The Nacatoch Formation of the East Texas Basin is the
middle formation of the Navarro Group and consists of marine sandstones and
mudstones derived largely from source areas to the northwest, north, and
northeast of the East Texas Embayment. Terrigenous clastics were supplied to
the Nacatoch Basin by a major northeastern dispersal system originating in
southwest Arkansas. Three minor fluvial-delta systems contributed sediment in
southern Red River, Delta, and Hunt Counties, Texas. Five facies are recognized
in Nacatoch outcrops in southwest Arkansas: tidal-flat, tidal-channel,
tidal-inlet- associated, shoreface, and shelf facies. In northeast Texas, a
delta sequence occurs in south-central Hunt County, and shelf sandstones and
mudstones are present in Navarro and Kaufman Counties. The lateral association
of deltaic deposits and tidal-flat sequences, together with the type, scale,
and distribution pattern of inferred tide-produced structures, suggests that
tides within the upper microtidal to lower mesotidal range (3 to 8 ft; 1 to 2.5
m) occurred in the East Texas and North Louisiana Embayments during deposition
of the Nacatoch Formation. The Nacatoch Formation in the East Texas Basin is
restricted to the northern and western parts of the basin. The sandstone bodies
trend mainly northeast to southwest in the northern part of the basin and north
to south along the western margin. In the southern half of the basin, the
Nacatoch Formation consists of mudstones. In the subsurface of the East Texas
Basin, the Nacatoch Formation can generally be subdivided into nearshore and
shelf deposits. Nearshore sequences include deltaic deposits in the north and
the northwest parts of the basin that are located downdip from surface
exposures of the same facies. Two thick net-sand axes, oriented perpendicularly
to the outcrop belt, extend southward into the basin. Orientation of these sand
axes changes abruptly to become parallel within the dominant
northeast-southwest trend, suggesting that the delta was dominated by tides and
waves. It is inferred that interdeltaic areas were sites of short barrier
islands, broad tidal inlets with associated tidal deltas, and tidal flats.
Offshore deposits can be arbitrarily divided into a lower and an upper
sandstone sequence separated by 50 to 100 ft. (16.6 to 33.3 m) of marine
mudstone.

The Paluxy Formation is a geological formation found in Texas, Louisiana, Arkansas, Mississippi and Oklahoma, whose
strata date back to the Early
Cretaceous. Dinosaur remains are among the fossils that
have been recovered from the formation. Proposals for the exact age of the
Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of
2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a)
was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for
the boundary to c. 121–122 Ma. There is a possible link between this
anoxic event and a series of Early Cretaceous large igneous provinces (LIP).

The
Ontong Java-Manihiki-Hikurangi
large igneous province, emplaced in the South Pacific at c. 120 Ma, is by
far the largest LIP in earth's history. The Ontong Java Plateau today covers an
area of 1,860,000 km². In the Indian Ocean another LIP began to form at c.
120 Ma, the Kerguelen Plateau-Broken Ridge
together covering 2,300,000 km².[4]
Another LIP on the Liaodong Peninsula, China,
c. 131–117 Ma lasted for 10 million years. It was the result of the
subduction of the Kula and Pacific
plates, which was probably caused by a superplume.    

The Glen Rose is the uppermost, thickest and most extensively exposed formation
of the Trinity Group, a series of
shallow-water marine formations deposited on a southeastward flank of the Llano Uplift,
through a number of sea regressions and transgressions. Wells drilled in
eastern Travis County have encountered over
1,000 feet of the Glen Rose. In the northern part, the Glen Rose is laterally
continuous with the Paluxy Formation. The Glen Rose overlies the Hensel Sand
and is overlain in turn by formations of the Fredericksburg division.
In 1974, Keith Young concluded, based on ammonite zonation, that the formation
ranges from late Upper Aptian into the Lower Albian,
about 115-105 million years old.

The formation consists mostly of hard limestone
strata alternating with marl or marly limestone, but is replaced by sandy
facies shoreward (to the northwest). Because of the differing strengths of the
layers, the limestone weathers to form a staircase profile on hills. These
strata were originally referred to as the "Alternating Beds", which
term included the overlying Fredericksburg formations.

The Glen Rose has been divided into upper and lower portions, separated by a
one-foot layer of Corbula shells, a small bivalve. 

The Woodbine Group is
a geological formation in east Texas whose strata date
back to the Early to Middle Cenomanian age of the Late
Cretaceous. It is the producing formation of the giant East Texas Oil Field (also known as the
"Black Giant") from which over 5.42 billion barrels of oil have been
produced. The Woodbine overlies the Maness Shale, Buda
Limestone, or older rocks, and underlies the Eagle Ford
Group or Austin Chalk. In outcrop the Woodbine Group has
been subdivided into the Lewisville Sandstone, Dexter Sandstone, and/or Pepper
Shale formations. Thin-bedded sands of the Woodbine and Eagle Ford are
collectively referred to as the "Eaglebine" oil and gas play in the
southwestern portion of the East Texas region.

Dinosaur and crocodilian remains are among the
fossils that have been recovered from the formation. This fossil formation
preserves organisms that were endemic to Appalachia.

The Woodbine Group was first mapped and named by Robert T.
Hill, known as the "Father of Texas Geology", for outcrops
near the small town of Woodbine, Texas in 1901. The Woodbine
represents ancient river and delta systems that originated from erosion of the
Ouachita Uplift in modern-day Oklahoma and Arkansas and the Sabine Uplift in modern-day Texas and Louisiana.
Sediments from these deltas flowed into the East Texas and Brazos Basins of the
ancient East Texas
shelf.