Saved in:
| Main Author: | |
|---|---|
| Format: | Artículo científico |
| Language: | en |
| Published: |
Universitat de Barcelona
2004
|
| Subjects: | |
| Online Access: | https://www.redalyc.org/articulo.oa?id=50520403 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Table of Contents:
- Oriented calcite concretions in Upper Miocene carbonate rocks of Menorca, Spain: evidence for fluid flow through a heterogeneous porous system L. Pomar H. Westphal A. Obrador Ciencias de la Tierra Miocene Carbonates Diagenesis Fluid flow Balearic Islands Elongate calcite concretions in Upper Miocene dolomitic, shallow-marine grainstones and packstones ofMenorca document fluid flow through heterogeneous systems. These post-dolomitization concretions arethought to have grown with elongation axes parallel to groundwater flow direction, and to reflect the hydraulicgradient and the anisotropy of the hydraulic conductivity. Differences in shape, size and orientation of concretions,as well as the spatial and crosscutting relationships reflect two phases of calcite-cementing fluids. This isin contrast to most examples in the literature that distinguish just one phase of precipitating fluids. The firstphase of cementing fluids flowed horizontally, most likely in the phreatic zone, across hydraulic high-conductivitylayers that resulted from sediment-packing heterogeneities and preferential dissolution during dolomitization.These first-phase fluids were most likely injected into the host rock through fracture zones and probablyoriginated in deeper settings. The second phase of cementing fluids was downward directed and possibly ofmeteoric origin. First-generation concretions, acting as permeability barriers, partly controlled the fluid pathways,precipitation patterns, and concretion type and loci. 2004 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50520403 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.4 Vol.2