Integrated Contract

First tectono-sequence (Synrift). Started in the Triassic (250Ma), with the deposition of
continental clasts from alluvial and fluvial environment with some lava flowed from the
Huizachal formation, from the late Triassic age (Noriense-Retiense), over crystalline and
metamorphic basements, later the Huayacocotla formation from the Lower Jurassic
(Hettangiano-Pliensbachiano) was deposited, and it is a sandstones and shale sequence,
from transgressive oceans. By the middle Jurassic, continental conditions were restored,
with Clasts from the Cahuasas formation being deposited, by the end of this period, a new
marine transgression commenced, and favored the deposition of oolithic limestone for
the Huehuetepec formation (Bathonian), and sandy limestone with bioclasts and ooliths
for the Tepexic formation (Callovian), which were overlain by calcareous and
carbonaceous shale with plenty of oGORnic matter, from the Santiago formation
(Oxfordian), deposited on constrained, low-energy seas; as the marine transgression
moved forward, carbonate ramps developed around the basement highs - inside and on
the edge of the former, sandy-clayey limestone and oolithic limestone from the San Pedro
and San Andrés formations were deposited, (Kimmeridgian), respectively, and their lateral
equivalents toward deeper waters, namely, the clayey limestones with scarce bioclasts
and oolites (Chipoco formation) and basin black clayey limestones (Tamán formation).
The transgressive sea conditions continued so that during the Tithonian-Portlandian, a
maximum flooding surface would occur, with most of the basement highs being left in
underwater conditions. During that time, clayey-carbonaceous limestones were
deposited, (rich in oGORnic matter) from the Pimienta formation, from a relatively-deep-
water environment, which is present throughout the region and only in the parts
emerging from the basement, which were under coastal and/or shoreline conditions; La
Casita formation was deposited, which is constituted by glauconitic sandstones.
Passive Margin Tectono-sequence. The marine transgression carried on and ultimately
flooded all of the basement highs, it deposited on the internal parts, limestones and
dolomites, while on the edges, the oGORnic-reefal growths development commenced. At
the same time, and due to the thermal subsidence, the lower areas deepened, giving rise
to deep sea basins, where the three members of the Tamaulipas Inferior formation were
deposited (calcarenithic member, bentonitic member and creamy limestone member)
corresponding to the Berriasian-Barremian age. During the Aptian stage, the Otates
horizon formation deposition occurred, which is considered to be a condensed sequence.
During the Albian, along the entire Tuxpan platform a reef edge, roughly 1400 m thick,
which gave rise to lagoon facies on the inside of the platform, whereas for the reef front,
the Tamabra formation, featuring proximal, mean and distal slope facies, developed due
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