I want to end my two-column body text halfway down a page, insert a horizontal shape to signal the end of the story, and then begin my citations on the lower half of the page. But if the horizontal shape does not occupy the whole lower half of the page, t

Try Menu > Insert > Layout break

2 Column layout

Layout break

1 column layout with object

Layout break

2 Column layout

Peter

PS You should use paragraph rules not shapes to divide your layouts.

What text boxes and shapes are they? Could you describe in more detail what you have on this page?

Paragraph borders and rules are just neat ways of applying the divider lines, they don't of themselves alter the layout.

Not following what you are saying about citations. Do you mean Footnotes?

Yes, Footnotes ignore Wrap. That is either a bug or bad design. Report it to Apple:

Menu > Pages > Provide Pages Feedback

Peter

Providing the example makes it much easier to describe a simple solution. Just use text boxes. After your two column text ends place another box (below where the two-columns end). Highlight the box and in the graphic inspector use the Fill to select the box color and the Line to outline the box with a line the thickness you want.

Then place another text box below that horizontal box and click anywhere inside the box (so that the handles do not show) and change the number of columns to two. Now you can adjust this two-column box to fit the page the way you want.

Then just add the line and additional text. Add additional paragraph spaces at the top of the second column to get the text in the second column to begin below the line or to line up with the first citation in the first column.

Except you can't have Footnotes with TextBoxes.

Peter