Edit in JSFiddle

<div class="container">
    <div class="floater"></div>
    <span class="img clear"></span>
</div>
.container {
    background-color: #eee;
    height: 200px;
    text-align: center;
}
.img {
    display: inline-block;
    width: 64px;
    height: 64px;
    background-color: green;
    margin-top: -32px;
}
.floater {
    float: left;
    height: 50%;
    width: 100%;
}
.clear {
    clear: both;
}