Meta: Humanities Lit Reviews

My current dilemma of living between two worlds (humanities and social sciences) centers on the lit review. Because the social scientists are all hung up about causality and other quantitative issues, they're having a hard time with questions I'm asking about what counts as a lit review....How would you define a lit review in the humanities? In the social sciences, the definition of a good literature review is supposed to be a narrative that tells the story of who's talking about what (in the field as you conceive of it), but there's an argument that says that such work doesn't count as research (though some are willing enough to substitute the term "scholarship"). But as I think about most of the papers I wrote for two different literature degrees, they start to sound pretty close to their definition of literature reviews. Is this a function of the fallacy where high school teachers talk about "research papers" but really mean lit reviews (since the quality and quantity of original thinking required is pretty much nil)? Is this a snobbery about how much "original thinking" is required (or what counts as original thinking--i.e., if one can't make causal claims one is simply describing the world as we already know it)?
So I've been trying to make sense of what differentiates a literature review in English (or the humanities generally) from "original research"...is it just the lit review is the narrative of what's missing and the original research is where you fill the gaps with your own interpretations?
If one rejects the attempt to make the dissertation resemble the hard sciences' lab report (where great attention is paid to describing how the "experiment" is put together so that it can be reproduced to gather--ostensibly--the same data), how does one define the section that represents original research without positing a collection of data and interpretation of that dataset. In other words, if I don't count something (quantitative), or at least interview someone (to go the qualitative route), and I just make a list of thinkers that I'm going to apply to this given situation (phenomenon, if you like), and then make sense of how these different thinkers inform our understanding of that situation (and give us a new understanding of that situation--hence creating original scholarship?), is that act of gathering the thinkers a lit review or a description of the experiment? Is the description of the situation the declaration of the parameters of the dataset?
How do I map these required concepts (that don't really fit the experience of working in the humanities) onto what I'm looking to do?