CONSTRAINING THE RELATIVE TIMING AND DURATION OF THESE AQUEOUS PERIODS BASED ON THE GEOLOGIC RECORD IS OF FUNDAMENTAL IMPORTANCE TO AN ACCURATE CHARACTERIZATION OF PAST CLIMATE CONDITIONS ON MARS. WHILE PAST RESEARCH HAS FOCUSED ON FLUVIAL LANDFORMS MAINLY VALLEY NETWORKS ALLUVIAL FANS ARE LANDFORMS THAT CAN PROVIDE INSIGHT INTO THIS CRITICAL QUESTION BECAUSE THEIR FLOW PROCESSES HAVE DISCRIMINABLE DIFFERENCES IN THE RESULTING DEPOSITS THAT CAN BE DIRECTLY TIED TO WATER VOLUME AND DURATION. DOCUMENTING THE DETAILED STRATIGRAPHIC CONTEXT OF ALLUVIAL FAN DEPOSITS GLOBALLY WILL IMPROVE OUR UNDERSTANDING OF THE RELATIVE TIMING OF CLIMATIC CONDITIONS. EXAMINATION OF THE GLOBAL RECORD OF ALLUVIAL FANS PROVIDES A TEST BETWEEN THE WARM WET AND THE COLD DRY CLIMATE HYPOTHESES AND WILL PROVIDE CLIMATE MODELERS WITH HARD CONSTRAINTS ON THE TIMING MAGNITUDE AND DURATION OF WARM-WET CONDITIONS. THE SYNTHESIS OF ORBITAL DATA (IMAGE TOPOGRAPHIC AND COMPOSITIONAL) WITH HYDRAULIC MODELING IN THIS INTERDISCIPLINARY INVESTIGATION IS CONSISTENT WITH THE SCIENTIFIC OBJECTIVES OF THE MARS DATA ANALYSIS PROGRAM (MDAP). IN ADDITION THIS INVESTIGATION ADDRESSES MULTIPLE MEPAG (2015) SCIENCE GOALS INCLUDING II.C2 (FIND AND INTERPRET PHYSICAL AND CHEMICAL RECORDS OF PAST CLIMATES AND FACTORS THAT AFFECT CLIMATE) AND III.A1 (IDENTIFY AND CHARACTERIZE PAST AND PRESENT GEOLOGIC ENVIRONMENTS AND PROCESSES RELEVANT TO THE CRUST). CONSTRAINING THE PALEO-HYDROLOGIC CONDITIONS AND TIMESCALES OF AQUEOUS ACTIVITY ASSOCIATED WITH ALLUVIAL FAN FORMATION AT SITES AROUND THE GLOBE CONTRIBUTES TO A BETTER UNDERSTANDING PAST CLIMATE CONDITIONS AND HABITABLE REGIONS. LARGE ALLUVIAL FANS IN MARTIAN HIGHLAND CRATERS HAVE BEEN INTERPRETED AS EVIDENCE OF A LATE-STAGE PERIOD OF FLUVIAL ACTIVITY BETWEEN EARLY HESPERIAN AND EARLY AMAZONIAN (3.7 TO 3.3 GYR). THUS LARGE ALLUVIAL FANS DOCUMENT DEPOSITIONAL CONDITIONS FOR A CRITICAL WINDOW IN MARS CLIMATE HISTORY WITH PROFOUND IMPLICATIONS FOR UNDERSTANDING THE PRESENCE LOCATION AND PERSISTENCE OF SURFACE HABITABLE ENVIRONMENTS. THE PROPOSED INVESTIGATION WILL CONDUCT MAPPING OF APPROXIMATELY 30 ALLUVIAL FAN SITES AROUND THE GLOBE TO DOCUMENT FLOW PROCESS AND STRATIGRAPHIC CONTEXT. HIGH RESOLUTION IMAGES FROM THE CTX HIRISE AND MOC INSTRUMENTS WILL BE USED TO DIFFERENTIATE SEDIMENT-GRAVITY FLOW DEPOSITS FROM FLUID-GRAVITY DEPOSITS AS WELL AS THE SUPERPOSITION RELATIONSHIPS BETWEEN DEPOSITS TO DEVELOP AN EVOLUTIONARY SEQUENCE. THE MINERALOGY IN FAN DEPOSITS DETERMINED IN SPECTRAL DATA WILL SHED INSIGHT ON FLOW RHEOLOGY AND COMPOSITION. HYDRAULIC MODELING OF FAN FLOWS WILL BE BASED ON THE GEOMORPHIC ANALYSIS UNDERPINNED BY TOPOGRAPHIC DATA FROM MOLA AND ELEVATION MODELS CONSTRUCTED FROM STEREO IMAGE PAIRS. ULTIMATELY THE EVOLUTIONARY SEQUENCE OF ALLUVIAL FANS WILL BE DETERMINED THROUGH THE COMBINED GEOLOGIC MAPPING AND MODELLING RESULTS.