THE NOACHIAN (4.1-3.7 GA) IS AN INTERESTING GEOLOGICAL PERIOD OF ANCIENT MARS AS MANY AQUEOUS PROCESSES SHAPED THE ROCK MINERALOGY AND LANDSCAPES OF MARS' SURFACE DURING THIS TIME PERIOD. UNDERSTANDING THE GEOLOGICAL ENVIRONMENTS OF THE NOACHIAN IS IMPORTANT TO DETERMINE THE KEY GEOLOGICAL PROCESSES THAT CONTRIBUTED TO THE EVOLUTION OF THE MARTIAN SURFACE. FURTHERMORE SUCH AQUEOUS ENVIRONMENTS DURING THE NOACHIAN MAY HAVE BEEN HABITABLE AND COULD CONTAIN BIOSIGNATURES FOR FUTURE IN-SITU EXPLORATION. WE PROPOSE TO STUDY THE NOACHIAN BASEMENT SURROUNDING ISIDIS IMPACT CRATER. THIS REGION IS PARTICULARLY INTERESTING BECAUSE IT ENCOMPASSES TWO OF THE THREE PROPOSED LANDING SITES FOR THE MARS 2020 ROVER. IN ADDITION THE ISIDIS IMPACT ITSELF GENERATED GEOLOGICAL FEATURES AS A RESULT OF THE TEMPERATURES PRESSURES AND STRESSES INVOLVED WITH A BASIN-SCALE (HUNDREDS OF KILOMETERS) IMPACT EVENT. ONE OF THESE FEATURES IS MEGABRECCIA (MULTI-METER SCALE BRECCIA BLOCKS THAT FORM FROM IMPACTS TECTONIC AND VOLCANIC PROCESSES). STUDYING SUCH FEATURES WILL HELP OTHER RESEARCHERS CONSTRAIN MODELS OF BASIN-SCALE IMPACTS IN FUTURE. THE PROJECT WILL INVOLVE THREE GOALS: 1) UNDERSTANDING THE GEOLOGICAL STRUCTURES FROM BASIN-SCALE IMPACTS. 2) UNDERSTANDING COMPOSITION GEOLOGICAL STRUCTURES AND PROCESSES OF THE NOACHIAN BASEMENT. 3) PROVIDING FURTHER INFORMATION ON AN IMPORTANT GEOLOGICAL UNIT IN TWO OF THE THREE PROPOSED LANDING SITES FOR MARS 2020 MISSION. THE PROJECT ENCOMPASSES FOUR RESEARCH OBJECTIVES AND SEVEN TASKS. TWO RESEARCH OBJECTIVES INCLUDE DETERMINING THE TYPES AND DISTRIBUTION OF GEOLOGICAL FEATURES CREATED FROM THE ISIDIS IMPACT AS WELL AS CHARACTERIZING THE COMPOSITION AND MORPHOLOGY OF THE MEGABRECCIA IN PARTICULAR. THESE TWO OBJECTIVES FOSTER THREE TASKS: 1) CLASSIFYING AND MAPPING IMPACT FEATURES THROUGH HIRISE THE HIGH-RESOLUTION CAMERA ON THE MARS RECONNAISSANCE ORBITER (MRO). 2) CHARACTERIZING THE MINERALOGY OF MEGABRECCIA THROUGH CRISM THE IMAGING SPECTROMETER ON THE MRO. 3) CREATING ELEVATION DATA FROM HIRISE IMAGES (HIRISE DEMS) AND USING THESE TO PERFORM STRUCTURAL ANALYSIS TO DETERMINE ORIENTATIONS AND RELATIVE AGES OF DIFFERENT GEOLOGICAL STRUCTURES OF THE NOACHIAN BASEMENT. A THIRD RESEARCH OBJECTIVE CONCENTRATES ON COUPLING THE MINERALOGY OF THE NOACHIAN BASEMENT OBSERVED VIA CRISM WITH THE GEOLOGICAL STRUCTURES OF THE NOACHIAN BASEMENT OBSERVED VIA HIRISE. THIS OBJECTIVE COMPRISES TWO TASKS: 1) INVESTIGATING ~50 CRISM IMAGES TO MAP THE DIFFERENT MINERALOGIES OF THE BASEMENT. 2) ANALYZING THE GEOLOGICAL STRUCTURES IN HIRISE IMAGES CORRESPONDING TO THE ~50 CRISM IMAGES AND INTEGRATING PREVIOUS MAPPING RESULTS FROM BRAMBLE ET AL. (2017) AND GROUDGE ET AL. (2015). THE LAST RESEARCH OBJECTIVE FOCUSES ON UNDERSTANDING THE GEOLOGICAL HISTORY OF THE NOACHIAN BASEMENT. THIS OBJECTIVE WILL ENCOMPASS THE LAST TWO TASKS OF THE RESEARCH PROJECT WHERE DATA FROM KEY LOCATIONS WILL BE CO-REGISTERED AND A COLLECTIVE INTERPRETATION OF GEOLOGICAL PROCESSES AND THEIR TIMING WILL BE FORMED PROGRESSIVELY. THE PROPOSED PROJECT IS DIRECTLY RELEVANT TO THE PLANETARY SCIENCE DIVISION OBJECTIVE 1.5 OF THE 2014 NASA STRATEGIC PLAN AS IT ADDRESSES THE GEOLOGICAL PROCESSES DOMINATING ANCIENT MARS AS WELL AS THE POTENTIAL FOR LIFE IN A PROPOSED MARS 2020 LANDING SITE. MORE SPECIFICALLY THE PROJECT FULFILLS THE FOLLOWING PLANETARY SCIENCE PROGRAM GOALS FROM THE SCIENCE MISSION DIRECTORATE 2014 SCIENCE PLAN: 1) EXPLORE AND OBSERVE THE OBJECTS IN THE SOLAR SYSTEM TO UNDERSTAND HOW THEY FORMED AND EVOLVED. 2) ADVANCE THE UNDERSTANDING OF HOW THE CHEMICAL AND PHYSICAL PROCESSES IN THE SOLAR SYSTEM OPERATE INTERACT AND EVOLVE. 3) EXPLORE AND FIND LOCATIONS WHERE LIFE COULD HAVE EXISTED OR COULD EXIST TODAY. THE PROJECT INVOLVES ALL THESE THREE GOALS AS IT WILL ADDRESS IMPACT PROCESSES CHEMICAL AND PHYSICAL SURFACE FORMATION AND EVOLUTION PROCESSES AND HABITABILITY POTENTIAL OF ANCIENT MARS.