Distribution of Porosity and Permeability in Platform Dolomites: Insight from the Permian of West Texas: Discussion
Bibliographic record
Abstract
Saller and Henderson (1998) presented an article concerning porosity and permeability variations in two west Texas oil fields (North Riley and South Cowden fields). These fields occur within dolomitized Permian platform carbonates near the basinward shelf edge of the Central Basin platform, a paleogeographic element that influenced Permian deposition in west Texas. Their carefully documented study outlines several anomalous aspects concerning porosity distribution. They noted, in particular, that porosity distribution is not strictly facies dependent but that porosity tends to increase in a basinward direction. They suggested that porosity developed largely during dolomitization by the action of hypersaline evaporative fluids that flowed downdip in a basinward direction during the Permian. These brines were generated in restricted shelf interior lagoons and moved downdip parallel with bedding in a shallow reflux type of hydrologic system driven by subsurface fluid density differences in the Permian Clear Fork and Grayburg formations, as shown here in Figure 1 (see figure 18 in Saller and Henderson [1998]). Figure 1 Part A shows the scenario proposed by Saller and Henderson (1998) for porosity creation, dolomitization, and dolomite cementation of the Permian Clear Fork and Grayburg formations of west Texas. They suggested that macrodissolution of calcium carbonate occurred contemporaneously with dolomitization and dolomite cementation. This process of brine backreaction, however, would cause a net increase of porosity in the shelf interior, the opposite of what is observed. Part B shows a two-stage scenario proposed here to circumvent the problem of limestone macrodissolution by shelf interior brines that must have been initially in approximate bulk equilibrium with calcium carbonate. The first stage records dolomitization by replacement of limestone with little macrodissolution. In stage two, evaporative shelf interior brines may have evolved in equilibrium with dolomite only and became undersaturated with calcite and aragonite. Reflux migration of these brines downdip may …
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".