Creamsicle Cheesecake

In a large bowl, whisk together orange Jell-O and boiling water until Jell-O is completely dissolved. Set aside to cool completely. Make crust: In a medium bowl, mix together Oreo crumbs, butter, and salt. Press into the bottom of an 8" springform pan and up the sides.  Make filling: In another large bowl, beat cream cheese and sour cream until smooth, then add powdered sugar, vanilla, and salt. Fold whipped topping into cream cheese mixture, then pour half of mixture into cooled Jell-O. Whisk until smooth.  Onto the crust, alternate pouring 1/4 cup dollops of cream cheese and Jell-O mixtures until both mixtures are used up. With a butter knife, gently swirl the layers. Cover and refrigerate for 6 hours, or until firm.  To serve: When firm, pipe dollops of whipped topping around the outside of the cheesecake. Top each dollop with a clementine segment, garnish with orange zest, and serve.