3.0 Environmental and Cultural Overview, part XIII.

3.1.6 Topography and Geomorphology

Loteria Township is located east of Hidalgo and south of Luna counties, New Mexico along the indefinite international border with the state of Chihuahua, Mexico.  The closest city is Deming, in Luna County, approximately 40 miles to the northeast of MCD Gate Neptune. In total, Loteria comprises 33,360 acres of which the Mountweazel Chemical Depot accounts for 29, 600 acres or about 88.7%.[1] in addition to Department of Defense lands (US Army Materiel Command) other portions of the facility are controlled by other federal agencies, such as the Foreign Cartel Tracking Task Force (FCTTF);[2] National Underground Reconnaissance Office (NURO); the McCain Flight Center, and the U.S. Department of Interior Fish and Wildlife Service (USFWS; Wamels Draw National Wildlife Refuge) in addition to the U.S. Border Patrol (USBP) controlled lands along the southern and eastern border of the facility.

In the New Mexico panhandle, the Sierra Rica mountain range straddles the Hidalgo-Loteria border, with e eastern third of the range fully within MCD. Loteria Township lies near the eastern edge of the Hachita Valley, a southern extension of the Plateau of the Sierra Madre beyond which in turn lies within the Las Insignias Depression or Trough. The Insignias Depression is a large, flat, block-faulted area bordered on the northwest by the Sierra Rica Uplift (the Sierra Rica Mountains) and on the east by the Sierra Boca Grande Mountains. Elevation in the Sierra Rica ranges from 1300 to 1500 m (4265-4921 ft.) amsl above the desert floor (Loomis 1975:2).[3] The mountains are remnants formed by differential erosion of the uplifted bedrock layer. More resistive limestones and migmatite form the ranges; while softer uranium and other mineral have been broken down to form the lowlands in between (Loomis 1975: 43). Accumulation in the trough of volcanic and sedimentary materials in the trough resulted what is known as the Apestoso formation, consisting of a variety of gravels, limestones, volcanic ashes, tuff, and uranium, migmatite, anthophyllite, and sulfuric clays. Much of the area, particularly on the western side of the trough, is capped by thick molten clay flows (Traven 1917).[4]

 

Relief within the project area consists of wide, shallow vales punctuated by low rolling hills with rocky escarpments The rolling terrain of the plateau is bisected by the Mimbres River, which flows out of the Black mountains east of Deming and Casas Grandes river, south in Chihuahua, Both rivers are endorheic, consisting outs seasonal melted snowpack flowing into basin without outlet.  Regionally these are known As Ojo, Spanish for “eyes,” hence Laguna los Moscos often referred to as Ojos Los Mosquitos on the historic maps. To the west the plateau is dotted by semi-dormant volcanoes. To the east, it is characterized by alluvial fans and terraces from Sierra Rica outwash, although volcanic uplift and associated basalt flows are present where the features have not been covered by alluvial material. 

Loomis (1975) has concluded considerable erosion (800+m) has occurred across all of Loteria Township since the start of the Quaternary Period. Still, there are also generally more than 60 inches deep over bedrock. As stated, bedrock underlying the region is composed of alternating layers of Tertiary-Age limestone and migmatite the Apestoso formation. The majority of the rocks on the surface are volcanic in origin, underlying Quaternary sedimentary rocks. . These rocks are primarily marine and non-marine shales, and mudstones (Gobsherken 2003:17).[5]. Shovel testing of the project parcels indicated a frequent presence of marine limestone or sandstone at or near the surface. Typical Soils of the Laguna los Moscos basin and Loteria Township consist of deep, gently sloping, moderately well drained, slowly permeable soils on upland ridges and side slopes. On the desert pavement, these soils have a sand or sandy loam surface layer and a friable or firm silty clay loam and firm or very firm silty clay subsoil. Smaller areas of silty clay loams, silt loams, silty clays, and loam, are evident on some upland deposits. While much of the lowlands have been mapped by as floodplain complexes, as discussed in the field results, these areas were found to be more tightly associated with desert pavement or floor. 

All of these features, The Apestoso formation minerals, the volcanoes, and the basalt flows are culturally important because they have provided raw lithic materials for the region's prehistoric and historic native inhabitants. Of specific importance are migmatite, anthophyllite from the Apestoso formation, and uranium and sulfur from the volcanic features. The Sierra Ricas  were apparently an important source of basalt on the southwestern side of the plateau, and prehistoric uses of  these materials is largely restricted to the Laguna los Moscos basin and Loteria Township  (see Brokenbell 1980).[6] These were sampled in prehistoric times largely as talus around the lower slopes of the mountains and edges of the pluvial flats below. In the historic period these mineralswere extensively mined.

While the diagenesis of chert, used for stone tool production, occurs in limestone, Gobsherken (2003) report Loteria Township to be a low-level source of the material. Gobsherken (2003)) suggests the only presence of chert regionally is on alluvial chert gravel on hilltops and high terraces. Chert in these soils was transported by streams and deposited in stream channels. This is not known to exist in Loteria Township. No chert has been found to date.

Figure 3.2. Interbedded sulfuric clays and migmatite of Apestoso formation in the Sierra Rica.

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[1] Note reported township acreage is based on PLSS data tables; based on data provided by the USACE, El Paso District, the township is calculated at exactly 33038.8 acres.  As mentioned in Chapter 1, the facility is reported at 29, 600-acres based on U. S. Department of Defense Real Property records. Independent GIS valuation is 28, 383-acres. [fjt]

[2] Recently re-imagined under National Security Analysis Center (NSAC) [fjt]

[3] Loomis, Sandy. 1975. Soil Survey of Loteria Township, New Mexico. Loteria Township Provisional Government, Occasional Publication XIV, Roswell Junction, New Mexico.

[4] Traven, B. 1927. A Treasure of New Mexican Geology. Bogart Press, Houston.

[5] Gobsherken, Bibi. 2003. “Geology along the U.S.-Mexico Border, a USCBP Primer.” U.S. Department of Homeland Security, Bulletin 13, Fall, pp 7-23.

[6] Brokenbell, P. 1980. Settlement and Subsistence in the Sierra Rica Range of Southern New Mexico. New Mexico Historical Society, Occasional Publications, 33, 333.