The First Geologic Map of New Mexico Spencer G
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The first geologic map of New Mexico Spencer G. Lucas, New Mexico Museum of Natural History and Science, 1801 Mountain Road NW, Albuquerque, New Mexico 87104 Introduction 2), and Kues (1985a, fig. 11; 1985b, fig. 7) the United States that placed him among a reproduced parts of the map in black and competitive group of compilers of such In 1858 the French geologist Jules Marcou white. DeFord (1972) also discussed some maps, including James Hall, Edward (1824–1898) published the first geologic aspects of Marcou’s map. Here, I re-pub- Hitchcock, and Henry Rogers, who map of New Mexico. This map was a prod- lish Marcou’s entire map in color at about worked in the decades immediately pre- uct of Marcou’s 1853 traverse of the New half of its original size (Fig. 2). My text is in ceding the Civil War (Nelson, 1999). Mexico Territory as the geologist of the four parts—a brief overview of the context Indeed, as Goetzmann (1959, p. 311) Whipple expedition to determine a route of Marcou’s map, an explanation of the noted, Marcou “published the first geolog- for a transcontinental railroad (Fig. 1; geologic units Marcou mapped, a summa- ic map of the West, which made him a con- Kues, 1985a). Marcou’s map (Fig. 2) is not ry of the map, and a brief evaluation of its troversial figure in American scientific cir- a complete geologic map of the territory strengths and weaknesses. cles for most of his later career.” Much of (nor of the current state)—it encompasses the controversy focused on Marcou’s work about one degree of latitude around 35°N. in New Mexico, where he identified vast Nevertheless, it was the first map explicit- Context of Marcou’s map expanses of Triassic and Jurassic strata, ly titled “Geological Map of New Mexico.” particularly under the southern High It predates, by about 70 yrs, the first pub- In 1853 Marcou served as chief geologist of Plains (e.g., Goetzmann, 1959; Kues, 1985b; lished, statewide maps of Ellis (1925) and the Army Corp of Topographical Engin- Nelson, 1989, 1999). Darton (1928). Indeed, Blake’s (1856) geo- eers’ Survey of the 35th Parallel Route for logic map of Marcou’s route is a crude the Pacific Railroad, under the leadership Marcou’s stratigraphy effort based on Marcou’s data by some- of Lieutenant Amiel Whipple (Goetzmann, body who never visited the state (Kues, 1959). This survey was authorized and Born in Salins, France, near the Jura Moun- 1985a). funded by the U.S. Congress and traversed tains, Marcou first studied mathematics Marcou’s map is little known to geolo- from Fort Smith, Arkansas, to Los Angeles, and then trained in geology. His outstand- gists working in New Mexico today, large- California, between July 1853 and March ing talent brought him a professorship in ly because of the rarity of the book in 1854 (Fig. 1). As survey geologist, one of mineralogy at the Sorbonne in 1846 and a which it first appeared as an approximate- Marcou’s (1853, p. 58) primary goals was curatorship (in fossil conchology) at the ly 63 x 14 cm (25 x 6 inch) color foldout “to synchronize the sedimentary rocks of Jardin de Plantes in 1847. He subsequently (Marcou, 1858, pl. 8). Kelley and Northrop America with those of Europe.” The results traveled to the United States, married into (1975, fig. 8), Hook and Cobban (1979, fig. of Marcou’s efforts were geologic maps of a wealthy family, and ultimately spent 84 NEW MEXICO GEOLOGY August 2001 Marcou’s map employs eight carto- graphic units, three of igneous or meta- California Oklahoma morphic rocks and five of sedimentary rocks. In temporal order (oldest to Los Fort youngest), they are: Angeles Arizona New Smith (1) Granite, Gneiss, Porphyry, etc. (G); Mexico (2) Carboniferous (M for Mountain Lime- stone); (3) New Red Sandstone (R); Texas (4) Jurassic (J); (5) Cretaceous (C); (6) Volcanos (sic) (V); Marcou’s (7) Trap (T); and Map (8) Quaternary (O). FIGURE 1—Route of the Whipple expedition of 1853, and area included in FIGURE 2—Jules Marcou’s geologic map of Marcou’s (1858) geological map of New Mexico (Fig. 2; after Goetzmann, 1959). New Mexico (from Marcou, 1858, pl. 8). most of his later life in this country (Lurie, above). Thus, his 1858 text abounds in Granite, gneiss, porphyry, etc. 1974). In reviewing Marcou’s geologic map close comparison of the European and of New Mexico, we should realize that, North American rock successions, tinged Based on his observations in the Sangre de although Marcou was an all-round geolo- with clear satisfaction when a close corre- Cristo and Sandia Mountains, Marcou gist in the best tradition of his times, his spondence/correlation is established. This (1858, pp. 20–21) noted that “masses of research and expertise focused on sedi- is well reflected by Marcou’s ready use of Granite…form the centre of the line of dis- mentary rocks and fossils. Indeed, Sarjeant European names such as “Mountain location of the Rocky Mountains.” He fur- (1980, p. 1648) appropriately labeled Limestone” and “New Red Sandstone” for ther observed (p. 21) that in the Sandia Marcou a “stratigrapher, structural geolo- New Mexican strata. And, where he Mountains (Tijeras Canyon) he encoun- gist and invertebrate paleontologist.” judged lithologic similarity to be less close, tered a succession of “quartzose metamor- Like most European geologists of the Marcou proposed direct correlation of the phic rocks,” then “serpentine,” and then early nineteenth century, Marcou expected New Mexican units to their European granite. However, Marcou provided no to find a close correspondence between the equivalents; for example, his correlation of further information on these basement rock formations already delineated in the marine Cretaceous strata of north-cen- rocks, probably because his interests and western Europe and those in North tral New Mexico to the European “White expertise lay elsewhere. America (see quote from Marcou, 1853 Chalk.” August 2001 NEW MEXICO GEOLOGY 85 Carboniferous Jurassic is mostly the Entrada Sandstone, river….” Marcou, however, offered no now recognized across the state and detailed description of these rocks, which Based on what he’d seen of the European known to be of Middle Jurassic age. he probably assumed to be very young section, Marcou would have expected the because of their coarse-grained and uncon- New Mexican Carboniferous to consist of a solidated textures. lower, limestone-dominated interval and Cretaceous an upper, coal-bearing interval. Marcou Marcou gave no thickness for these rocks applied the British terms “Mountain and described them (p. 22) as mostly a Summary of the map Limestone” (in Europe these strata form white, friable sandstone that is horizontal- Four pages of explanatory text (Marcou, mountains) and “Coal Measures” to these ly stratified with index fossils of the 1858, pp. 54–57) accompany Marcou’s geo- rocks. In New Mexico, Marcou’s most Cretaceous, including Inoceramus, “Ammo- logic map. This text begins with a short detailed examination of these rocks was in nites,” and Scaphites. The shark tooth found introduction, concluded by a disclaimer: the Sandia Mountains (Tijeras Canyon) near Galisteo in these strata that Marcou “This map must be regarded as a first essay where he described them as “grayish blue named Ptychodus whipplei was the first ver- upon a country about which the geological limestone, containing a great quantity of tebrate fossil described from New Mexico. notions have hitherto been very vague, and fossils” (p. 20). Above them are a “black Marcou correlated the New Mexican I publish it only as a first attempt upon a slate” or “black schistose clay” assigned to Cretaceous to the White Chalk (Craie terra incognita.” The remaining text is struc- the “coal measures” but not mapped sepa- Blanche) of France. He also stated (p. 22) tured as a narrative organized by Marcou’s rately (p. 20). Marcou states the Mountain that “the discordance of stratification of 38 camps in New Mexico and the traverses Limestone in New Mexico has a mean the Upper Cretaceous of New Mexico, between these camps. Here, I divide thickness of 700 ft (p. 21). His assessment with all the sedimentary rocks found there, Marcou’s map into three geographic por- of the fossils he collected and described indicates that this formation was deposit- tions—east-central, north-central, and (mostly brachiopods) led him to incorrect- ed after the principal dislocation of the west-central New Mexico. ly assign the New Mexican Mountain Rocky Mountains, which took place at the Limestone to the Early Carboniferous. But, end of the American Jurassic period.” This East-central New Mexico as Newberry (1861) first determined, and repudiation of basic principles led Marcou Marcou traversed east-central New Mexico as stressed by Kelley and Northrop (1975, to an erroneous conclusion, as the from east to west, just north of the 35th pp. 35–44), who reviewed Marcou’s Cenozoic uplift of the Rocky Mountains parallel, and stayed at ten camps. The geo- Carboniferous fossils in detail, they are all postdates the Cretaceous strata that are, in logic map across this traverse identifies Pennsylvanian in age. part, dislocated by the Rocky Mountain only two stratigraphic units—lowlands of orogeny, not the reverse! New Red Sandstone and uplands of New Red Sandstone Jurassic strata. Volcanos (sic) Marcou’s observations at Pyramid During the early 1800s British geologists Mountain (pp. 18–21; Fig. 3), between referred to most of the strata between the Marcou mapped volcanic rocks across camps 4 and 5, proved critical to these Carboniferous and Lower Jurassic (Liassic) large parts of north-central and west-cen- determinations (DeFord, 1972; Kues, as the New Red Sandstone (Wilmarth, tral New Mexico.