boundary. This study demonstrates that facies type, bed thickness, and internal lithologic contrasts collectively influence fracture dimensions and propagation trends. The results underscore the importance of depositional processes and stacking patterns, where mechanical consistency creates larger fractures, while internal textural heterogeneity creates effective mechanical barriers. These results refine the understanding of deep-water resedimented carbonate deposits and provide critical insights applicable to reservoir modelling of conventional hydrocarbon reservoirs and induced-fracture propagation in unconventional reservoirs.

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Geology and Geological Engineering

Grantor dc:publisher

Colorado School of Mines. Arthur Lakes Library

Year dc:date.issued

2025

Author dc:creator

• Begimbetov, Sanzhar

Advisor dc:contributor.advisor

• Jobe, Zane R.

Committee members dc:contributor.committeemember

• Wood, Lesli J.
• Plink-Björklund, Piret
• Bishop, James
• Heesakkers, Vincent

• carbonates
• deep-water
• fractures
• mechanical stratigraphy
• sedimentology
• stratigraphy

Statement dc:rights

• Copyright of the original work is retained by the author.

Language dc:language.iso

eng, English

Identifier

T 9958

OAI identifier oai:identifier

oai:repository.mines.edu:11124/181156