MOTIVATION: HESPERIAN- TO AMAZONIAN-AGED DEPOSITIONAL FEATURES SUCH AS ALLUVIAL FANS MAY REPRESENT ONE OF THE LAST WIDE-SPREAD SIGNS OF FLUVIAL ACTIVITY ON MARS' SURFACE. AS SUCH UNDERSTANDING THE CLIMATIC CONDITIONS DURING THE FORMATION OF THESE FEATURES MAY PROVIDE KEY INSIGHTS ON HABITABILITY AND CLIMATE CHANGE AS MARS WENT FROM BEING POTENTIALLY WET AND WARM TO ITS CURRENT COLD AND DRY STATE. NUMEROUS STUDIES HAVE USED MORPHOMETRIC PARAMETERS FROM TERRESTRIAL FAN SYSTEMS SUCH AS FAN LENGTH OR SLOPE TO DIFFERENTIATE BETWEEN LOW ROCK TO WATER RATIO FLUVIAL PROCESSES (I.E. PARTICLES ARE TRANSPORTED BY FLOWING WATER) AND HIGH ROCK TO WATER RATIO INERTIAL PROCESSES (E.G. DEBRIS FLOWS). THIS COMBINED WITH MEASUREMENTS OF CHANNEL GEOMETRY OR THE GEOMETRY OF ELEVATED CHANNEL BEDS (NOW RIDGES) ALLOW FOR THE ESTIMATION OF FLOW DISCHARGES RUNOFF RATES AND TOTAL WATER VOLUMES THAT LIKELY BUILT MARTIAN FANS. HOWEVER MOST TERRESTRIAL WORK HAS BEEN CONDUCTED ON ALLUVIAL FANS THAT ARE IN DRY AND ARID LOCATIONS WHERE THE SOURCE OF WATER IS FROM PRECIPITATION EVENTS OCCURRING OVER THE ENTIRE FAN. THIS DIFFERS FROM THE CURRENT HYPOTHESIS THAT MOST MARTIAN FANS SOURCED WATER ONLY FROM THEIR UPSLOPE CATCHMENTS LIKELY FROM SNOWMELT AND PERHAPS UNDER COLD AND ICY CONDITIONS. AS SUCH THERE IS A KNOWLEDGE GAP ABOUT THE DOMINANT PROCESSES AND ENVIRONMENT NEEDED TO BUILD FANS UNDER COLD AND ICY CONDITIONS AND IMPORTANTLY FOR MARS A LACK OF UNDERSTANDING ABOUT THE CHARACTERISTIC FLOW MAGNITUDES (I.E. WATER VOLUMES) DURING DEPOSITIONAL EVENTS. OBJECTIVES AND METHODOLOGY: WE PROPOSE A FIELD-BASED TERRESTRIAL ANALOG STUDY TO FULLY CHARACTERIZE PERIGLACIAL ALLUVIAL FANS IN THE RICHARDSON MOUNTAINS NORTHWEST TERRITORIES CANADA. THIS PROJECT HAS THREE MAIN OBJECTIVES ALL AIMED AT UNDERSTANDING THE DOMINANT PROCESSES THAT LED TO MARTIAN ALLUVIAL FAN FORMATION AND IMPORTANTLY THE CLIMATIC IMPLICATIONS FOR POST-NOACHIAN MARS. THE FIRST OBJECTIVE IS TO QUALITATIVELY DESCRIBE THE RANGE OF SEDIMENTARY PROCESSES OCCURRING ON PERIGLACIAL ALLUVIAL FANS. THE SECOND IS TO CHARACTERIZE THE INFLUENCE OF WATER-ICE ON FAN DYNAMICS SUCH AS WHEN AND WHERE FLOW EVENTS INITIATE AND THE AMOUNT OF WATER INVOLVED. THE THIRD IS TO DETERMINE WHETHER PERIGLACIAL ALLUVIAL FANS HAVE CHARACTERISTIC FEATURES RECOGNIZABLE AT THE SCALES AT WHICH REMOTE SENSING DATASETS OF MARS ARE ACQUIRED. THE OBJECTIVES OF THIS PROPOSED RESEARCH WILL BE ACCOMPLISHED MAINLY IN THE FIELD USING A COMBINATION OF TRADITIONAL SEDIMENTOLOGY AND GEOMORPHOLOGY FIELD TECHNIQUES (E.G. GRAIN SIZE ANALYSIS CHARACTERIZATION OF BEDDING AND IMBRICATION AND SURFICIAL MAPPING) REMOTE SENSING (E.G. DRONE FLIGHTS TO CAPTURE TOPOGRAPHY THERMAL DATA AND HIGH-RESOLUTION IMAGERY) AND GEOPHYSICAL TOOLS (E.G. GROUND PENETRATING RADAR). RELEVANCE: THIS PROPOSAL IS A FIELD-BASED TERRESTRIAL ANALOG STUDY OF ALLUVIAL FAN FORMATION UNDER COLD AND ICY CONDITIONS WHICH IS WITHIN THE SCOPE OF THE SOLAR SYSTEMS WORKINGS (SSW) PROGRAM. IT IS RELEVANT TO THE SSW PROGRAM AS WELL AS TO NASAS MARS INTERESTS IN GENERAL IN THAT IT WILL PROVIDE MUCH NEEDED DATA ON DEPOSITIONAL PROCESSES AND WATER AMOUNTS AND VOLUMES IN A CLIMATE THAT MAY MORE CLOSELY RESEMBLE MARTIAN CONDITIONS IN THE POST-NOACHIAN. THIS PROPOSAL WILL AID IN OUR UNDERSTANDING OF THE EVOLUTION AND MODIFICATION OF THE MARTIAN SURFACE (AS WELL AS OUR OWN PLANET UNDER A CHANGING CLIMATE) AND WILL PROVIDE DATA FOR DEVELOPING THEORETICAL AND/OR EMPIRICAL MODELS FOR FAN DEPOSITION PROCESSES UNDER DIFFERENT CLIMATE SCENARIOS (INCLUDING UNDERSTANDING ALLUVIAL FAN FORMATION IN OTHER COLD ICY ENVIRONMENTS SUCH AS TITAN).