Datos para estimar el IVP

The Upper Devonian Ermita Fm. is exposed in and above the MQ (figure 3.2A), and in the LCQ (figure 2.3B). On the outcrop, the presence of the Ermita Fm. is locally indicated by a subtle topographic high and the rare occurrence of small exposures. Its thickness ranges from 7 m in the MQ to 3 m in the LCQ. The Ermita Fm. is composed of sandstones, locally containing numerous

bioclast molds, with a conglomerate basal level. The Lower Carboniferous Vegamián Fm. is intensely eroded and forms topographic lows within the outcrop (figure 3.2A). It is only exposed in both quarries (figures 2.3B & 3.2B), where it has a thickness of 2.5 (MQ) to 4 m (LCQ). The first member of the overlying Alba Fm. is composed of 3 m (MQ and LCQ) of beige to red nodular limestones (figure 3.2B), while the second member is composed of 6.5 (MQ) to 9 m (LCQ) of thinly bedded chert layers (figure 3.2C). Both first and second members are only exposed in the quarries, and are weathered on the outcrop (figure 3.2A). The third member is composed of 25 (LCQ) to 32 m (MQ) of red to gray limestones representing a gradual transition towards the overlying Barcaliente Fm. (figures 2.3C & 3.2D). The latter is exposed along both road sections, in the quarries, and on the outcrop itself. It has a thickness of 280 m along the Millaró road section increasing to 350 m along the Los Chábanos road section. The Barcaliente Fm. is made up of well- bedded dark mudstones with very little fossil content (figure 2.3D).

Figure 3.2: Upper Devonian and Lower Carboniferous successions in KO 1. (A) Exposure of Upper Devonian and Lower

Carboniferous successions 400 m west of the MQ. From north to south: (1) Ermita Fm., (2) depression corresponding to the eroded Vegamián Fm. and the eroded lower and middle members of the Alba Fm., (3) third member of the Alba Fm. and (4) Barcaliente Fm. The exposed Ermita Fm. has a thickness of approximately 4 m. (B) Exposure in the MQ showing Vegamián shales (right) grading into beige nodular limestones of the first member of the Alba Fm. (left). (C) Thinly bedded chert layers of the middle member of the Alba Fm. exposed in the LCQ. Hammer for scale (32 cm). (D) Exposure of the upper member of the Alba Fm. (left) grading into the Barcaliente Fm. (right) in the LCQ. Person for scale on the left (white arrow).

The stratigraphic framework and internal structure of the Valdeteja Fm. in KO 1 are more complex compared to the Alba and Barcaliente Fm. Satellite images indicate that the Valdeteja Fm. has an irregular thickness, which is confirmed based on log data (see Appendix I). Its thickness approaches 770 m along the Millaró and 650 m along the Los Chábanos road section, but decreases to 480 m in the central part of the outcrop. Stratal patterns are clearly visible on satellite images and indicate a sequence of (1) a first depositional unit composed of large mounds, overlain by (2) a second depositional unit composed of well-bedded deposits with local occurrence of smaller mounds and (3) a third depositional unit made up of massive carbonate wedges along both road sections which pinch out towards the central part of the outcrop (figure 3.3).

The first depositional unit, made up of large mound-like structures, occurs directly on top of the Barcaliente Fm. and has a very irregular thickness (figure 3.3). The mounds are up to 250 m thick along both road sections and pinch out towards the central part of the outcrop, where they locally increase in thickness up to 100 m. The entire first unit is dolomitized, which makes it very hard to discriminate depositional facies or internal sedimentary structures, as they are obliterated. The mounds are characterized by steeply dipping flanks and a lack of obvious frame-building organisms such as corals. Based on the few stratal patterns and bedding surfaces recognizable within the mounds (figure 3.4A), it seems that they are composed of an amalgamation of smaller coalesced buildups. These buildups are characterized by pink (figure 3.4A) to white colors (figure 3.4B) upon dolomitization, and the local presence of large pores (figure 3.4A). In several samples of these buildups, sponge spicules have been observed, although they are often (partly) dissolved leaving behind molds. Deposits of dolomitized mudstone occur in between the porous deposits.

The second depositional unit is composed of well-bedded carbonates characterized by subvertical bedding planes (figure 3.5A) and the local occurrence of small buildups (figure 3.3). The well- bedded carbonates represent numerous fining-upward sequences made up of bioclastic grainstone (with local levels of rudstone) evolving into wackestone or mudstone (figures 3.5B &

Figure 3.4: Outcrop photographs of the first generation of mounds in the Valdeteja Fm. of KO 1. (A) Massive dolomitized

deposits exposed along the Millaró road section. They are porous and characterized by a typical pink color. In this particular exposure, a few bedding planes are present (white arrows). Hammer for scale (32 cm; black arrow). (B) Example of massive white dolomite, exposed along the Millaró road section. Hammer for scale (32 cm; black arrow).

C). Bioclasts include echinoderm, brachiopod and gastropod fragments. Silicified bioturbations are often observed in these deposits (figure 3.5D). Locally, exposed layers of fine-grained siliciclastics can be found in between the carbonate sequences (figure 3.5E), as well as layers up to a few m thick composed of calcareous limestone breccia (figure 3.3).

Figure 3.5: Outcrop photographs of well-bedded carbonates in KO 1. Hammer for scale (32 cm). (A) Exposure of bedded

successions on top of the outcrop. Hammer for scale (32 cm; white arrow). (B) Example of a fining-upward sequence made up of pack- to rudstone (left) evolving into mudstone (right). Top of the outcrop. (C) Example of a dolomitized fining- upward sequence along the Los Chábanos road section. (D) Silicified bioturbations in a fine-grained bed. Top of the outcrop.

Numerous small carbonate buildups occur in the fining-upward successions (figures 3.3 & 3.6A). These buildups are a few to 15 m thick and most of them resemble massive structureless beds (even though they have not been dolomitized) in between the bedded successions (figure 3.6B). Clear mound geometries with dipping flanks are only recognizable in the larger buildups (e.g. figures 3.6A & B). The buildups are composed of tight peloidal micrite-rich boundstones with

Donezella (a characteristic carbonate mound builder during the Carboniferous; Choh and Kirkland,

2006), brachiopod, coral, sponge and foraminifera fragments. Abundant relics of fibrous cements occur in the boundstones (figure 3.6C), which indicate that they possessed a high primary porosity.

Figure 3.6: Outcrop and thin section photographs of small buildups in between the bedded carbonates of KO 1. (A) Two

buildups (white arrows) exposed in between bedded successions 400 m west of the Millaró road section. Beds making up the flank of the lower buildup are indicated with black dashed lines. Black arrows indicate dolomitized successions. The two buildups are also visible in the upper left corner of figure 2.3E, where their size can be compared to the size of the larger mounds of the first depositional unit. (B) Detailed photograph of the bedded substrate of the second small buildup from figure A. The beds are approximately 20 to 30 cm in thickness (gray arrow). Both buildups from figure 3.6A are indicated with white arrows. (C) PP photomicrograph of brown fibrous cements filling a primary cavity in boundstone derived from the core of the second buildup of figures 3.6A and B. The fibrous cements have been neomorphosed but are still recognizable. Note the secondary blocky calcite cement filling the remaining pore space (right).

The massive carbonate wedges making up the third depositional unit of the Valdeteja Fm. in KO 1 (figure 3.3) are composed of carbonate mounds, thick packages of limestone breccia and local levels of grain- to rudstone. As these successions grade into each other and are almost entirely dolomitized, it is difficult to delineate stratal patterns or facies changes both on satellite images or during fieldwork. The carbonate mounds resemble those making up the first depositional unit of the Valdeteja Fm., with pink to white colors and the omnipresence of large irregular pores. In several locations on the outcrop, the paleosurface of the mounds in the third depositional unit can be recognized (figures 3.7A & B). The packages of limestone breccia are thick deposits of matrix-free breccias (figures 3.7C & D). Individual clasts are relatively large and have dimensions of a few cm to several dm (figure 3.7D).

Figure 3.7: Massive carbonate wedges composed of carbonate mounds and limestone breccia in KO 1. (A) Large exposed

paleosurface of a carbonate buildup in depositional unit three. Notebook for scale (20 cm; white arrow). (B) Smaller exposed paleosurface of a buildup. (C) Exposure of dolomitized limestone breccia along the Millaró road section. (D) Thick deposits of undolomitized limestone breccia on top of the outcrop. Hammer for scale (32 cm).