Martian simulants are an essential part of in situ resource utilization (ISRU) technology development and testing, and aid in providing new astrobiology insights regarding Mars's past habitability. This study proposes a new method involving average and standard deviation (ASD), complementary to figure of merit (FOM) simulant evaluation methods, for geochemical prospection and evaluation of simulant feedstock using portable XRF (pXRF) and whole-rock (ICP-OES) analyses. It also presents simulant modification calculations (SMC) that integrate multiple approaches used in simulant production and design, and provides theoretical mineral recipes (estimated mineral composition) and their estimated geochemical compositions for FOM evaluation of an intended target composition. These methods were used to prospect simulant material in volcanic-subvolcanic outcrops at the SW edge of the Atacama Desert in Chile, and to evaluate their potential for standard and enhanced simulant development. Through ASD (pXRF data) and FOM (ICP-OES data) evaluation, this resulted in the presentation of the first Chilean basic Martian bedrock simulant that can be used for biomining applications, which is tentatively labeled as Chilean Atacama Desert 1 (CAD-1). An Excel file with the applied prospection method and database is also available for simulant feedstock prospection (Supplementary section). Applying these methods will provide more base materials and components for simulant development and allow flexibility in their design for general and specific applications. C1 Tech Univ Bergakademie Freiberg, D-09599 Freiberg, Germany. [Leone, Giovanni] Univ Atacama, Inst Invest Astron & Ciencias Planetarias, Copiapo, Chile. [Riveros-Jensen, Karl] Univ Atacama, Dept Geol, Copiapo, Chile. [Alam, Mohammad Ayaz] Univ Santiago Chile, Dept Ingn Geoespacial & Ambiental, Santiago, Chile. [Cabrera, Ricardo; San Martin, Diego; Guiliani, Nicolas] Univ Chile, Fac Ciencias, Dept Biol, Santiago, Chile. [Oses, Romulo] Univ Atacama, Ctr Reg Invest & Desarrollo Sustentable Atacama, Copiapo, Chile. [Blamey, Jenny M.] Fdn Cient & Cultural Biociencia, Santiago, Chile. [Demergasso, Cecilia] Univ Catolica Norte, Ctr Biotecnol, Antofagasta, Chile. [Abrevaya, Ximena C.] UBA, Inst Astron & Fis Espacio IAFE, CONICET, Pabellon IAFE, Ciudad Univ,C1428EGA, Buenos Aires, DF, Argentina. [Britt, Daniel T.] Univ Cent Florida, Dept Phys, POB 162385, Orlando, FL 32816 USA. [Liu, Yang] CALTECH, NASA Jet Prop Lab, Pasadena, CA USA. [Silva, Washington] Univ Atacama, IDICTEC, Copiapo, Chile. [Tovar, David; Leal, Maria Angelica] Univ Nacl Colombia, Grp Ciencias Planetarias & Astrobiol GCPA, Bogota, Colombia. [Pablo, Miguel Angel de] Univ Alcala, Dept Geol Geog & Medio Ambiente, Alcala De Henares 28805, Spain. [Abrevaya, Ximena C.] UNIV BUENOS AIRES, FAC CIENCIAS EXACTAS & NAT, Ciudad Univ,C1428EGA, BUENOS AIRES, Argentina. [Abrevaya, Ximena C.] Graz Univ, Inst Phys, Dept Geophys Astrophys & Meteorol, Univ Pl 5, A-8010 Graz, Austria. [Abrevaya, Ximena C.] Argentinian Res Unit Astrobiol, Buenos Aires, Argentina. [Slumba, Karlis] Univ Adelaide, Fac Sci Engn & Technol, Sch Architecture & Civil Engn, Adelaide 5005, Australia. C3 Technical University Freiberg; Universidad de Atacama; Universidad de Atacama; Universidad de Santiago de Chile; Universidad de Chile; Universidad de Atacama; Universidad Catolica del Norte; Instituto de Astronomia y Fisica del Espacio (IAFE); University of Buenos Aires; Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET); State University System of Florida; University of Central Florida; National Aeronautics & Space Administration (NASA); NASA Jet Propulsion Laboratory (JPL); California Institute of Technology; Universidad de Atacama; Universidad Nacional de Colombia; Universidad de Alcala; University of Buenos Aires; University of Graz; University of Adelaide