U.S. Silica Holdings owns the Lamesa mine and processing plant.
July 31, 2024, U.S. Silica Holdings and Apollo announced that funds managed by aliates of Apollo have completed the previously announced acquisition of the Company. The Company will continue to operate under the U.S. Silica name and brand. As of July 31, 2024, U.S. Silica Holdings, Inc. was taken private.
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Summary:
Surficial geologic units overlying the area in and around the Lamesa Operation are predominantly comprised of undifferentiated Quaternary Age unconsolidated deposits, ranging from aeolian (windblown) sheet sands and dunes to alluvial sands, silts, clays, and caliche. Geologic mapping shows additional surficial stratigraphic units present in the vicinity of the project; however, the surface geology of the Lamesa Property is primarily comprised of these aeolian sand deposits.
The following text discusses the strata encountered in and around the Lamesa Operation in ascending depositional order.
Ogallala Formation
The Ogallala Formation is predominantly comprised of weakly cemented to unconsolidated fine- to medium-grained sands, which may be silty and calcareous in places. A caliche caprock is frequently exhibited, which resists weathering and forms ledges. Thickness of this formation has been recorded up to 550 ft.
Blackwater Draw
Formation The Blackwater Draw Formation covers a majority of the surface of Dawson County. While not clearly present on the surface at the Lamesa Operation, the Blackwater Draw Formation is predominantly comprised of fine- to medium-grained sand that is silty, calcareous, and locally clayey. Caliche nodules may be present, and deposition is noted as being massive; however, the unit generally is found to be less than 25 ft thick.
Quaternary Sheet and Dune Sands
Most of the subject property is covered by Quaternary sheet and dune sands generally consisting of fine- to medium-grained quartz sand grains, mixed with varying degrees of clays and silts. Exploration completed on the Lamesa Property indicates two surficial sand units being present, an upper clean sand unit and an underlying clayey cover sand unit.
Surficial geologic strata at the Lamesa Operation are predominantly comprised of aeolian (windblown) sand deposits. There is not any discernable overburden material present except for sparse areas of vegetation and roots, which are easily removed during early phases of the processing operations.
The surface sheet and dune sands deposited on the subject property consist of two distinct intervals of mineable sand: 1) an upper “clean sand” unit, and 2) a lower “cover sand” unit. Underlying the surface sand deposits is a hard, red clay basal unit, commonly referred to as hardpan.
Exploration data suggest the clean sand unit generally consists of unconsolidated, fine- to medium-grained, well sorted and subangular to rounded sand grains. Thickness of this unit ranges from 13 to 46 ft. The clean sand is noted as containing generally less than 10% to 15% very fine (clay) material. The central and western extents of the Lamesa Property exhibit the clean sand unit at the surface, thinning to the east, and is absent over the eastern-most third of the property. The limit of the clean sand deposit is delineated by a clearly visible “dune line” running north to south and bisecting the subject property.
East of the dune line, the cover sand unit is present at the surface. The cover sand is also present and underlies nearly all the clean sand west of the dune line on the Lamesa property. Geologic logs describe this unit as consisting of a clayey, hard sandstone interval, with very fine- to medium-grained, subangular to rounded sand grains, and ranging in thickness from 0 to 25 ft. The cover sand is noted as consisting of 15% to 45% fine material due to the higher clay content.
The two sand units are generally mineable from the ground surface down to the basal red clay unit. Combined thickness of both sand units ranges from 25 to 65 ft across the property.
he sand mined at the Lamesa Operation is processed to produce proppant sand. Proppant sand is a naturally occurring, high silica content quartz sand, with grains that are generally well-rounded. The main difference between proppant sand and other sands is that proppant sand grains are relatively pure in composition, consisting almost entirely of quartz; other sands have numerous impurities that may be cemented to the quartz grains. The pure quartz composition of proppant sand grains, along with being wellrounded and spherical in shape, gives these sands the characteristics (crush strength, high acid solubility, low turbidity) that are sought after by oil and gas producers for use in developing wells.