没有“delta”，但您可以访问X和Y。
这意味着你可以编写一些代码来触发触摸移动并计算“delta”：

element.addEventListener("touchstart", touchStart, false);
element.addEventListener("touchmove", touchMove, false);

var start = {x:0, y:0};

function touchStart(event) {
  start.x = event.touches[0].pageX;
  start.y = event.touches[0].pageY;
}

function touchMove(event) {
  offset = {};

  offset.x = start.x - event.touches[0].pageX;
  offset.y = start.y - event.touches[0].pageY;

  return offset;  
}

进一步参考：http://developer.apple.com/library/safari/#documentation/appleapplications/reference/safariwebcontent/HandlingEvents/HandlingEvents.html

如果你不需要realtime delta，那么你只能使用press & realease delta，用途：

• touchstart
• touchend
• TouchEvent.changedTouches

基于@samccone代码。

element.addEventListener("touchstart", touchStart, false);
element.addEventListener("touchend", touchEnd, false);

var start = {x:0, y:0};

function touchStart(event) {
  start.x = event.changedTouches[0].pageX;
  start.y = event.changedTouches[0].pageY;
}

function touchEnd(event) {
  offset = {};

  offset.x = start.x - event.changedTouches[0].pageX;
  offset.y = start.y - event.changedTouches[0].pageY;

  return offset;  
}